PIC18F452-I/PTVAO - Microchip Technology, Inc.

PIC18FXX2

Data Sheet

High-Performance, Enhanced Flash

Microcontrollers with 10-Bit A/D

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Printed on recycled paper.

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:2002 certification for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona, Gresham, Oregon and Mountain View, California. The

Company’s quality system processes and procedures are for its

PICmicro

8-bit MCUs, KEELOQ

code hopping devices, Serial

EEPROMs, microperipherals, nonvolatile memory and analog

products. In addition, Microchip’s quality system for the design and

manufacture of development systems is ISO 9001:2000 certified.

PIC18FXX2

High Performance RISC CPU:

• C compiler optimized architecture/instruction set

- Source code compatible with the PIC16 and

PIC17 instruction sets

• Linear program memory addressing to 32 Kbytes

•Linear data memory addressing to 1.5 Kbytes

• Up to 10 MIPs operation:

- DC - 40 MHz osc./clock input

- 4 MHz - 10 MHz osc./clock input with PLL active

• 16-bit wide instructions, 8-bit wide data path

• Priority levels for interrupts

• 8 x 8 Single Cycle Hardware Multiplier

Peripheral Features:

• High current sink/source 25 mA/25 mA

• Three external interrupt pins

• Timer0 module: 8-bit/16-bit timer/counter with

8-bit programmable prescaler

• Timer1 module: 16-bit timer/counter

• Timer2 module: 8-bit timer/counter with 8-bit

period register (time-base for PWM)

• Timer3 module: 16-bit timer/counter

• Secondary oscillator clock option - Timer1/Timer3

• Two Capture/Compare/PWM (CCP) modules.

CCP pins that can be configured as:

- Capture input: capture is 16-bit,

max. resolution 6.25 ns (TCY/16)

- Compare is 16-bit, max. resolution 100 ns (TCY)

- PWM output: PWM resolution is 1- to 10-bit,

max. PWM freq. @: 8-bit resolution = 156 kHz

10-bit resolution = 39 kHz

• Master Synchronous Serial Port (MSSP) module,

Two modes of operation:

- 3-wire SPI™ (supports all 4 SPI modes)

-I

2C™ Master and Slave mode

Peripheral Features (Continued):

• Addressable USART module:

- Supports RS-485 and RS-232

• Parallel Slave Port (PSP) module

Analog Features:

• Compatible 10-bit Analog-to-Digital Converter

module (A/D) with:

- Fast sampling rate

- Conversion available during SLEEP

-Linearity ≤ 1 LSb

• Programmable Low Voltage Detection (PLVD)

- Supports interrupt on-Low Voltage Detection

• Programmable Brown-out Reset (BOR)

Special Microcontroller Features:

• 100,000 erase/write cycle Enhanced FLASH

program memory typical

• 1,000,000 erase/write cycle Data EEPROM

memory

• FLASH/Data EEPROM Retention: > 40 years

• Self-reprogrammable under software control

• Power-on Reset (POR), Power-up Timer (PWRT)

and Oscillator Start-up Timer (OST)

• Watchdog Timer (WDT) with its own On-Chip RC

Oscillator for reliable operation

• Programmable code protection

• Power saving SLEEP mode

• Selectable oscillator options including:

- 4X Phase Lock Loop (of primary oscillator)

- Secondary Oscillator (32 kHz) clock input

• Single supply 5V In-Circuit Serial Programming™

(ICSP™) via two pins

• In-Circuit Debug (ICD) via two pins

CMOS Technology:

• Low power, high speed FLASH/EEPROM

technology

• Fully static design

• Wide operating voltage range (2.0V to 5.5V)

• Industrial and Extended temperature ranges

• Low power consumption:

- < 1.6 mA typical @ 5V, 4 MHz

-25 μA typical @ 3V, 32 kHz

- < 0.2 μA typical standby current

Device

On-Chip Program

Memory On-Chip

RAM

(bytes)

Data

EEPROM

(bytes)

FLASH

(bytes)

# Single Word

Instructions

PIC18F242 16K 8192 768 256

PIC18F252 32K 16384 1536 256

PIC18F442 16K 8192 768 256

PIC18F452 32K 16384 1536 256

28/40-pin High Performance, Enhanced FLASH

Microcontrollers with 10-Bit A/D

PIC18FXX2

Pin Diagrams

PIC18F442

RA4/T0CKI

RA5/AN4/SS/LVDIN

RE0/RD/AN5

OSC2/CLKO/RA6

RE1/WR/AN6

RE2/CS/AN7

VDD

OSC1/CLKI

RB3/CCP2*

RB2/INT2

RB1/INT1

RB0/INT0

VDD

VSS

RD7/PSP7

RD6/PSP6

RD5/PSP5

RD4/PSP4

RC7/RX/DT

RA3/AN3/VREF+

RA2/AN2/VREF-

RA1/AN1

RA0/AN0

MCLR/VPP

RB7/PGD

RB6/PGC

RB5/PGM

RB4

RC6/TX/CK

RC5/SDO

RC4/SDI/SDA

RD3/PSP3

RD2/PSP2

RD1/PSP1

RD0/PSP0

RC3/SCK/SCL

RC2/CCP1

RC1/T1OSI/CCP2*

PIC18F442

RA3/AN3/VREF+

RA2/AN2/VREF-

RA1/AN1

RA0/AN0

MCLR/VPP

RB7/PGD

RB6/PGC

RB5/PGM

RB4

RC6/TX/CK

RC5/SDO

RC4/SDI/SDA

RD3/PSP3

RD2/PSP2

RD1/PSP1

RD0/PSP0

RC3/SCK/SCL

RC2/CCP1

RC1/T1OSI/CCP2*

RC0/T1OSO/T1CKI

OSC2/CLKO/RA6

OSC1/CLKI

VSS

VDD

RE2/AN7/CS

RE1/AN6/WR

RE0/AN5/RD

RA5/AN4/SS/LVDIN

RA4/T0CKI

RC7/RX/DT

RD4/PSP4

RD5/PSP5

RD6/PSP6

RD7/PSP7

VSS

VDD

RB0/INT0

RB1/INT1

RB2/INT2

RB3/CCP2*

PLCC

TQFP

* RB3 is the alternate pin for the CCP2 pin multiplexing.

VSS

RC0/T1OSO/T1CKI

PIC18F452

PIC18FXX2

Pin Diagrams (Cont.’d)

RB7/PGD

RB6/PGC

RB5/PGM

RB4

RB3/CCP2*

RB2/INT2

RB1/INT1

RB0/INT0

VDD

VSS

RD7/PSP7

RD6/PSP6

RD5/PSP5

RD4/PSP4

RC7/RX/DT

RC6/TX/CK

RC5/SDO

RC4/SDI/SDA

RD3/PSP3

RD2/PSP2

MCLR/VPP

RA0/AN0

RA1/AN1

RA2/AN2/VREF-

RA3/AN3/VREF+

RA4/T0CKI

RA5/AN4/SS/LVDIN

RE0/RD/AN5

RE1/WR/AN6

RE2/CS/AN7

VDD

VSS

OSC1/CLKI

OSC2/CLKO/RA6

RC0/T1OSO/T1CKI

RC1/T1OSI/CCP2*

RC2/CCP1

RC3/SCK/SCL

RD0/PSP0

RD1/PSP1

PIC18F442

PIC18F242

14 15

MCLR/VPP

RA0/AN0

RA1/AN1

RA2/AN2/VREF-

RA3/AN3/VREF+

RA4/T0CKI

RA5/AN4/SS/LVDIN

VSS

OSC1/CLKI

OSC2/CLKO/RA6

RC0/T1OSO/T1CKI

RC1/T1OSI/CCP2*

RC2/CCP1

RC3/SCK/SCL

RB7/PGD

RB6/PGC

RB5/PGM

RB4

RB3/CCP2*

RB2/INT2

RB1/INT1

RB0/INT0

VDD

VSS

RC7/RX/DT

RC6/TX/CK

RC5/SDO

RC4/SDI/SDA

* RB3 is the alternate pin for the CCP2 pin multiplexing.

DIP

DIP, SOIC

Note: Pin compatible with 40-pin PIC16C7X devices.

PIC18F452

PIC18F252

PIC18FXX2
DS39564C-page 4 © 2006 Microchip Technology Inc.
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 17
3.0 Reset .......................................................................................................................................................................................... 25
4.0 Memory Organization ................................................................................................................................................................. 35
5.0 FLASH Program Memory ........................................................................................................................................................... 55
6.0 Data EEPROM Memory ............................................................................................................................................................. 65
7.0 8 X 8 Hardware Multiplier ........................................................................................................................................................... 71
8.0 Interrupts .................................................................................................................................................................................... 73
9.0 I/O Ports ..................................................................................................................................................................................... 87
10.0 Timer0 Module ......................................................................................................................................................................... 103
11.0 Timer1 Module ......................................................................................................................................................................... 107
12.0 Timer2 Module ......................................................................................................................................................................... 111
13.0 Timer3 Module ......................................................................................................................................................................... 113
14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 117
15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 125
16.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART).............................................................. 165
17.0 Compatible 10-bit Analog-to-Digital Converter (A/D) Module................................................................................................... 181
18.0 Low Voltage Detect .................................................................................................................................................................. 189
19.0 Special Features of the CPU.................................................................................................................................................... 195
20.0 Instruction Set Summary .......................................................................................................................................................... 211
21.0 Development Support............................................................................................................................................................... 253
22.0 Electrical Characteristics .......................................................................................................................................................... 259
23.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 289
24.0 Packaging Information.............................................................................................................................................................. 305
Appendix A:  Revision History ............................................................................................................................................................ 313
Appendix B:  Device Differences........................................................................................................................................................ 313
Appendix C:  Conversion Considerations........................................................................................................................................... 314
Appendix D:  Migration from Baseline to Enhanced Devices ............................................................................................................. 314
Appendix E:  Migration from Mid-range to Enhanced Devices........................................................................................................... 315
Appendix F:  Migration from High-end to Enhanced Devices ............................................................................................................ 315
Index .................................................................................................................................................................................................. 317
On-Line Support................................................................................................................................................................................. 327
Reader Response .............................................................................................................................................................................. 328
PIC18FXX2 Product Identification System......................................................................................................................................... 329

PIC18FXX2

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Customer Notification System

PIC18FXX2

NOTES:

PIC18FXX2

1.0 DEVICE OVERVIEW

This document contains device specific information for

the following devices:

These devices come in 28-pin and 40/44-pin packages.

The 28-pin devices do not have a Parallel Slave Port

(PSP) implemented and the number of Analog-to-

Digital (A/D) converter input channels is reduced to 5.

An overview of features is shown in Table 1-1.

The following two figures are device block diagrams

sorted by pin count: 28-pin for Figure 1-1 and 40/44-pin

for Figure 1-2. The 28-pin and 40/44-pin pinouts are

listed in Table 1-2 and Table 1-3, respectively.

TABLE 1-1: DEVICE FEATURES

•PIC18F242 •PIC18F442

•PIC18F252 •PIC18F452

Features PIC18F242 PIC18F252 PIC18F442 PIC18F452

Operating Frequency DC - 40 MHz DC - 40 MHz DC - 40 MHz DC - 40 MHz

Program Memory (Bytes) 16K 32K 16K 32K

Program Memory (Instructions) 8192 16384 8192 16384

Data Memory (Bytes) 768 1536 768 1536

Data EEPROM Memory (Bytes) 256 256 256 256

Interrupt Sources 17 17 18 18

I/O Ports Ports A, B, C Ports A, B, C Ports A, B, C, D, E Ports A, B, C, D, E

Timers 4 4 4 4

Capture/Compare/PWM Modules 2 2 2 2

Serial Communications

MSSP,

Addressable

USART

MSSP,

Addressable

USART

MSSP,

Addressable

USART

MSSP,

Addressable

USART

Parallel Communications — — PSP PSP

10-bit Analog-to-Digital Module 5 input channels 5 input channels 8 input channels 8 input channels

RESETS (and Delays)

POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow

(PWRT, OST)

POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow

(PWRT, OST)

POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow

(PWRT, OST)

POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow

(PWRT, OST)

Programmable Low Voltage

Detect

Yes Yes Yes Ye s

Programmable Brown-out Reset Yes Yes Yes Yes

Instruction Set 75 Instructions 75 Instructions 75 Instructions 75 Instructions

Packages 28-pin DIP

28-pin SOIC

28-pin DIP

28-pin SOIC

40-pin DIP

44-pin PLCC

44-pin TQFP

40-pin DIP

44-pin PLCC

44-pin TQFP

PIC18FXX2

FIGURE 1-1: PIC18F2X2 BLOCK DIAGRAM

Instruction

Decode &

Control

PORTA

PORTB

PORTC

RA4/T0CKI

RA5/AN4/SS/LVDIN

RC0/T1OSO/T1CKI

RC1/T1OSI/CCP2(1)

RC2/CCP1

RC3/SCK/SCL

RC4/SDI/SDA

RC5/SDO

RC6/TX/CK

RC7/RX/DT

Note 1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit.

2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction).

3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations

are device dependent.

Addressable

CCP1 Synchronous

Timer0 Timer1 Timer2

Serial Port

RA3/AN3/VREF+

RA2/AN2/VREF-

RA1/AN1

RA0/AN0

A/D Converter

Data Latch

Data RAM

Address Latch

Address<12>

12(2)

BSR FSR0

FSR1

FSR2

412 4

PCH PCL

PCLATH

31 Level Stack

Program Counter

PRODLPRODH

8 x 8 Multiply

WREG

BIT OP

ALU<8>

Address Latch

Program Memory

(up to 2 Mbytes)

Data Latch

inc/dec logic

Data Bus<8>

Instruction

ROM Latch

Timer3

CCP2

Bank0, F

PCLATU

PCU

RA6

USART

Master

Table Latch

Table Pointer

inc/dec

logic

Decode

RB0/INT0

RB4

RB1/INT1

RB2/INT2

RB3/CCP2(1)

RB5/PGM

RB6/PCG

RB7/PGD

Data EEPROM

Power-up

Timer

Oscillator

Start-up Timer

Power-on

Reset

Watchdog

Timer

OSC1/CLKI

OSC2/CLKO

MCLR

VDD, VSS

Brown-out

Reset

Timing

Generation

4X PLL

T1OSCI

T1OSCO

Precision

Reference

Voltage

Low Voltage

Programming

In-Circuit

Debugger

PIC18FXX2

FIGURE 1-2: PIC18F4X2 BLOCK DIAGRAM

Power-up

Timer

Oscillator

Start-up Timer

Power-on

Reset

Watchdog

Timer

Instruction

Decode &

Control

OSC1/CLKI

OSC2/CLKO

MCLR

VDD, VSS

PORTA

PORTB

PORTC

RA4/T0CKI

RA5/AN4/SS/LVDIN

RB0/INT0

RB4

RC0/T1OSO/T1CKI

RC1/T1OSI/CCP2(1)

RC2/CCP1

RC3/SCK/SCL

RC4/SDI/SDA

RC5/SDO

RC6/TX/CK

RC7/RX/DT

Brown-out

Reset

Note 1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit.

2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction).

3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations

are device dependent.

Addressable

CCP1

Master

Timer0 Timer1 Timer2

Serial Port

RA3/AN3/VREF+

RA2/AN2/VREF-

RA1/AN1

RA0/AN0

Parallel Slave Port

Timing

Generation

4X PLL

A/D Converter

RB1/INT1

Data Latch

Data RAM

(up to 4K

address reach)

Address Latch

Address<12>

12(2)

Bank0, F

BSR FSR0

FSR1

FSR2

412 4

PCH PCL

PCLATH

31 Level Stack

Program Counter

PRODLPRODH

8 x 8 Multiply

WREG

BIT OP

ALU<8>

Address Latch

Program Memory

(up to 2 Mbytes)

Data Latch

inc/dec logic

Data Bus<8>

Table Latch

Instruction

ROM Latch

Timer3

PORTD

PORTE

RE0/AN5/RD

RE1/AN6/WR

RE2/AN7/CS

CCP2

RB2/INT2

RB3/CCP2(1)

T1OSCI

T1OSCO

PCLATU

PCU

RA6

Precision

Reference

Voltage

Synchronous USART

Table Pointer

inc/dec

logic

Decode

RD0/PSP0

RD1/PSP1

RD2/PSP2

RD3/PSP3

RD4/PSP4

RD5/PSP5

RD6/PSP6

RD7/PSP7

Low Voltage

Programming

In-Circuit

Debugger

Data EEPROM

RB5/PGM

RB6/PCG

RB7/PGD

PIC18FXX2

TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP SOIC

MCLR/VPP

MCLR

VPP

Master Clear (input) or high voltage ICSP programming

enable pin.

Master Clear (Reset) input. This pin is an active low

RESET to the device.

High voltage ICSP programming enable pin.

NC — — — — These pins should be left unconnected.

OSC1/CLKI

OSC1

CLKI

CMOS

Oscillator crystal or external clock input.

Oscillator crystal input or external clock source input.

ST buffer when configured in RC mode, CMOS otherwise.

External clock source input. Always associated with

pin function OSC1. (See related OSC1/CLKI,

OSC2/CLKO pins.)

OSC2/CLKO/RA6

OSC2

CLKO

RA6

10 10

I/O

—

TTL

Oscillator crystal or clock output.

Oscillator crystal output. Connects to crystal or

resonator in Crystal Oscillator mode.

In RC mode, OSC2 pin outputs CLKO which has 1/4

the frequency of OSC1, and denotes the instruction

cycle rate.

General Purpose I/O pin.

PORTA is a bi-directional I/O port.

RA0/AN0

RA0

AN0

I/O

TTL

Analog

Digital I/O.

Analog input 0.

RA1/AN1

RA1

AN1

I/O

TTL

Analog

Digital I/O.

Analog input 1.

RA2/AN2/VREF-

RA2

AN2

VREF-

I/O

TTL

Analog

Digital I/O.

Analog input 2.

A/D Reference Voltage (Low) input.

RA3/AN3/VREF+

RA3

AN3

VREF+

I/O

TTL

Analog

Digital I/O.

Analog input 3.

A/D Reference Voltage (High) input.

RA4/T0CKI

RA4

T0CKI

I/O

ST/OD

Digital I/O. Open drain when configured as output.

Timer0 external clock input.

RA5/AN4/SS/LVDIN

RA5

AN4

LVDIN

I/O

TTL

Analog

Digital I/O.

Analog input 4.

SPI Slave Select input.

Low Voltage Detect Input.

RA6 See the OSC2/CLKO/RA6 pin.

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

PORTB is a bi-directional I/O port. PORTB can be software

programmed for internal weak pull-ups on all inputs.

RB0/INT0

RB0

INT0

21 21

I/O

TTL

Digital I/O.

External Interrupt 0.

RB1/INT1

RB1

INT1

22 22

I/O

TTL

ST External Interrupt 1.

RB2/INT2

RB2

INT2

23 23

I/O

TTL

Digital I/O.

External Interrupt 2.

RB3/CCP2

RB3

CCP2

24 24

I/O

TTL

Digital I/O.

Capture2 input, Compare2 output, PWM2 output.

RB4 25 25 I/O TTL Digital I/O.

Interrupt-on-change pin.

RB5/PGM

RB5

PGM

26 26

I/O

TTL

Digital I/O. Interrupt-on-change pin.

Low Voltage ICSP programming enable pin.

RB6/PGC

RB6

PGC

27 27

I/O

TTL

Digital I/O. Interrupt-on-change pin.

In-Circuit Debugger and ICSP programming clock pin.

RB7/PGD

RB7

PGD

28 28

I/O

TTL

Digital I/O. Interrupt-on-change pin.

In-Circuit Debugger and ICSP programming data pin.

TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP SOIC

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

PORTC is a bi-directional I/O port.

RC0/T1OSO/T1CKI

RC0

T1OSO

T1CKI

11 11

I/O

—

Digital I/O.

Timer1 oscillator output.

Timer1/Timer3 external clock input.

RC1/T1OSI/CCP2

RC1

T1OSI

CCP2

12 12

I/O

CMOS

Digital I/O.

Timer1 oscillator input.

Capture2 input, Compare2 output, PWM2 output.

RC2/CCP1

RC2

CCP1

13 13

I/O

Digital I/O.

Capture1 input/Compare1 output/PWM1 output.

RC3/SCK/SCL

RC3

SCK

SCL

14 14

I/O

Digital I/O.

Synchronous serial clock input/output for SPI mode.

Synchronous serial clock input/output for I2C mode

RC4/SDI/SDA

RC4

SDI

SDA

15 15

I/O

Digital I/O.

SPI Data In.

I2C Data I/O.

RC5/SDO

RC5

SDO

16 16

I/O

—

Digital I/O.

SPI Data Out.

RC6/TX/CK

RC6

17 17

I/O

—

Digital I/O.

USART Asynchronous Transmit.

USART Synchronous Clock (see related RX/DT).

RC7/RX/DT

RC7

18 18

I/O

Digital I/O.

USART Asynchronous Receive.

USART Synchronous Data (see related TX/CK).

VSS 8, 19 8, 19 P — Ground reference for logic and I/O pins.

VDD 20 20 P — Positive supply for logic and I/O pins.

TABLE 1-2: PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP SOIC

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP PLCC TQFP

MCLR/VPP

MCLR

VPP

1218

Master Clear (input) or high voltage ICSP

programming enable pin.

Master Clear (Reset) input. This pin is an active

low RESET to the device.

High voltage ICSP programming enable pin.

NC — — — These pins should be left unconnected.

OSC1/CLKI

OSC1

CLKI

13 14 30

CMOS

Oscillator crystal or external clock input.

Oscillator crystal input or external clock source

input. ST buffer when configured in RC mode,

CMOS otherwise.

External clock source input. Always associated

with pin function OSC1. (See related OSC1/CLKI,

OSC2/CLKO pins.)

OSC2/CLKO/RA6

OSC2

CLKO

RA6

14 15 31

I/O

—

TTL

Oscillator crystal or clock output.

Oscillator crystal output. Connects to crystal

or resonator in Crystal Oscillator mode.

In RC mode, OSC2 pin outputs CLKO,

which has 1/4 the frequency of OSC1 and

denotes the instruction cycle rate.

General Purpose I/O pin.

PORTA is a bi-directional I/O port.

RA0/AN0

RA0

AN0

2319

I/O

TTL

Analog

Digital I/O.

Analog input 0.

RA1/AN1

RA1

AN1

3420

I/O

TTL

Analog

Digital I/O.

Analog input 1.

RA2/AN2/VREF-

RA2

AN2

VREF-

4521

I/O

TTL

Analog

Digital I/O.

Analog input 2.

A/D Reference Voltage (Low) input.

RA3/AN3/VREF+

RA3

AN3

VREF+

5622

I/O

TTL

Analog

Digital I/O.

Analog input 3.

A/D Reference Voltage (High) input.

RA4/T0CKI

RA4

T0CKI

6723

I/O

ST/OD

Digital I/O. Open drain when configured as output.

Timer0 external clock input.

RA5/AN4/SS/LVDIN

RA5

AN4

LVDIN

7824

I/O

TTL

Analog

Digital I/O.

Analog input 4.

SPI Slave Select input.

Low Voltage Detect Input.

RA6 (See the OSC2/CLKO/RA6 pin.)

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

PORTB is a bi-directional I/O port. PORTB can be

software programmed for internal weak pull-ups on all

inputs.

RB0/INT0

RB0

INT0

33 36 8

I/O

TTL

Digital I/O.

External Interrupt 0.

RB1/INT1

RB1

INT1

34 37 9

I/O

TTL

ST External Interrupt 1.

RB2/INT2

RB2

INT2

35 38 10

I/O

TTL

Digital I/O.

External Interrupt 2.

RB3/CCP2

RB3

CCP2

36 39 11

I/O

TTL

Digital I/O.

Capture2 input, Compare2 output, PWM2 output.

RB4 37 41 14 I/O TTL Digital I/O. Interrupt-on-change pin.

RB5/PGM

RB5

PGM

38 42 15

I/O

TTL

Digital I/O. Interrupt-on-change pin.

Low Voltage ICSP programming enable pin.

RB6/PGC

RB6

PGC

39 43 16

I/O

TTL

Digital I/O. Interrupt-on-change pin.

In-Circuit Debugger and ICSP programming clock

pin.

RB7/PGD

RB7

PGD

40 44 17

I/O

TTL

Digital I/O. Interrupt-on-change pin.

In-Circuit Debugger and ICSP programming data

pin.

TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP PLCC TQFP

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

PORTC is a bi-directional I/O port.

RC0/T1OSO/T1CKI

RC0

T1OSO

T1CKI

15 16 32

I/O

—

Digital I/O.

Timer1 oscillator output.

Timer1/Timer3 external clock input.

RC1/T1OSI/CCP2

RC1

T1OSI

CCP2

16 18 35

I/O

CMOS

Digital I/O.

Timer1 oscillator input.

Capture2 input, Compare2 output, PWM2 output.

RC2/CCP1

RC2

CCP1

17 19 36

I/O

Digital I/O.

Capture1 input/Compare1 output/PWM1 output.

RC3/SCK/SCL

RC3

SCK

SCL

18 20 37

I/O

Digital I/O.

Synchronous serial clock input/output for

SPI mode.

Synchronous serial clock input/output for

I2C mode.

RC4/SDI/SDA

RC4

SDI

SDA

23 25 42

I/O

Digital I/O.

SPI Data In.

I2C Data I/O.

RC5/SDO

RC5

SDO

24 26 43

I/O

—

Digital I/O.

SPI Data Out.

RC6/TX/CK

RC6

25 27 44

I/O

—

Digital I/O.

USART Asynchronous Transmit.

USART Synchronous Clock (see related RX/DT).

RC7/RX/DT

RC7

26 29 1

I/O

Digital I/O.

USART Asynchronous Receive.

USART Synchronous Data (see related TX/CK).

TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP PLCC TQFP

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

PORTD is a bi-directional I/O port, or a Parallel Slave

Port (PSP) for interfacing to a microprocessor port.

These pins have TTL input buffers when PSP module

is enabled.

RD0/PSP0 19 21 38 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD1/PSP1 20 22 39 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD2/PSP2 21 23 40 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD3/PSP3 22 24 41 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD4/PSP4 27 30 2 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD5/PSP5 28 31 3 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD6/PSP6 29 32 4 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

RD7/PSP7 30 33 5 I/O ST

TTL

Digital I/O.

Parallel Slave Port Data.

PORTE is a bi-directional I/O port.

RE0/RD/AN5

RE0

AN5

8 9 25 I/O

TTL

Analog

Digital I/O.

Read control for parallel slave port

(see also WR and CS pins).

Analog input 5.

RE1/WR/AN6

RE1

AN6

9 10 26 I/O

TTL

Analog

Digital I/O.

Write control for parallel slave port

(see CS and RD pins).

Analog input 6.

RE2/CS/AN7

RE2

AN7

10 11 27 I/O

TTL

Analog

Digital I/O.

Chip Select control for parallel slave port

(see related RD and WR).

Analog input 7.

VSS 12, 31 13, 34 6, 29 P — Ground reference for logic and I/O pins.

VDD 11, 32 12, 35 7, 28 P — Positive supply for logic and I/O pins.

TABLE 1-3: PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

DIP PLCC TQFP

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

OD = Open Drain (no P diode to VDD)

PIC18FXX2

2.0 OSCILLATOR

CONFIGURATIONS

2.1 Oscillator Types

The PIC18FXX2 can be operated in eight different

Oscillator modes. The user can program three configu-

ration bits (FOSC2, FOSC1, and FOSC0) to select one

of these eight modes:

1. LP Low Power Crystal

2. XT Crystal/Resonator

3. HS High Speed Crystal/Resonator

4. HS + PLL High Speed Crystal/Resonator

with PLL enabled

5. RC External Resistor/Capacitor

6. RCIO External Resistor/Capacitor with

I/O pin enabled

7. EC External Clock

8. ECIO External Clock with I/O pin

enabled

2.2 Crystal Oscillator/Ceramic

Resonators

In XT, LP, HS or HS+PLL Oscillator modes, a crystal or

ceramic resonator is connected to the OSC1 and

OSC2 pins to establish oscillation. Figure 2-1 shows

the pin connections.

The PIC18FXX2 oscillator design requires the use of a

parallel cut crystal.

FIGURE 2-1: CRYSTAL/CERAMIC

RESONATOR OPERATION

(HS, XT OR LP

CONFIGURATION)

TABLE 2-1: CAPACITOR SELECTION FOR

CERAMIC RESONATORS

Note: Use of a series cut crystal may give a fre-

quency out of the crystal manufacturers

specifications.

Note 1: See Table 2-1 and Table 2-2 for

recommended values of C1 and C2.

2: A series resistor (RS) may be required for

AT strip cut crystals.

3: RF varies with the Oscillator mode chosen.

C1(1)

C2(1)

XTAL

OSC2

OSC1

RF(3)

SLEEP

Logic

PIC18FXXX

RS(2)

Internal

Ranges Tested:

Mode Freq C1 C2

XT 455 kHz

2.0 MHz

4.0 MHz

68 - 100 pF

15 - 68 pF

68 - 100 pF

15 - 68 pF

HS 8.0 MHz

16.0 MHz

10 - 68 pF

10 - 22 pF

10 - 68 pF

10 - 22 pF

These values are for design guidance only.

See notes following this table.

Resonators Used:

455 kHz Panasonic EFO-A455K04B ± 0.3%

2.0 MHz Murata Erie CSA2.00MG ± 0.5%

4.0 MHz Murata Erie CSA4.00MG ± 0.5%

8.0 MHz Murata Erie CSA8.00MT ± 0.5%

16.0 MHz Murata Erie CSA16.00MX ± 0.5%

All resonators used did not have built-in capacitors.

Note 1: Higher capacitance increases the stability

of the oscillator, but also increases the

start-up time.

2: When operating below 3V VDD, or when

using certain ceramic resonators at any

voltage, it may be necessary to use

high-gain HS mode, try a lower frequency

resonator, or switch to a crystal oscillator.

3: Since each resonator/crystal has its own

characteristics, the user should consult the

resonator/crystal manufacturer for appro-

priate values of external components, or

verify oscillator performance.

PIC18FXX2

TABLE 2-2: CAPACITOR SELECTION FOR

CRYSTAL OSCILLATOR

An external clock source may also be connected to the

OSC1 pin in the HS, XT and LP modes, as shown in

Figure 2-2.

FIGURE 2-2: EXTERNAL CLOCK INPUT

OPERATION (HS, XT OR LP

OSC CONFIGURATION)

2.3 RC Oscillator

For timing-insensitive applications, the “RC” and

“RCIO” device options offer additional cost savings.

The RC oscillator frequency is a function of the supply

voltage, the resistor (REXT) and capacitor (CEXT) val-

ues and the operating temperature. In addition to this,

the oscillator frequency will vary from unit to unit due to

normal process parameter variation. Furthermore, the

difference in lead frame capacitance between package

types will also affect the oscillation frequency, espe-

cially for low CEXT values. The user also needs to take

into account variation due to tolerance of external R

and C components used. Figure 2-3 shows how the

R/C combination is connected.

In the RC Oscillator mode, the oscillator frequency

divided by 4 is available on the OSC2 pin. This signal

may be used for test purposes or to synchronize other

logic.

FIGURE 2-3: RC OSCILLATOR MODE

The RCIO Oscillator mode functions like the RC mode,

except that the OSC2 pin becomes an additional gen-

eral purpose I/O pin. The I/O pin becomes bit 6 of

PORTA (RA6).

Ranges Tested:

Mode Freq C1 C2

LP 32.0 kHz 33 pF 33 pF

200 kHz 15 pF 15 pF

XT 200 kHz 22-68 pF 22-68 pF

1.0 MHz 15 pF 15 pF

4.0 MHz 15 pF 15 pF

HS 4.0 MHz 15 pF 15 pF

8.0 MHz 15-33 pF 15-33 pF

20.0 MHz 15-33 pF 15-33 pF

25.0 MHz 15-33 pF 15-33 pF

These values are for design guidance only.

See notes following this table.

Crystals Used

32.0 kHz Epson C-001R32.768K-A ± 20 PPM

200 kHz STD XTL 200.000KHz ± 20 PPM

1.0 MHz ECS ECS-10-13-1 ± 50 PPM

4.0 MHz ECS ECS-40-20-1 ± 50 PPM

8.0 MHz Epson CA-301 8.000M-C ± 30 PPM

20.0 MHz Epson CA-301 20.000M-C ± 30 PPM

Note 1: Higher capacitance increases the stability

of the oscillator, but also increases the

start-up time.

2: Rs may be required in HS mode, as well

as XT mode, to avoid overdriving crystals

with low drive level specification.

3: Since each resonator/crystal has its own

characteristics, the user should consult the

resonator/crystal manufacturer for appro-

priate values of external components., or

verify oscillator performance.

OSC1

OSC2

Open

Clock from

Ext. System PIC18FXXX

Note: If the oscillator frequency divided by 4 sig-

nal is not required in the application, it is

recommended to use RCIO mode to save

current.

OSC2/CLKO

CEXT

REXT

PIC18FXXX

OSC1

FOSC/4

Internal

Clock

VDD

VSS

Recommended values:3 kΩ ≤ REXT ≤ 100 kΩ

CEXT > 20pF

PIC18FXX2

2.4 External Clock Input

The EC and ECIO Oscillator modes require an external

clock source to be connected to the OSC1 pin. The

feedback device between OSC1 and OSC2 is turned

off in these modes to save current. There is no oscilla-

tor start-up time required after a Power-on Reset or

after a recovery from SLEEP mode.

In the EC Oscillator mode, the oscillator frequency

divided by 4 is available on the OSC2 pin. This signal

may be used for test purposes or to synchronize other

logic. Figure 2-4 shows the pin connections for the EC

Oscillator mode.

FIGURE 2-4: EXTERNAL CLOCK INPUT

OPERATION

(EC CONFIGURATION)

The ECIO Oscillator mode functions like the EC mode,

except that the OSC2 pin becomes an additional gen-

eral purpose I/O pin. The I/O pin becomes bit 6 of

PORTA (RA6). Figure 2-5 shows the pin connections

for the ECIO Oscillator mode.

FIGURE 2-5: EXTERNAL CLOCK INPUT

OPERATION

(ECIO CONFIGURATION)

2.5 HS/PLL

A Phase Locked Loop circuit is provided as a program-

mable option for users that want to multiply the fre-

quency of the incoming crystal oscillator signal by 4.

For an input clock frequency of 10 MHz, the internal

clock frequency will be multiplied to 40 MHz. This is

useful for customers who are concerned with EMI due

to high frequency crystals.

The PLL can only be enabled when the oscillator con-

figuration bits are programmed for HS mode. If they are

programmed for any other mode, the PLL is not

enabled and the system clock will come directly from

OSC1.

The PLL is one of the modes of the FOSC<2:0> config-

uration bits. The Oscillator mode is specified during

device programming.

A PLL lock timer is used to ensure that the PLL has

locked before device execution starts. The PLL lock

timer has a time-out that is called TPLL.

FIGURE 2-6: PLL BLOCK DIAGRAM

OSC1

OSC2

FOSC/4

Clock from

Ext. System PIC18FXXX

OSC1

I/O (OSC2)

RA6

Clock from

Ext. System PIC18FXXX

MUX

VCO

Loop

Filter

Divide by 4

Crystal

Osc

OSC2

OSC1

PLL Enable

FIN

FOUT SYSCLK

Phase

Comparator

(from Configuration HS Osc

bit Register)

PIC18FXX2

2.6 Oscillator Switching Feature

The PIC18FXX2 devices include a feature that allows

the system clock source to be switched from the main

oscillator to an alternate low frequency clock source.

For the PIC18FXX2 devices, this alternate clock source

is the Timer1 oscillator. If a low frequency crystal (32

kHz, for example) has been attached to the Timer1

oscillator pins and the Timer1 oscillator has been

enabled, the device can switch to a Low Power Execu-

tion mode. Figure 2-7 shows a block diagram of the

system clock sources. The clock switching feature is

enabled by programming the Oscillator Switching

Enable (OSCSEN) bit in Configuration Register1H to a

’0’. Clock switching is disabled in an erased device.

See Section 11.0 for further details of the Timer1 oscil-

lator. See Section 19.0 for Configuration Register

details.

FIGURE 2-7: DEVICE CLOCK SOURCES

PIC18FXXX

TOSC

4 x PLL

TT1P

TSCLK

Clock

Source

MUX

TOSC/4

Timer1 Oscillator

T1OSCEN

Enable

Oscillator

T1OSO

T1OSI

Clock Source option

for other modules

OSC1

OSC2

SLEEP

Main Oscillator

PIC18FXX2

2.6.1 SYSTEM CLOCK SWITCH BIT

The system clock source switching is performed under

software control. The system clock switch bit, SCS

(OSCCON<0>) controls the clock switching. When the

SCS bit is ’0’, the system clock source comes from the

main oscillator that is selected by the FOSC configura-

tion bits in Configuration Register1H. When the SCS bit

is set, the system clock source will come from the

Timer1 oscillator. The SCS bit is cleared on all forms of

RESET.

Note: The Timer1 oscillator must be enabled and

operating to switch the system clock

source. The Timer1 oscillator is enabled by

setting the T1OSCEN bit in the Timer1

control register (T1CON). If the Timer1

oscillator is not enabled, then any write to

the SCS bit will be ignored (SCS bit forced

cleared) and the main oscillator will

continue to be the system clock source.

U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-1

— — — — — — —SCS

bit 7 bit 0

bit 7-1 Unimplemented: Read as '0'

bit 0 SCS: System Clock Switch bit

When OSCSEN configuration bit = ’0’ and T1OSCEN bit is set:

1 = Switch to Timer1 oscillator/clock pin

0 = Use primary oscillator/clock input pin

When OSCSEN and T1OSCEN are in other states:

bit is forced clear

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

2.6.2 OSCILLATOR TRANSITIONS

The PIC18FXX2 devices contain circuitry to prevent

“glitches” when switching between oscillator sources.

Essentially, the circuitry waits for eight rising edges of

the clock source that the processor is switching to. This

ensures that the new clock source is stable and that its

pulse width will not be less than the shortest pulse

width of the two clock sources.

A timing diagram indicating the transition from the main

oscillator to the Timer1 oscillator is shown in

Figure 2-8. The Timer1 oscillator is assumed to be run-

ning all the time. After the SCS bit is set, the processor

is frozen at the next occurring Q1 cycle. After eight syn-

chronization cycles are counted from the Timer1 oscil-

lator, operation resumes. No additional delays are

required after the synchronization cycles.

FIGURE 2-8: TIMING DIAGRAM FOR TRANSITION FROM OSC1 TO TIMER1 OSCILLATOR

The sequence of events that takes place when switch-

ing from the Timer1 oscillator to the main oscillator will

depend on the mode of the main oscillator. In addition

to eight clock cycles of the main oscillator, additional

delays may take place.

If the main oscillator is configured for an external crys-

tal (HS, XT, LP), then the transition will take place after

an oscillator start-up time (T

OST) has occurred. A timing

diagram, indicating the transition from the Timer1 oscil-

lator to the main oscillator for HS, XT and LP modes, is

shown in Figure 2-9.

FIGURE 2-9: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS, XT, LP)

Q3Q2Q1Q4Q3Q2

OSC1

Internal

SCS

(OSCCON<0>)

Program PC + 2PC

Note 1: Delay on internal system clock is eight oscillator cycles for synchronization.

T1OSI

Q4 Q1

PC + 4

Tscs

Clock

Counter

System

Q2 Q3 Q4 Q1

TDLY

TT1P

TOSC

21 34 5678

Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2

OSC1

Internal System

SCS

(OSCCON<0>)

Program Counter PC PC + 2

Note 1: TOST = 1024 TOSC (drawing not to scale).

T1OSI

Clock

OSC2

TOST

PC + 6

TT1P

TOSC

TSCS

1 234 5678

PIC18FXX2

If the main oscillator is configured for HS-PLL mode, an

oscillator start-up time (TOST) plus an additional PLL

time-out (TPLL) will occur. The PLL time-out is typically

2 ms and allows the PLL to lock to the main oscillator

frequency. A timing diagram indicating the transition

from the Timer1 oscillator to the main oscillator for

HS-PLL mode is shown in Figure 2-10.

FIGURE 2-10: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS WITH PLL)

If the main oscillator is configured in the RC, RCIO, EC

or ECIO modes, there is no oscillator start-up time-out.

Operation will resume after eight cycles of the main

oscillator have been counted. A timing diagram, indi-

cating the transition from the Timer1 oscillator to the

main oscillator for RC, RCIO, EC and ECIO modes, is

shown in Figure 2-11.

FIGURE 2-11: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (RC, EC)

Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2

OSC1

Internal System

SCS

(OSCCON<0>)

Program Counter PC PC + 2

Note 1: TOST = 1024 TOSC (drawing not to scale).

T1OSI

Clock

TOST

PC + 4

TPLL

TOSC

TT1P

TSCS

OSC2

PLL Clock

Input 1 234 56 78

Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3

OSC1

Internal System

SCS

(OSCCON<0>)

Program Counter PC PC + 2

Note 1: RC Oscillator mode assumed.

PC + 4

T1OSI

Clock

OSC2

TT1P

TOSC

TSCS

123

45678

PIC18FXX2

2.7 Effects of SLEEP Mode on the

On-Chip Oscillator

When the device executes a SLEEP instruction, the

on-chip clocks and oscillator are turned off and the

device is held at the beginning of an instruction cycle

(Q1 state). With the oscillator off, the OSC1 and OSC2

signals will stop oscillating. Since all the transistor

switching currents have been removed, SLEEP mode

achieves the lowest current consumption of the device

(only leakage currents). Enabling any on-chip feature

that will operate during SLEEP will increase the current

consumed during SLEEP. The user can wake from

SLEEP through external RESET, Watchdog Timer

Reset, or through an interrupt.

TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE

2.8 Power-up Delays

Power up delays are controlled by two timers, so that

no external RESET circuitry is required for most appli-

cations. The delays ensure that the device is kept in

RESET, until the device power supply and clock are

stable. For additional information on RESET operation,

see Section 3.0.

The first timer is the Power-up Timer (PWRT), which

optionally provides a fixed delay of 72 ms (nominal) on

power-up only (POR and BOR). The second timer is

the Oscillator Start-up Timer (OST), intended to keep

the chip in RESET until the crystal oscillator is stable.

With the PLL enabled (HS/PLL Oscillator mode), the

time-out sequence following a Power-on Reset is differ-

ent from other Oscillator modes. The time-out

sequence is as follows: First, the PWRT time-out is

invoked after a POR time delay has expired. Then, the

Oscillator Start-up Timer (OST) is invoked. However,

this is still not a sufficient amount of time to allow the

PLL to lock at high frequencies. The PWRT timer is

used to provide an additional fixed 2 ms (nominal)

time-out to allow the PLL ample time to lock to the

incoming clock frequency.

OSC Mode OSC1 Pin OSC2 Pin

RC Floating, external resistor

should pull high

At logic low

RCIO Floating, external resistor

should pull high

Configured as PORTA, bit 6

ECIO Floating Configured as PORTA, bit 6

EC Floating At logic low

LP, XT, and HS Feedback inverter disabled, at

quiescent voltage level

Feedback inverter disabled, at

quiescent voltage level

Note: See Table 3-1, in the “Reset” section, for time-outs due to SLEEP and MCLR Reset.

PIC18FXX2

3.0 RESET

The PIC18FXXX differentiates between various kinds

of RESET:

a) Power-on Reset (POR)

b) MCLR Reset during normal operation

c) MCLR Reset during SLEEP

d) Watchdog Timer (WDT) Reset (during normal

operation)

e) Programmable Brown-out Reset (BOR)

f) RESET Instruction

g) Stack Full Reset

h) Stack Underflow Reset

Most registers are unaffected by a RESET. Their status

is unknown on POR and unchanged by all other

RESETS. The other registers are forced to a “RESET

state” on Power-on Reset, MCLR, WDT Reset, Brown-

out Reset, MCLR Reset during SLEEP and by the

RESET instruction.

Most registers are not affected by a WDT wake-up,

since this is viewed as the resumption of normal oper-

ation. Status bits from the RCON register, RI, TO, PD,

POR and BOR, are set or cleared differently in different

RESET situations, as indicated in Table 3-2. These bits

are used in software to determine the nature of the

RESET. See Table 3-3 for a full description of the

RESET states of all registers.

A simplified block diagram of the On-Chip Reset Circuit

is shown in Figure 3-1.

The Enhanced MCU devices have a MCLR noise filter

in the MCLR Reset path. The filter will detect and

ignore small pulses.

The MCLR pin is not driven low by any internal

RESETS, including the WDT.

FIGURE 3-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External Reset

MCLR

VDD

OSC1

WDT

Module

VDD Rise

Detect

OST/PWRT

On-chip

RC OSC

(1)

WDT

Time-out

Power-on Reset

OST

10-bit Ripple Counter

PWRT

Chip_Reset

10-bit Ripple Counter

Reset

Enable OST(2)

Enable PWRT

SLEEP

Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin.

2: See Table 3-1 for time-out situations.

Brown-out

Reset BOREN

RESET

Instruction

Stack

Pointer Stack Full/Underflow Reset

PIC18FXX2
DS39564C-page 26 © 2006 Microchip Technology Inc.
3.1 Power-On Reset (POR)
A Power-on Reset pulse is generated on-chip when
VDD rise is detected. To take advantage of the POR cir-
cuitry, just tie the MCLR pin directly (or through a resis-
tor) to VDD. This will eliminate external RC components
usually needed to create a Power-on Reset delay. A
minimum rise rate for VDD is specified
(parameter D004). For a slow rise time, see Figure 3-2.
When the device starts normal operation (i.e., exits the
RESET condition), device operating parameters (volt-
age, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in RESET until the operating
conditions are met.
FIGURE 3-2: EXTERNAL POWER-ON 
RESET CIRCUIT (FOR 
SLOW VDD POWER-UP)        
3.2 Power-up Timer (PWRT)
The Power-up Timer provides a fixed nominal time-out
(parameter 33) only on power-up from the POR. The
Power-up Timer operates on an internal RC oscillator.
The chip is kept in RESET as long as the PWRT is
active. The PWRT’s time delay allows VDD to rise to an
acceptable level. A configuration bit is provided to
enable/disable the PWRT.
The power-up time delay will vary from chip-to-chip due
to VDD, temperature and process variation. See DC
parameter D033 for details.
3.3 Oscillator Start-up Timer (OST)
The Oscillator Start-up Timer (OST) provides a 1024
oscillator cycle (from OSC1 input) delay after the
PWRT delay is over (parameter 32). This ensures that
the crystal oscillator or resonator has started and
stabilized.
The OST time-out is invoked only for XT, LP and HS
modes and only on Power-on Reset or wake-up from
SLEEP.
3.4 PLL Lock Time-out
With the PLL enabled, the time-out sequence following
a Power-on Reset is different from other Oscillator
modes. A portion of the Power-up Timer is used to pro-
vide a fixed time-out that is sufficient for the PLL to lock
to the main oscillator frequency. This PLL lock time-out
(TPLL) is typically 2 ms and follows the oscillator
start-up time-out (OST).
3.5 Brown-out Reset (BOR)
A configuration bit, BOREN, can disable (if clear/
programmed), or enable (if set) the Brown-out Reset
circuitry. If VDD falls below parameter D005 for greater
than parameter 35, the brown-out situation will reset
the chip. A RESET may not occur if VDD falls below
parameter D005 for less than parameter 35. The chip
will remain in Brown-out Reset until VDD rises above
BVDD. If the Power-up Timer is enabled, it will be
invoked after VDD rises above BVDD; it then will keep
the chip in RESET for an additional time delay
(parameter 33). If VDD drops below BVDD while the
Power-up Timer is running, the chip will go back into a
Brown-out Reset and the Power-up Timer will be initial-
ized. Once VDD rises above BVDD, the Power-up Timer
will execute the additional time delay. 
3.6 Time-out Sequence
On power-up, the time-out sequence is as follows:
First, PWRT time-out is invoked after the POR time
delay has expired. Then, OST is activated. The total
time-out will vary based on oscillator configuration and
the status of the PWRT. For example, in RC mode with
the PWRT disabled, there will be no time-out at all.
Figure 3-3, Figure 3-4, Figure 3-5, Figure 3-6 and
Figure 3-7 depict time-out sequences on power-up.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the time-outs will expire.
Bringing MCLR high will begin execution immediately
(Figure 3-5). This is useful for testing purposes or to
synchronize more than one PIC18FXXX device operat-
ing in parallel.
Table 3-2 shows the RESET conditions for some
Special Function Registers, while Table 3-3 shows the
RESET conditions for all the registers. 
Note 1: External Power-on Reset circuit is required
only if the VDD power-up slope is too slow.
The diode D helps discharge the capacitor
quickly when VDD powers down.
2: R < 40 kΩ is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
3: R1 = 100Ω to 1 kΩ will limit any current flow-
ing into MCLR from external capacitor C, in
the event of MCLR/VPP pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
C
R1
R
D
VDD
MCLR
PIC18FXXX

PIC18FXX2

TABLE 3-1: TIME-OUT IN VARIOUS SITUATIONS

TABLE 3-2: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR

RCON REGISTER

Oscillator

Configuration

Power-up(2)

Brown-out

Wake-up from

SLEEP or

Oscillator Switch

PWRTE = 0 PWRTE = 1

HS with PLL enabled(1) 72 ms + 1024 TOSC

+ 2ms

1024 TOSC

+ 2 ms

72 ms(2) + 1024 TOSC

+ 2 ms 1024 T

OSC + 2 ms

HS, XT, LP 72 ms + 1024 TOSC 1024 TOSC 72 ms(2) + 1024 TOSC 1024 TOSC

EC 72 ms — 72 ms(2) —

External RC 72 ms — 72 ms(2) —

Note 1: 2 ms is the nominal time required for the 4x PLL to lock.

2: 72 ms is the nominal power-up timer delay, if implemented.

R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0

IPEN ——RITO PD POR BOR

bit 7 bit 0

Note 1: Refer to Section 4.14 (page 53) for bit definitions.

Condition Program

Counter

RCON

Power-on Reset 0000h 0--1 1100 1 1 1 0 0 u u

MCLR Reset during normal

operation

0000h 0--u uuuu u u u u u u u

Software Reset during normal

operation

0000h 0--0 uuuu 0 u u u u u u

Stack Full Reset during normal

operation

0000h 0--u uu11 u u u u u u 1

Stack Underflow Reset during

normal operation

0000h 0--u uu11 u u u u u 1 u

MCLR Reset during SLEEP 0000h 0--u 10uu u 1 0 u u u u

WDT Reset 0000h 0--u 01uu 1 0 1 u u u u

WDT Wake-up PC + 2 u--u 00uu u 0 0 u u u u

Brown-out Reset 0000h 0--1 11u0 1 1 1 1 0 u u

Interrupt wake-up from SLEEP PC + 2(1) u--u 00uu u 1 0 u u u u

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0'

Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the

interrupt vector (0x000008h or 0x000018h).

PIC18FXX2

TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS

Brown-out Reset

MCLR Resets

WDT Reset

RESET Instruction

Stack Resets

Wake-up via WDT

or Interrupt

TOSU 242 442 252 452 ---0 0000 ---0 0000 ---0 uuuu(3)

TOSH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(3)

TOSL 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(3)

STKPTR 242 442 252 452 00-0 0000 uu-0 0000 uu-u uuuu(3)

PCLATU 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu

PCLATH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

PCL 242 442 252 452 0000 0000 0000 0000 PC + 2(2)

TBLPTRU 242 442 252 452 --00 0000 --00 0000 --uu uuuu

TBLPTRH 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

TBLPTRL 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

TABLAT 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

PRODH 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

PRODL 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

INTCON 242 442 252 452 0000 000x 0000 000u uuuu uuuu(1)

INTCON2 242 442 252 452 1111 -1-1 1111 -1-1 uuuu -u-u(1)

INTCON3 242 442 252 452 11-0 0-00 11-0 0-00 uu-u u-uu(1)

INDF0 242 442 252 452 N/A N/A N/A

POSTINC0 242 442 252 452 N/A N/A N/A

POSTDEC0 242 442 252 452 N/A N/A N/A

PREINC0 242 442 252 452 N/A N/A N/A

PLUSW0 242 442 252 452 N/A N/A N/A

FSR0H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu

FSR0L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

WREG 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

INDF1 242 442 252 452 N/A N/A N/A

POSTINC1 242 442 252 452 N/A N/A N/A

POSTDEC1 242 442 252 452 N/A N/A N/A

PREINC1 242 442 252 452 N/A N/A N/A

PLUSW1 242 442 252 452 N/A N/A N/A

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.

Shaded cells indicate conditions do not apply for the designated device.

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt

vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 3-2 for RESET value for specific condition.

5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other

Oscillator modes, they are disabled and read ’0’.

6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.

PIC18FXX2

FSR1H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu

FSR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

BSR 242 442 252 452 ---- 0000 ---- 0000 ---- uuuu

INDF2 242 442 252 452 N/A N/A N/A

POSTINC2 242 442 252 452 N/A N/A N/A

POSTDEC2 242 442 252 452 N/A N/A N/A

PREINC2 242 442 252 452 N/A N/A N/A

PLUSW2 242 442 252 452 N/A N/A N/A

FSR2H 242 442 252 452 ---- xxxx ---- uuuu ---- uuuu

FSR2L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

STATUS 242 442 252 452 ---x xxxx ---u uuuu ---u uuuu

TMR0H 242 442 252 452 0000 0000 uuuu uuuu uuuu uuuu

TMR0L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

T0CON 242 442 252 452 1111 1111 1111 1111 uuuu uuuu

OSCCON 242 442 252 452 ---- ---0 ---- ---0 ---- ---u

LVDCON 242 442 252 452 --00 0101 --00 0101 --uu uuuu

WDTCON 242 442 252 452 ---- ---0 ---- ---0 ---- ---u

RCON(4) 242 442 252 452 0--q 11qq 0--q qquu u--u qquu

TMR1H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

TMR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

T1CON 242 442 252 452 0-00 0000 u-uu uuuu u-uu uuuu

TMR2 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

PR2 242 442 252 452 1111 1111 1111 1111 1111 1111

T2CON 242 442 252 452 -000 0000 -000 0000 -uuu uuuu

SSPBUF 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

SSPADD 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

SSPSTAT 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

SSPCON1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

SSPCON2 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Brown-out Reset

MCLR Resets

WDT Reset

RESET Instruction

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.

Shaded cells indicate conditions do not apply for the designated device.

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt

vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 3-2 for RESET value for specific condition.

5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other

Oscillator modes, they are disabled and read ’0’.

6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.

PIC18FXX2

ADRESH 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

ADRESL 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

ADCON0 242 442 252 452 0000 00-0 0000 00-0 uuuu uu-u

ADCON1 242 442 252 452 00-- 0000 00-- 0000 uu-- uuuu

CCPR1H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

CCPR1L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

CCP1CON 242 442 252 452 --00 0000 --00 0000 --uu uuuu

CCPR2H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

CCPR2L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

CCP2CON 242 442 252 452 --00 0000 --00 0000 --uu uuuu

TMR3H 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

TMR3L 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

T3CON 242 442 252 452 0000 0000 uuuu uuuu uuuu uuuu

SPBRG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

RCREG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

TXREG 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

TXSTA 242 442 252 452 0000 -010 0000 -010 uuuu -uuu

RCSTA 242 442 252 452 0000 000x 0000 000x uuuu uuuu

EEADR 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

EEDATA 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

EECON1 242 442 252 452 xx-0 x000 uu-0 u000 uu-0 u000

EECON2 242 442 252 452 ---- ---- ---- ---- ---- ----

TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Brown-out Reset

MCLR Resets

WDT Reset

RESET Instruction

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.

Shaded cells indicate conditions do not apply for the designated device.

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt

vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 3-2 for RESET value for specific condition.

5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other

Oscillator modes, they are disabled and read ’0’.

6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.

PIC18FXX2

IPR2 242 442 252 452 ---1 1111 ---1 1111 ---u uuuu

PIR2 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu(1)

PIE2 242 442 252 452 ---0 0000 ---0 0000 ---u uuuu

IPR1 242 442 252 452 1111 1111 1111 1111 uuuu uuuu

242 442 252 452 -111 1111 -111 1111 -uuu uuuu

PIR1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu(1)

242 442 252 452 -000 0000 -000 0000 -uuu uuuu(1)

PIE1 242 442 252 452 0000 0000 0000 0000 uuuu uuuu

242 442 252 452 -000 0000 -000 0000 -uuu uuuu

TRISE 242 442 252 452 0000 -111 0000 -111 uuuu -uuu

TRISD 242 442 252 452 1111 1111 1111 1111 uuuu uuuu

TRISC 242 442 252 452 1111 1111 1111 1111 uuuu uuuu

TRISB 242 442 252 452 1111 1111 1111 1111 uuuu uuuu

TRISA(5,6) 242 442 252 452 -111 1111(5) -111 1111(5) -uuu uuuu(5)

LATE 242 442 252 452 ---- -xxx ---- -uuu ---- -uuu

LATD 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

LATC 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

LATB 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

LATA(5,6) 242 442 252 452 -xxx xxxx(5) -uuu uuuu(5) -uuu uuuu(5)

PORTE 242 442 252 452 ---- -000 ---- -000 ---- -uuu

PORTD 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

PORTC 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

PORTB 242 442 252 452 xxxx xxxx uuuu uuuu uuuu uuuu

PORTA(5,6) 242 442 252 452 -x0x 0000(5) -u0u 0000(5) -uuu uuuu(5)

TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Brown-out Reset

MCLR Resets

WDT Reset

RESET Instruction

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.

Shaded cells indicate conditions do not apply for the designated device.

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt

vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 3-2 for RESET value for specific condition.

5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other

Oscillator modes, they are disabled and read ’0’.

6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.

PIC18FXX2

FIGURE 3-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)

FIGURE 3-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1

FIGURE 3-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2

TPWRT

TOST

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

TPWRT

TOST

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

TPWRT

TOST

PIC18FXX2

FIGURE 3-6: SLOW RISE TIME (MCLR TIED TO VDD)

FIGURE 3-7: TIME-OUT SEQUENCE ON POR W/ PLL ENABLED (MCLR TIED TO VDD)

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

0V 1V

TPWRT

TOST

TPWRT

TOST

VDD

MCLR

IINTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

PLL TIME-OUT

TPLL

Note: TOST = 1024 clock cycles.

TPLL ≈ 2 ms max. First three stages of the PWRT timer.

PIC18FXX2

NOTES:

PIC18FXX2

4.0 MEMORY ORGANIZATION

There are three memory blocks in Enhanced MCU

devices. These memory blocks are:

• Program Memory

• Data RAM

• Data EEPROM

Data and program memory use separate busses,

which allows for concurrent access of these blocks.

Additional detailed information for FLASH program

memory and Data EEPROM is provided in Section 5.0

and Section 6.0, respectively.

4.1 Program Memory Organization

A 21-bit program counter is capable of addressing the

2-Mbyte program memory space. Accessing a location

between the physically implemented memory and the

2-Mbyte address will cause a read of all ’0’s (a NOP

instruction).

The PIC18F252 and PIC18F452 each have 32 Kbytes

of FLASH memory, while the PIC18F242 and

PIC18F442 have 16 Kbytes of FLASH. This means that

PIC18FX52 devices can store up to 16K of single word

instructions, and PIC18FX42 devices can store up to

8K of single word instructions.

The RESET vector address is at 0000h and the

interrupt vector addresses are at 0008h and 0018h.

Figure 4-1 shows the Program Memory Map for

PIC18F242/442 devices and Figure 4-2 shows the

Program Memory Map for PIC18F252/452 devices.

PIC18FXX2

FIGURE 4-1: PROGRAM MEMORY MAP

AND STACK FOR

PIC18F442/242

FIGURE 4-2: PROGRAM MEMORY MAP

AND STACK FOR

PIC18F452/252

PC<20:0>

Stack Level 1

•

Stack Level 31

RESET Vector

Low Priority Interrupt Vector

•

CALL,RCALL,RETURN

RETFIE,RETLW

0000h

0018h

On-Chip

Program Memory

High Priority Interrupt Vector 0008h

User Memory Space

1FFFFFh

4000h

3FFFh

Read '0'

200000h

PC<20:0>

Stack Level 1

•

Stack Level 31

RESET Vector

Low Priority Interrupt Vector

•

CALL,RCALL,RETURN

RETFIE,RETLW

0000h

0018h

8000h

7FFFh

On-Chip

Program Memory

High Priority Interrupt Vector 0008h

User Memory Space

Read '0'

1FFFFFh

200000h

PIC18FXX2

4.2 Return Address Stack

The return address stack allows any combination of up

to 31 program calls and interrupts to occur. The PC

(Program Counter) is pushed onto the stack when a

CALL or RCALL instruction is executed, or an interrupt

is acknowledged. The PC value is pulled off the stack

on a RETURN, RETLW or a RETFIE instruction.

PCLATU and PCLATH are not affected by any of the

RETURN or CALL instructions.

The stack operates as a 31-word by 21-bit RAM and a

5-bit stack pointer, with the stack pointer initialized to

00000b after all RESETS. There is no RAM associated

with stack pointer 00000b. This is only a RESET value.

During a CALL type instruction, causing a push onto the

stack, the stack pointer is first incremented and the

RAM location pointed to by the stack pointer is written

with the contents of the PC. During a RETURN type

instruction, causing a pop from the stack, the contents

of the RAM location pointed to by the STKPTR are

transferred to the PC and then the stack pointer is

decremented.

The stack space is not part of either program or data

space. The stack pointer is readable and writable, and

the address on the top of the stack is readable and writ-

able through SFR registers. Data can also be pushed

to, or popped from, the stack using the top-of-stack

SFRs. Status bits indicate if the stack pointer is at, or

beyond the 31 levels provided.

4.2.1 TOP-OF-STACK ACCESS

The top of the stack is readable and writable. Three

contents of the stack location pointed to by the

STKPTR register. This allows users to implement a

software stack if necessary. After a CALL, RCALL or

interrupt, the software can read the pushed value by

reading the TOSU, TOSH and TOSL registers. These

values can be placed on a user defined software stack.

At return time, the software can replace the TOSU,

TOSH and TOSL and do a return.

The user must disable the global interrupt enable bits

during this time to prevent inadvertent stack

operations.

4.2.2 RETURN STACK POINTER

(STKPTR)

The STKPTR register contains the stack pointer value,

the STKFUL (stack full) status bit, and the STKUNF

(stack underflow) status bits. Register 4-1 shows the

STKPTR register. The value of the stack pointer can be

0 through 31. The stack pointer increments when val-

ues are pushed onto the stack and decrements when

values are popped off the stack. At RESET, the stack

pointer value will be 0. The user may read and write the

stack pointer value. This feature can be used by a Real

Time Operating System for return stack maintenance.

After the PC is pushed onto the stack 31 times (without

popping any values off the stack), the STKFUL bit is

set. The STKFUL bit can only be cleared in software or

by a POR.

The action that takes place when the stack becomes

full depends on the state of the STVREN (Stack Over-

flow Reset Enable) configuration bit. Refer to

Section 20.0 for a description of the device configura-

tion bits. If STVREN is set (default), the 31st push will

push the (PC + 2) value onto the stack, set the STKFUL

bit, and reset the device. The STKFUL bit will remain

set and the stack pointer will be set to ‘0’.

If STVREN is cleared, the STKFUL bit will be set on the

31st push and the stack pointer will increment to 31.

Any additional pushes will not overwrite the 31st push,

and STKPTR will remain at 31.

When the stack has been popped enough times to

unload the stack, the next pop will return a value of zero

to the PC and sets the STKUNF bit, while the stack

pointer remains at 0. The STKUNF bit will remain set

until cleared in software or a POR occurs.

Note: Returning a value of zero to the PC on an

underflow has the effect of vectoring the

program to the RESET vector, where the

stack conditions can be verified and

appropriate actions can be taken.

PIC18FXX2

FIGURE 4-3: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS

4.2.3 PUSH AND POP INSTRUCTIONS

Since the Top-of-Stack (TOS) is readable and writable,

the ability to push values onto the stack and pull values

off the stack without disturbing normal program execu-

tion is a desirable option. To push the current PC value

onto the stack, a PUSH instruction can be executed.

This will increment the stack pointer and load the cur-

rent PC value onto the stack. TOSU, TOSH and TOSL

can then be modified to place a return address on the

stack.

The ability to pull the TOS value off of the stack and

replace it with the value that was previously pushed

onto the stack, without disturbing normal execution, is

achieved by using the POP instruction. The POP instruc-

tion discards the current TOS by decrementing the

stack pointer. The previous value pushed onto the

stack then becomes the TOS value.

4.2.4 STACK FULL/UNDERFLOW RESETS

These resets are enabled by programming the

STVREN configuration bit. When the STVREN bit is

disabled, a full or underflow condition will set the appro-

priate STKFUL or STKUNF bit, but not cause a device

RESET. When the STVREN bit is enabled, a full or

underflow will set the appropriate STKFUL or STKUNF

bit and then cause a device RESET. The STKFUL or

STKUNF bits are only cleared by the user software or

a POR Reset.

R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

STKOVF STKUNF — SP4 SP3 SP2 SP1 SP0

bit 7 bit 0

bit 7(1) STKOVF: Stack Full Flag bit

1 = Stack became full or overflowed

0 = Stack has not become full or overflowed

bit 6(1) STKUNF: Stack Underflow Flag bit

1 = Stack underflow occurred

0 = Stack underflow did not occur

bit 5 Unimplemented: Read as '0'

bit 4-0 SP4:SP0: Stack Pointer Location bits

Note 1: Bit 7 and bit 6 can only be cleared in user software or by a POR.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

00011

0x001A34

11111

11110

11101

00010

00001

00000

00010

Return Address Stack

Top of Stack 0x000D58

TOSLTOSHTOSU

0x340x1A0x00

STKPTR<4:0>

PIC18FXX2

4.3 Fast Register Stack

A “fast interrupt return” option is available for interrupts.

A Fast Register Stack is provided for the STATUS,

WREG and BSR registers and are only one in depth.

The stack is not readable or writable and is loaded with

the current value of the corresponding register when

the processor vectors for an interrupt. The values in the

registers are then loaded back into the working regis-

ters, if the FAST RETURN instruction is used to return

from the interrupt.

A low or high priority interrupt source will push values

into the stack registers. If both low and high priority

interrupts are enabled, the stack registers cannot be

used reliably for low priority interrupts. If a high priority

interrupt occurs while servicing a low priority interrupt,

the stack register values stored by the low priority inter-

rupt will be overwritten.

If high priority interrupts are not disabled during low pri-

ority interrupts, users must save the key registers in

software during a low priority interrupt.

If no interrupts are used, the fast register stack can be

used to restore the STATUS, WREG and BSR registers

at the end of a subroutine call. To use the fast register

stack for a subroutine call, a FAST CALL instruction

must be executed.

Example 4-1 shows a source code example that uses

the fast register stack.

EXAMPLE 4-1: FAST REGISTER STACK

CODE EXAMPLE

4.4 PCL, PCLATH and PCLATU

The program counter (PC) specifies the address of the

instruction to fetch for execution. The PC is 21-bits

wide. The low byte is called the PCL register. This reg-

ister is readable and writable. The high byte is called

the PCH register. This register contains the PC<15:8>

bits and is not directly readable or writable. Updates to

the PCH register may be performed through the

PCLATH register. The upper byte is called PCU. This

readable or writable. Updates to the PCU register may

be performed through the PCLATU register.

The PC addresses bytes in the program memory. To

prevent the PC from becoming misaligned with word

instructions, the LSB of PCL is fixed to a value of ’0’.

The PC increments by 2 to address sequential

instructions in the program memory.

The CALL, RCALL, GOTO and program branch

instructions write to the program counter directly. For

these instructions, the contents of PCLATH and

PCLATU are not transferred to the program counter.

The contents of PCLATH and PCLATU will be trans-

ferred to the program counter by an operation that

writes PCL. Similarly, the upper two bytes of the pro-

gram counter will be transferred to PCLATH and

PCLATU by an operation that reads PCL. This is useful

for computed offsets to the PC (see Section 4.8.1).

4.5 Clocking Scheme/Instruction

Cycle

The clock input (from OSC1) is internally divided by

four to generate four non-overlapping quadrature

clocks, namely Q1, Q2, Q3 and Q4. Internally, the pro-

gram counter (PC) is incremented every Q1, the

instruction is fetched from the program memory and

latched into the instruction register in Q4. The instruc-

tion is decoded and executed during the following Q1

through Q4. The clocks and instruction execution flow

are shown in Figure 4-4.

FIGURE 4-4: CLOCK/INSTRUCTION CYCLE

CALL SUB1, FAST ;STATUS, WREG, BSR

;SAVED IN FAST REGISTER

;STACK

•

SUB1 •

•

RETURN FAST ;RESTORE VALUES SAVED

;IN FAST REGISTER STACK

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

OSC1

OSC2/CLKO

(RC mode)

PC PC+2 PC+4

Fetch INST (PC)

Execute INST (PC-2)

Fetch INST (PC+2)

Execute INST (PC)

Fetch INST (PC+4)

Execute INST (PC+2)

Internal

Phase

Clock

PIC18FXX2

4.6 Instruction Flow/Pipelining

An “Instruction Cycle” consists of four Q cycles (Q1,

Q2, Q3 and Q4). The instruction fetch and execute are

pipelined such that fetch takes one instruction cycle,

while decode and execute takes another instruction

cycle. However, due to the pipelining, each instruction

effectively executes in one cycle. If an instruction

causes the program counter to change (e.g., GOTO)

then two cycles are required to complete the instruction

(Example 4-2).

A fetch cycle begins with the program counter (PC)

incrementing in Q1.

In the execution cycle, the fetched instruction is latched

into the “Instruction Register” (IR) in cycle Q1. This

instruction is then decoded and executed during the

Q2, Q3, and Q4 cycles. Data memory is read during Q2

(operand read) and written during Q4 (destination

write).

EXAMPLE 4-2: INSTRUCTION PIPELINE FLOW

4.7 Instructions in Program Memory

The program memory is addressed in bytes. Instruc-

tions are stored as two bytes or four bytes in program

memory. The Least Significant Byte of an instruction

word is always stored in a program memory location

with an even address (LSB =’0’). Figure 4-5 shows an

example of how instruction words are stored in the pro-

gram memory. To maintain alignment with instruction

boundaries, the PC increments in steps of 2 and the

LSB will always read ’0’ (see Section 4.4).

The CALL and GOTO instructions have an absolute pro-

gram memory address embedded into the instruction.

Since instructions are always stored on word bound-

aries, the data contained in the instruction is a word

address. The word address is written to PC<20:1>,

which accesses the desired byte address in program

memory. Instruction #2 in Figure 4-5 shows how the

instruction “GOTO 000006h’ is encoded in the program

memory. Program branch instructions which encode a

relative address offset operate in the same manner.

The offset value stored in a branch instruction repre-

sents the number of single word instructions that the

PC will be offset by. Section 20.0 provides further

details of the instruction set.

FIGURE 4-5: INSTRUCTIONS IN PROGRAM MEMORY

All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction

is “flushed” from the pipeline while the new instruction is being fetched and then executed.

TCY0TCY1TCY2TCY3TCY4TCY5

1. MOVLW 55h Fetch 1 Execute 1

2. MOVWF PORTB Fetch 2 Execute 2

3. BRA SUB_1 Fetch 3 Execute 3

4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP)

5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1

Word Address

LSB = 1 LSB = 0 ↓

Program Memory

Byte Locations →

000000h

000002h

000004h

000006h

Instruction 1: MOVLW 055h 0Fh 55h 000008h

Instruction 2: GOTO 000006h EFh 03h 00000Ah

F0h 00h 00000Ch

Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh

F4h 56h 000010h

000012h

000014h

PIC18FXX2

4.7.1 TWO-WORD INSTRUCTIONS

The PIC18FXX2 devices have four two-word instruc-

tions: MOVFF, CALL, GOTO and LFSR. The second

word of these instructions has the 4 MSBs set to 1’s

and is a special kind of NOP instruction. The lower 12

bits of the second word contain data to be used by the

instruction. If the first word of the instruction is exe-

cuted, the data in the second word is accessed. If the

second word of the instruction is executed by itself (first

word was skipped), it will execute as a NOP. This action

is necessary when the two-word instruction is preceded

by a conditional instruction that changes the PC. A pro-

gram example that demonstrates this concept is shown

in Example 4-3. Refer to Section 20.0 for further details

of the instruction set.

EXAMPLE 4-3: TWO-WORD INSTRUCTIONS

4.8 Lookup Tables

Lookup tables are implemented two ways. These are:

• Computed GOTO

• Table Reads

4.8.1 COMPUTED GOTO

A computed GOTO is accomplished by adding an offset

to the program counter (ADDWF PCL).

A lookup table can be formed with an ADDWF PCL

instruction and a group of RETLW 0xnn instructions.

WREG is loaded with an offset into the table before

executing a call to that table. The first instruction of the

called routine is the ADDWF PCL instruction. The next

instruction executed will be one of the RETLW 0xnn

instructions, that returns the value 0xnn to the calling

function.

The offset value (value in WREG) specifies the number

of bytes that the program counter should advance.

In this method, only one data byte may be stored in

each instruction location and room on the return

address stack is required.

4.8.2 TABLE READS/TABLE WRITES

A better method of storing data in program memory

allows 2 bytes of data to be stored in each instruction

location.

Lookup table data may be stored 2 bytes per program

word by using table reads and writes. The table pointer

(TBLPTR) specifies the byte address and the table

latch (TABLAT) contains the data that is read from, or

written to program memory. Data is transferred to/from

program memory, one byte at a time.

A description of the Table Read/Table Write operation

is shown in Section 3.0.

CASE 1:

Object Code Source Code

0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?

1100 0001 0010 0011 MOVFF REG1, REG2 ; No, execute 2-word instruction

1111 0100 0101 0110 ; 2nd operand holds address of REG2

0010 0100 0000 0000 ADDWF REG3 ; continue code

CASE 2:

Object Code Source Code

0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?

1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes

1111 0100 0101 0110 ; 2nd operand becomes NOP

0010 0100 0000 0000 ADDWF REG3 ; continue code

Note: The ADDWF PCL instruction does not

update PCLATH and PCLATU. A read

operation on PCL must be performed to

update PCLATH and PCLATU.

PIC18FXX2

4.9 Data Memory Organization

The data memory is implemented as static RAM. Each

allowing up to 4096 bytes of data memory. Figure 4-6

and Figure 4-7 show the data memory organization for

the PIC18FXX2 devices.

The data memory map is divided into as many as 16

banks that contain 256 bytes each. The lower 4 bits of

the Bank Select Register (BSR<3:0>) select which

bank will be accessed. The upper 4 bits for the BSR are

not implemented.

The data memory contains Special Function Registers

(SFR) and General Purpose Registers (GPR). The

SFRs are used for control and status of the controller

and peripheral functions, while GPRs are used for data

storage and scratch pad operations in the user’s appli-

cation. The SFRs start at the last location of Bank 15

(0xFFF) and extend downwards. Any remaining space

beyond the SFRs in the Bank may be implemented as

GPRs. GPRs start at the first location of Bank 0 and

grow upwards. Any read of an unimplemented location

will read as ’0’s.

The entire data memory may be accessed directly or

indirectly. Direct addressing may require the use of the

BSR register. Indirect addressing requires the use of a

File Select Register (FSRn) and a corresponding Indi-

rect File Operand (INDFn). Each FSR holds a 12-bit

address value that can be used to access any location

in the Data Memory map without banking.

The instruction set and architecture allow operations

across all banks. This may be accomplished by indirect

addressing or by the use of the MOVFF instruction. The

MOVFF instruction is a two-word/two-cycle instruction

that moves a value from one register to another.

To ensure that commonly used registers (SFRs and

select GPRs) can be accessed in a single cycle,

regardless of the current BSR values, an Access Bank

is implemented. A segment of Bank 0 and a segment of

Bank 15 comprise the Access RAM. Section 4.10

provides a detailed description of the Access RAM.

4.9.1 GENERAL PURPOSE REGISTER

FILE

The register file can be accessed either directly or indi-

rectly. Indirect addressing operates using a File Select

operation of indirect addressing is shown in

Section 4.12.

Enhanced MCU devices may have banked memory in

the GPR area. GPRs are not initialized by a Power-on

Reset and are unchanged on all other RESETS.

Data RAM is available for use as GPR registers by all

instructions. The top half of Bank 15 (0xF80 to 0xFFF)

contains SFRs. All other banks of data memory contain

GPR registers, starting with Bank 0.

4.9.2 SPECIAL FUNCTION REGISTERS

The Special Function Registers (SFRs) are registers

used by the CPU and Peripheral Modules for control-

ling the desired operation of the device. These regis-

ters are implemented as static RAM. A list of these

registers is given in Table 4-1 and Table 4-2.

The SFRs can be classified into two sets; those asso-

ciated with the “core” function and those related to the

peripheral functions. Those registers related to the

“core” are described in this section, while those related

to the operation of the peripheral features are

described in the section of that peripheral feature.

The SFRs are typically distributed among the

peripherals whose functions they control.

The unused SFR locations will be unimplemented and

read as '0's. See Table 4-1 for addresses for the SFRs.

PIC18FXX2

FIGURE 4-6: DATA MEMORY MAP FOR PIC18F242/442

Bank 0

Bank 1

Bank 14

Bank 15

Data Memory Map

BSR<3:0>

= 0000

= 0001

= 1111

080h

07Fh

F80h

FFFh

00h

7Fh

80h

FFh

Access Bank

When a = 0,

the BSR is ignored and the

Access Bank is used.

The first 128 bytes are General

Purpose RAM (from Bank 0).

The second 128 bytes are

Special Function Registers

(from Bank 15).

When a = 1,

the BSR is used to specify the

RAM location that the

instruction uses.

F7Fh

F00h

EFFh

1FFh

100h

0FFh

000h

Access RAM

FFh

00h

FFh

00h

FFh

00h

GPR

SFR

Unused

Access RAM high

Access RAM low

Bank 3

200h

Unused

Read ’00h’

= 1110

= 0011

(SFRs)

GPR

2FFh

300h

FFh

00h

Bank 2

= 0010

PIC18FXX2

FIGURE 4-7: DATA MEMORY MAP FOR PIC18F252/452

Bank 0

Bank 1

Bank 14

Bank 15

Data Memory Map

BSR<3:0>

= 0000

= 0001

= 1110

= 1111

080h

07Fh

F80h

FFFh

00h

7Fh

80h

FFh

Access Bank

When a = 0,

the BSR is ignored and the

Access Bank is used.

The first 128 bytes are General

Purpose RAM (from Bank 0).

The second 128 bytes are

Special Function Registers

(from Bank 15).

When a = 1,

the BSR is used to specify the

RAM location that the

instruction uses.

Bank 4

Bank 3

Bank 2

F7Fh

F00h

EFFh

3FFh

300h

2FFh

200h

1FFh

100h

0FFh

000h

= 0110

= 0101

= 0011

= 0010

Access RAM

FFh

00h

FFh

00h

FFh

00h

FFh

00h

FFh

00h

FFh

00h

GPR

SFR

Unused

Access RAM high

Access RAM low

Bank 5

GPR

Bank 6

4FFh

400h

5FFh

500h

600h

Unused

Read ’00h’

= 0100

(SFR’s)

PIC18FXX2

TABLE 4-1: SPECIAL FUNCTION REGISTER MAP

Address Name Address Name Address Name Address Name

FFFh TOSU FDFh INDF2(3) FBFh CCPR1H F9Fh IPR1

FFEh TOSH FDEh POSTINC2(3) FBEh CCPR1L F9Eh PIR1

FFDh TOSL FDDh POSTDEC2(3) FBDh CCP1CON F9Dh PIE1

FFCh STKPTR FDCh PREINC2(3) FBCh CCPR2H F9Ch —

FFBh PCLATU FDBh PLUSW2(3) FBBh CCPR2L F9Bh —

FFAh PCLATH FDAh FSR2H FBAh CCP2CON F9Ah —

FF9h PCL FD9h FSR2L FB9h — F99h —

FF8h TBLPTRU FD8h STATUS FB8h — F98h —

FF7h TBLPTRH FD7h TMR0H FB7h — F97h —

FF6h TBLPTRL FD6h TMR0L FB6h — F96h TRISE(2)

FF5h TABLAT FD5h T0CON FB5h — F95h TRISD(2)

FF4h PRODH FD4h — FB4h — F94h TRISC

FF3h PRODL FD3h OSCCON FB3h TMR3H F93h TRISB

FF2h INTCON FD2h LVDCON FB2h TMR3L F92h TRISA

FF1h INTCON2 FD1h WDTCON FB1h T3CON F91h —

FF0h INTCON3 FD0h RCON FB0h — F90h —

FEFh INDF0(3) FCFh TMR1H FAFh SPBRG F8Fh —

FEEh POSTINC0(3) FCEh TMR1L FAEh RCREG F8Eh —

FEDh POSTDEC0(3) FCDh T1CON FADh TXREG F8Dh LATE(2)

FECh PREINC0(3) FCCh TMR2 FACh TXSTA F8Ch LATD(2)

FEBh PLUSW0(3) FCBh PR2 FABh RCSTA F8Bh LATC

FEAh FSR0H FCAh T2CON FAAh — F8Ah LATB

FE9h FSR0L FC9h SSPBUF FA9h EEADR F89h LATA

FE8h WREG FC8h SSPADD FA8h EEDATA F88h —

FE7h INDF1(3) FC7h SSPSTAT FA7h EECON2 F87h —

FE6h POSTINC1(3) FC6h SSPCON1 FA6h EECON1 F86h —

FE5h POSTDEC1(3) FC5h SSPCON2 FA5h — F85h —

FE4h PREINC1(3) FC4h ADRESH FA4h — F84h PORTE(2)

FE3h PLUSW1(3) FC3h ADRESL FA3h — F83h PORTD(2)

FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h PORTC

FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB

FE0h BSR FC0h — FA0h PIE2 F80h PORTA

Note 1: Unimplemented registers are read as ’0’.

2: This register is not available on PIC18F2X2 devices.

3: This is not a physical register.

PIC18FXX2
DS39564C-page 46 © 2006 Microchip Technology Inc.
TABLE 4-2: REGISTER FILE SUMMARY
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details 
on page:
TOSU — — — Top-of-Stack upper Byte (TOS<20:16>) ---0 0000 37
TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 37
TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 37
STKPTR STKFUL STKUNF — Return Stack Pointer 00-0 0000 38
PCLATU — — — Holding Register for PC<20:16> ---0 0000 39
PCLATH Holding Register for PC<15:8> 0000 0000 39
PCL PC Low Byte (PC<7:0>) 0000 0000 39
TBLPTRU ——bit21
(2) Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 58
TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 58
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 58
TABLAT Program Memory Table Latch 0000 0000 58
PRODH Product Register High Byte xxxx xxxx 71
PRODL Product Register Low Byte xxxx xxxx 71
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 75
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 —TMR0IP—RBIP1111 -1-1 76
INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 77
INDF0 Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register) n/a 50
POSTINC0 Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register) n/a 50
POSTDEC0 Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register) n/a 50
PREINC0 Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) n/a 50
PLUSW0 Uses contents of FSR0 to address data memory - value of FSR0 (not a physical register). 
Offset by value in WREG.
n/a 50
FSR0H — — — — Indirect Data Memory Address Pointer 0 High Byte ---- 0000 50
FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 50
WREG Working Register xxxx xxxx n/a
INDF1 Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register) n/a 50
POSTINC1 Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register) n/a 50
POSTDEC1 Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register) n/a 50
PREINC1 Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) n/a 50
PLUSW1 Uses contents of FSR1 to address data memory - value of FSR1 (not a physical register). 
Offset by value in WREG.
n/a 50
FSR1H — — — — Indirect Data Memory Address Pointer 1 High Byte ---- 0000 50
FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 50
BSR — — — — Bank Select Register ---- 0000 49
INDF2 Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register) n/a 50
POSTINC2 Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register) n/a 50
POSTDEC2 Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register) n/a 50
PREINC2 Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) n/a 50
PLUSW2 Uses contents of FSR2 to address data memory - value of FSR2 (not a physical register). 
Offset by value in WREG.
n/a 50
FSR2H — — — — Indirect Data Memory Address Pointer 2 High Byte ---- 0000 50
FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 50
STATUS — — —NOVZDCC---x xxxx 52
TMR0H Timer0 Register High Byte 0000 0000 105
TMR0L Timer0 Register Low Byte xxxx xxxx 105
T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 103
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
2: Bit 21 of the TBLPTRU allows access to the device configuration bits.
3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.

© 2006 Microchip Technology Inc. DS39564C-page 47
PIC18FXX2
OSCCON — — — — — — —SCS---- ---0 21
LVDCON —— IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 --00 0101 191
WDTCON — — — — — — —SWDTE---- ---0 203
RCON IPEN ——RITO PD POR BOR 0--1 11qq 53, 28, 84
TMR1H Timer1 Register High Byte xxxx xxxx 107
TMR1L Timer1 Register Low Byte xxxx xxxx 107
T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 107
TMR2 Timer2 Register 0000 0000 111
PR2 Timer2 Period Register 1111 1111 112
T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 111
SSPBUF SSP Receive Buffer/Transmit Register xxxx xxxx 125
SSPADD SSP Address Register in I2C Slave mode. SSP Baud Rate Reload Register in I2C Master mode. 0000 0000 134
SSPSTAT SMP CKE D/A PSR/WUA BF 0000 0000 126
SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 127
SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 137
ADRESH A/D Result Register High Byte xxxx xxxx 187,188
ADRESL A/D Result Register Low Byte xxxx xxxx 187,188
ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE —ADON0000 00-0 181
ADCON1 ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 182
CCPR1H Capture/Compare/PWM Register1 High Byte xxxx xxxx 121, 123
CCPR1L Capture/Compare/PWM Register1 Low Byte xxxx xxxx 121, 123
CCP1CON —— DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 117
CCPR2H Capture/Compare/PWM Register2 High Byte xxxx xxxx 121, 123
CCPR2L Capture/Compare/PWM Register2 Low Byte xxxx xxxx 121, 123
CCP2CON —— DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 117
TMR3H Timer3 Register High Byte xxxx xxxx 113
TMR3L Timer3 Register Low Byte xxxx xxxx 113
T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 113
SPBRG USART1 Baud Rate Generator 0000 0000 168
RCREG USART1 Receive Register 0000 0000 175, 178, 
180
TXREG USART1 Transmit Register 0000 0000 173, 176, 
179
TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 166
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 167
EEADR Data EEPROM Address Register 0000 0000 65, 69
EEDATA Data EEPROM Data Register 0000 0000 69
EECON2 Data EEPROM Control Register 2 (not a physical register) ---- ---- 65, 69
EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 66
TABLE 4-2: REGISTER FILE SUMMARY (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details 
on page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
2: Bit 21 of the TBLPTRU allows access to the device configuration bits.
3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.

PIC18FXX2
DS39564C-page 48 © 2006 Microchip Technology Inc.
IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 83
PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 79
PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 81
IPR1 PSPIP(3) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 1111 1111 82
PIR1 PSPIF(3) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 78
PIE1 PSPIE(3) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 80
TRISE(3) IBF OBF IBOV PSPMODE — Data Direction bits for PORTE 0000 -111 98
TRISD(3) Data Direction Control Register for PORTD 1111 1111 96
TRISC Data Direction Control Register for PORTC 1111 1111 93
TRISB Data Direction Control Register for PORTB 1111 1111 90
TRISA —TRISA6
(1) Data Direction Control Register for PORTA -111 1111 87
LATE(3) — — — — — Read PORTE Data Latch, 
Write PORTE Data Latch
---- -xxx 99
LATD(3) Read PORTD Data Latch, Write PORTD Data Latch xxxx xxxx 95
LATC Read PORTC Data Latch, Write PORTC Data Latch xxxx xxxx 93
LATB Read PORTB Data Latch, Write PORTB Data Latch xxxx xxxx 90
LATA —LATA6
(1) Read PORTA Data Latch, Write PORTA Data Latch(1) -xxx xxxx 87
PORTE(3) Read PORTE pins, Write PORTE Data Latch ---- -000 99
PORTD(3) Read PORTD pins, Write PORTD Data Latch xxxx xxxx 95
PORTC Read PORTC pins, Write PORTC Data Latch xxxx xxxx 93
PORTB Read PORTB pins, Write PORTB Data Latch xxxx xxxx 90
PORTA —RA6
(1) Read PORTA pins, Write PORTA Data Latch(1) -x0x 0000 87
TABLE 4-2: REGISTER FILE SUMMARY (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details 
on page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
2: Bit 21 of the TBLPTRU allows access to the device configuration bits.
3: These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.

PIC18FXX2

4.10 Access Bank

The Access Bank is an architectural enhancement

which is very useful for C compiler code optimization.

The techniques used by the C compiler may also be

useful for programs written in assembly.

This data memory region can be used for:

• Intermediate computational values

• Local variables of subroutines

• Faster context saving/switching of variables

• Common variables

• Faster evaluation/control of SFRs (no banking)

The Access Bank is comprised of the upper 128 bytes

in Bank 15 (SFRs) and the lower 128 bytes in Bank 0.

These two sections will be referred to as Access RAM

High and Access RAM Low, respectively. Figure 4-6

and Figure 4-7 indicate the Access RAM areas.

A bit in the instruction word specifies if the operation is

to occur in the bank specified by the BSR register or in

the Access Bank. This bit is denoted by the ’a’ bit (for

access bit).

When forced in the Access Bank (a = 0), the last

address in Access RAM Low is followed by the first

address in Access RAM High. Access RAM High maps

the Special Function registers, so that these registers

can be accessed without any software overhead. This is

useful for testing status flags and modifying control bits.

4.11 Bank Select Register (BSR)

The need for a large general purpose memory space

dictates a RAM banking scheme. The data memory is

partitioned into sixteen banks. When using direct

addressing, the BSR should be configured for the

desired bank.

BSR<3:0> holds the upper 4 bits of the 12-bit RAM

address. The BSR<7:4> bits will always read ’0’s, and

writes will have no effect.

A MOVLB instruction has been provided in the

instruction set to assist in selecting banks.

If the currently selected bank is not implemented, any

read will return all '0's and all writes are ignored. The

STATUS register bits will be set/cleared as appropriate

for the instruction performed.

Each Bank extends up to FFh (256 bytes). All data

memory is implemented as static RAM.

A MOVFF instruction ignores the BSR, since the 12-bit

addresses are embedded into the instruction word.

Section 4.12 provides a description of indirect address-

ing, which allows linear addressing of the entire RAM

space.

FIGURE 4-8: DIRECT ADDRESSING

Note 1: For register file map detail, see Table 4-1.

2: The access bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the

registers of the Access Bank.

3: The MOVFF instruction embeds the entire 12-bit address in the instruction.

Data

Memory(1)

Direct Addressing

Bank Select(2) Location Select(3)

BSR<3:0> 7 0

From Opcode(3)

00h 01h 0Eh 0Fh

Bank 0 Bank 1 Bank 14 Bank 15

1FFh

100h

0FFh

000h

EFFh

E00h

FFFh

F00h

PIC18FXX2

4.12 Indirect Addressing, INDF and

FSR Registers

Indirect addressing is a mode of addressing data mem-

ory, where the data memory address in the instruction

is not fixed. An FSR register is used as a pointer to the

data memory location that is to be read or written. Since

this pointer is in RAM, the contents can be modified by

the program. This can be useful for data tables in the

data memory and for software stacks. Figure 4-9

shows the operation of indirect addressing. This shows

the moving of the value to the data memory address

specified by the value of the FSR register.

Indirect addressing is possible by using one of the

INDF registers. Any instruction using the INDF register

actually accesses the register pointed to by the File

Select Register, FSR. Reading the INDF register itself,

indirectly (FSR = 0), will read 00h. Writing to the INDF

Figure 4-10.

The INDFn register is not a physical register. Address-

ing INDFn actually addresses the register whose

address is contained in the FSRn register (FSRn is a

pointer). This is indirect addressing.

Example 4-4 shows a simple use of indirect addressing

to clear the RAM in Bank1 (locations 100h-1FFh) in a

minimum number of instructions.

EXAMPLE 4-4: HOW TO CLEAR RAM

(BANK1) USING INDIRECT

ADDRESSING

There are three indirect addressing registers. To

address the entire data memory space (4096 bytes),

these registers are 12-bit wide. To store the 12-bits of

addressing information, two 8-bit registers are

required. These indirect addressing registers are:

1. FSR0: composed of FSR0H:FSR0L

2. FSR1: composed of FSR1H:FSR1L

3. FSR2: composed of FSR2H:FSR2L

In addition, there are registers INDF0, INDF1 and

INDF2, which are not physically implemented. Reading

or writing to these registers activates indirect address-

ing, with the value in the corresponding FSR register

being the address of the data. If an instruction writes a

value to INDF0, the value will be written to the address

pointed to by FSR0H:FSR0L. A read from INDF1 reads

the data from the address pointed to by

FSR1H:FSR1L. INDFn can be used in code anywhere

an operand can be used.

If INDF0, INDF1 or INDF2 are read indirectly via an

FSR, all '0's are read (zero bit is set). Similarly, if

INDF0, INDF1 or INDF2 are written to indirectly, the

operation will be equivalent to a NOP instruction and the

STATUS bits are not affected.

4.12.1 INDIRECT ADDRESSING

OPERATION

Each FSR register has an INDF register associated

with it, plus four additional register addresses. Perform-

ing an operation on one of these five registers deter-

mines how the FSR will be modified during indirect

addressing.

When data access is done to one of the five INDFn

locations, the address selected will configure the FSRn

• Do nothing to FSRn after an indirect access (no

change) - INDFn

• Auto-decrement FSRn after an indirect access

(post-decrement) - POSTDECn

• Auto-increment FSRn after an indirect access

(post-increment) - POSTINCn

• Auto-increment FSRn before an indirect access

(pre-increment) - PREINCn

• Use the value in the WREG register as an offset

to FSRn. Do not modify the value of the WREG or

the FSRn register after an indirect access (no

change) - PLUSWn

When using the auto-increment or auto-decrement fea-

tures, the effect on the FSR is not reflected in the

STATUS register. For example, if the indirect address

causes the FSR to equal '0', the Z bit will not be set.

Incrementing or decrementing an FSR affects all 12

bits. That is, when FSRnL overflows from an increment,

FSRnH will be incremented automatically.

Adding these features allows the FSRn to be used as a

stack pointer, in addition to its uses for table operations

in data memory.

Each FSR has an address associated with it that per-

forms an indexed indirect access. When a data access

to this INDFn location (PLUSWn) occurs, the FSRn is

configured to add the signed value in the WREG regis-

ter and the value in FSR to form the address before an

indirect access. The FSR value is not changed.

If an FSR register contains a value that points to one of

the INDFn, an indirect read will read 00h (zero bit is

set), while an indirect write will be equivalent to a NOP

(STATUS bits are not affected).

If an indirect addressing operation is done where the

target address is an FSRnH or FSRnL register, the

write operation will dominate over the pre- or

post-increment/decrement functions.

LFSR FSR0 ,0x100 ;

NEXT CLRF POSTINC0 ; Clear INDF

; register and

; inc pointer

BTFSS FSR0H, 1 ; All done with

; Bank1?

GOTO NEXT ; NO, clear next

CONTINUE ; YES, continue

PIC18FXX2

FIGURE 4-9: INDIRECT ADDRESSING OPERATION

FIGURE 4-10: INDIRECT ADDRESSING

Opcode Address

File Address = access of an indirect addressing register

FSR

Instruction

Executed

Instruction

Fetched

RAM

Opcode File

BSR<3:0>

FFFh

Note 1: For register file map detail, see Table 4-1.

Data

Memory(1)

Indirect Addressing

FSR Register11 0

0FFFh

0000h

Location Select

PIC18FXX2

4.13 STATUS Register

The STATUS register, shown in Register 4-2, contains

the arithmetic status of the ALU. The STATUS register

can be the destination for any instruction, as with any

other register. If the STATUS register is the destination

for an instruction that affects the Z, DC, C, OV, or N bits,

then the write to these five bits is disabled. These bits

are set or cleared according to the device logic. There-

fore, the result of an instruction with the STATUS

For example, CLRF STATUS will clear the upper three

bits and set the Z bit. This leaves the STATUS register

as 000u u1uu (where u = unchanged).

It is recommended, therefore, that only BCF, BSF,

SWAPF, MOVFF and MOVWF instructions are used to

alter the STATUS register, because these instructions

do not affect the Z, C, DC, OV, or N bits from the

STATUS register. For other instructions not affecting

any status bits, see Table 20-2.

Note: The C and DC bits operate as a borrow and

digit borrow bit respectively, in subtraction.

U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x

— — —NOVZDCC

bit 7 bit 0

bit 7-5 Unimplemented: Read as '0'

bit 4 N: Negative bit

This bit is used for signed arithmetic (2’s complement). It indicates whether the result was

negative (ALU MSB = 1).

1 = Result was negative

0 = Result was positive

bit 3 OV: Overflow bit

This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the

7-bit magnitude, which causes the sign bit (bit7) to change state.

1 = Overflow occurred for signed arithmetic (in this arithmetic operation)

0 = No overflow occurred

bit 2 Z: Zero bit

1 = The result of an arithmetic or logic operation is zero

0 = The result of an arithmetic or logic operation is not zero

bit 1 DC: Digit carry/borrow bit

For ADDWF, ADDLW, SUBLW, and SUBWF instructions

1 = A carry-out from the 4th low order bit of the result occurred

0 = No carry-out from the 4th low order bit of the result

Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two’s

complement of the second operand. For rotate (RRF, RLF) instructions, this bit is

loaded with either the bit 4 or bit 3 of the source register.

bit 0 C: Carry/borrow bit

For ADDWF, ADDLW, SUBLW, and SUBWF instructions

1 = A carry-out from the Most Significant bit of the result occurred

0 = No carry-out from the Most Significant bit of the result occurred

Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two’s

complement of the second operand. For rotate (RRF, RLF) instructions, this bit is

loaded with either the high or low order bit of the source register.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

4.14 RCON Register

The Reset Control (RCON) register contains flag bits

that allow differentiation between the sources of a

device RESET. These flags include the TO, PD, POR,

BOR and RI bits. This register is readable and writable.

Note 1: If the BOREN configuration bit is set

(Brown-out Reset enabled), the BOR bit is

’1’ on a Power-on Reset. After a Brown-

out Reset has occurred, the BOR bit will

be cleared, and must be set by firmware to

indicate the occurrence of the next

Brown-out Reset.

2: It is recommended that the POR bit be set

after a Power-on Reset has been

detected, so that subsequent Power-on

Resets may be detected.

R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0

IPEN ——RITO PD POR BOR

bit 7 bit 0

bit 7 IPEN: Interrupt Priority Enable bit

1 = Enable priority levels on interrupts

0 = Disable priority levels on interrupts (16CXXX Compatibility mode)

bit 6-5 Unimplemented: Read as '0'

bit 4 RI: RESET Instruction Flag bit

1 = The RESET instruction was not executed

0 = The RESET instruction was executed causing a device RESET

(must be set in software after a Brown-out Reset occurs)

bit 3 TO: Watchdog Time-out Flag bit

1 = After power-up, CLRWDT instruction, or SLEEP instruction

0 = A WDT time-out occurred

bit 2 PD: Power-down Detection Flag bit

1 = After power-up or by the CLRWDT instruction

0 = By execution of the SLEEP instruction

bit 1 POR: Power-on Reset Status bit

1 = A Power-on Reset has not occurred

0 = A Power-on Reset occurred

(must be set in software after a Power-on Reset occurs)

bit 0 BOR: Brown-out Reset Status bit

1 = A Brown-out Reset has not occurred

0 = A Brown-out Reset occurred

(must be set in software after a Brown-out Reset occurs)

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

NOTES:

PIC18FXX2

5.0 FLASH PROGRAM MEMORY

The FLASH Program Memory is readable, writable,

and erasable during normal operation over the entire

VDD range.

A read from program memory is executed on one byte

at a time. A write to program memory is executed on

blocks of 8 bytes at a time. Program memory is erased

in blocks of 64 bytes at a time. A bulk erase operation

may not be issued from user code.

Writing or erasing program memory will cease instruc-

tion fetches until the operation is complete. The pro-

gram memory cannot be accessed during the write or

erase, therefore, code cannot execute. An internal pro-

gramming timer terminates program memory writes

and erases.

A value written to program memory does not need to be

a valid instruction. Executing a program memory

location that forms an invalid instruction results in a

NOP.

5.1 Table Reads and Table Writes

In order to read and write program memory, there are

two operations that allow the processor to move bytes

between the program memory space and the data

RAM:

• Table Read (TBLRD)

• Table Write (TBLWT)

The program memory space is 16-bits wide, while the

data RAM space is 8-bits wide. Table Reads and Table

Writes move data between these two memory spaces

through an 8-bit register (TABLAT).

Table Read operations retrieve data from program

memory and places it into the data RAM space.

Figure 5-1 shows the operation of a Table Read with

program memory and data RAM.

Table Write operations store data from the data mem-

ory space into holding registers in program memory.

The procedure to write the contents of the holding reg-

isters into program memory is detailed in Section 5.5,

'”Writing to FLASH Program Memory”. Figure 5-2

shows the operation of a Table Write with program

memory and data RAM.

Table operations work with byte entities. A table block

containing data, rather than program instructions, is not

required to be word aligned. Therefore, a table block

can start and end at any byte address. If a Table Write

is being used to write executable code into program

memory, program instructions will need to be word

aligned.

FIGURE 5-1: TABLE READ OPERATION

Table Pointer(1)

Table Latch (8-bit)

Program Memory

TBLPTRH TBLPTRL

TABLAT

TBLPTRU

Instruction: TBLRD*

Note 1: Table Pointer points to a byte in program memory.

Program Memory

(TBLPTR)

PIC18FXX2

FIGURE 5-2: TABLE WRITE OPERATION

5.2 Control Registers

Several control registers are used in conjunction with

the TBLRD and TBLWT instructions. These include the:

• EECON1 register

• EECON2 register

• TABLAT register

• TBLPTR registers

5.2.1 EECON1 AND EECON2 REGISTERS

EECON1 is the control register for memory accesses.

EECON2 is not a physical register. Reading EECON2

will read all '0's. The EECON2 register is used

exclusively in the memory write and erase sequences.

Control bit EEPGD determines if the access will be a

program or data EEPROM memory access. When

clear, any subsequent operations will operate on the

data EEPROM memory. When set, any subsequent

operations will operate on the program memory.

Control bit CFGS determines if the access will be to the

configuration registers or to program memory/data

EEPROM memory. When set, subsequent operations

will operate on configuration registers, regardless of

EEPGD (see “Special Features of the CPU”,

Section 19.0). When clear, memory selection access is

determined by EEPGD.

The FREE bit, when set, will allow a program memory

erase operation. When the FREE bit is set, the erase

operation is initiated on the next WR command. When

FREE is clear, only writes are enabled.

The WREN bit, when set, will allow a write operation.

On power-up, the WREN bit is clear. The WRERR bit is

set when a write operation is interrupted by a MCLR

Reset or a WDT Time-out Reset during normal opera-

tion. In these situations, the user can check the

WRERR bit and rewrite the location. It is necessary to

reload the data and address registers (EEDATA and

EEADR), due to RESET values of zero.

Control bit WR initiates write operations. This bit cannot

be cleared, only set, in software. It is cleared in hard-

ware at the completion of the write operation. The

inability to clear the WR bit in software prevents the

accidental or premature termination of a write

operation.

Table Pointer(1) Table Latch (8-bit)

TBLPTRH TBLPTRL TABLAT

Program Memory

(TBLPTR)

TBLPTRU

Instruction: TBLWT*

Note 1: Table Pointer actually points to one of eight holding registers, the address of which is determined by

TBLPTRL<2:0>. The process for physically writing data to the Program Memory Array is discussed in

Section 5.5.

Holding Registers

Program Memory

Note: Interrupt flag bit EEIF, in the PIR2 register,

is set when the write is complete. It must

be cleared in software.

PIC18FXX2

R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0

EEPGD CFGS — FREE WRERR WREN WR RD

bit 7 bit 0

bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit

1 = Access FLASH Program memory

0 = Access Data EEPROM memory

bit 6 CFGS: FLASH Program/Data EE or Configuration Select bit

1 = Access Configuration registers

0 = Access FLASH Program or Data EEPROM memory

bit 5 Unimplemented: Read as '0'

bit 4 FREE: FLASH Row Erase Enable bit

1 = Erase the program memory row addressed by TBLPTR on the next WR command

(cleared by completion of erase operation)

0 = Perform write only

bit 3 WRERR: FLASH Program/Data EE Error Flag bit

1 = A write operation is prematurely terminated

(any RESET during self-timed programming in normal operation)

0 = The write operation completed

Note: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows

tracing of the error condition.

bit 2 WREN: FLASH Program/Data EE Write Enable bit

1 = Allows write cycles

0 = Inhibits write to the EEPROM

bit 1 WR: Write Control bit

1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.

(The operation is self timed and the bit is cleared by hardware once write is complete. The

WR bit can only be set (not cleared) in software.)

0 = Write cycle to the EEPROM is complete

bit 0 RD: Read Control bit

1 = Initiates an EEPROM read

(Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared)

in software. RD bit cannot be set when EEPGD = 1.)

0 = Does not initiate an EEPROM read

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

5.2.2 TABLAT - TABLE LATCH REGISTER

The Table Latch (TABLAT) is an 8-bit register mapped

into the SFR space. The Table Latch is used to hold

8-bit data during data transfers between program

memory and data RAM.

5.2.3 TBLPTR - TABLE POINTER

The Table Pointer (TBLPTR) addresses a byte within

the program memory. The TBLPTR is comprised of

three SFR registers: Table Pointer Upper Byte, Table

Pointer High Byte and Table Pointer Low Byte

(TBLPTRU:TBLPTRH:TBLPTRL). These three regis-

ters join to form a 22-bit wide pointer. The low order 21

bits allow the device to address up to 2 Mbytes of pro-

gram memory space. The 22nd bit allows access to the

Device ID, the User ID and the Configuration bits.

The table pointer, TBLPTR, is used by the TBLRD and

TBLWT instructions. These instructions can update the

TBLPTR in one of four ways based on the table opera-

tion. These operations are shown in Table 5-1. These

operations on the TBLPTR only affect the low order

21 bits.

5.2.4 TABLE POINTER BOUNDARIES

TBLPTR is used in reads, writes, and erases of the

FLASH program memory.

When a TBLRD is executed, all 22 bits of the Table

Pointer determine which byte is read from program

memory into TABLAT.

When a TBLWT is executed, the three LSbs of the Table

Pointer (TBLPTR<2:0>) determine which of the eight

program memory holding registers is written to. When

the timed write to program memory (long write) begins,

the 19 MSbs of the Table Pointer, TBLPTR

(TBLPTR<21:3>), will determine which program mem-

ory block of 8 bytes is written to. For more detail, see

Section 5.5 (“Writing to FLASH Program Memory”).

When an erase of program memory is executed, the 16

MSbs of the Table Pointer (TBLPTR<21:6>) point to the

64-byte block that will be erased. The Least Significant

bits (TBLPTR<5:0>) are ignored.

Figure 5-3 describes the relevant boundaries of

TBLPTR based on FLASH program memory

operations.

TABLE 5-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS

FIGURE 5-3: TABLE POINTER BOUNDARIES BASED ON OPERATION

Example Operation on Table Pointer

TBLRD*

TBLWT* TBLPTR is not modified

TBLRD*+

TBLWT*+ TBLPTR is incremented after the read/write

TBLRD*-

TBLWT*- TBLPTR is decremented after the read/write

TBLRD+*

TBLWT+* TBLPTR is incremented before the read/write

21 16 15 87 0

ERASE - TBLPTR<21:6>

WRITE - TBLPTR<21:3>

READ - TBLPTR<21:0>

TBLPTRL

TBLPTRH

TBLPTRU

PIC18FXX2

5.3 Reading the FLASH Program

Memory

The TBLRD instruction is used to retrieve data from pro-

gram memory and place into data RAM. Table Reads

from program memory are performed one byte at a

time.

TBLPTR points to a byte address in program space.

Executing TBLRD places the byte pointed to into

TABLAT. In addition, TBLPTR can be modified

automatically for the next Table Read operation.

The internal program memory is typically organized by

words. The Least Significant bit of the address selects

between the high and low bytes of the word. Figure 5-4

shows the interface between the internal program

memory and the TABLAT.

FIGURE 5-4: READS FROM FLASH PROGRAM MEMORY

EXAMPLE 5-1: READING A FLASH PROGRAM MEMORY WORD

(Even Byte Address)

Program Memory

(Odd Byte Address)

TBLRD TABLAT

TBLPTR = xxxxx1

FETCH

Instruction Register

(IR) Read Register

TBLPTR = xxxxx0

MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base

MOVWF TBLPTRU ; address of the word

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

READ_WORD

TBLRD*+ ; read into TABLAT and increment

MOVF TABLAT, W ; get data

MOVWF WORD_EVEN

TBLRD*+ ; read into TABLAT and increment

MOVF TABLAT, W ; get data

MOVWF WORD_ODD

PIC18FXX2

5.4 Erasing FLASH Program memory

The minimum erase block is 32 words or 64 bytes. Only

through the use of an external programmer, or through

ICSP control can larger blocks of program memory be

bulk erased. Word erase in the FLASH array is not

supported.

When initiating an erase sequence from the micro-

controller itself, a block of 64 bytes of program memory

is erased. The Most Significant 16 bits of the

TBLPTR<21:6> point to the block being erased.

TBLPTR<5:0> are ignored.

The EECON1 register commands the erase operation.

The EEPGD bit must be set to point to the FLASH pro-

gram memory. The WREN bit must be set to enable

write operations. The FREE bit is set to select an erase

operation.

For protection, the write initiate sequence for EECON2

must be used.

A long write is necessary for erasing the internal

FLASH. Instruction execution is halted while in a long

write cycle. The long write will be terminated by the

internal programming timer.

5.4.1 FLASH PROGRAM MEMORY

ERASE SEQUENCE

The sequence of events for erasing a block of internal

program memory location is:

1. Load table pointer with address of row being

erased.

2. Set EEPGD bit to point to program memory,

clear CFGS bit to access program memory, set

WREN bit to enable writes, and set FREE bit to

enable the erase.

3. Disable interrupts.

4. Write 55h to EECON2.

5. Write AAh to EECON2.

6. Set the WR bit. This will begin the row erase

cycle.

7. The CPU will stall for duration of the erase

(about 2 ms using internal timer).

8. Re-enable interrupts.

EXAMPLE 5-2: ERASING A FLASH PROGRAM MEMORY ROW

MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

ERASE_ROW

BSF EECON1,EEPGD ; point to FLASH program memory

BCF EECON1,CFGS ; access FLASH program memory

BSF EECON1,WREN ; enable write to memory

BSF EECON1,FREE ; enable Row Erase operation

BCF INTCON,GIE ; disable interrupts

MOVLW 55h

Required MOVWF EECON2 ; write 55h

Sequence MOVLW AAh

MOVWF EECON2 ; write AAh

BSF EECON1,WR ; start erase (CPU stall)

BSF INTCON,GIE ; re-enable interrupts

PIC18FXX2

5.5 Writing to FLASH Program

Memory

The minimum programming block is 4 words or 8 bytes.

Word or byte programming is not supported.

Table Writes are used internally to load the holding reg-

isters needed to program the FLASH memory. There

are 8 holding registers used by the Table Writes for

programming.

Since the Table Latch (TABLAT) is only a single byte,

the TBLWT instruction has to be executed 8 times for

each programming operation. All of the Table Write

operations will essentially be short writes, because only

the holding registers are written. At the end of updating

8 registers, the EECON1 register must be written to, to

start the programming operation with a long write.

The long write is necessary for programming the inter-

nal FLASH. Instruction execution is halted while in a

long write cycle. The long write will be terminated by

the internal programming timer.

The EEPROM on-chip timer controls the write time.

The write/erase voltages are generated by an on-chip

charge pump rated to operate over the voltage range of

the device for byte or word operations.

FIGURE 5-5: TABLE WRITES TO FLASH PROGRAM MEMORY

5.5.1 FLASH PROGRAM MEMORY WRITE

SEQUENCE

The sequence of events for programming an internal

program memory location should be:

1. Read 64 bytes into RAM.

2. Update data values in RAM as necessary.

3. Load Table Pointer with address being erased.

4. Do the row erase procedure.

5. Load Table Pointer with address of first byte

being written.

6. Write the first 8 bytes into the holding registers

with auto-increment (TBLWT*+ or TBLWT+*).

7. Set EEPGD bit to point to program memory,

clear the CFGS bit to access program memory,

and set WREN to enable byte writes.

8. Disable interrupts.

9. Write 55h to EECON2.

10. Write AAh to EECON2.

11. Set the WR bit. This will begin the write cycle.

12. The CPU will stall for duration of the write (about

2 ms using internal timer).

13. Re-enable interrupts.

14. Repeat steps 6-14 seven times, to write

64 bytes.

15. Verify the memory (Table Read).

This procedure will require about 18 ms to update one

row of 64 bytes of memory. An example of the required

code is given in Example 5-3.

Holding Register

TABLAT

Holding Register

TBLPTR = xxxxx7

Holding Register

TBLPTR = xxxxx1

Holding Register

TBLPTR = xxxxx0

88 8 8

Write Register

TBLPTR = xxxxx2

Program Memory

Note: Before setting the WR bit, the table pointer

address needs to be within the intended

address range of the 8 bytes in the holding

registers.

PIC18FXX2

EXAMPLE 5-3: WRITING TO FLASH PROGRAM MEMORY

MOVLW D'64 ; number of bytes in erase block

MOVWF COUNTER

MOVLW BUFFER_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW BUFFER_ADDR_LOW

MOVWF FSR0L

MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

READ_BLOCK

TBLRD*+ ; read into TABLAT, and inc

MOVF TABLAT, W ; get data

MOVWF POSTINC0 ; store data

DECFSZ COUNTER ; done?

BRA READ_BLOCK ; repeat

MODIFY_WORD

MOVLW DATA_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW DATA_ADDR_LOW

MOVWF FSR0L

MOVLW NEW_DATA_LOW ; update buffer word

MOVWF POSTINC0

MOVLW NEW_DATA_HIGH

MOVWF INDF0

ERASE_BLOCK

MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

BSF EECON1,EEPGD ; point to FLASH program memory

BCF EECON1,CFGS ; access FLASH program memory

BSF EECON1,WREN ; enable write to memory

BSF EECON1,FREE ; enable Row Erase operation

BCF INTCON,GIE ; disable interrupts

MOVLW 55h

MOVWF EECON2 ; write 55h

MOVLW AAh

MOVWF EECON2 ; write AAh

BSF EECON1,WR ; start erase (CPU stall)

BSF INTCON,GIE ; re-enable interrupts

TBLRD*- ; dummy read decrement

WRITE_BUFFER_BACK

MOVLW 8 ; number of write buffer groups of 8 bytes

MOVWF COUNTER_HI

MOVLW BUFFER_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW BUFFER_ADDR_LOW

MOVWF FSR0L

PROGRAM_LOOP

MOVLW 8 ; number of bytes in holding register

MOVWF COUNTER

WRITE_WORD_TO_HREGS

MOVF POSTINC0, W ; get low byte of buffer data

MOVWF TABLAT ; present data to table latch

TBLWT+* ; write data, perform a short write

; to internal TBLWT holding register.

DECFSZ COUNTER ; loop until buffers are full

BRA WRITE_WORD_TO_HREGS

PIC18FXX2

EXAMPLE 5-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED)

5.5.2 WRITE VERIFY

Depending on the application, good programming

practice may dictate that the value written to the mem-

ory should be verified against the original value. This

should be used in applications where excessive writes

can stress bits near the specification limit.

5.5.3 UNEXPECTED TERMINATION OF

WRITE OPERATION

If a write is terminated by an unplanned event, such as

loss of power or an unexpected RESET, the memory

location just programmed should be verified and repro-

grammed if needed.The WRERR bit is set when a write

operation is interrupted by a MCLR Reset, or a WDT

Time-out Reset during normal operation. In these situ-

ations, users can check the WRERR bit and rewrite the

location.

5.5.4 PROTECTION AGAINST SPURIOUS

WRITES

To protect against spurious writes to FLASH program

memory, the write initiate sequence must also be fol-

lowed. See “Special Features of the CPU”

(Section 19.0) for more detail.

5.6 FLASH Program Operation During

Code Protection

See “Special Features of the CPU” (Section 19.0) for

details on code protection of FLASH program memory.

TABLE 5-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY

PROGRAM_MEMORY

BSF EECON1,EEPGD ; point to FLASH program memory

BCF EECON1,CFGS ; access FLASH program memory

BSF EECON1,WREN ; enable write to memory

BCF INTCON,GIE ; disable interrupts

MOVLW 55h

Required MOVWF EECON2 ; write 55h

Sequence MOVLW AAh

MOVWF EECON2 ; write AAh

BSF EECON1,WR ; start program (CPU stall)

BSF INTCON,GIE ; re-enable interrupts

DECFSZ COUNTER_HI ; loop until done

BRA PROGRAM_LOOP

BCF EECON1,WREN ; disable write to memory

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on:

POR, BOR

Value on

All Other

RESETS

FF8h TBLPTRU —— bit21 Program Memory Table Pointer Upper Byte

(TBLPTR<20:16>)

--00 0000 --00 0000

FF7h TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 0000 0000

FF6h TBLPTRL Program Memory Table Pointer High Byte (TBLPTR<7:0>) 0000 0000 0000 0000

FF5h TABLAT Program Memory Table Latch 0000 0000 0000 0000

FF2h INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INTE RBIE TMR0IF INTF RBIF 0000 000x 0000 000u

FA7h EECON2 EEPROM Control Register2 (not a physical register) — —

FA6h EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000

FA2h IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111

FA1h PIR2 — — —EEIFBCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000

FA0h PIE2 — — —EEIEBCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000

Legend: x = unknown, u = unchanged, r = reserved, - = unimplemented read as '0'.

Shaded cells are not used during FLASH/EEPROM access.

PIC18FXX2

NOTES:

PIC18FXX2

6.0 DATA EEPROM MEMORY

The Data EEPROM is readable and writable during

normal operation over the entire VDD range. The data

memory is not directly mapped in the register file

space. Instead, it is indirectly addressed through the

Special Function Registers (SFR).

There are four SFRs used to read and write the

program and data EEPROM memory. These registers

are:

• EECON1

• EECON2

• EEDATA

• EEADR

The EEPROM data memory allows byte read and write.

When interfacing to the data memory block, EEDATA

holds the 8-bit data for read/write and EEADR holds the

address of the EEPROM location being accessed.

These devices have 256 bytes of data EEPROM with

an address range from 0h to FFh.

The EEPROM data memory is rated for high erase/

write cycles. A byte write automatically erases the loca-

tion and writes the new data (erase-before-write). The

write time is controlled by an on-chip timer. The write

time will vary with voltage and temperature, as well as

from chip to chip. Please refer to parameter D122

(Electrical Characteristics, Section 22.0) for exact

limits.

6.1 EEADR

The address register can address up to a maximum of

256 bytes of data EEPROM.

6.2 EECON1 and EECON2 Registers

EECON1 is the control register for EEPROM memory

accesses.

EECON2 is not a physical register. Reading EECON2

will read all '0's. The EECON2 register is used

exclusively in the EEPROM write sequence.

Control bits RD and WR initiate read and write opera-

tions, respectively. These bits cannot be cleared, only

set, in software. They are cleared in hardware at the

completion of the read or write operation. The inability

to clear the WR bit in software prevents the accidental

or premature termination of a write operation.

The WREN bit, when set, will allow a write operation.

On power-up, the WREN bit is clear. The WRERR bit is

set when a write operation is interrupted by a MCLR

Reset, or a WDT Time-out Reset during normal opera-

tion. In these situations, the user can check the

WRERR bit and rewrite the location. It is necessary to

reload the data and address registers (EEDATA and

EEADR), due to the RESET condition forcing the

contents of the registers to zero.

Note: Interrupt flag bit, EEIF in the PIR2 register,

is set when write is complete. It must be

cleared in software.

PIC18FXX2

R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0

EEPGD CFGS — FREE WRERR WREN WR RD

bit 7 bit 0

bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit

1 = Access FLASH Program memory

0 = Access Data EEPROM memory

bit 6 CFGS: FLASH Program/Data EE or Configuration Select bit

1 = Access Configuration or Calibration registers

0 = Access FLASH Program or Data EEPROM memory

bit 5 Unimplemented: Read as '0'

bit 4 FREE: FLASH Row Erase Enable bit

1 = Erase the program memory row addressed by TBLPTR on the next WR command

(cleared by completion of erase operation)

0 = Perform write only

bit 3 WRERR: FLASH Program/Data EE Error Flag bit

1 = A write operation is prematurely terminated

(any MCLR or any WDT Reset during self-timed programming in normal operation)

0 = The write operation completed

Note: When a WRERR occurs, the EEPGD or FREE bits are not cleared. This allows tracing

of the error condition.

bit 2 WREN: FLASH Program/Data EE Write Enable bit

1 = Allows write cycles

0 = Inhibits write to the EEPROM

bit 1 WR: Write Control bit

1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.

(The operation is self-timed and the bit is cleared by hardware once write is complete. The

WR bit can only be set (not cleared) in software.)

0 = Write cycle to the EEPROM is complete

bit 0 RD: Read Control bit

1 = Initiates an EEPROM read

(Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared)

in software. RD bit cannot be set when EEPGD = 1.)

0 = Does not initiate an EEPROM read

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

6.3 Reading the Data EEPROM

Memory

To read a data memory location, the user must write the

address to the EEADR register, clear the EEPGD con-

trol bit (EECON1<7>), clear the CFGS control bit

(EECON1<6>), and then set control bit RD

(EECON1<0>). The data is available for the very next

instruction cycle; therefore, the EEDATA register can

be read by the next instruction. EEDATA will hold this

value until another read operation, or until it is written to

by the user (during a write operation).

EXAMPLE 6-1: DATA EEPROM READ

6.4 Writing to the Data EEPROM

Memory

To write an EEPROM data location, the address must

first be written to the EEADR register and the data writ-

ten to the EEDATA register. Then the sequence in

Example 6-2 must be followed to initiate the write cycle.

The write will not initiate if the above sequence is not

exactly followed (write 55h to EECON2, write AAh to

EECON2, then set WR bit) for each byte. It is strongly

recommended that interrupts be disabled during this

code segment.

Additionally, the WREN bit in EECON1 must be set to

enable writes. This mechanism prevents accidental

writes to data EEPROM due to unexpected code exe-

cution (i.e., runaway programs). The WREN bit should

be kept clear at all times, except when updating the

EEPROM. The WREN bit is not cleared by hardware.

After a write sequence has been initiated, EECON1,

EEADR and EDATA cannot be modified. The WR bit

will be inhibited from being set unless the WREN bit is

set. The WREN bit must be set on a previous instruc-

tion. Both WR and WREN cannot be set with the same

instruction.

At the completion of the write cycle, the WR bit is

cleared in hardware and the EEPROM Write Complete

Interrupt Flag bit (EEIF) is set. The user may either

enable this interrupt, or poll this bit. EEIF must be

cleared by software.

EXAMPLE 6-2: DATA EEPROM WRITE

MOVLW DATA_EE_ADDR ;

MOVWF EEADR ; Data Memory Address to read

BCF EECON1, EEPGD ; Point to DATA memory

BCF EECON1, CFGS ; Access program FLASH or Data EEPROM memory

BSF EECON1, RD ; EEPROM Read

MOVF EEDATA, W ; W = EEDATA

MOVLW DATA_EE_ADDR ;

MOVWF EEADR ; Data Memory Address to read

MOVLW DATA_EE_DATA ;

MOVWF EEDATA ; Data Memory Value to write

BCF EECON1, EEPGD ; Point to DATA memory

BCF EECON1, CFGS ; Access program FLASH or Data EEPROM memory

BSF EECON1, WREN ; Enable writes

BCF INTCON, GIE ; Disable interrupts

Required MOVLW 55h ;

Sequence MOVWF EECON2 ; Write 55h

MOVLW AAh ;

MOVWF EECON2 ; Write AAh

BSF EECON1, WR ; Set WR bit to begin write

BSF INTCON, GIE ; Enable interrupts

.; user code execution

BCF EECON1, WREN ; Disable writes on write complete (EEIF set)

PIC18FXX2

6.5 Write Verify

Depending on the application, good programming

practice may dictate that the value written to the mem-

ory should be verified against the original value. This

should be used in applications where excessive writes

can stress bits near the specification limit.

6.6 Protection Against Spurious Write

There are conditions when the device may not want to

write to the data EEPROM memory. To protect against

spurious EEPROM writes, various mechanisms have

been built-in. On power-up, the WREN bit is cleared.

Also, the Power-up Timer (72 ms duration) prevents

EEPROM write.

The write initiate sequence and the WREN bit together

help prevent an accidental write during brown-out,

power glitch, or software malfunction.

6.7 Operation During Code Protect

Data EEPROM memory has its own code protect

mechanism. External Read and Write operations are

disabled if either of these mechanisms are enabled.

The microcontroller itself can both read and write to the

internal Data EEPROM, regardless of the state of the

code protect configuration bit. Refer to “Special Features

of the CPU” (Section 19.0) for additional information.

6.8 Using the Data EEPROM

The data EEPROM is a high endurance, byte address-

able array that has been optimized for the storage of

frequently changing information (e.g., program vari-

ables or other data that are updated often). Frequently

changing values will typically be updated more often

than specification D124. If this is not the case, an array

refresh must be performed. For this reason, variables

that change infrequently (such as constants, IDs, cali-

bration, etc.) should be stored in FLASH program

memory.

A simple data EEPROM refresh routine is shown in

Example 6-3.

EXAMPLE 6-3: DATA EEPROM REFRESH ROUTINE

Note: If data EEPROM is only used to store con-

stants and/or data that changes rarely, an

array refresh is likely not required. See

specification D124.

clrf EEADR ; Start at address 0

bcf EECON1,CFGS ; Set for memory

bcf EECON1,EEPGD ; Set for Data EEPROM

bcf INTCON,GIE ; Disable interrupts

bsf EECON1,WREN ; Enable writes

Loop ; Loop to refresh array

bsf EECON1,RD ; Read current address

movlw 55h ;

movwf EECON2 ; Write 55h

movlw AAh ;

movwf EECON2 ; Write AAh

bsf EECON1,WR ; Set WR bit to begin write

btfsc EECON1,WR ; Wait for write to complete

bra $-2

incfsz EEADR,F ; Increment address

bra Loop ; Not zero, do it again

bcf EECON1,WREN ; Disable writes

bsf INTCON,GIE ; Enable interrupts

PIC18FXX2

TABLE 6-1: REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on:

POR, BOR

Value on

All Other

RESETS

FF2h INTCON GIE/

GIEH

PEIE/

GIEL

T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u

FA9h EEADR EEPROM Address Register 0000 0000 0000 0000

FA8h EEDATA EEPROM Data Register 0000 0000 0000 0000

FA7h EECON2 EEPROM Control Register2 (not a physical register) — —

FA6h EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 uu-0 u000

FA2h IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111

FA1h PIR2 — — —EEIFBCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000

FA0h PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000

Legend: x = unknown, u = unchanged, r = reserved, - = unimplemented, read as '0'.

Shaded cells are not used during FLASH/EEPROM access.

PIC18FXX2

NOTES:

PIC18FXX2

7.0 8 X 8 HARDWARE MULTIPLIER

7.1 Introduction

An 8 x 8 hardware multiplier is included in the ALU of

the PIC18FXX2 devices. By making the multiply a

hardware operation, it completes in a single instruction

cycle. This is an unsigned multiply that gives a 16-bit

result. The result is stored into the 16-bit product regis-

ter pair (PRODH:PRODL). The multiplier does not

affect any flags in the ALUSTA register.

Making the 8 x 8 multiplier execute in a single cycle

gives the following advantages:

• Higher computational throughput

• Reduces code size requirements for multiply

algorithms

The performance increase allows the device to be used

in applications previously reserved for Digital Signal

Processors.

Table 7-1 shows a performance comparison between

enhanced devices using the single cycle hardware mul-

tiply, and performing the same function without the

hardware multiply.

TABLE 7-1: PERFORMANCE COMPARISON

7.2 Operation

Example 7-1 shows the sequence to do an 8 x 8

unsigned multiply. Only one instruction is required

when one argument of the multiply is already loaded in

the WREG register.

Example 7-2 shows the sequence to do an 8 x 8 signed

multiply. To account for the sign bits of the arguments,

each argument’s Most Significant bit (MSb) is tested

and the appropriate subtractions are done.

EXAMPLE 7-1: 8 x 8 UNSIGNED

MULTIPLY ROUTINE

EXAMPLE 7-2: 8 x 8 SIGNED MULTIPLY

ROUTINE

Example 7-3 shows the sequence to do a 16 x 16

unsigned multiply. Equation 7-1 shows the algorithm

that is used. The 32-bit result is stored in four registers,

RES3:RES0.

EQUATION 7-1: 16 x 16 UNSIGNED

MULTIPLICATION

ALGORITHM

Routine Multiply Method

Program

Memory

(Words)

Cycles

(Max)

Time

@ 40 MHz @ 10 MHz @ 4 MHz

8 x 8 unsigned Without hardware multiply 13 69 6.9 μs27.6 μs69 μs

Hardware multiply 1 1 100 ns 400 ns 1 μs

8 x 8 signed Without hardware multiply 33 91 9.1 μs36.4 μs91 μs

Hardware multiply 6 6 600 ns 2.4 μs6 μs

16 x 16 unsigned Without hardware multiply 21 242 24.2 μs96.8 μs242 μs

Hardware multiply 24 24 2.4 μs9.6 μs24 μs

16 x 16 signed Without hardware multiply 52 254 25.4 μs 102.6 μs254 μs

Hardware multiply 36 36 3.6 μs14.4 μs36 μs

MOVF ARG1, W ;

MULWF ARG2 ; ARG1 * ARG2 ->

; PRODH:PRODL

MOVF ARG1, W

MULWF ARG2 ; ARG1 * ARG2 ->

; PRODH:PRODL

BTFSC ARG2, SB ; Test Sign Bit

SUBWF PRODH, F ; PRODH = PRODH

; - ARG1

MOVF ARG2, W

BTFSC ARG1, SB ; Test Sign Bit

SUBWF PRODH, F ; PRODH = PRODH

; - ARG2

RES3:RES0 = ARG1H:ARG1L • ARG2H :ARG2L

= (ARG1H • ARG2H • 216) +

(ARG1H • ARG2L • 28) +

(ARG1L • ARG2H • 28) +

(ARG1L • ARG2L)

PIC18FXX2

EXAMPLE 7-3: 16 x 16 UNSIGNED

MULTIPLY ROUTINE

Example 7-4 shows the sequence to do a 16 x 16

signed multiply. Equation 7-2 shows the algorithm

used. The 32-bit result is stored in four registers,

RES3:RES0. To account for the sign bits of the argu-

ments, each argument pairs Most Significant bit (MSb)

is tested and the appropriate subtractions are done.

EQUATION 7-2: 16 x 16 SIGNED

MULTIPLICATION

ALGORITHM

EXAMPLE 7-4: 16 x 16 SIGNED

MULTIPLY ROUTINE

MOVF ARG1L, W

MULWF ARG2L ; ARG1L * ARG2L ->

; PRODH:PRODL

MOVFF PRODH, RES1 ;

MOVFF PRODL, RES0 ;

;

MOVF ARG1H, W

MULWF ARG2H ; ARG1H * ARG2H ->

; PRODH:PRODL

MOVFF PRODH, RES3 ;

MOVFF PRODL, RES2 ;

;

MOVF ARG1L, W

MULWF ARG2H ; ARG1L * ARG2H ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

MOVF ARG1H, W ;

MULWF ARG2L ; ARG1H * ARG2L ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

RES3:RES0

=ARG1H:ARG1L • ARG2H:ARG2L

= (ARG1H • ARG2 H • 216) +

(ARG1H • ARG2L • 28) +

(ARG1L • ARG2H • 28) +

(ARG1L • ARG2L) +

(-1 • ARG2H<7> • ARG1H:ARG1L • 216) +

(-1 • ARG1H<7> • ARG2H:ARG2L • 216)

MOVF ARG1L, W

MULWF ARG2L ; ARG1L * ARG2L ->

; PRODH:PRODL

MOVFF PRODH, RES1 ;

MOVFF PRODL, RES0 ;

;

MOVF ARG1H, W

MULWF ARG2H ; ARG1H * ARG2H ->

; PRODH:PRODL

MOVFF PRODH, RES3 ;

MOVFF PRODL, RES2 ;

;

MOVF ARG1L, W

MULWF ARG2H ; ARG1L * ARG2H ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

MOVF ARG1H, W ;

MULWF ARG2L ; ARG1H * ARG2L ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

BTFSS ARG2H, 7 ; ARG2H:ARG2L neg?

BRA SIGN_ARG1 ; no, check ARG1

MOVF ARG1L, W ;

SUBWF RES2 ;

MOVF ARG1H, W ;

SUBWFB RES3

;

SIGN_ARG1

BTFSS ARG1H, 7 ; ARG1H:ARG1L neg?

BRA CONT_CODE ; no, done

MOVF ARG2L, W ;

SUBWF RES2 ;

MOVF ARG2H, W ;

SUBWFB RES3

;

CONT_CODE

PIC18FXX2

8.0 INTERRUPTS

The PIC18FXX2 devices have multiple interrupt

sources and an interrupt priority feature that allows

each interrupt source to be assigned a high priority

level or a low priority level. The high priority interrupt

vector is at 000008h and the low priority interrupt vector

is at 000018h. High priority interrupt events will over-

ride any low priority interrupts that may be in progress.

There are ten registers which are used to control

interrupt operation. These registers are:

• RCON

•INTCON

• INTCON2

• INTCON3

• PIR1, PIR2

• PIE1, PIE2

• IPR1, IPR2

It is recommended that the Microchip header files sup-

plied with MPLAB® IDE be used for the symbolic bit

names in these registers. This allows the assembler/

compiler to automatically take care of the placement of

these bits within the specified register.

Each interrupt source, except INT0, has three bits to

control its operation. The functions of these bits are:

• Flag bit to indicate that an interrupt event

occurred

• Enable bit that allows program execution to

branch to the interrupt vector address when the

flag bit is set

• Priority bit to select high priority or low priority

The interrupt priority feature is enabled by setting the

IPEN bit (RCON<7>). When interrupt priority is

enabled, there are two bits which enable interrupts glo-

bally. Setting the GIEH bit (INTCON<7>) enables all

interrupts that have the priority bit set. Setting the GIEL

bit (INTCON<6>) enables all interrupts that have the

priority bit cleared. When the interrupt flag, enable bit

and appropriate global interrupt enable bit are set, the

interrupt will vector immediately to address 000008h or

000018h, depending on the priority level. Individual

interrupts can be disabled through their corresponding

enable bits.

When the IPEN bit is cleared (default state), the inter-

rupt priority feature is disabled and interrupts are com-

patible with PICmicro® mid-range devices. In

Compatibility mode, the interrupt priority bits for each

source have no effect. INTCON<6> is the PEIE bit,

which enables/disables all peripheral interrupt sources.

INTCON<7> is the GIE bit, which enables/disables all

interrupt sources. All interrupts branch to address

000008h in Compatibility mode.

When an interrupt is responded to, the Global Interrupt

Enable bit is cleared to disable further interrupts. If the

IPEN bit is cleared, this is the GIE bit. If interrupt priority

levels are used, this will be either the GIEH or GIEL bit.

High priority interrupt sources can interrupt a low

priority interrupt.

The return address is pushed onto the stack and the

PC is loaded with the interrupt vector address

(000008h or 000018h). Once in the Interrupt Service

Routine, the source(s) of the interrupt can be deter-

mined by polling the interrupt flag bits. The interrupt

flag bits must be cleared in software before re-enabling

interrupts to avoid recursive interrupts.

The “return from interrupt” instruction, RETFIE, exits

the interrupt routine and sets the GIE bit (GIEH or GIEL

if priority levels are used), which re-enables interrupts.

For external interrupt events, such as the INT pins or

the PORTB input change interrupt, the interrupt latency

will be three to four instruction cycles. The exact

latency is the same for one or two-cycle instructions.

Individual interrupt flag bits are set, regardless of the

status of their corresponding enable bit or the GIE bit.

Note: Do not use the MOVFF instruction to modify

any of the Interrupt control registers while

any interrupt is enabled. Doing so may

cause erratic microcontroller behavior.

PIC18FXX2

FIGURE 8-1: INTERRUPT LOGIC

TMR0IE

GIEH/GIE

GIEL/PEIE

Wake-up if in SLEEP mode

Interrupt to CPU

Vector to location

0008h

INT2IF

INT2IE

INT2IP

INT1IF

INT1IE

INT1IP

TMR0IF

TMR0IE

TMR0IP

RBIF

RBIE

RBIP

IPEN

TMR0IF

TMR0IP

INT1IF

INT1IE

INT1IP

INT2IF

INT2IE

INT2IP

RBIF

RBIE

RBIP

INT0IF

INT0IE

GIEL/PEIE

Interrupt to CPU

Vector to Location

IPEN

IPE

0018h

Peripheral Interrupt Flag bit

Peripheral Interrupt Enable bit

Peripheral Interrupt Priority bit

Peripheral Interrupt Flag bit

Peripheral Interrupt Enable bit

Peripheral Interrupt Priority bit

TMR1IF

TMR1IE

TMR1IP

XXXXIF

XXXXIE

XXXXIP

Additional Peripheral Interrupts

TMR1IF

TMR1IE

TMR1IP

High Priority Interrupt Generation

Low Priority Interrupt Generation

XXXXIF

XXXXIE

XXXXIP

Additional Peripheral Interrupts

GIE/GIEH

PIC18FXX2

8.1 INTCON Registers

The INTCON Registers are readable and writable reg-

isters, which contain various enable, priority and flag

bits.

Note: Interrupt flag bits are set when an interrupt

condition occurs, regardless of the state of

its corresponding enable bit or the global

enable bit. User software should ensure

the appropriate interrupt flag bits are clear

prior to enabling an interrupt. This feature

allows for software polling.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x

GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF

bit 7 bit 0

bit 7 GIE/GIEH: Global Interrupt Enable bit

When IPEN = 0:

1 = Enables all unmasked interrupts

0 = Disables all interrupts

When IPEN = 1:

1 = Enables all high priority interrupts

0 = Disables all interrupts

bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit

When IPEN = 0:

1 = Enables all unmasked peripheral interrupts

0 = Disables all peripheral interrupts

When IPEN = 1:

1 = Enables all low priority peripheral interrupts

0 = Disables all low priority peripheral interrupts

bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit

1 = Enables the TMR0 overflow interrupt

0 = Disables the TMR0 overflow interrupt

bit 4 INT0IE: INT0 External Interrupt Enable bit

1 = Enables the INT0 external interrupt

0 = Disables the INT0 external interrupt

bit 3 RBIE: RB Port Change Interrupt Enable bit

1 = Enables the RB port change interrupt

0 = Disables the RB port change interrupt

bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit

1 = TMR0 register has overflowed (must be cleared in software)

0 = TMR0 register did not overflow

bit 1 INT0IF: INT0 External Interrupt Flag bit

1 = The INT0 external interrupt occurred (must be cleared in software)

0 = The INT0 external interrupt did not occur

bit 0 RBIF: RB Port Change Interrupt Flag bit

1 = At least one of the RB7:RB4 pins changed state (must be cleared in software)

0 = None of the RB7:RB4 pins have changed state

Note: A mismatch condition will continue to set this bit. Reading PORTB will end the

mismatch condition and allow the bit to be cleared.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 U-0 R/W-1

RBPU INTEDG0 INTEDG1 INTEDG2 —TMR0IP—RBIP

bit 7 bit 0

bit 7 RBPU: PORTB Pull-up Enable bit

1 = All PORTB pull-ups are disabled

0 = PORTB pull-ups are enabled by individual port latch values

bit 6 INTEDG0:External Interrupt0 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 5 INTEDG1: External Interrupt1 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 4 INTEDG2: External Interrupt2 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 3 Unimplemented: Read as '0'

bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit

1 = High priority

0 = Low priority

bit 1 Unimplemented: Read as '0'

bit 0 RBIP: RB Port Change Interrupt Priority bit

1 = High priority

0 = Low priority

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state

of its corresponding enable bit or the global enable bit. User software should ensure

the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature

allows for software polling.

PIC18FXX2

R/W-1 R/W-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0

INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF

bit 7 bit 0

bit 7 INT2IP: INT2 External Interrupt Priority bit

1 = High priority

0 = Low priority

bit 6 INT1IP: INT1 External Interrupt Priority bit

1 = High priority

0 = Low priority

bit 5 Unimplemented: Read as '0'

bit 4 INT2IE: INT2 External Interrupt Enable bit

1 = Enables the INT2 external interrupt

0 = Disables the INT2 external interrupt

bit 3 INT1IE: INT1 External Interrupt Enable bit

1 = Enables the INT1 external interrupt

0 = Disables the INT1 external interrupt

bit 2 Unimplemented: Read as '0'

bit 1 INT2IF: INT2 External Interrupt Flag bit

1 = The INT2 external interrupt occurred (must be cleared in software)

0 = The INT2 external interrupt did not occur

bit 0 INT1IF: INT1 External Interrupt Flag bit

1 = The INT1 external interrupt occurred (must be cleared in software)

0 = The INT1 external interrupt did not occur

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state

of its corresponding enable bit or the global enable bit. User software should ensure

the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature

allows for software polling.

PIC18FXX2

8.2 PIR Registers

The PIR registers contain the individual flag bits for the

peripheral interrupts. Due to the number of peripheral

interrupt sources, there are two Peripheral Interrupt

Flag Registers (PIR1, PIR2).

Note 1: Interrupt flag bits are set when an interrupt

condition occurs, regardless of the state of

its corresponding enable bit or the global

enable bit, GIE (INTCON<7>).

2: User software should ensure the appropriate

interrupt flag bits are cleared prior to enabling

an interrupt, and after servicing that interrupt.

R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0

PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF

bit 7 bit 0

bit 7 PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit

1 = A read or a write operation has taken place (must be cleared in software)

0 = No read or write has occurred

bit 6 ADIF: A/D Converter Interrupt Flag bit

1 = An A/D conversion completed (must be cleared in software)

0 = The A/D conversion is not complete

bit 5 RCIF: USART Receive Interrupt Flag bit

1 = The USART receive buffer, RCREG, is full (cleared when RCREG is read)

0 = The USART receive buffer is empty

bit 4 TXIF: USART Transmit Interrupt Flag bit (see Section 16.0 for details on TXIF functionality)

1 = The USART transmit buffer, TXREG, is empty (cleared when TXREG is written)

0 = The USART transmit buffer is full

bit 3 SSPIF: Master Synchronous Serial Port Interrupt Flag bit

1 = The transmission/reception is complete (must be cleared in software)

0 = Waiting to transmit/receive

bit 2 CCP1IF: CCP1 Interrupt Flag bit

Capture mode:

1 = A TMR1 register capture occurred (must be cleared in software)

0 = No TMR1 register capture occurred

Compare mode:

1 = A TMR1 register compare match occurred (must be cleared in software)

0 = No TMR1 register compare match occurred

PWM mode:

Unused in this mode

bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit

1 = TMR2 to PR2 match occurred (must be cleared in software)

0 = No TMR2 to PR2 match occurred

bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit

1 = TMR1 register overflowed (must be cleared in software)

0 = MR1 register did not overflow

Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

— — — EEIF BCLIF LVDIF TMR3IF CCP2IF

bit 7 bit 0

bit 7-5 Unimplemented: Read as '0'

bit 4 EEIF: Data EEPROM/FLASH Write Operation Interrupt Flag bit

1 = The Write operation is complete (must be cleared in software)

0 = The Write operation is not complete, or has not been started

bit 3 BCLIF: Bus Collision Interrupt Flag bit

1 = A bus collision occurred (must be cleared in software)

0 = No bus collision occurred

bit 2 LVDIF: Low Voltage Detect Interrupt Flag bit

1 = A low voltage condition occurred (must be cleared in software)

0 = The device voltage is above the Low Voltage Detect trip point

bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit

1 = TMR3 register overflowed (must be cleared in software)

0 = TMR3 register did not overflow

bit 0 CCP2IF: CCPx Interrupt Flag bit

Capture mode:

1 = A TMR1 register capture occurred (must be cleared in software)

0 = No TMR1 register capture occurred

Compare mode:

1 = A TMR1 register compare match occurred (must be cleared in software)

0 = No TMR1 register compare match occurred

PWM mode:

Unused in this mode

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

8.3 PIE Registers

The PIE registers contain the individual enable bits for

the peripheral interrupts. Due to the number of periph-

eral interrupt sources, there are two Peripheral Inter-

rupt Enable Registers (PIE1, PIE2). When IPEN = 0,

the PEIE bit must be set to enable any of these

peripheral interrupts.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE

bit 7 bit 0

bit 7 PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit

1 = Enables the PSP read/write interrupt

0 = Disables the PSP read/write interrupt

bit 6 ADIE: A/D Converter Interrupt Enable bit

1 = Enables the A/D interrupt

0 = Disables the A/D interrupt

bit 5 RCIE: USART Receive Interrupt Enable bit

1 = Enables the USART receive interrupt

0 = Disables the USART receive interrupt

bit 4 TXIE: USART Transmit Interrupt Enable bit

1 = Enables the USART transmit interrupt

0 = Disables the USART transmit interrupt

bit 3 SSPIE: Master Synchronous Serial Port Interrupt Enable bit

1 = Enables the MSSP interrupt

0 = Disables the MSSP interrupt

bit 2 CCP1IE: CCP1 Interrupt Enable bit

1 = Enables the CCP1 interrupt

0 = Disables the CCP1 interrupt

bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit

1 = Enables the TMR2 to PR2 match interrupt

0 = Disables the TMR2 to PR2 match interrupt

bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit

1 = Enables the TMR1 overflow interrupt

0 = Disables the TMR1 overflow interrupt

Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

— — — EEIE BCLIE LVDIE TMR3IE CCP2IE

bit 7 bit 0

bit 7-5 Unimplemented: Read as '0'

bit 4 EEIE: Data EEPROM/FLASH Write Operation Interrupt Enable bit

1 = Enabled

0 = Disabled

bit 3 BCLIE: Bus Collision Interrupt Enable bit

1 = Enabled

0 = Disabled

bit 2 LVDIE: Low Voltage Detect Interrupt Enable bit

1 = Enabled

0 = Disabled

bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit

1 = Enables the TMR3 overflow interrupt

0 = Disables the TMR3 overflow interrupt

bit 0 CCP2IE: CCP2 Interrupt Enable bit

1 = Enables the CCP2 interrupt

0 = Disables the CCP2 interrupt

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

8.4 IPR Registers

The IPR registers contain the individual priority bits for

the peripheral interrupts. Due to the number of periph-

eral interrupt sources, there are two Peripheral Inter-

rupt Priority Registers (IPR1, IPR2). The operation of

the priority bits requires that the Interrupt Priority

Enable (IPEN) bit be set.

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP

bit 7 bit 0

bit 7 PSPIP(1): Parallel Slave Port Read/Write Interrupt Priority bit

1 = High priority

0 = Low priority

bit 6 ADIP: A/D Converter Interrupt Priority bit

1 = High priority

0 = Low priority

bit 5 RCIP: USART Receive Interrupt Priority bit

1 = High priority

0 = Low priority

bit 4 TXIP: USART Transmit Interrupt Priority bit

1 = High priority

0 = Low priority

bit 3 SSPIP: Master Synchronous Serial Port Interrupt Priority bit

1 = High priority

0 = Low priority

bit 2 CCP1IP: CCP1 Interrupt Priority bit

1 = High priority

0 = Low priority

bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit

1 = High priority

0 = Low priority

bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit

1 = High priority

0 = Low priority

Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit set.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

— — — EEIP BCLIP LVDIP TMR3IP CCP2IP

bit 7 bit 0

bit 7-5 Unimplemented: Read as '0'

bit 4 EEIP: Data EEPROM/FLASH Write Operation Interrupt Priority bit

1 = High priority

0 = Low priority

bit 3 BCLIP: Bus Collision Interrupt Priority bit

1 = High priority

0 = Low priority

bit 2 LVDIP: Low Voltage Detect Interrupt Priority bit

1 = High priority

0 = Low priority

bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit

1 = High priority

0 = Low priority

bit 0 CCP2IP: CCP2 Interrupt Priority bit

1 = High priority

0 = Low priority

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

8.5 RCON Register

The RCON register contains the bit which is used to

enable prioritized interrupts (IPEN).

R/W-0 U-0 U-0 R/W-1 R-1 R-1 R/W-0 R/W-0

IPEN ——RITO PD POR BOR

bit 7 bit 0

bit 7 IPEN: Interrupt Priority Enable bit

1 = Enable priority levels on interrupts

0 = Disable priority levels on interrupts (16CXXX Compatibility mode)

bit 6-5 Unimplemented: Read as '0'

bit 4 RI: RESET Instruction Flag bit

For details of bit operation, see Register 4-3

bit 3 TO: Watchdog Time-out Flag bit

For details of bit operation, see Register 4-3

bit 2 PD: Power-down Detection Flag bit

For details of bit operation, see Register 4-3

bit 1 POR: Power-on Reset Status bit

For details of bit operation, see Register 4-3

bit 0 BOR: Brown-out Reset Status bit

For details of bit operation, see Register 4-3

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

8.6 INT0 Interrupt

External interrupts on the RB0/INT0, RB1/INT1 and

RB2/INT2 pins are edge triggered: either rising, if the

corresponding INTEDGx bit is set in the INTCON2 reg-

ister, or falling, if the INTEDGx bit is clear. When a valid

edge appears on the RBx/INTx pin, the corresponding

flag bit INTxF is set. This interrupt can be disabled by

clearing the corresponding enable bit INTxE. Flag bit

INTxF must be cleared in software in the Interrupt Ser-

vice Routine before re-enabling the interrupt. All exter-

nal interrupts (INT0, INT1 and INT2) can wake-up the

processor from SLEEP, if bit INTxE was set prior to

going into SLEEP. If the global interrupt enable bit GIE

is set, the processor will branch to the interrupt vector

following wake-up.

Interrupt priority for INT1 and INT2 is determined by the

value contained in the interrupt priority bits, INT1IP

(INTCON3<6>) and INT2IP (INTCON3<7>). There is

no priority bit associated with INT0. It is always a high

priority interrupt source.

8.7 TMR0 Interrupt

In 8-bit mode (which is the default), an overflow

(FFh → 00h) in the TMR0 register will set flag bit

TMR0IF. In 16-bit mode, an overflow (FFFFh → 0000h)

in the TMR0H:TMR0L registers will set flag bit TMR0IF.

The interrupt can be enabled/disabled by setting/

clearing enable bit T0IE (INTCON<5>). Interrupt prior-

ity for Timer0 is determined by the value contained in

the interrupt priority bit TMR0IP (INTCON2<2>). See

Section 10.0 for further details on the Timer0 module.

8.8 PORTB Interrupt-on-Change

An input change on PORTB<7:4> sets flag bit RBIF

(INTCON<0>). The interrupt can be enabled/disabled

by setting/clearing enable bit, RBIE (INTCON<3>).

Interrupt priority for PORTB interrupt-on-change is

determined by the value contained in the interrupt

priority bit, RBIP (INTCON2<0>).

8.9 Context Saving During Interrupts

During an interrupt, the return PC value is saved on the

stack. Additionally, the WREG, STATUS and BSR regis-

ters are saved on the fast return stack. If a fast return

from interrupt is not used (See Section 4.3), the user

may need to save the WREG, STATUS and BSR regis-

ters in software. Depending on the user’s application,

other registers may also need to be saved. Equation 8-1

saves and restores the WREG, STATUS and BSR

registers during an Interrupt Service Routine.

EXAMPLE 8-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM

MOVWF W_TEMP ; W_TEMP is in virtual bank

MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere

MOVFF BSR, BSR_TEMP ; BSR located anywhere

;

; USER ISR CODE

;

MOVFF BSR_TEMP, BSR ; Restore BSR

MOVF W_TEMP, W ; Restore WREG

MOVFF STATUS_TEMP,STATUS ; Restore STATUS

PIC18FXX2

NOTES:

PIC18FXX2

9.0 I/O PORTS

Depending on the device selected, there are either five

ports or three ports available. Some pins of the I/O

ports are multiplexed with an alternate function from

the peripheral features on the device. In general, when

a peripheral is enabled, that pin may not be used as a

general purpose I/O pin.

Each port has three registers for its operation. These

registers are:

• TRIS register (data direction register)

• PORT register (reads the levels on the pins of the

device)

• LAT register (output latch)

The data latch (LAT register) is useful for read-modify-

write operations on the value that the I/O pins are

driving.

9.1 PORTA, TRISA and LATA

Registers

PORTA is a 7-bit wide, bi-directional port. The corre-

sponding Data Direction register is TRISA. Setting a

TRISA bit (= 1) will make the corresponding PORTA pin

an input (i.e., put the corresponding output driver in a

Hi-Impedance mode). Clearing a TRISA bit (= 0) will

make the corresponding PORTA pin an output (i.e., put

the contents of the output latch on the selected pin).

Reading the PORTA register reads the status of the

pins, whereas writing to it will write to the port latch.

The Data Latch register (LATA) is also memory

mapped. Read-modify-write operations on the LATA

PORTA.

The RA4 pin is multiplexed with the Timer0 module

clock input to become the RA4/T0CKI pin. The RA4/

T0CKI pin is a Schmitt Trigger input and an open drain

output. All other RA port pins have TTL input levels and

full CMOS output drivers.

The other PORTA pins are multiplexed with analog

inputs and the analog VREF+ and VREF- inputs. The

operation of each pin is selected by clearing/setting the

control bits in the ADCON1 register (A/D Control

Register1).

The TRISA register controls the direction of the RA

pins, even when they are being used as analog inputs.

The user must ensure the bits in the TRISA register are

maintained set when using them as analog inputs.

EXAMPLE 9-1: INITIALIZING PORTA

FIGURE 9-1: BLOCK DIAGRAM OF

RA3:RA0 AND RA5 PINS

Note: On a Power-on Reset, RA5 and RA3:RA0

are configured as analog inputs and read

as ‘0’. RA6 and RA4 are configured as

digital inputs.

CLRF PORTA ; Initialize PORTA by

; clearing output

; data latches

CLRF LATA ; Alternate method

; to clear output

; data latches

MOVLW 0x07 ; Configure A/D

MOVWF ADCON1 ; for digital inputs

MOVLW 0xCF ; Value used to

; initialize data

; direction

MOVWF TRISA ; Set RA<3:0> as inputs

; RA<5:4> as outputs

Data

Bus

WR LATA

WR TRISA

Data Latch

TRIS Latch

RD TRISA

RD PORTA

VSS

VDD

I/O pin(1)

Note 1: I/O pins have protection diodes to VDD and VSS.

Analog

Input

Mode

TTL

Input

Buffer

To A/D Converter and LVD Modules

RD LATA

PORTA

SS Input (RA5 only)

PIC18FXX2

FIGURE 9-2: BLOCK DIAGRAM OF

RA4/T0CKI PIN

FIGURE 9-3: BLOCK DIAGRAM OF

RA6 PIN

Data

Bus

WR TRISA

RD PORTA

Data Latch

TRIS Latch

RD TRISA

Schmitt

Trigger

Input

Buffer

VSS

I/O pin(1)

TMR0 Clock Input

RD LATA

WR LATA

PORTA

Note 1: I/O pin has protection diode to VSS only.

Data

Bus

WR LATA

Data Latch

TRIS Latch

RD TRISA

RD PORTA

VSS

VDD

I/O pin(1)

Note 1: I/O pins have protection diodes to VDD and VSS.

PORTA

RD LATA

ECRA6 or

Enable

TTL

Input

Buffer

RCRA6

RCRA6 Enable

TRISA

PIC18FXX2

TABLE 9-1: PORTA FUNCTIONS

TABLE 9-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA

Name Bit# Buffer Function

RA0/AN0 bit0 TTL Input/output or analog input.

RA1/AN1 bit1 TTL Input/output or analog input.

RA2/AN2/VREF- bit2 TTL Input/output or analog input or VREF-.

RA3/AN3/VREF+ bit3 TTL Input/output or analog input or VREF+.

RA4/T0CKI bit4 ST Input/output or external clock input for Timer0.

Output is open drain type.

RA5/SS/AN4/LVDIN bit5 TTL Input/output or slave select input for synchronous serial port or analog

input, or low voltage detect input.

OSC2/CLKO/RA6 bit6 TTL OSC2 or clock output or I/O pin.

Legend: TTL = TTL input, ST = Schmitt Trigger input

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Value on

POR,

BOR

Value on

All Other

RESETS

PORTA — RA6 RA5 RA4 RA3 RA2 RA1 RA0 -x0x 0000 -u0u 0000

LATA — LATA Data Output Register -xxx xxxx -uuu uuuu

TRISA — PORTA Data Direction Register -111 1111 -111 1111

ADCON1 ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000

Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.

PIC18FXX2

9.2 PORTB, TRISB and LATB

Registers

PORTB is an 8-bit wide, bi-directional port. The corre-

sponding Data Direction register is TRISB. Setting a

TRISB bit (= 1) will make the corresponding PORTB pin

an input (i.e., put the corresponding output driver in a

Hi-Impedance mode). Clearing a TRISB bit (= 0) will

make the corresponding PORTB pin an output (i.e., put

the contents of the output latch on the selected pin).

The Data Latch register (LATB) is also memory

mapped. Read-modify-write operations on the LATB

PORTB.

EXAMPLE 9-2: INITIALIZING PORTB

Each of the PORTB pins has a weak internal pull-up. A

single control bit can turn on all the pull-ups. This is per-

formed by clearing bit RBPU (INTCON2<7>). The

weak pull-up is automatically turned off when the port

pin is configured as an output. The pull-ups are

disabled on a Power-on Reset.

Four of the PORTB pins, RB7:RB4, have an interrupt-

on-change feature. Only pins configured as inputs can

cause this interrupt to occur (i.e., any RB7:RB4 pin

configured as an output is excluded from the interrupt-

on-change comparison). The input pins (of RB7:RB4)

are compared with the old value latched on the last

read of PORTB. The “mismatch” outputs of RB7:RB4

are OR’ed together to generate the RB Port Change

Interrupt with flag bit, RBIF (INTCON<0>).

This interrupt can wake the device from SLEEP. The

user, in the Interrupt Service Routine, can clear the

interrupt in the following manner:

a) Any read or write of PORTB (except with the

MOVFF instruction). This will end the mismatch

condition.

b) Clear flag bit RBIF.

A mismatch condition will continue to set flag bit RBIF.

Reading PORTB will end the mismatch condition and

allow flag bit RBIF to be cleared.

The interrupt-on-change feature is recommended for

wake-up on key depression operation and operations

where PORTB is only used for the interrupt-on-change

feature. Polling of PORTB is not recommended while

using the interrupt-on-change feature.

RB3 can be configured by the configuration bit

CCP2MX as the alternate peripheral pin for the CCP2

module (CCP2MX=’0’).

FIGURE 9-4: BLOCK DIAGRAM OF

RB7:RB4 PINS

Note: On a Power-on Reset, these pins are

configured as digital inputs.

CLRF PORTB ; Initialize PORTB by

; clearing output

; data latches

CLRF LATB ; Alternate method

; to clear output

; data latches

MOVLW 0xCF ; Value used to

; initialize data

; direction

MOVWF TRISB ; Set RB<3:0> as inputs

; RB<5:4> as outputs

; RB<7:6> as inputs

Note 1: While in Low Voltage ICSP mode, the

RB5 pin can no longer be used as a gen-

eral purpose I/O pin, and should be held

low during normal operation to protect

against inadvertent ICSP mode entry.

2: When using Low Voltage ICSP program-

ming (LVP), the pull-up on RB5 becomes

disabled. If TRISB bit 5 is cleared,

thereby setting RB5 as an output, LATB

bit 5 must also be cleared for proper

operation.

Data Latch

From other

RBPU(2)

VDD

I/O pin(1)

Data Bus

WR LATB

WR TRISB

Set RBIF

TRIS Latch

RD TRISB

RD PORTB

RB7:RB4 pins

Weak

Pull-up

RD PORTB

Latch

TTL

Input

Buffer ST

Buffer

RB7:RB5 in Serial Programming mode

RD LATB

PORTB

Note 1: I/O pins have diode protection to VDD and VSS.

2: To enable weak pull-ups, set the appropriate TRIS bit(s)

and clear the RBPU bit (INTCON2<7>).

PIC18FXX2

FIGURE 9-5: BLOCK DIAGRAM OF RB2:RB0 PINS

FIGURE 9-6: BLOCK DIAGRAM OF RB3 PIN

Data Latch

RBPU(2)

VDD

Data Bus

WR Port

WR TRIS

RD TRIS

RD Port

Weak

Pull-up

RD Port

RB0/INT

I/O pin(1)

TTL

Input

Buffer

Schmitt Trigger

Buffer

TRIS Latch

Note 1: I/O pins have diode protection to VDD and VSS.

2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>).

Data Latch

VDD

Data Bus

WR LATB or

WR TRISB

RD TRISB

RD PORTB

Weak

Pull-up

CCP2 Input(3)

TTL

Input

Buffer

Schmitt Trigger

Buffer

TRIS Latch

RD LATB

WR PORTB

RBPU(2)

Enable(3)

CCP Output

RD PORTB

CCP Output(3) 1

VDD

VSS

I/O pin(1)

CCP2MX

CCP2MX = 0

Note 1: I/O pin has diode protection to VDD and VSS.

2: To enable weak pull-ups, set the appropriate DDR bit(s) and clear the RBPU bit (INTCON2<7>).

3: The CCP2 input/output is multiplexed with RB3 if the CCP2MX bit is enabled (=’0’) in the configuration register.

PIC18FXX2

TABLE 9-3: PORTB FUNCTIONS

TABLE 9-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB

Name Bit# Buffer Function

RB0/INT0 bit0 TTL/ST(1) Input/output pin or external interrupt input0.

Internal software programmable weak pull-up.

RB1/INT1 bit1 TTL/ST(1) Input/output pin or external interrupt input1.

Internal software programmable weak pull-up.

RB2/INT2 bit2 TTL/ST(1) Input/output pin or external interrupt input2.

Internal software programmable weak pull-up.

RB3/CCP2(3) bit3 TTL/ST(4) Input/output pin or Capture2 input/Compare2 output/PWM output when

CCP2MX configuration bit is enabled.

Internal software programmable weak pull-up.

RB4 bit4 TTL Input/output pin (with interrupt-on-change).

Internal software programmable weak pull-up.

RB5/PGM(5) bit5 TTL/ST(2) Input/output pin (with interrupt-on-change).

Internal software programmable weak pull-up.

Low voltage ICSP enable pin.

RB6/PGC bit6 TTL/ST(2) Input/output pin (with interrupt-on-change).

Internal software programmable weak pull-up.

Serial programming clock.

RB7/PGD bit7 TTL/ST(2) Input/output pin (with interrupt-on-change).

Internal software programmable weak pull-up.

Serial programming data.

Legend: TTL = TTL input, ST = Schmitt Trigger input

Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.

2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.

3: A device configuration bit selects which I/O pin the CCP2 pin is multiplexed on.

4: This buffer is a Schmitt Trigger input when configured as the CCP2 input.

5: Low Voltage ICSP Programming (LVP) is enabled by default, which disables the RB5 I/O function. LVP

must be disabled to enable RB5 as an I/O pin and allow maximum compatibility to the other 28-pin and

40-pin mid-range devices.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx uuuu uuuu

LATB LATB Data Output Register xxxx xxxx uuuu uuuu

TRISB PORTB Data Direction Register 1111 1111 1111 1111

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 —TMR0IP —RBIP1111 -1-1 1111 -1-1

INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 11-0 0-00 11-0 0-00

Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.

PIC18FXX2

9.3 PORTC, TRISC and LATC

Registers

PORTC is an 8-bit wide, bi-directional port. The corre-

sponding Data Direction register is TRISC. Setting a

TRISC bit (= 1) will make the corresponding PORTC

pin an input (i.e., put the corresponding output driver in

a Hi-Impedance mode). Clearing a TRISC bit (= 0) will

make the corresponding PORTC pin an output (i.e., put

the contents of the output latch on the selected pin).

The Data Latch register (LATC) is also memory

mapped. Read-modify-write operations on the LATC

PORTC.

PORTC is multiplexed with several peripheral functions

(Table 9-5). PORTC pins have Schmitt Trigger input

buffers.

When enabling peripheral functions, care should be

taken in defining TRIS bits for each PORTC pin. Some

peripherals override the TRIS bit to make a pin an out-

put, while other peripherals override the TRIS bit to

make a pin an input. The user should refer to the corre-

sponding peripheral section for the correct TRIS bit

settings.

The pin override value is not loaded into the TRIS reg-

ister. This allows read-modify-write of the TRIS register,

without concern due to peripheral overrides.

RC1 is normally configured by configuration bit,

CCP2MX, as the default peripheral pin of the CCP2

module (default/erased state, CCP2MX = ’1’).

EXAMPLE 9-3: INITIALIZING PORTC

FIGURE 9-7: PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE)

Note: On a Power-on Reset, these pins are

configured as digital inputs.

CLRF PORTC ; Initialize PORTC by

; clearing output

; data latches

CLRF LATC ; Alternate method

; to clear output

; data latches

MOVLW 0xCF ; Value used to

; initialize data

; direction

MOVWF TRISC ; Set RC<3:0> as inputs

; RC<5:4> as outputs

; RC<7:6> as inputs

Data Bus

WR LATC or

WR TRISC

RD TRISC

Peripheral Data Out

RD PORTC

Peripheral Data In

WR PORTC

RD LATC

Peripheral Output

Schmitt

Port/Peripheral Select(2)

Enable(3)

VSS

VDD

I/O pin(1)

Note 1: I/O pins have diode protection to VDD and VSS.

2: Port/Peripheral Select signal selects between port data (input) and peripheral output.

3: Peripheral Output Enable is only active if peripheral select is active.

Data Latch

TRIS Latch

Trigger

PIC18FXX2

TABLE 9-5: PORTC FUNCTIONS

TABLE 9-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC

Name Bit# Buffer Type Function

RC0/T1OSO/T1CKI bit0 ST Input/output port pin or Timer1 oscillator output/Timer1 clock input.

RC1/T1OSI/CCP2 bit1 ST Input/output port pin, Timer1 oscillator input, or Capture2 input/

Compare2 output/PWM output when CCP2MX configuration bit is

set.

RC2/CCP1 bit2 ST Input/output port pin or Capture1 input/Compare1 output/PWM1

output.

RC3/SCK/SCL bit3 ST RC3 can also be the synchronous serial clock for both SPI and I2C

modes.

RC4/SDI/SDA bit4 ST RC4 can also be the SPI Data In (SPI mode) or Data I/O (I2C mode).

RC5/SDO bit5 ST Input/output port pin or Synchronous Serial Port data output.

RC6/TX/CK bit6 ST Input/output port pin, Addressable USART Asynchronous Transmit, or

Addressable USART Synchronous Clock.

RC7/RX/DT bit7 ST Input/output port pin, Addressable USART Asynchronous Receive, or

Addressable USART Synchronous Data.

Legend: ST = Schmitt Trigger input

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx uuuu uuuu

LATC LATC Data Output Register xxxx xxxx uuuu uuuu

TRISC PORTC Data Direction Register 1111 1111 1111 1111

Legend: x = unknown, u = unchanged

PIC18FXX2

9.4 PORTD, TRISD and LATD

Registers

This section is applicable only to the PIC18F4X2

devices.

PORTD is an 8-bit wide, bi-directional port. The corre-

sponding Data Direction register is TRISD. Setting a

TRISD bit (= 1) will make the corresponding PORTD

pin an input (i.e., put the corresponding output driver in

a Hi-Impedance mode). Clearing a TRISD bit (= 0) will

make the corresponding PORTD pin an output (i.e., put

the contents of the output latch on the selected pin).

The Data Latch register (LATD) is also memory

mapped. Read-modify-write operations on the LATD

PORTD.

PORTD is an 8-bit port with Schmitt Trigger input buff-

ers. Each pin is individually configurable as an input or

output.

PORTD can be configured as an 8-bit wide micropro-

cessor port (parallel slave port) by setting control bit

PSPMODE (TRISE<4>). In this mode, the input buffers

are TTL. See Section 9.6 for additional information on

the Parallel Slave Port (PSP).

EXAMPLE 9-4: INITIALIZING PORTD

FIGURE 9-8: PORTD BLOCK DIAGRAM

IN I/O PORT MODE

Note: On a Power-on Reset, these pins are

configured as digital inputs.

CLRF PORTD ; Initialize PORTD by

; clearing output

; data latches

CLRF LATD ; Alternate method

; to clear output

; data latches

MOVLW 0xCF ; Value used to

; initialize data

; direction

MOVWF TRISD ; Set RD<3:0> as inputs

; RD<5:4> as outputs

; RD<7:6> as inputs

Data

Bus

WR LATD

WR TRISD

RD PORTD

Data Latch

TRIS Latch

RD TRISD

Schmitt

Trigger

Input

Buffer

I/O pin(1)

RD LATD

PORTD

Note 1: I/O pins have diode protection to VDD and VSS.

PIC18FXX2

TABLE 9-7: PORTD FUNCTIONS

TABLE 9-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD

Name Bit# Buffer Type Function

RD0/PSP0 bit0 ST/TTL(1) Input/output port pin or parallel slave port bit0.

RD1/PSP1 bit1 ST/TTL(1) Input/output port pin or parallel slave port bit1.

RD2/PSP2 bit2 ST/TTL(1) Input/output port pin or parallel slave port bit2.

RD3/PSP3 bit3 ST/TTL(1) Input/output port pin or parallel slave port bit3.

RD4/PSP4 bit4 ST/TTL(1) Input/output port pin or parallel slave port bit4.

RD5/PSP5 bit5 ST/TTL(1) Input/output port pin or parallel slave port bit5.

RD6/PSP6 bit6 ST/TTL(1) Input/output port pin or parallel slave port bit6.

RD7/PSP7 bit7 ST/TTL(1) Input/output port pin or parallel slave port bit7.

Legend: ST = Schmitt Trigger input, TTL = TTL input

Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffer when in Parallel Slave Port mode.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx uuuu uuuu

LATD LATD Data Output Register xxxx xxxx uuuu uuuu

TRISD PORTD Data Direction Register 1111 1111 1111 1111

TRISE IBF OBF IBOV PSPMODE —PORTE Data Direction bits 0000 -111 0000 -111

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTD.

PIC18FXX2

9.5 PORTE, TRISE and LATE

Registers

This section is only applicable to the PIC18F4X2

devices.

PORTE is a 3-bit wide, bi-directional port. The corre-

sponding Data Direction register is TRISE. Setting a

TRISE bit (= 1) will make the corresponding PORTE pin

an input (i.e., put the corresponding output driver in a

Hi-Impedance mode). Clearing a TRISE bit (= 0) will

make the corresponding PORTE pin an output (i.e., put

the contents of the output latch on the selected pin).

The Data Latch register (LATE) is also memory

mapped. Read-modify-write operations on the LATE

PORTE.

PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6

and RE2/CS/AN7) which are individually configurable

as inputs or outputs. These pins have Schmitt Trigger

input buffers.

controls the parallel slave port operation.

PORTE pins are multiplexed with analog inputs. When

selected as an analog input, these pins will read as '0's.

TRISE controls the direction of the RE pins, even when

they are being used as analog inputs. The user must

make sure to keep the pins configured as inputs when

using them as analog inputs.

EXAMPLE 9-5: INITIALIZING PORTE

FIGURE 9-9: PORTE BLOCK DIAGRAM

IN I/O PORT MODE

Note: On a Power-on Reset, these pins are

configured as analog inputs.

CLRF PORTE ; Initialize PORTE by

; clearing output

; data latches

CLRF LATE ; Alternate method

; to clear output

; data latches

MOVLW 0x07 ; Configure A/D

MOVWF ADCON1 ; for digital inputs

MOVLW 0x05 ; Value used to

; initialize data

; direction

MOVWF TRISE ; Set RE<0> as inputs

; RE<1> as outputs

; RE<2> as inputs

Data

Bus

WR LATE

WR TRISE

RD PORTE

Data Latch

TRIS Latch

RD TRISE

Schmitt

Trigger

Input

Buffer

I/O pin(1)

RD LATE

PORTE

To Analog Converter

Note 1: I/O pins have diode protection to VDD and VSS.

PIC18FXX2

R-0 R-0 R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1

IBF OBF IBOV PSPMODE — TRISE2 TRISE1 TRISE0

bit 7 bit 0

bit 7 IBF: Input Buffer Full Status bit

1 = A word has been received and waiting to be read by the CPU

0 = No word has been received

bit 6 OBF: Output Buffer Full Status bit

1 = The output buffer still holds a previously written word

0 = The output buffer has been read

bit 5 IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode)

1 = A write occurred when a previously input word has not been read

(must be cleared in software)

0 = No overflow occurred

bit 4 PSPMODE: Parallel Slave Port Mode Select bit

1 = Parallel Slave Port mode

0 = General purpose I/O mode

bit 3 Unimplemented: Read as '0'

bit 2 TRISE2: RE2 Direction Control bit

1 = Input

0 = Output

bit 1 TRISE1: RE1 Direction Control bit

1 = Input

0 = Output

bit 0 TRISE0: RE0 Direction Control bit

1 = Input

0 = Output

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

TABLE 9-9: PORTE FUNCTIONS

TABLE 9-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE

Name Bit# Buffer Type Function

RE0/RD/AN5 bit0 ST/TTL(1)

Input/output port pin or read control input in Parallel Slave Port mode

or analog input:

1 = Not a read operation

0 = Read operation. Reads PORTD register (if chip selected).

RE1/WR/AN6 bit1 ST/TTL(1)

Input/output port pin or write control input in Parallel Slave Port mode

or analog input:

1 = Not a write operation

0 = Write operation. Writes PORTD register (if chip selected).

RE2/CS/AN7 bit2 ST/TTL(1)

Input/output port pin or chip select control input in Parallel Slave Port

mode or analog input:

1 = Device is not selected

0 = Device is selected

Legend: ST = Schmitt Trigger input, TTL = TTL input

Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

PORTE — — — — —RE2RE1RE0---- -000 ---- -000

LATE — — — — — LATE Data Output Register ---- -xxx ---- -uuu

TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111

ADCON1 ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTE.

PIC18FXX2

9.6 Parallel Slave Port

The Parallel Slave Port is implemented on the 40-pin

devices only (PIC18F4X2).

PORTD operates as an 8-bit wide Parallel Slave Port,

or microprocessor port when control bit, PSPMODE

(TRISE<4>) is set. It is asynchronously readable and

writable by the external world through RD control input

pin, RE0/RD and WR control input pin, RE1/WR.

It can directly interface to an 8-bit microprocessor data

bus. The external microprocessor can read or write the

PORTD latch as an 8-bit latch. Setting bit PSPMODE

enables port pin RE0/RD to be the RD input, RE1/WR

to be the WR input and RE2/CS to be the CS (chip

select) input. For this functionality, the corresponding

data direction bits of the TRISE register (TRISE<2:0>)

must be configured as inputs (set). The A/D port config-

uration bits PCFG2:PCFG0 (ADCON1<2:0>) must be

set, which will configure pins RE2:RE0 as digital I/O.

A write to the PSP occurs when both the CS and WR

lines are first detected low. A read from the PSP occurs

when both the CS and RD lines are first detected low.

The PORTE I/O pins become control inputs for the

microprocessor port when bit PSPMODE (TRISE<4>)

is set. In this mode, the user must make sure that the

TRISE<2:0> bits are set (pins are configured as digital

inputs), and the ADCON1 is configured for digital I/O.

In this mode, the input buffers are TTL.

FIGURE 9-10: PORTD AND PORTE

BLOCK DIAGRAM

(PARALLEL SLAVE

PORT)

FIGURE 9-11: PARALLEL SLAVE PORT WRITE WAVEFORMS

Data Bus

WR LATD

RDx

RD PORTD

One bit of PORTD

Set Interrupt Flag

PSPIF (PIR1<7>)

Read

Chip Select

Write

Note: I/O pin has protection diodes to VDD and VSS.

TTL

PORTD

RD LATD

Data Latch

TRIS Latch

Q1 Q2 Q3 Q4

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

IBF

OBF

PSPIF

PORTD<7:0>

PIC18FXX2

FIGURE 9-12: PARALLEL SLAVE PORT READ WAVEFORMS

TABLE 9-11: REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT

Q1 Q2 Q3 Q4

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

IBF

PSPIF

OBF

PORTD<7:0>

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

PORTD Port Data Latch when written; Port pins when read xxxx xxxx uuuu uuuu

LATD LATD Data Output bits xxxx xxxx uuuu uuuu

TRISD PORTD Data Direction bits 1111 1111 1111 1111

PORTE — — — — —RE2RE1RE0---- -000 ---- -000

LATE — — — — — LATE Data Output bits ---- -xxx ---- -uuu

TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IF INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

ADCON1 ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0 00-- 0000 00-- 0000

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Parallel Slave Port.

PIC18FXX2

NOTES:

PIC18FXX2

10.0 TIMER0 MODULE

The Timer0 module has the following features:

• Software selectable as an 8-bit or 16-bit timer/

counter

• Readable and writable

• Dedicated 8-bit software programmable prescaler

• Clock source selectable to be external or internal

• Interrupt-on-overflow from FFh to 00h in 8-bit

mode and FFFFh to 0000h in 16-bit mode

• Edge select for external clock

Figure 10-1 shows a simplified block diagram of the

Timer0 module in 8-bit mode and Figure 10-2 shows a

simplified block diagram of the Timer0 module in 16-bit

mode.

The T0CON register (Register 10-1) is a readable and

writable register that controls all the aspects of Timer0,

including the prescale selection.

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0

bit 7 bit 0

bit 7 TMR0ON: Timer0 On/Off Control bit

1 = Enables Timer0

0 = Stops Timer0

bit 6 T08BIT: Timer0 8-bit/16-bit Control bit

1 = Timer0 is configured as an 8-bit timer/counter

0 = Timer0 is configured as a 16-bit timer/counter

bit 5 T0CS: Timer0 Clock Source Select bit

1 = Transition on T0CKI pin

0 = Internal instruction cycle clock (CLKO)

bit 4 T0SE: Timer0 Source Edge Select bit

1 = Increment on high-to-low transition on T0CKI pin

0 = Increment on low-to-high transition on T0CKI pin

bit 3 PSA: Timer0 Prescaler Assignment bit

1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler.

0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.

bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits

111 = 1:256 prescale value

110 = 1:128 prescale value

101 = 1:64 prescale value

100 = 1:32 prescale value

011 = 1:16 prescale value

010 = 1:8 prescale value

001 = 1:4 prescale value

000 = 1:2 prescale value

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

FIGURE 10-1: TIMER0 BLOCK DIAGRAM IN 8-BIT MODE

FIGURE 10-2: TIMER0 BLOCK DIAGRAM IN 16-BIT MODE

Note: Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.

RA4/T0CKI pin

T0SE

T0CS

FOSC/4

Programmable

Prescaler

Sync with

Internal

Clocks

TMR0L

(2 TCY delay)

Data Bus

PSA

T0PS2, T0PS1, T0PS0

Set Interrupt

Flag bit TMR0IF

on Overflow

Note: Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.

T0CKI pin

T0SE

T0CS

FOSC/4

Programmable

Prescaler

Sync with

Internal

Clocks TMR0L

(2 TCY delay)

Data Bus<7:0>

PSA

T0PS2, T0PS1, T0PS0

Set Interrupt

Flag bit TMR0IF

on Overflow

TMR0

TMR0H

High Byte

Read TMR0L

Write TMR0L

PIC18FXX2

10.1 Timer0 Operation

Timer0 can operate as a timer or as a counter.

Timer mode is selected by clearing the T0CS bit. In

Timer mode, the Timer0 module will increment every

instruction cycle (without prescaler). If the TMR0L reg-

ister is written, the increment is inhibited for the follow-

ing two instruction cycles. The user can work around

this by writing an adjusted value to the TMR0L register.

Counter mode is selected by setting the T0CS bit. In

Counter mode, Timer0 will increment, either on every

rising or falling edge of pin RA4/T0CKI. The increment-

ing edge is determined by the Timer0 Source Edge

Select bit (T0SE). Clearing the T0SE bit selects the ris-

ing edge. Restrictions on the external clock input are

discussed below.

When an external clock input is used for Timer0, it must

meet certain requirements. The requirements ensure

the external clock can be synchronized with the internal

phase clock (TOSC). Also, there is a delay in the actual

incrementing of Timer0 after synchronization.

10.2 Prescaler

An 8-bit counter is available as a prescaler for the Timer0

module. The prescaler is not readable or writable.

The PSA and T0PS2:T0PS0 bits determine the

prescaler assignment and prescale ratio.

Clearing bit PSA will assign the prescaler to the Timer0

module. When the prescaler is assigned to the Timer0

module, prescale values of 1:2, 1:4,..., 1:256 are

selectable.

When assigned to the Timer0 module, all instructions

writing to the TMR0L register (e.g., CLRF TMR0,

MOVWF TMR0, BSF TMR0, x....etc.) will clear the

prescaler count.

10.2.1 SWITCHING PRESCALER ASSIGNMENT

The prescaler assignment is fully under software con-

trol, (i.e., it can be changed “on-the-fly” during program

execution).

10.3 Timer0 Interrupt

The TMR0 interrupt is generated when the TMR0 reg-

ister overflows from FFh to 00h in 8-bit mode, or FFFFh

to 0000h in 16-bit mode. This overflow sets the TMR0IF

bit. The interrupt can be masked by clearing the

TMR0IE bit. The TMR0IE bit must be cleared in soft-

ware by the Timer0 module Interrupt Service Routine

before re-enabling this interrupt. The TMR0 interrupt

cannot awaken the processor from SLEEP, since the

timer is shut-off during SLEEP.

10.4 16-Bit Mode Timer Reads and

Writes

TMR0H is not the high byte of the timer/counter in

16-bit mode, but is actually a buffered version of the

high byte of Timer0 (refer to Figure 10-2). The high byte

of the Timer0 counter/timer is not directly readable nor

writable. TMR0H is updated with the contents of the

high byte of Timer0 during a read of TMR0L. This pro-

vides the ability to read all 16-bits of Timer0 without

having to verify that the read of the high and low byte

were valid due to a rollover between successive reads

of the high and low byte.

A write to the high byte of Timer0 must also take place

through the TMR0H buffer register. Timer0 high byte is

updated with the contents of TMR0H when a write

occurs to TMR0L. This allows all 16-bits of Timer0 to be

updated at once.

TABLE 10-1: REGISTERS ASSOCIATED WITH TIMER0

Note: Writing to TMR0L when the prescaler is

assigned to Timer0 will clear the prescaler

count, but will not change the prescaler

assignment.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

TMR0L Timer0 Module Low Byte Register xxxx xxxx uuuu uuuu

TMR0H Timer0 Module High Byte Register 0000 0000 0000 0000

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 1111 1111

TRISA — PORTA Data Direction Register -111 1111 -111 1111

Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0.

PIC18FXX2

NOTES:

PIC18FXX2

11.0 TIMER1 MODULE

The Timer1 module timer/counter has the following

features:

• 16-bit timer/counter

(two 8-bit registers; TMR1H and TMR1L)

• Readable and writable (both registers)

• Internal or external clock select

• Interrupt-on-overflow from FFFFh to 0000h

• RESET from CCP module special event trigger

Figure 11-1 is a simplified block diagram of the Timer1

module.

module, and contains the Timer1 oscillator enable bit

(T1OSCEN). Timer1 can be enabled or disabled by

setting or clearing control bit TMR1ON (T1CON<0>).

R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON

bit 7 bit 0

bit 7 RD16: 16-bit Read/Write Mode Enable bit

1 = Enables register Read/Write of Timer1 in one 16-bit operation

0 = Enables register Read/Write of Timer1 in two 8-bit operations

bit 6 Unimplemented: Read as '0'

bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits

11 = 1:8 Prescale value

10 = 1:4 Prescale value

01 = 1:2 Prescale value

00 = 1:1 Prescale value

bit 3 T1OSCEN: Timer1 Oscillator Enable bit

1 = Timer1 Oscillator is enabled

0 = Timer1 Oscillator is shut-off

The oscillator inverter and feedback resistor are turned off to eliminate power drain.

bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit

When TMR1CS = 1:

1 = Do not synchronize external clock input

0 = Synchronize external clock input

When TMR1CS = 0:

This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.

bit 1 TMR1CS: Timer1 Clock Source Select bit

1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge)

0 = Internal clock (FOSC/4)

bit 0 TMR1ON: Timer1 On bit

1 = Enables Timer1

0 = Stops Timer1

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

11.1 Timer1 Operation

Timer1 can operate in one of these modes:

•As a timer

• As a synchronous counter

• As an asynchronous counter

The Operating mode is determined by the clock select

bit, TMR1CS (T1CON<1>).

When TMR1CS = 0, Timer1 increments every instruc-

tion cycle. When TMR1CS = 1, Timer1 increments on

every rising edge of the external clock input or the

Timer1 oscillator, if enabled.

When the Timer1 oscillator is enabled (T1OSCEN is

set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins

become inputs. That is, the TRISC<1:0> value is

ignored, and the pins are read as ‘0’.

Timer1 also has an internal “RESET input”. This

RESET can be generated by the CCP module

(Section 14.0).

FIGURE 11-1: TIMER1 BLOCK DIAGRAM

FIGURE 11-2: TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE

TMR1H TMR1L

T1SYNC

TMR1CS

T1CKPS1:T1CKPS0 SLEEP Input

FOSC/4

Internal

Clock

TMR1ON

On/Off

Prescaler

1, 2, 4, 8

Synchronize

det

Synchronized

Clock Input

TMR1IF

Overflow TMR1

CLR

CCP Special Event Trigger

T1OSCEN

Enable

Oscillator(1)

T1OSC

Interrupt

Flag Bit

Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

T1OSI

T1CKI/T1OSO

Timer 1 TMR1L

T1OSC

T1SYNC

TMR1CS

T1CKPS1:T1CKPS0

SLEEP Input

T1OSCEN

Enable

Oscillator(1)

TMR1IF

Overflow

Interrupt

FOSC/4

Internal

Clock

TMR1ON

on/off

Prescaler

1, 2, 4, 8

Synchronize

det

Synchronized

Clock Input

T13CKI/T1OSO

T1OSI

TMR1

Flag bit

Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

High Byte

Data Bus<7:0>

TMR1H

Read TMR1L

Write TMR1L

CLR

CCP Special Event Trigger

PIC18FXX2

11.2 Timer1 Oscillator

A crystal oscillator circuit is built-in between pins T1OSI

(input) and T1OSO (amplifier output). It is enabled by

setting control bit T1OSCEN (T1CON<3>). The oscilla-

tor is a low power oscillator rated up to 200 kHz. It will

continue to run during SLEEP. It is primarily intended

for a 32 kHz crystal. Table 11-1 shows the capacitor

selection for the Timer1 oscillator.

The user must provide a software time delay to ensure

proper start-up of the Timer1 oscillator.

TABLE 11-1: CAPACITOR SELECTION FOR

THE ALTERNATE

OSCILLATOR

11.3 Timer1 Interrupt

The TMR1 Register pair (TMR1H:TMR1L) increments

from 0000h to FFFFh and rolls over to 0000h. The

TMR1 Interrupt, if enabled, is generated on overflow,

which is latched in interrupt flag bit TMR1IF (PIR1<0>).

This interrupt can be enabled/disabled by setting/

clearing TMR1 interrupt enable bit, TMR1IE (PIE1<0>).

11.4 Resetting Timer1 using a CCP

Trigger Output

If the CCP module is configured in Compare mode to

generate a “special event trigger” (CCP1M3:CCP1M0

= 1011), this signal will reset Timer1 and start an A/D

conversion (if the A/D module is enabled).

Timer1 must be configured for either Timer or Synchro-

nized Counter mode to take advantage of this feature.

If Timer1 is running in Asynchronous Counter mode,

this RESET operation may not work.

In the event that a write to Timer1 coincides with a

special event trigger from CCP1, the write will take

precedence.

In this mode of operation, the CCPR1H:CCPR1L regis-

ters pair effectively becomes the period register for

Timer1.

11.5 Timer1 16-Bit Read/Write Mode

Timer1 can be configured for 16-bit reads and writes

(see Figure 11-2). When the RD16 control bit

(T1CON<7>) is set, the address for TMR1H is mapped

to a buffer register for the high byte of Timer1. A read

from TMR1L will load the contents of the high byte of

Timer1 into the Timer1 high byte buffer. This provides

the user with the ability to accurately read all 16-bits of

Timer1 without having to determine whether a read of

the high byte followed by a read of the low byte is valid,

due to a rollover between reads.

A write to the high byte of Timer1 must also take place

through the TMR1H buffer register. Timer1 high byte is

updated with the contents of TMR1H when a write

occurs to TMR1L. This allows a user to write all 16 bits

to both the high and low bytes of Timer1 at once.

The high byte of Timer1 is not directly readable or writ-

able in this mode. All reads and writes must take place

through the Timer1 high byte buffer register. Writes to

TMR1H do not clear the Timer1 prescaler. The

prescaler is only cleared on writes to TMR1L.

Osc Type Freq C1 C2

LP 32 kHz TBD(1) TBD(1)

Crystal to be Tested:

32.768 kHz Epson C-001R32.768K-A ± 20 PPM

Note 1: Microchip suggests 33 pF as a starting

point in validating the oscillator circuit.

2: Higher capacitance increases the stability

of the oscillator, but also increases the

start-up time.

3: Since each resonator/crystal has its own

characteristics, the user should consult

the resonator/crystal manufacturer

for appropriate values of external

components.

4: Capacitor values are for design guidance

only.

Note: The special event triggers from the CCP1

module will not set interrupt flag bit

TMR1IF (PIR1<0>).

PIC18FXX2

TABLE 11-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu

TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu

T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

PIC18FXX2

12.0 TIMER2 MODULE

The Timer2 module timer has the following features:

• 8-bit timer (TMR2 register)

• 8-bit period register (PR2)

• Readable and writable (both registers)

• Software programmable prescaler (1:1, 1:4, 1:16)

• Software programmable postscaler (1:1 to 1:16)

• Interrupt on TMR2 match of PR2

• SSP module optional use of TMR2 output to

generate clock shift

Timer2 has a control register shown in Register 12-1.

Timer2 can be shut-off by clearing control bit TMR2ON

(T2CON<2>) to minimize power consumption.

Figure 12-1 is a simplified block diagram of the Timer2

module. Register 12-1 shows the Timer2 control regis-

ter. The prescaler and postscaler selection of Timer2

are controlled by this register.

12.1 Timer2 Operation

Timer2 can be used as the PWM time-base for the

PWM mode of the CCP module. The TMR2 register is

readable and writable, and is cleared on any device

RESET. The input clock (FOSC/4) has a prescale option

of 1:1, 1:4 or 1:16, selected by control bits

T2CKPS1:T2CKPS0 (T2CON<1:0>). The match out-

put of TMR2 goes through a 4-bit postscaler (which

gives a 1:1 to 1:16 scaling inclusive) to generate a

TMR2 interrupt (latched in flag bit TMR2IF, (PIR1<1>)).

The prescaler and postscaler counters are cleared

when any of the following occurs:

• a write to the TMR2 register

• a write to the T2CON register

• any device RESET (Power-on Reset, MCLR

Reset, Watchdog Timer Reset, or Brown-out

Reset)

TMR2 is not cleared when T2CON is written.

U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

— TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0

bit 7 bit 0

bit 7 Unimplemented: Read as '0'

bit 6-3 TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits

0000 = 1:1 Postscale

0001 = 1:2 Postscale

•

1111 = 1:16 Postscale

bit 2 TMR2ON: Timer2 On bit

1 = Timer2 is on

0 = Timer2 is off

bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits

00 = Prescaler is 1

01 = Prescaler is 4

1x = Prescaler is 16

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

12.2 Timer2 Interrupt

The Timer2 module has an 8-bit period register, PR2.

Timer2 increments from 00h until it matches PR2 and

then resets to 00h on the next increment cycle. PR2 is

a readable and writable register. The PR2 register is

initialized to FFh upon RESET.

12.3 Output of TMR2

The output of TMR2 (before the postscaler) is fed to the

Synchronous Serial Port module, which optionally uses

it to generate the shift clock.

FIGURE 12-1: TIMER2 BLOCK DIAGRAM

TABLE 12-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER

Comparator

TMR2 Sets Flag

TMR2

Output(1)

RESET

Postscaler

Prescaler

PR2

FOSC/4

1:1 to 1:16

1:1, 1:4, 1:16

bit TMR2IF

Note 1: TMR2 register output can be software selected by the SSP Module as a baud clock.

TOUTPS3:TOUTPS0

T2CKPS1:T2CKPS0

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

TMR2 Timer2 Module Register 0000 0000 0000 0000

T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000

PR2 Timer2 Period Register 1111 1111 1111 1111

Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer2 module.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

PIC18FXX2

13.0 TIMER3 MODULE

The Timer3 module timer/counter has the following

features:

• 16-bit timer/counter

(two 8-bit registers; TMR3H and TMR3L)

• Readable and writable (both registers)

• Internal or external clock select

• Interrupt-on-overflow from FFFFh to 0000h

• RESET from CCP module trigger

Figure 13-1 is a simplified block diagram of the Timer3

module.

module and sets the CCP clock source.

module, as well as contains the Timer1 oscillator

enable bit (T1OSCEN), which can be a clock source for

Timer3.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON

bit 7 bit 0

bit 7 RD16: 16-bit Read/Write Mode Enable bit

1 = Enables register Read/Write of Timer3 in one 16-bit operation

0 = Enables register Read/Write of Timer3 in two 8-bit operations

bit 6-3 T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits

1x = Timer3 is the clock source for compare/capture CCP modules

01 = Timer3 is the clock source for compare/capture of CCP2,

Timer1 is the clock source for compare/capture of CCP1

00 = Timer1 is the clock source for compare/capture CCP modules

bit 5-4 T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits

11 = 1:8 Prescale value

10 = 1:4 Prescale value

01 = 1:2 Prescale value

00 = 1:1 Prescale value

bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit

(Not usable if the system clock comes from Timer1/Timer3)

When TMR3CS = 1:

1 = Do not synchronize external clock input

0 = Synchronize external clock input

When TMR3CS = 0:

This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0.

bit 1 TMR3CS: Timer3 Clock Source Select bit

1 = External clock input from Timer1 oscillator or T1CKI

(on the rising edge after the first falling edge)

0 = Internal clock (FOSC/4)

bit 0 TMR3ON: Timer3 On bit

1 = Enables Timer3

0 = Stops Timer3

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

13.1 Timer3 Operation

Timer3 can operate in one of these modes:

•As a timer

• As a synchronous counter

• As an asynchronous counter

The Operating mode is determined by the clock select

bit, TMR3CS (T3CON<1>).

When TMR3CS = 0, Timer3 increments every instruc-

tion cycle. When TMR3CS = 1, Timer3 increments on

every rising edge of the Timer1 external clock input or

the Timer1 oscillator, if enabled.

When the Timer1 oscillator is enabled (T1OSCEN is

set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins

become inputs. That is, the TRISC<1:0> value is

ignored, and the pins are read as ‘0’.

Timer3 also has an internal “RESET input”. This RESET

can be generated by the CCP module (Section 14.0).

FIGURE 13-1: TIMER3 BLOCK DIAGRAM

FIGURE 13-2: TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE

TMR3H TMR3L

T1OSC

T3SYNC

TMR3CS

T3CKPS1:T3CKPS0

SLEEP Input

T1OSCEN

Enable

Oscillator(1)

TMR3IF

Overflow

Interrupt

FOSC/4

Internal

Clock

TMR3ON

On/Off

Prescaler

1, 2, 4, 8

Synchronize

det

Synchronized

Clock Input

T1OSO/

T1OSI

Flag bit

(3)

Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

T13CKI

CLR

CCP Special Trigger

T3CCPx

Timer3

TMR3L

T1OSC T3SYNC

TMR3CS

T3CKPS1:T3CKPS0 SLEEP Input

T1OSCEN

Enable

Oscillator(1)

FOSC/4

Internal

Clock

TMR3ON

On/Off

Prescaler

1, 2, 4, 8

Synchronize

det

Synchronized

Clock Input

T1OSO/

T1OSI

TMR3

T13CKI

CLR

CCP Special Trigger

T3CCPx

To Timer1 Clock Input

Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

High Byte

Data Bus<7:0>

TMR3H

Read TMR3L

Write TMR3L

Set TMR3IF Flag bit

on Overflow

PIC18FXX2

13.2 Timer1 Oscillator

The Timer1 oscillator may be used as the clock source

for Timer3. The Timer1 oscillator is enabled by setting

the T1OSCEN (T1CON<3>) bit. The oscillator is a low

power oscillator rated up to 200 KHz. See Section 11.0

for further details.

13.3 Timer3 Interrupt

The TMR3 Register pair (TMR3H:TMR3L) increments

from 0000h to FFFFh and rolls over to 0000h. The

TMR3 Interrupt, if enabled, is generated on overflow,

which is latched in interrupt flag bit, TMR3IF

(PIR2<1>). This interrupt can be enabled/disabled by

setting/clearing TMR3 interrupt enable bit, TMR3IE

(PIE2<1>).

13.4 Resetting Timer3 Using a CCP

Trigger Output

If the CCP module is configured in Compare mode to

generate a “special event trigger” (CCP1M3:CCP1M0

= 1011), this signal will reset Timer3.

Timer3 must be configured for either Timer or Synchro-

nized Counter mode to take advantage of this feature.

If Timer3 is running in Asynchronous Counter mode,

this RESET operation may not work. In the event that a

write to Timer3 coincides with a special event trigger

from CCP1, the write will take precedence. In this mode

of operation, the CCPR1H:CCPR1L registers pair

effectively becomes the period register for Timer3.

TABLE 13-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER

Note: The special event triggers from the CCP

module will not set interrupt flag bit,

TMR3IF (PIR1<0>).

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000

PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000

IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111

TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu

TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu

T1CON RD16 —T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu

T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.

PIC18FXX2

NOTES:

PIC18FXX2

14.0 CAPTURE/COMPARE/PWM

(CCP) MODULES

Each CCP (Capture/Compare/PWM) module contains

a 16-bit register which can operate as a 16-bit Capture

Master/Slave Duty Cycle register. Table 14-1 shows

the timer resources of the CCP Module modes.

The operation of CCP1 is identical to that of CCP2, with

the exception of the special event trigger. Therefore,

operation of a CCP module in the following sections is

described with respect to CCP1.

Table 14-2 shows the interaction of the CCP modules.

U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

—— DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0

bit 7 bit 0

bit 7-6 Unimplemented: Read as '0'

bit 5-4 DCxB1:DCxB0: PWM Duty Cycle bit1 and bit0

Capture mode:

Unused

Compare mode:

Unused

PWM mode:

These bits are the two LSbs (bit1 and bit0) of the 10-bit PWM duty cycle. The upper eight bits

(DCx9:DCx2) of the duty cycle are found in CCPRxL.

bit 3-0 CCPxM3:CCPxM0: CCPx Mode Select bits

0000 = Capture/Compare/PWM disabled (resets CCPx module)

0001 = Reserved

0010 = Compare mode, toggle output on match (CCPxIF bit is set)

0011 = Reserved

0100 = Capture mode, every falling edge

0101 = Capture mode, every rising edge

0110 = Capture mode, every 4th rising edge

0111 = Capture mode, every 16th rising edge

1000 = Compare mode,

Initialize CCP pin Low, on compare match force CCP pin High (CCPIF bit is set)

1001 = Compare mode,

Initialize CCP pin High, on compare match force CCP pin Low (CCPIF bit is set)

1010 = Compare mode,

Generate software interrupt on compare match (CCPIF bit is set, CCP pin is unaffected)

1011 = Compare mode,

Trigger special event (CCPIF bit is set)

11xx =PWM mode

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

14.1 CCP1 Module

Capture/Compare/PWM Register 1 (CCPR1) is com-

prised of two 8-bit registers: CCPR1L (low byte) and

CCPR1H (high byte). The CCP1CON register controls

the operation of CCP1. All are readable and writable.

TABLE 14-1: CCP MODE - TIMER

RESOURCE

14.2 CCP2 Module

Capture/Compare/PWM Register2 (CCPR2) is com-

prised of two 8-bit registers: CCPR2L (low byte) and

CCPR2H (high byte). The CCP2CON register controls

the operation of CCP2. All are readable and writable.

TABLE 14-2: INTERACTION OF TWO CCP MODULES

CCP Mode Timer Resource

Capture

Compare

PWM

Timer1 or Timer3

Timer2

CCPx Mode CCPy Mode Interaction

Capture Capture TMR1 or TMR3 time-base. Time-base can be different for each CCP.

Capture Compare The compare could be configured for the special event trigger,

which clears either TMR1 or TMR3 depending upon which time-base is used.

Compare Compare The compare(s) could be configured for the special event trigger,

which clears TMR1 or TMR3 depending upon which time-base is used.

PWM PWM The PWMs will have the same frequency and update rate

(TMR2 interrupt).

PWM Capture None

PWM Compare None

PIC18FXX2

14.3 Capture Mode

In Capture mode, CCPR1H:CCPR1L captures the

16-bit value of the TMR1 or TMR3 registers when an

event occurs on pin RC2/CCP1. An event is defined as

one of the following:

• every falling edge

• every rising edge

• every 4th rising edge

• every 16th rising edge

The event is selected by control bits CCP1M3:CCP1M0

(CCP1CON<3:0>). When a capture is made, the inter-

rupt request flag bit CCP1IF (PIR1<2>) is set; it must be

cleared in software. If another capture occurs before the

value in register CCPR1 is read, the old captured value

is overwritten by the new captured value.

14.3.1 CCP PIN CONFIGURATION

In Capture mode, the RC2/CCP1 pin should be

configured as an input by setting the TRISC<2> bit.

14.3.2 TIMER1/TIMER3 MODE SELECTION

The timers that are to be used with the capture feature

(either Timer1 and/or Timer3) must be running in Timer

mode or Synchronized Counter mode. In Asynchro-

nous Counter mode, the capture operation may not

work. The timer to be used with each CCP module is

selected in the T3CON register.

14.3.3 SOFTWARE INTERRUPT

When the Capture mode is changed, a false capture

interrupt may be generated. The user should keep bit

CCP1IE (PIE1<2>) clear to avoid false interrupts and

should clear the flag bit, CCP1IF, following any such

change in Operating mode.

14.3.4 CCP PRESCALER

There are four prescaler settings, specified by bits

CCP1M3:CCP1M0. Whenever the CCP module is

turned off or the CCP module is not in Capture mode,

the prescaler counter is cleared. This means that any

RESET will clear the prescaler counter.

Switching from one capture prescaler to another may

generate an interrupt. Also, the prescaler counter will

not be cleared, therefore, the first capture may be from

a non-zero prescaler. Example 14-1 shows the recom-

mended method for switching between capture pres-

calers. This example also clears the prescaler counter

and will not generate the “false” interrupt.

EXAMPLE 14-1: CHANGING BETWEEN

CAPTURE PRESCALERS

FIGURE 14-1: CAPTURE MODE OPERATION BLOCK DIAGRAM

Note: If the RC2/CCP1 is configured as an out-

put, a write to the port can cause a capture

condition.

CLRF CCP1CON, F ; Turn CCP module off

MOVLW NEW_CAPT_PS ; Load WREG with the

; new prescaler mode

; value and CCP ON

MOVWF CCP1CON ; Load CCP1CON with

; this value

CCPR1H CCPR1L

TMR1H TMR1L

Set Flag bit CCP1IF

TMR3

Enable

Q’s

CCP1CON<3:0>

CCP1 pin

Prescaler

÷ 1, 4, 16

and

Edge Detect

TMR3H TMR3L

TMR1

Enable

T3CCP2

CCPR2H CCPR2L

TMR1H TMR1L

Set Flag bit CCP2IF

TMR3

Enable

Q’s

CCP2CON<3:0>

CCP2 pin

Prescaler

÷ 1, 4, 16

and

Edge Detect

TMR3H TMR3L

TMR1

Enable

T3CCP2

T3CCP1

T3CCP2

T3CCP1

PIC18FXX2

14.4 Compare Mode

In Compare mode, the 16-bit CCPR1 (CCPR2) register

value is constantly compared against either the TMR1

When a match occurs, the RC2/CCP1 (RC1/CCP2) pin

is:

• driven High

• driven Low

• toggle output (High to Low or Low to High)

• remains unchanged

The action on the pin is based on the value of control

bits CCP1M3:CCP1M0 (CCP2M3:CCP2M0). At the

same time, interrupt flag bit CCP1IF (CCP2IF) is set.

14.4.1 CCP PIN CONFIGURATION

The user must configure the CCPx pin as an output by

clearing the appropriate TRISC bit.

14.4.2 TIMER1/TIMER3 MODE SELECTION

Timer1 and/or Timer3 must be running in Timer mode

or Synchronized Counter mode if the CCP module is

using the compare feature. In Asynchronous Counter

mode, the compare operation may not work.

14.4.3 SOFTWARE INTERRUPT MODE

When generate software interrupt is chosen, the CCP1

pin is not affected. Only a CCP interrupt is generated (if

enabled).

14.4.4 SPECIAL EVENT TRIGGER

In this mode, an internal hardware trigger is generated,

which may be used to initiate an action.

The special event trigger output of CCP1 resets the

TMR1 register pair. This allows the CCPR1 register to

effectively be a 16-bit programmable period register for

Timer1.

The special trigger output of CCPx resets either the

TMR1 or TMR3 register pair. Additionally, the CCP2

Special Event Trigger will start an A/D conversion if the

A/D module is enabled.

FIGURE 14-2: COMPARE MODE OPERATION BLOCK DIAGRAM

Note: Clearing the CCP1CON register will force

the RC2/CCP1 compare output latch to the

default low level. This is not the PORTC

I/O data latch.

Note: The special event trigger from the CCP2

module will not set the Timer1 or Timer3

interrupt flag bits.

CCPR1H CCPR1L

TMR1H TMR1L

Comparator

Output

Logic

Special Event Trigger

Set Flag bit CCP1IF

Match

RC2/CCP1 pin

TRISC<2>

CCP1CON<3:0>

Mode Select

Output Enable

Special Event Trigger will:

Reset Timer1 or Timer3, but not set Timer1 or Timer3 interrupt flag bit,

and set bit GO/DONE (ADCON0<2>)

which starts an A/D conversion (CCP2 only)

TMR3H TMR3L

T3CCP2

CCPR2H CCPR2L

Comparator

T3CCP2

T3CCP1

Output

Logic

Special Event Trigger

Set Flag bit CCP2IF

Match

RC1/CCP2 pin

TRISC<1>

CCP2CON<3:0>

Mode Select

Output Enable

PIC18FXX2

TABLE 14-3: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

TRISC PORTC Data Direction Register 1111 1111 1111 1111

TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu

TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu

T1CON RD16 — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu

CCPR1L Capture/Compare/PWM Register1 (LSB) xxxx xxxx uuuu uuuu

CCPR1H Capture/Compare/PWM Register1 (MSB) xxxx xxxx uuuu uuuu

CCP1CON — — DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000

CCPR2L Capture/Compare/PWM Register2 (LSB) xxxx xxxx uuuu uuuu

CCPR2H Capture/Compare/PWM Register2 (MSB) xxxx xxxx uuuu uuuu

CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000

PIR2 — — — EEIE BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000

PIE2 — — — EEIF BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000

IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 1111

TMR3L Holding Register for the Least Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu

TMR3H Holding Register for the Most Significant Byte of the 16-bit TMR3 Register xxxx xxxx uuuu uuuu

T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Capture and Timer1.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2x2 devices; always maintain these bits clear.

PIC18FXX2

14.5 PWM Mode

In Pulse Width Modulation (PWM) mode, the CCP1 pin

produces up to a 10-bit resolution PWM output. Since

the CCP1 pin is multiplexed with the PORTC data latch,

the TRISC<2> bit must be cleared to make the CCP1

pin an output.

Figure 14-3 shows a simplified block diagram of the

CCP module in PWM mode.

For a step-by-step procedure on how to set up the CCP

module for PWM operation, see Section 14.5.3.

FIGURE 14-3: SIMPLIFIED PWM BLOCK

DIAGRAM

A PWM output (Figure 14-4) has a time-base (period)

and a time that the output stays high (duty cycle). The

frequency of the PWM is the inverse of the period

(1/period).

FIGURE 14-4: PWM OUTPUT

14.5.1 PWM PERIOD

The PWM period is specified by writing to the PR2

following formula:

PWM per iod = (PR2) + 1] • 4 • TOSC •

(TMR 2 pr e sc ale value)

PWM frequency is defined as 1 / [PWM period].

When TMR2 is equal to PR2, the following three events

occur on the next increment cycle:

•TMR2 is cleared

• The CCP1 pin is set (exception: if PWM duty

cycle = 0%, the CCP1 pin will not be set)

• The PWM duty cycle is latched from CCPR1L into

CCPR1H

14.5.2 PWM DUTY CYCLE

The PWM duty cycle is specified by writing to the

CCPR1L register and to the CCP1CON<5:4> bits. Up

to 10-bit resolution is available. The CCPR1L contains

the eight MSbs and the CCP1CON<5:4> contains the

two LSbs. This 10-bit value is represented by

CCPR1L:CCP1CON<5:4>. The following equation is

used to calculate the PWM duty cycle in time:

PWM duty cycle = (CCPR1L:CCP1CON<5:4>) •

TOSC • (TMR2 prescale value)

CCPR1L and CCP1CON<5:4> can be written to at any

time, but the duty cycle value is not latched into

CCPR1H until after a match between PR2 and TMR2

occurs (i.e., the period is complete). In PWM mode,

CCPR1H is a read only register.

The CCPR1H register and a 2-bit internal latch are

used to double buffer the PWM duty cycle. This double

buffering is essential for glitchless PWM operation.

When the CCPR1H and 2-bit latch match TMR2 con-

catenated with an internal 2-bit Q clock or 2 bits of the

TMR2 prescaler, the CCP1 pin is cleared.

The maximum PWM resolution (bits) for a given PWM

frequency is given by the equation:

Note: Clearing the CCP1CON register will force

the CCP1 PWM output latch to the default

low level. This is not the PORTC I/O data

latch.

CCPR1L

CCPR1H (Slave)

Comparator

TMR2

Comparator

PR2

(Note 1)

Duty Cycle Registers CCP1CON<5:4>

Clear Timer,

CCP1 pin and

latch D.C.

TRISC<2>

RC2/CCP1

Note: 8-bit timer is concatenated with 2-bit internal Q clock or 2

bits of the prescaler to create 10-bit time-base.

Period

Duty Cycle

TMR2 = PR2

TMR2 = Duty Cycle

TMR2 = PR2

Note: The Timer2 postscaler (see Section 12.0)

is not used in the determination of the

PWM frequency. The postscaler could be

used to have a servo update rate at a

different frequency than the PWM output.

Note: If the PWM duty cycle value is longer than

the PWM period, the CCP1 pin will not be

cleared.

FOSC

FPWM

---------------

⎝⎠

⎛⎞

log

2()log

----------------------------- b i t s=

PWM Resolution (max)

PIC18FXX2

14.5.3 SETUP FOR PWM OPERATION

The following steps should be taken when configuring

the CCP module for PWM operation:

1. Set the PWM period by writing to the PR2 register.

2. Set the PWM duty cycle by writing to the

CCPR1L register and CCP1CON<5:4> bits.

3. Make the CCP1 pin an output by clearing the

TRISC<2> bit.

4. Set the TMR2 prescale value and enable Timer2

by writing to T2CON.

5. Configure the CCP1 module for PWM operation.

TABLE 14-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz

TABLE 14-5: REGISTERS ASSOCIATED WITH PWM AND TIMER2

PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz

Timer Prescaler (1, 4, 16)1641111

PR2 Value 0xFF 0xFF 0xFF 0x3F 0x1F 0x17

Maximum Resolution (bits) 14 12 10 8 7 6.58

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

TRISC PORTC Data Direction Register 1111 1111 1111 1111

TMR2 Timer2 Module Register 0000 0000 0000 0000

PR2 Timer2 Module Period Register 1111 1111 1111 1111

T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000

CCPR1L Capture/Compare/PWM Register1 (LSB) xxxx xxxx uuuu uuuu

CCPR1H Capture/Compare/PWM Register1 (MSB) xxxx xxxx uuuu uuuu

CCP1CON —— DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000

CCPR2L Capture/Compare/PWM Register2 (LSB) xxxx xxxx uuuu uuuu

CCPR2H Capture/Compare/PWM Register2 (MSB) xxxx xxxx uuuu uuuu

CCP2CON — — DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PWM and Timer2.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

PIC18FXX2

NOTES:

PIC18FXX2

15.0 MASTER SYNCHRONOUS

SERIAL PORT (MSSP)

MODULE

15.1 Master SSP (MSSP) Module

Overview

The Master Synchronous Serial Port (MSSP) module is

a serial interface useful for communicating with other

peripheral or microcontroller devices. These peripheral

devices may be serial EEPROMs, shift registers, dis-

play drivers, A/D converters, etc. The MSSP module

can operate in one of two modes:

• Serial Peripheral Interface (SPI)

• Inter-Integrated Circuit (I2C)

- Full Master mode

- Slave mode (with general address call)

The I2C interface supports the following modes in

hardware:

•Master mode

• Multi-Master mode

• Slave mode

15.2 Control Registers

The MSSP module has three associated registers.

These include a status register (SSPSTAT) and two

control registers (SSPCON1 and SSPCON2). The use

of these registers and their individual configuration bits

differ significantly, depending on whether the MSSP

module is operated in SPI or I2C mode.

Additional details are provided under the individual

sections.

15.3 SPI Mode

The SPI mode allows 8-bits of data to be synchronously

transmitted and received, simultaneously. All four modes

of SPI are supported. To accomplish communication,

typically three pins are used:

• Serial Data Out (SDO) - RC5/SDO

• Serial Data In (SDI) - RC4/SDI/SDA

• Serial Clock (SCK) - RC3/SCK/SCL/LVDIN

Additionally, a fourth pin may be used when in a Slave

mode of operation:

• Slave Select (SS) - RA5/SS/AN4

Figure 15-1 shows the block diagram of the MSSP

module when operating in SPI mode.

FIGURE 15-1: MSSP BLOCK DIAGRAM

(SPI MODE)

Read Write

Internal

Data Bus

SSPSR reg

SSPM3:SSPM0

bit0 shift

clock

SS Control

Enable

Edge

Select

Clock Select

TMR2 output

TOSC

Prescaler

4, 16, 64

Edge

Select

Data to TX/RX in SSPSR

TRIS bit

SMP:CKE

RC5/SDO

( )

SSPBUF reg

RC4/SDI/SDA

RA5/SS/AN4

RC3/SCK/

SCL/LVDIN

PIC18FXX2

15.3.1 REGISTERS

The MSSP module has four registers for SPI mode

operation. These are:

• MSSP Control Register1 (SSPCON1)

• MSSP Status Register (SSPSTAT)

• Serial Receive/Transmit Buffer (SSPBUF)

• MSSP Shift Register (SSPSR) - Not directly

accessible

SSPCON1 and SSPSTAT are the control and status

registers in SPI mode operation. The SSPCON1 regis-

ter is readable and writable. The lower 6 bits of the

SSPSTAT are read only. The upper two bits of the

SSPSTAT are read/write.

SSPSR is the shift register used for shifting data in or

out. SSPBUF is the buffer register to which data bytes

are written to or read from.

In receive operations, SSPSR and SSPBUF together

create a double buffered receiver. When SSPSR

receives a complete byte, it is transferred to SSPBUF

and the SSPIF interrupt is set.

During transmission, the SSPBUF is not double buff-

ered. A write to SSPBUF will write to both SSPBUF and

SSPSR.

R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0

SMP CKE D/A PSR/WUA BF

bit 7 bit 0

bit 7 SMP: Sample bit

SPI Master mode:

1 = Input data sampled at end of data output time

0 = Input data sampled at middle of data output time

SPI Slave mode:

SMP must be cleared when SPI is used in Slave mode

bit 6 CKE: SPI Clock Edge Select

When CKP = 0:

1 = Data transmitted on rising edge of SCK

0 = Data transmitted on falling edge of SCK

When CKP = 1:

1 = Data transmitted on falling edge of SCK

0 = Data transmitted on rising edge of SCK

bit 5 D/A: Data/Address bit

Used in I2C mode only

bit 4 P: STOP bit

Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is

cleared.

bit 3 S: START bit

Used in I2C mode only

bit 2 R/W: Read/Write bit information

Used in I2C mode only

bit 1 UA: Update Address

Used in I2C mode only

bit 0 BF: Buffer Full Status bit (Receive mode only)

1 = Receive complete, SSPBUF is full

0 = Receive not complete, SSPBUF is empty

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0

bit 7 bit 0

bit 7 WCOL: Write Collision Detect bit (Transmit mode only)

1 = The SSPBUF register is written while it is still transmitting the previous word

(must be cleared in software)

0 = No collision

bit 6 SSPOV: Receive Overflow Indicator bit

SPI Slave mode:

1 = A new byte is received while the SSPBUF register is still holding the previous data. In case

of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode.The user

must read the SSPBUF, even if only transmitting data, to avoid setting overflow

(must be cleared in software).

0 = No overflow

Note: In Master mode, the overflow bit is not set since each new reception (and

transmission) is initiated by writing to the SSPBUF register.

bit 5 SSPEN: Synchronous Serial Port Enable bit

1 = Enables serial port and configures SCK, SDO, SDI, and SS as serial port pins

0 = Disables serial port and configures these pins as I/O port pins

Note: When enabled, these pins must be properly configured as input or output.

bit 4 CKP: Clock Polarity Select bit

1 = IDLE state for clock is a high level

0 = IDLE state for clock is a low level

bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits

0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin

0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled

0011 = SPI Master mode, clock = TMR2 output/2

0010 = SPI Master mode, clock = FOSC/64

0001 = SPI Master mode, clock = FOSC/16

0000 = SPI Master mode, clock = FOSC/4

Note: Bit combinations not specifically listed here are either reserved, or implemented in

I2C mode only.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

15.3.2 OPERATION

When initializing the SPI, several options need to be

specified. This is done by programming the appropriate

control bits (SSPCON1<5:0>) and SSPSTAT<7:6>.

These control bits allow the following to be specified:

• Master mode (SCK is the clock output)

• Slave mode (SCK is the clock input)

• Clock Polarity (IDLE state of SCK)

• Data input sample phase (middle or end of data

output time)

• Clock edge (output data on rising/falling edge of

SCK)

• Clock Rate (Master mode only)

• Slave Select mode (Slave mode only)

The MSSP consists of a transmit/receive Shift Register

(SSPSR) and a buffer register (SSPBUF). The SSPSR

shifts the data in and out of the device, MSb first. The

SSPBUF holds the data that was written to the SSPSR,

until the received data is ready. Once the 8 bits of data

have been received, that byte is moved to the SSPBUF

(SSPSTAT<0>), and the interrupt flag bit, SSPIF, are

set. This double buffering of the received data

(SSPBUF) allows the next byte to start reception before

reading the data that was just received. Any write to the

SSPBUF register during transmission/reception of data

will be ignored, and the write collision detect bit, WCOL

(SSPCON1<7>), will be set. User software must clear

the WCOL bit so that it can be determined if the follow-

ing write(s) to the SSPBUF register completed

successfully.

When the application software is expecting to receive

valid data, the SSPBUF should be read before the next

byte of data to transfer is written to the SSPBUF. Buffer

full bit, BF (SSPSTAT<0>), indicates when SSPBUF

has been loaded with the received data (transmission

is complete). When the SSPBUF is read, the BF bit is

cleared. This data may be irrelevant if the SPI is only a

transmitter. Generally, the MSSP Interrupt is used to

determine when the transmission/reception has com-

pleted. The SSPBUF must be read and/or written. If the

interrupt method is not going to be used, then software

polling can be done to ensure that a write collision does

not occur. Example 15-1 shows the loading of the

SSPBUF (SSPSR) for data transmission.

The SSPSR is not directly readable or writable, and

can only be accessed by addressing the SSPBUF reg-

ister. Additionally, the MSSP status register (SSPSTAT)

indicates the various status conditions.

EXAMPLE 15-1: LOADING THE SSPBUF (SSPSR) REGISTER

LOOP BTFSS SSPSTAT, BF ;Has data been received(transmit complete)?

BRA LOOP ;No

MOVF SSPBUF, W ;WREG reg = contents of SSPBUF

MOVWF RXDATA ;Save in user RAM, if data is meaningful

MOVF TXDATA, W ;W reg = contents of TXDATA

MOVWF SSPBUF ;New data to xmit

PIC18FXX2

15.3.3 ENABLING SPI I/O

To enable the serial port, SSP Enable bit, SSPEN

(SSPCON1<5>), must be set. To reset or reconfigure

SPI mode, clear the SSPEN bit, re-initialize the

SSPCON registers, and then set the SSPEN bit. This

configures the SDI, SDO, SCK, and SS pins as serial

port pins. For the pins to behave as the serial port func-

tion, some must have their data direction bits (in the

TRIS register) appropriately programmed. That is:

• SDI is automatically controlled by the SPI module

• SDO must have TRISC<5> bit cleared

• SCK (Master mode) must have TRISC<3> bit

cleared

• SCK (Slave mode) must have TRISC<3> bit set

•SS

must have TRISC<4> bit set

Any serial port function that is not desired may be

overridden by programming the corresponding data

direction (TRIS) register to the opposite value.

15.3.4 TYPICAL CONNECTION

Figure 15-2 shows a typical connection between two

microcontrollers. The master controller (Processor 1)

initiates the data transfer by sending the SCK signal.

Data is shifted out of both shift registers on their pro-

grammed clock edge, and latched on the opposite

edge of the clock. Both processors should be pro-

grammed to the same Clock Polarity (CKP), then both

controllers would send and receive data at the same

time. Whether the data is meaningful (or dummy data)

depends on the application software. This leads to

three scenarios for data transmission:

• Master sends data — Slave sends dummy data

• Master sends data — Slave sends data

• Master sends dummy data — Slave sends data

FIGURE 15-2: SPI MASTER/SLAVE CONNECTION

Serial Input Buffer

(SSPBUF)

Shift Register

(SSPSR)

MSb LSb

SDO

SDI

PROCESSOR 1

SCK

SPI Master SSPM3:SSPM0 = 00xxb

Serial Input Buffer

(SSPBUF)

Shift Register

(SSPSR)

LSb

MSb

SDI

SDO

PROCESSOR 2

SCK

SPI Slave SSPM3:SSPM0 = 010xb

Serial Clock

PIC18FXX2

15.3.5 MASTER MODE

The master can initiate the data transfer at any time

because it controls the SCK. The master determines

when the slave (Processor 2, Figure 15-2) is to

broadcast data by the software protocol.

In Master mode, the data is transmitted/received as

soon as the SSPBUF register is written to. If the SPI is

only going to receive, the SDO output could be dis-

abled (programmed as an input). The SSPSR register

will continue to shift in the signal present on the SDI pin

at the programmed clock rate. As each byte is

received, it will be loaded into the SSPBUF register as

if a normal received byte (interrupts and status bits

appropriately set). This could be useful in receiver

applications as a “Line Activity Monitor” mode.

The clock polarity is selected by appropriately program-

ming the CKP bit (SSPCON1<4>). This then, would

give waveforms for SPI communication as shown in

Figure 15-3, Figure 15-5, and Figure 15-6, where the

MSB is transmitted first. In Master mode, the SPI clock

rate (bit rate) is user programmable to be one of the

following:

•F

OSC/4 (or TCY)

•FOSC/16 (or 4 • TCY)

•F

OSC/64 (or 16 • TCY)

• Timer2 output/2

This allows a maximum data rate (at 40 MHz) of

10.00 Mbps.

Figure 15-3 shows the waveforms for Master mode.

When the CKE bit is set, the SDO data is valid before

there is a clock edge on SCK. The change of the input

sample is shown based on the state of the SMP bit. The

time when the SSPBUF is loaded with the received

data is shown.

FIGURE 15-3: SPI MODE WAVEFORM (MASTER MODE)

SCK

(CKP = 0

SCK

(CKP = 1

SCK

(CKP = 0

SCK

(CKP = 1

4 Clock

Modes

Input

Sample

Input

Sample

SDI

bit7 bit0

SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

bit7 bit0

SDI

SSPIF

(SMP = 1)

(SMP = 0)

(SMP = 1)

CKE = 1)

CKE = 0)

CKE = 1)

CKE = 0)

(SMP = 0)

Write to

SSPBUF

SSPSR to

SSPBUF

SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

(CKE = 0)

(CKE = 1)

Next Q4 cycle

after Q2↓

PIC18FXX2

15.3.6 SLAVE MODE

In Slave mode, the data is transmitted and received as

the external clock pulses appear on SCK. When the

last bit is latched, the SSPIF interrupt flag bit is set.

While in Slave mode, the external clock is supplied by

the external clock source on the SCK pin. This external

clock must meet the minimum high and low times as

specified in the electrical specifications.

While in SLEEP mode, the slave can transmit/receive

data. When a byte is received, the device will wake-up

from sleep.

15.3.7 SLAVE SELECT

SYNCHRONIZATION

The SS pin allows a Synchronous Slave mode. The

SPI must be in Slave mode with SS pin control enabled

(SSPCON1<3:0> = 04h). The pin must not be driven

low for the SS pin to function as an input. The Data

Latch must be high. When the SS pin is low, transmis-

sion and reception are enabled and the SDO pin is

driven. When the SS pin goes high, the SDO pin is no

longer driven, even if in the middle of a transmitted

byte, and becomes a floating output. External pull-up/

pull-down resistors may be desirable, depending on the

application.

When the SPI module resets, the bit counter is forced

to 0. This can be done by either forcing the SS pin to a

high level or clearing the SSPEN bit.

To emulate two-wire communication, the SDO pin can

be connected to the SDI pin. When the SPI needs to

operate as a receiver the SDO pin can be configured as

an input. This disables transmissions from the SDO.

The SDI can always be left as an input (SDI function),

since it cannot create a bus conflict.

FIGURE 15-4: SLAVE SYNCHRONIZATION WAVEFORM

Note 1: When the SPI is in Slave mode with SS

pin control enabled (SSPCON<3:0> =

0100), the SPI module will reset if the SS

pin is set to VDD.

2: If the SPI is used in Slave mode with CKE

set, then the SS pin control must be

enabled.

SCK

(CKP = 1

SCK

(CKP = 0

Input

Sample

SDI

bit7

SDO bit7 bit6 bit7

SSPIF

Interrupt

(SMP = 0)

CKE = 0)

(SMP = 0)

Write to

SSPBUF

SSPSR to

SSPBUF

Flag

bit0

bit7

bit0

Next Q4 cycle

after Q2↓

PIC18FXX2

FIGURE 15-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)

FIGURE 15-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)

SCK

(CKP = 1

SCK

(CKP = 0

Input

Sample

SDI

bit7 bit0

SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

SSPIF

Interrupt

(SMP = 0)

CKE = 0)

(SMP = 0)

Write to

SSPBUF

SSPSR to

SSPBUF

Flag

Optional

Next Q4 cycle

after Q2↓

SCK

(CKP = 1

SCK

(CKP = 0

Input

Sample

SDI

bit7 bit0

SDO bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

SSPIF

Interrupt

(SMP = 0)

CKE = 1)

(SMP = 0)

Write to

SSPBUF

SSPSR to

SSPBUF

Flag

Not Optional

Next Q4 cycle

after Q2↓

PIC18FXX2

15.3.8 SLEEP OPERATION

In Master mode, all module clocks are halted and the

transmission/reception will remain in that state until the

device wakes from SLEEP. After the device returns to

Normal mode, the module will continue to transmit/

receive data.

In Slave mode, the SPI transmit/receive shift register

operates asynchronously to the device. This allows the

device to be placed in SLEEP mode and data to be

shifted into the SPI transmit/receive shift register.

When all 8 bits have been received, the MSSP interrupt

flag bit will be set and if enabled, will wake the device

from SLEEP.

15.3.9 EFFECTS OF A RESET

A RESET disables the MSSP module and terminates

the current transfer.

15.3.10 BUS MODE COMPATIBILITY

Table 15-1 shows the compatibility between the

standard SPI modes and the states the CKP and CKE

control bits.

TABLE 15-1: SPI BUS MODES

There is also a SMP bit which controls when the data is

sampled.

TABLE 15-2: REGISTERS ASSOCIATED WITH SPI OPERATION

Standard SPI Mode

Terminology

Control Bits State

CKP CKE

0, 0 0 1

0, 1 0 0

1, 0 1 1

1, 1 1 0

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

TRISC PORTC Data Direction Register 1111 1111 1111 1111

SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx uuuu uuuu

SSPCON WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000

TRISA — PORTA Data Direction Register -111 1111 -111 1111

SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 0000 0000

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the MSSP in SPI mode.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18C2X2 devices; always maintain these bits clear.

PIC18FXX2

15.4 I2C Mode

The MSSP module in I2C mode fully implements all

master and slave functions (including general call sup-

port) and provides interrupts on START and STOP bits

in hardware to determine a free bus (multi-master func-

tion). The MSSP module implements the Standard

mode specifications, as well as 7-bit and 10-bit

addressing.

Two pins are used for data transfer:

• Serial clock (SCL) - RC3/SCK/SCL

• Serial data (SDA) - RC4/SDI/SDA

The user must configure these pins as inputs or outputs

through the TRISC<4:3> bits.

FIGURE 15-7: MSSP BLOCK DIAGRAM

(I2C MODE)

15.4.1 REGISTERS

The MSSP module has six registers for I2C operation.

These are:

• MSSP Control Register1 (SSPCON1)

• MSSP Control Register2 (SSPCON2)

• MSSP Status Register (SSPSTAT)

• Serial Receive/Transmit Buffer (SSPBUF)

• MSSP Shift Register (SSPSR) - Not directly

accessible

• MSSP Address Register (SSPADD)

SSPCON, SSPCON2 and SSPSTAT are the control

and status registers in I2C mode operation. The

SSPCON and SSPCON2 registers are readable and

writable. The lower 6 bits of the SSPSTAT are read

only. The upper two bits of the SSPSTAT are read/

write.

SSPSR is the shift register used for shifting data in or

out. SSPBUF is the buffer register to which data bytes

are written to or read from.

SSPADD register holds the slave device address

when the SSP is configured in I2C Slave mode. When

the SSP is configured in Master mode, the lower

seven bits of SSPADD act as the baud rate generator

reload value.

In receive operations, SSPSR and SSPBUF together,

create a double buffered receiver. When SSPSR

receives a complete byte, it is transferred to SSPBUF

and the SSPIF interrupt is set.

During transmission, the SSPBUF is not double buff-

ered. A write to SSPBUF will write to both SSPBUF and

SSPSR.

Read Write

SSPSR reg

Match Detect

SSPADD reg

START and

STOP bit Detect

SSPBUF reg

Internal

Data Bus

Addr Match

Set, Reset

S, P bits

(SSPSTAT reg)

RC3/SCK/SCL

RC4/

Shift

Clock

MSb

SDI/

LSb

SDA

PIC18FXX2

R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0

SMP CKE D/A PSR/WUA BF

bit 7 bit 0

bit 7 SMP: Slew Rate Control bit

In Master or Slave mode:

1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz)

0 = Slew rate control enabled for High Speed mode (400 kHz)

bit 6 CKE: SMBus Select bit

In Master or Slave mode:

1 = Enable SMBus specific inputs

0 = Disable SMBus specific inputs

bit 5 D/A: Data/Address bit

In Master mode:

Reserved

In Slave mode:

1 = Indicates that the last byte received or transmitted was data

0 = Indicates that the last byte received or transmitted was address

bit 4 P: STOP bit

1 = Indicates that a STOP bit has been detected last

0 = STOP bit was not detected last

Note: This bit is cleared on RESET and when SSPEN is cleared.

bit 3 S: START bit

1 = Indicates that a start bit has been detected last

0 = START bit was not detected last

Note: This bit is cleared on RESET and when SSPEN is cleared.

bit 2 R/W: Read/Write bit Information (I2C mode only)

In Slave mode:

1 = Read

0 = Write

Note: This bit holds the R/W bit information following the last address match. This bit is only

valid from the address match to the next START bit, STOP bit, or not ACK bit.

In Master mode:

1 = Transmit is in progress

0 = Transmit is not in progress

Note: ORing this bit with SEN, RSEN, PEN, RCEN, or ACKEN will indicate if the MSSP is

in IDLE mode.

bit 1 UA: Update Address (10-bit Slave mode only)

1 = Indicates that the user needs to update the address in the SSPADD register

0 = Address does not need to be updated

bit 0 BF: Buffer Full Status bit

In Transmit mode:

1 = Receive complete, SSPBUF is full

0 = Receive not complete, SSPBUF is empty

In Receive mode:

1 = Data transmit in progress (does not include the ACK and STOP bits), SSPBUF is full

0 = Data transmit complete (does not include the ACK and STOP bits), SSPBUF is empty

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0

bit 7 bit 0

bit 7 WCOL: Write Collision Detect bit

In Master Transmit mode:

1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for

a transmission to be started (must be cleared in software)

0 = No collision

In Slave Transmit mode:

1 = The SSPBUF register is written while it is still transmitting the previous word (must be

cleared in software)

0 = No collision

In Receive mode (Master or Slave modes):

This is a “don’t care” bit

bit 6 SSPOV: Receive Overflow Indicator bit

In Receive mode:

1 = A byte is received while the SSPBUF register is still holding the previous byte (must

be cleared in software)

0 = No overflow

In Transmit mode:

This is a “don’t care” bit in Transmit mode

bit 5 SSPEN: Synchronous Serial Port Enable bit

1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins

0 = Disables serial port and configures these pins as I/O port pins

Note: When enabled, the SDA and SCL pins must be properly configured as input or output.

bit 4 CKP: SCK Release Control bit

In Slave mode:

1 = Release clock

0 = Holds clock low (clock stretch), used to ensure data setup time

In Master mode:

Unused in this mode

bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits

1111 = I2C Slave mode, 10-bit address with START and STOP bit interrupts enabled

1110 = I2C Slave mode, 7-bit address with START and STOP bit interrupts enabled

1011 = I2C Firmware Controlled Master mode (Slave IDLE)

1000 = I2C Master mode, clock = FOSC / (4 * (SSPADD+1))

0111 = I2C Slave mode, 10-bit address

0110 = I2C Slave mode, 7-bit address

Note: Bit combinations not specifically listed here are either reserved, or implemented in

SPI mode only.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN

bit 7 bit 0

bit 7 GCEN: General Call Enable bit (Slave mode only)

1 = Enable interrupt when a general call address (0000h) is received in the SSPSR

0 = General call address disabled

bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only)

1 = Acknowledge was not received from slave

0 = Acknowledge was received from slave

bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)

1 = Not Acknowledge

0 = Acknowledge

Note: Value that will be transmitted when the user initiates an Acknowledge sequence at

the end of a receive.

bit 4 ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)

1 = Initiate Acknowledge sequence on SDA and SCL pins, and transmit ACKDT data bit.

Automatically cleared by hardware.

0 = Acknowledge sequence IDLE

bit 3 RCEN: Receive Enable bit (Master mode only)

1 = Enables Receive mode for I2C

0 = Receive IDLE

bit 2 PEN: STOP Condition Enable bit (Master mode only)

1 = Initiate STOP condition on SDA and SCL pins. Automatically cleared by hardware.

0 = STOP condition IDLE

bit 1 RSEN: Repeated START Condition Enabled bit (Master mode only)

1 = Initiate Repeated START condition on SDA and SCL pins.

Automatically cleared by hardware.

0 = Repeated START condition IDLE

bit 0 SEN: START Condition Enabled/Stretch Enabled bit

In Master mode:

1 = Initiate START condition on SDA and SCL pins. Automatically cleared by hardware.

0 = START condition IDLE

In Slave mode:

1 = Clock stretching is enabled for both Slave Transmit and Slave Receive (stretch enabled)

0 = Clock stretching is enabled for slave transmit only (Legacy mode)

Note: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the IDLE

mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or

writes to the SSPBUF are disabled).

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

15.4.2 OPERATION

The MSSP module functions are enabled by setting

MSSP Enable bit, SSPEN (SSPCON<5>).

The SSPCON1 register allows control of the I2C oper-

ation. Four mode selection bits (SSPCON<3:0>) allow

one of the following I2C modes to be selected:

•I

2C Master mode, clock = OSC/4 (SSPADD +1)

•I

2C Slave mode (7-bit address)

•I

2C Slave mode (10-bit address)

•I

2C Slave mode (7-bit address), with START and

STOP bit interrupts enabled

•I

2C Slave mode (10-bit address), with START and

STOP bit interrupts enabled

•I

2C Firmware controlled master operation, slave

is IDLE

Selection of any I2C mode, with the SSPEN bit set,

forces the SCL and SDA pins to be open drain, pro-

vided these pins are programmed to inputs by setting

the appropriate TRISC bits. To guarantee proper oper-

ation of the module, pull-up resistors must be provided

externally to the SCL and SDA pins.

15.4.3 SLAVE MODE

In Slave mode, the SCL and SDA pins must be config-

ured as inputs (TRISC<4:3> set). The MSSP module

will override the input state with the output data when

required (slave-transmitter).

The I2C Slave mode hardware will always generate an

interrupt on an address match. Through the mode

select bits, the user can also choose to interrupt on

START and STOP bits

When an address is matched or the data transfer after

an address match is received, the hardware automati-

cally will generate the Acknowledge (ACK) pulse and

load the SSPBUF register with the received value

currently in the SSPSR register.

Any combination of the following conditions will cause

the MSSP module not to give this ACK pulse:

• The buffer full bit BF (SSPSTAT<0>) was set

before the transfer was received.

• The overflow bit SSPOV (SSPCON<6>) was set

before the transfer was received.

In this case, the SSPSR register value is not loaded

into the SSPBUF, but bit SSPIF (PIR1<3>) is set. The

BF bit is cleared by reading the SSPBUF register, while

bit SSPOV is cleared through software.

The SCL clock input must have a minimum high and

low for proper operation. The high and low times of the

I2C specification, as well as the requirement of the

MSSP module, are shown in timing parameter 100 and

parameter 101.

15.4.3.1 Addressing

Once the MSSP module has been enabled, it waits for

a START condition to occur. Following the START con-

dition, the 8-bits are shifted into the SSPSR register. All

incoming bits are sampled with the rising edge of the

clock (SCL) line. The value of register SSPSR<7:1> is

compared to the value of the SSPADD register. The

address is compared on the falling edge of the eighth

clock (SCL) pulse. If the addresses match, and the BF

and SSPOV bits are clear, the following events occur:

1. The SSPSR register value is loaded into the

SSPBUF register.

2. The buffer full bit BF is set.

3. An ACK pulse is generated.

4. MSSP interrupt flag bit, SSPIF (PIR1<3>) is set

(interrupt is generated if enabled) on the falling

edge of the ninth SCL pulse.

In 10-bit Address mode, two address bytes need to be

received by the slave. The five Most Significant bits

(MSbs) of the first address byte specify if this is a 10-bit

address. Bit R/W (SSPSTAT<2>) must specify a write

so the slave device will receive the second address

byte. For a 10-bit address, the first byte would equal

‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two

MSbs of the address. The sequence of events for 10-bit

address is as follows, with steps 7 through 9 for the

slave-transmitter:

1. Receive first (high) byte of Address (bits SSPIF,

BF and bit UA (SSPSTAT<1>) are set).

2. Update the SSPADD register with second (low)

byte of Address (clears bit UA and releases the

SCL line).

3. Read the SSPBUF register (clears bit BF) and

clear flag bit SSPIF.

4. Receive second (low) byte of Address (bits

SSPIF, BF, and UA are set).

5. Update the SSPADD register with the first (high)

byte of Address. If match releases SCL line, this

will clear bit UA.

6. Read the SSPBUF register (clears bit BF) and

clear flag bit SSPIF.

7. Receive Repeated START condition.

8. Receive first (high) byte of Address (bits SSPIF

and BF are set).

9. Read the SSPBUF register (clears bit BF) and

clear flag bit SSPIF.

PIC18FXX2

15.4.3.2 Reception

When the R/W bit of the address byte is clear and an

address match occurs, the R/W bit of the SSPSTAT

the SSPBUF register and the SDA line is held low

(ACK).

When the address byte overflow condition exists, then

the no Acknowledge (ACK) pulse is given. An overflow

condition is defined as either bit BF (SSPSTAT<0>) is

set, or bit SSPOV (SSPCON1<6>) is set.

An MSSP interrupt is generated for each data transfer

byte. Flag bit SSPIF (PIR1<3>) must be cleared in soft-

ware. The SSPSTAT register is used to determine the

status of the byte.

If SEN is enabled (SSPCON1<0>=1), RC3/SCK/SCL

will be held low (clock stretch) following each data trans-

fer. The clock must be released by setting bit CKP

(SSPCON<4>). See Section 15.4.4 (“Clock Stretching”),

for more detail.

15.4.3.3 Transmission

When the R/W bit of the incoming address byte is set

and an address match occurs, the R/W bit of the

SSPSTAT register is set. The received address is

loaded into the SSPBUF register. The ACK pulse will

be sent on the ninth bit and pin RC3/SCK/SCL is held

low, regardless of SEN (see “Clock Stretching”,

Section 15.4.4, for more detail). By stretching the clock,

the master will be unable to assert another clock pulse

until the slave is done preparing the transmit data.The

transmit data must be loaded into the SSPBUF register,

which also loads the SSPSR register. Then pin RC3/

SCK/SCL should be enabled by setting bit CKP

(SSPCON1<4>). The eight data bits are shifted out on

the falling edge of the SCL input. This ensures that the

SDA signal is valid during the SCL high time

(Figure 15-9).

The ACK pulse from the master-receiver is latched on

the rising edge of the ninth SCL input pulse. If the SDA

line is high (not ACK), then the data transfer is com-

plete. In this case, when the ACK is latched by the

slave, the slave logic is reset (resets SSPSTAT regis-

ter) and the slave monitors for another occurrence of

the START bit. If the SDA line was low (ACK), the next

transmit data must be loaded into the SSPBUF register.

Again, pin RC3/SCK/SCL must be enabled by setting

bit CKP.

An MSSP interrupt is generated for each data transfer

byte. The SSPIF bit must be cleared in software and

the SSPSTAT register is used to determine the status

of the byte. The SSPIF bit is set on the falling edge of

the ninth clock pulse.

PIC18FXX2

FIGURE 15-8: I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

SSPOV (SSPCON<6>)

S1 234 56 7 891 2345 67 89 1 23 45 7 89 P

A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0

ACK

Receiving Data

ACK

Receiving Data

R/W = 0

ACK

Receiving Address

Cleared in software

SSPBUF is read

Bus Master

terminates

transfer

SSPOV is set

because SSPBUF is

still full. ACK is not sent.

(PIR1<3>)

CKP (CKP does not reset to ‘0’ when SEN = 0)

PIC18FXX2

FIGURE 15-9: I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)

SDA

SCL

SSPIF (PIR1<3>)

BF (SSPSTAT<0>)

A6 A5 A4 A3 A2 A1 D6 D5 D4 D3 D2 D1 D0

1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9

SSPBUF is written in software

Cleared in software

SCL held low

while CPU

responds to SSPIF

From SSPIF ISR

Data in

sampled

ACK

Transmitting Data

R/W = 1

ACK

Receiving Address

A7 D7

9 1

D6 D5 D4 D3 D2 D1 D0

2 3 4 5 6 7 8 9

SSPBUF is written in software

Cleared in software

From SSPIF ISR

Transmitting Data

CKP

ACK

CKP is set in software CKP is set in software

PIC18FXX2

FIGURE 15-10: I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

S1 234 56 7 89 1 2345 67 89 1 2345 7 89 P

1 1 1 1 0 A9A8 A7 A6A5A4A3A2A1A0 D7 D6D5D4D3 D1D0

Receive Data Byte

ACK

R/W = 0

ACK

Receive First Byte of Address

Cleared in software

(PIR1<3>)

Cleared in software

Receive Second Byte of Address

Cleared by hardware

when SSPADD is updated

with low byte of address

UA (SSPSTAT<1>)

Clock is held low until

update of SSPADD has

taken place

UA is set indicating that

the SSPADD needs to be

updated

UA is set indicating that

SSPADD needs to be

updated

Cleared by hardware when

SSPADD is updated with high

byte of address

SSPBUF is written with

contents of SSPSR

Dummy read of SSPBUF

to clear BF flag

ACK

CKP

12345 789

D7 D6 D5 D4 D3 D1 D0

Receive Data Byte

Bus Master

terminates

transfer

ACK

Cleared in software Cleared in software

SSPOV (SSPCON<6>)

SSPOV is set

because SSPBUF is

still full. ACK is not sent.

(CKP does not reset to ‘0’ when SEN = 0)

Clock is held low until

update of SSPADD has

taken place

PIC18FXX2

FIGURE 15-11: I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

S1 2 34 56 7 8 9 1 234 5 67 89 1 23 45 7 89 P

1 111 0A9A8 A7 A6A5A4A3A2A1A0 11110 A8

R/W=1

ACK

R/W = 0

ACK

Receive First Byte of Address

Cleared in software

Bus Master

terminates

transfer

(PIR1<3>)

Receive Second Byte of Address

Cleared by hardware when

SSPADD is updated with low

byte of address

UA (SSPSTAT<1>)

Clock is held low until

update of SSPADD has

taken place

UA is set indicating that

the SSPADD needs to be

updated

UA is set indicating that

SSPADD needs to be

updated

Cleared by hardware when

SSPADD is updated with high

byte of address.

SSPBUF is written with

contents of SSPSR

Dummy read of SSPBUF

to clear BF flag

Receive First Byte of Address

12345 789

D7 D6 D5 D4 D3 D1

ACK

Transmitting Data Byte

Dummy read of SSPBUF

to clear BF flag

Cleared in software

Write of SSPBUF

initiates transmit

Cleared in software

Completion of

clears BF flag

CKP (SSPCON<4>)

CKP is set in software

CKP is automatically cleared in hardware holding SCL low

Clock is held low until

update of SSPADD has

taken place

data transmission

Clock is held low until

CKP is set to ‘1’

BF flag is clear

third address sequence

at the end of the

PIC18FXX2

15.4.4 CLOCK STRETCHING

Both 7- and 10-bit Slave modes implement automatic

clock stretching during a transmit sequence.

The SEN bit (SSPCON2<0>) allows clock stretching to

be enabled during receives. Setting SEN will cause

the SCL pin to be held low at the end of each data

receive sequence.

15.4.4.1 Clock Stretching for 7-bit Slave

Receive Mode (SEN = 1)

In 7-bit Slave Receive mode, on the falling edge of the

ninth clock at the end of the ACK sequence, if the BF

bit is set, the CKP bit in the SSPCON1 register is auto-

matically cleared, forcing the SCL output to be held

low. The CKP being cleared to ‘0’ will assert the SCL

line low. The CKP bit must be set in the user’s ISR

before reception is allowed to continue. By holding the

SCL line low, the user has time to service the ISR and

read the contents of the SSPBUF before the master

device can initiate another receive sequence. This will

prevent buffer overruns from occurring (see

Figure 15-13).

15.4.4.2 Clock Stretching for 10-bit Slave

Receive Mode (SEN = 1)

In 10-bit Slave Receive mode, during the address

sequence, clock stretching automatically takes place

but CKP is not cleared. During this time, if the UA bit is

set after the ninth clock, clock stretching is initiated.

The UA bit is set after receiving the upper byte of the

10-bit address, and following the receive of the second

byte of the 10-bit address with the R/W bit cleared to

‘0’. The release of the clock line occurs upon updating

SSPADD. Clock stretching will occur on each data

receive sequence as described in 7-bit mode.

15.4.4.3 Clock Stretching for 7-bit Slave

Transmit Mode

7-bit Slave Transmit mode implements clock stretching

by clearing the CKP bit after the falling edge of the

ninth clock, if the BF bit is clear. This occurs,

regardless of the state of the SEN bit.

The user’s ISR must set the CKP bit before transmis-

sion is allowed to continue. By holding the SCL line

low, the user has time to service the ISR and load the

contents of the SSPBUF before the master device can

initiate another transmit sequence (see Figure 15-9).

15.4.4.4 Clock Stretching for 10-bit Slave

Transmit Mode

In 10-bit Slave Transmit mode, clock stretching is con-

trolled during the first two address sequences by the

state of the UA bit, just as it is in 10-bit Slave Receive

mode. The first two addresses are followed by a third

address sequence, which contains the high order bits

of the 10-bit address and the R/W bit set to ‘1’. After

the third address sequence is performed, the UA bit is

not set, the module is now configured in Transmit

mode, and clock stretching is controlled by the BF flag,

as in 7-bit Slave Transmit mode (see Figure 15-11).

Note 1: If the user reads the contents of the

SSPBUF before the falling edge of the

ninth clock, thus clearing the BF bit, the

CKP bit will not be cleared and clock

stretching will not occur.

2: The CKP bit can be set in software,

regardless of the state of the BF bit. The

user should be careful to clear the BF bit

in the ISR before the next receive

sequence, in order to prevent an overflow

condition.

Note: If the user polls the UA bit and clears it by

updating the SSPADD register before the

falling edge of the ninth clock occurs, and if

the user hasn’t cleared the BF bit by read-

ing the SSPBUF register before that time,

then the CKP bit will still NOT be asserted

low. Clock stretching on the basis of the

state of the BF bit only occurs during a data

sequence, not an address sequence.

Note 1: If the user loads the contents of SSPBUF,

setting the BF bit before the falling edge of

the ninth clock, the CKP bit will not be

cleared and clock stretching will not occur.

2: The CKP bit can be set in software,

regardless of the state of the BF bit.

PIC18FXX2

15.4.4.5 Clock Synchronization and

the CKP bit

If a user clears the CKP bit, the SCL output is forced to

‘0’. Setting the CKP bit will not assert the SCL output

low until the SCL output is already sampled low. If the

user attempts to drive SCL low, the CKP bit will not

assert the SCL line until an external I2C master device

has already asserted the SCL line. The SCL output will

remain low until the CKP bit is set, and all other

devices on the I2C bus have de-asserted SCL. This

ensures that a write to the CKP bit will not violate the

minimum high time requirement for SCL (see

Figure 15-12).

FIGURE 15-12: CLOCK SYNCHRONIZATION TIMING

SDA

SCL

DX-1DX

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

SSPCON

CKP

Master device

de-asserts clock

Master device

asserts clock

PIC18FXX2

FIGURE 15-13: I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

SSPOV (SSPCON<6>)

S1 234 56 7 8 9 1 234 5 67 89 1 2345 7 89 P

A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0

ACK

Receiving Data

ACK

Receiving Data

R/W = 0

ACK

Receiving Address

Cleared in software

SSPBUF is read

Bus Master

terminates

transfer

SSPOV is set

because SSPBUF is

still full. ACK is not sent.

(PIR1<3>)

CKP

written

to ‘1’ in

If BF is cleared

prior to the falling

edge of the 9th clock,

CKP will not be reset

to ‘0’ and no clock

stretching will occur

software

Clock is held low until

CKP is set to ‘1’

Clock is not held low

because buffer full bit is

clear prior to falling edge

of 9th clock

Clock is not held low

because ACK = 1

BF is set after falling

edge of the 9th clock,

CKP is reset to ‘0’ and

clock stretching occurs

PIC18FXX2

FIGURE 15-14: I2C SLAVE MODE TIMING SEN = 1 (RECEPTION, 10-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

S1 234 56 7 89 1 2345 67 89 1 2345 7 89 P

1 1 1 1 0 A9A8 A7 A6 A5 A4A3A2A1 A0 D7D6D5D4D3 D1D0

Receive Data Byte

ACK

R/W = 0

ACK

Receive First Byte of Address

Cleared in software

(PIR1<3>)

Cleared in software

Receive Second Byte of Address

Cleared by hardware when

SSPADD is updated with low

byte of address after falling edge

UA (SSPSTAT<1>)

Clock is held low until

update of SSPADD has

taken place

UA is set indicating that

the SSPADD needs to be

updated

UA is set indicating that

SSPADD needs to be

updated

Cleared by hardware when

SSPADD is updated with high

byte of address after falling edge

SSPBUF is written with

contents of SSPSR

Dummy read of SSPBUF

to clear BF flag

ACK

CKP

12345 789

D7 D6 D5 D4 D3 D1 D0

Receive Data Byte

Bus Master

terminates

transfer

ACK

Cleared in software Cleared in software

SSPOV (SSPCON<6>)

CKP written to ‘1’

Note: An update of the SSPADD

edge of the ninth clock will

have no effect on UA, and

UA will remain set.

Note: An update of the SSPADD

edge of the ninth clock will

have no effect on UA, and

UA will remain set.

in software

Clock is held low until

update of SSPADD has

taken place

of ninth clock.

SSPOV is set

because SSPBUF is

still full. ACK is not sent.

Dummy read of SSPBUF

to clear BF flag

Clock is held low until

CKP is set to ‘1’

Clock is not held low

because ACK = 1

PIC18FXX2

15.4.5 GENERAL CALL ADDRESS

SUPPORT

The addressing procedure for the I2C bus is such that

the first byte after the START condition usually deter-

mines which device will be the slave addressed by the

master. The exception is the general call address,

which can address all devices. When this address is

used, all devices should, in theory, respond with an

Acknowledge.

The general call address is one of eight addresses

reserved for specific purposes by the I2C protocol. It

consists of all 0’s with R/W = 0.

The general call address is recognized when the Gen-

eral Call Enable bit (GCEN) is enabled (SSPCON2<7>

set). Following a START bit detect, 8-bits are shifted

into the SSPSR and the address is compared against

the SSPADD. It is also compared to the general call

address and fixed in hardware.

If the general call address matches, the SSPSR is

transferred to the SSPBUF, the BF flag bit is set (eighth

bit), and on the falling edge of the ninth bit (ACK bit),

the SSPIF interrupt flag bit is set.

When the interrupt is serviced, the source for the inter-

rupt can be checked by reading the contents of the

SSPBUF. The value can be used to determine if the

address was device specific or a general call address.

In 10-bit mode, the SSPADD is required to be updated

for the second half of the address to match, and the UA

bit is set (SSPSTAT<1>). If the general call address is

sampled when the GCEN bit is set, while the slave is

configured in 10-bit Address mode, then the second

half of the address is not necessary, the UA bit will not

be set, and the slave will begin receiving data after the

Acknowledge (Figure 15-15).

FIGURE 15-15: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE

(7 OR 10-BIT ADDRESS MODE)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

SSPOV (SSPCON1<6>)

Cleared in software

SSPBUF is read

R/W = 0

ACK

General Call Address

Address is compared to General Call Address

GCEN (SSPCON2<7>)

Receiving data ACK

123456789123456789

D7 D6 D5 D4 D3 D2 D1 D0

after ACK, set interrupt

'0'

'1'

PIC18FXX2

15.4.6 MASTER MODE

Master mode is enabled by setting and clearing the

appropriate SSPM bits in SSPCON1 and by setting the

SSPEN bit. In Master mode, the SCL and SDA lines

are manipulated by the MSSP hardware.

Master mode of operation is supported by interrupt

generation on the detection of the START and STOP

conditions. The STOP (P) and START (S) bits are

cleared from a RESET or when the MSSP module is

disabled. Control of the I2C bus may be taken when the

P bit is set or the bus is IDLE, with both the S and P bits

clear.

In Firmware Controlled Master mode, user code con-

ducts all I2C bus operations based on START and

STOP bit conditions.

Once Master mode is enabled, the user has six

options.

1. Assert a START condition on SDA and SCL.

2. Assert a Repeated START condition on SDA

and SCL.

3. Write to the SSPBUF register initiating

transmission of data/address.

4. Configure the I2C port to receive data.

5. Generate an Acknowledge condition at the end

of a received byte of data.

6. Generate a STOP condition on SDA and SCL.

The following events will cause SSP interrupt flag bit,

SSPIF, to be set (SSP interrupt if enabled):

• START condition

• STOP condition

• Data transfer byte transmitted/received

• Acknowledge Transmit

• Repeated START

FIGURE 15-16: MSSP BLOCK DIAGRAM (I2C MASTER MODE)

Note: The MSSP Module, when configured in I2C

Master mode, does not allow queueing of

events. For instance, the user is not

allowed to initiate a START condition and

immediately write the SSPBUF register to

initiate transmission before the START

condition is complete. In this case, the

SSPBUF will not be written to and the

WCOL bit will be set, indicating that a write

to the SSPBUF did not occur.

Read Write

SSPSR

START bit, STOP bit,

START bit Detect

SSPBUF

Internal

Data Bus

Set/Reset, S, P, WCOL (SSPSTAT)

Shift

Clock

MSb LSb

SDA

Acknowledge

Generate

STOP bit Detect

Write Collision Detect

Clock Arbitration

State Counter for

end of XMIT/RCV

SCL

SCL in

Bus Collision

SDA in

Receive Enable

Clock Cntl

Clock Arbitrate/WCOL Detect

(hold off clock source)

SSPADD<6:0>

Baud

Set SSPIF, BCLIF

Reset ACKSTAT, PEN (SSPCON2)

Rate

Generator

SSPM3:SSPM0

PIC18FXX2

15.4.6.1 I2C Master Mode Operation

The master device generates all of the serial clock

pulses and the START and STOP conditions. A trans-

fer is ended with a STOP condition or with a Repeated

START condition. Since the Repeated START condi-

tion is also the beginning of the next serial transfer, the

I2C bus will not be released.

In Master Transmitter mode, serial data is output

through SDA, while SCL outputs the serial clock. The

first byte transmitted contains the slave address of the

receiving device (7 bits) and the Read/Write (R/W) bit.

In this case, the R/W bit will be logic '0'. Serial data is

transmitted 8 bits at a time. After each byte is transmit-

ted, an Acknowledge bit is received. START and STOP

conditions are output to indicate the beginning and the

end of a serial transfer.

In Master Receive mode, the first byte transmitted con-

tains the slave address of the transmitting device

(7 bits) and the R/W bit. In this case, the R/W bit will be

logic '1'. Thus, the first byte transmitted is a 7-bit slave

address followed by a '1' to indicate receive bit. Serial

data is received via SDA, while SCL outputs the serial

clock. Serial data is received 8 bits at a time. After each

byte is received, an Acknowledge bit is transmitted.

START and STOP conditions indicate the beginning

and end of transmission.

The baud rate generator used for the SPI mode opera-

tion is used to set the SCL clock frequency for either

100 kHz, 400 kHz or 1 MHz I2C operation. See

Section 15.4.7 (“Baud Rate Generator”), for more

detail.

A typical transmit sequence would go as follows:

1. The user generates a START condition by set-

ting the START enable bit, SEN

(SSPCON2<0>).

2. SSPIF is set. The MSSP module will wait the

required start time before any other operation

takes place.

3. The user loads the SSPBUF with the slave

address to transmit.

4. Address is shifted out the SDA pin until all 8 bits

are transmitted.

5. The MSSP Module shifts in the ACK bit from the

slave device and writes its value into the

SSPCON2 register (SSPCON2<6>).

6. The MSSP module generates an interrupt at the

end of the ninth clock cycle by setting the SSPIF

bit.

7. The user loads the SSPBUF with eight bits of

data.

8. Data is shifted out the SDA pin until all 8 bits are

transmitted.

9. The MSSP Module shifts in the ACK bit from the

slave device and writes its value into the

SSPCON2 register (SSPCON2<6>).

10. The MSSP module generates an interrupt at the

end of the ninth clock cycle by setting the SSPIF

bit.

11. The user generates a STOP condition by setting

the STOP enable bit PEN (SSPCON2<2>).

12. Interrupt is generated once the STOP condition

is complete.

PIC18FXX2

15.4.7 BAUD RATE GENERATOR

In I2C Master mode, the baud rate generator (BRG)

reload value is placed in the lower 7 bits of the

SSPADD register (Figure 15-17). When a write occurs

to SSPBUF, the baud rate generator will automatically

begin counting. The BRG counts down to 0 and stops

until another reload has taken place. The BRG count is

decremented twice per instruction cycle (T

CY) on the

Q2 and Q4 clocks. In I2C Master mode, the BRG is

reloaded automatically.

Once the given operation is complete (i.e., transmis-

sion of the last data bit is followed by ACK), the internal

clock will automatically stop counting and the SCL pin

will remain in its last state.

Table 15-3 demonstrates clock rates based on

instruction cycles and the BRG value loaded into

SSPADD.

FIGURE 15-17: BAUD RATE GENERATOR BLOCK DIAGRAM

TABLE 15-3: I2C CLOCK RATE W/BRG

SSPM3:SSPM0

BRG Down Counter

CLKO Fosc/4

SSPADD<6:0>

SSPM3:SSPM0

SCL

Reload

Control

Reload

FCY FCY*2 BRG Value FSCL(2)

(2 Rollovers of BRG)

10 MHz 20 MHz 19h 400 kHz(1)

10 MHz 20 MHz 20h 312.5 kHz

10 MHz 20 MHz 3Fh 100 kHz

4 MHz 8 MHz 0Ah 400 kHz(1)

4 MHz 8 MHz 0Dh 308 kHz

4 MHz 8 MHz 28h 100 kHz

1 MHz 2 MHz 03h 333 kHz(1)

1 MHz 2 MHz 0Ah 100kHz

1 MHz 2 MHz 00h 1 MHz(1)

Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than

100 kHz) in all details, but may be used with care where higher rates are required by the application.

2: Actual frequency will depend on bus conditions. Theoretically, bus conditions will add rise time and extend

low time of clock period, producing the effective frequency.

PIC18FXX2

15.4.7.1 Clock Arbitration

Clock arbitration occurs when the master, during any

receive, transmit or Repeated START/STOP condition,

de-asserts the SCL pin (SCL allowed to float high).

When the SCL pin is allowed to float high, the baud rate

generator (BRG) is suspended from counting until the

SCL pin is actually sampled high. When the SCL pin is

sampled high, the baud rate generator is reloaded with

the contents of SSPADD<6:0> and begins counting.

This ensures that the SCL high time will always be at

least one BRG rollover count, in the event that the clock

is held low by an external device (Figure 15-18).

FIGURE 15-18: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION

SDA

SCL

SCL de-asserted but slave holds

DX-1DX

BRG

SCL is sampled high, reload takes

place and BRG starts its count.

03h 02h 01h 00h (hold off) 03h 02h

Reload

BRG

Value

SCL low (clock arbitration)

SCL allowed to transition high

BRG decrements on

Q2 and Q4 cycles

PIC18FXX2

15.4.8 I2C MASTER MODE START

CONDITION TIMING

To initiate a START condition, the user sets the START

condition enable bit, SEN (SSPCON2<0>). If the SDA

and SCL pins are sampled high, the baud rate genera-

tor is reloaded with the contents of SSPADD<6:0> and

starts its count. If SCL and SDA are both sampled high

when the baud rate generator times out (TBRG), the

SDA pin is driven low. The action of the SDA being

driven low, while SCL is high, is the START condition

and causes the S bit (SSPSTAT<3>) to be set. Follow-

ing this, the baud rate generator is reloaded with the

contents of SSPADD<6:0> and resumes its count.

When the baud rate generator times out (TBRG), the

SEN bit (SSPCON2<0>) will be automatically cleared

by hardware, the baud rate generator is suspended,

leaving the SDA line held low and the START condition

is complete.

15.4.8.1 WCOL Status Flag

If the user writes the SSPBUF when a START

sequence is in progress, the WCOL is set and the con-

tents of the buffer are unchanged (the write doesn’t

occur).

FIGURE 15-19: FIRST START BIT TIMING

Note: If at the beginning of the START condition,

the SDA and SCL pins are already sam-

pled low, or if during the START condition

the SCL line is sampled low before the

SDA line is driven low, a bus collision

occurs, the Bus Collision Interrupt Flag,

BCLIF is set, the START condition is

aborted, and the I2C module is reset into its

IDLE state.

Note: Because queueing of events is not

allowed, writing to the lower 5 bits of

SSPCON2 is disabled until the START

condition is complete.

SDA

SCL

TBRG

1st bit 2nd bit

TBRG

SDA = 1, At completion of START bit,

SCL = 1

Write to SSPBUF occurs here

TBRG

Hardware clears SEN bit

TBRG

Write to SEN bit occurs here Set S bit (SSPSTAT<3>)

and sets SSPIF bit

PIC18FXX2

15.4.9 I2C MASTER MODE REPEATED

START CONDITION TIMING

A Repeated START condition occurs when the RSEN

bit (SSPCON2<1>) is programmed high and the I2C

logic module is in the IDLE state. When the RSEN bit is

set, the SCL pin is asserted low. When the SCL pin is

sampled low, the baud rate generator is loaded with the

contents of SSPADD<5:0> and begins counting. The

SDA pin is released (brought high) for one baud rate

generator count (TBRG). When the baud rate generator

times out, if SDA is sampled high, the SCL pin will be

de-asserted (brought high). When SCL is sampled

high, the baud rate generator is reloaded with the con-

tents of SSPADD<6:0> and begins counting. SDA and

SCL must be sampled high for one TBRG. This action is

then followed by assertion of the SDA pin (SDA = 0) for

one TBRG, while SCL is high. Following this, the RSEN

bit (SSPCON2<1>) will be automatically cleared and

the baud rate generator will not be reloaded, leaving

the SDA pin held low. As soon as a START condition is

detected on the SDA and SCL pins, the S bit

(SSPSTAT<3>) will be set. The SSPIF bit will not be set

until the baud rate generator has timed out.

Immediately following the SSPIF bit getting set, the

user may write the SSPBUF with the 7-bit address in

7-bit mode, or the default first address in 10-bit mode.

After the first eight bits are transmitted and an ACK is

received, the user may then transmit an additional eight

bits of address (10-bit mode) or eight bits of data (7-bit

mode).

15.4.9.1 WCOL Status Flag

If the user writes the SSPBUF when a Repeated

START sequence is in progress, the WCOL is set and

the contents of the buffer are unchanged (the write

doesn’t occur).

FIGURE 15-20: REPEAT START CONDITION WAVEFORM

Note 1: If RSEN is programmed while any other

event is in progress, it will not take effect.

2: A bus collision during the Repeated

START condition occurs if:

• SDA is sampled low when SCL goes

from low to high.

• SCL goes low before SDA is

asserted low. This may indicate that

another master is attempting to

transmit a data "1".

Note: Because queueing of events is not

allowed, writing of the lower 5 bits of

SSPCON2 is disabled until the Repeated

START condition is complete.

SDA

SCL

Sr = Repeated START

Write to SSPCON2

Write to SSPBUF occurs here

Falling edge of ninth clock

End of Xmit

At completion of START bit,

hardware clear RSEN bit

1st bit

Set S (SSPSTAT<3>)

TBRG

SDA = 1,

SCL (no change)

SCL = 1

occurs here.

TBRG TBRG TBRG

and set SSPIF

PIC18FXX2

15.4.10 I2C MASTER MODE

TRANSMISSION

Transmission of a data byte, a 7-bit address, or the

other half of a 10-bit address is accomplished by simply

writing a value to the SSPBUF register. This action will

set the buffer full flag bit, BF, and allow the baud rate

generator to begin counting and start the next transmis-

sion. Each bit of address/data will be shifted out onto

the SDA pin after the falling edge of SCL is asserted

(see data hold time specification parameter 106). SCL

is held low for one baud rate generator rollover count

(TBRG). Data should be valid before SCL is released

high (see data setup time specification parameter 107).

When the SCL pin is released high, it is held that way

for TBRG. The data on the SDA pin must remain stable

for that duration and some hold time after the next fall-

ing edge of SCL. After the eighth bit is shifted out (the

falling edge of the eighth clock), the BF flag is cleared

and the master releases SDA. This allows the slave

device being addressed to respond with an ACK bit

during the ninth bit time if an address match occurred

or if data was received properly. The status of ACK is

written into the ACKDT bit on the falling edge of the

ninth clock. If the master receives an Acknowledge, the

Acknowledge status bit, ACKSTAT, is cleared. If not,

the bit is set. After the ninth clock, the SSPIF bit is set

and the master clock (baud rate generator) is sus-

pended until the next data byte is loaded into the

SSPBUF, leaving SCL low and SDA unchanged

(Figure 15-21).

After the write to the SSPBUF, each bit of address will

be shifted out on the falling edge of SCL until all seven

address bits and the R/W bit are completed. On the fall-

ing edge of the eighth clock, the master will de-assert

the SDA pin, allowing the slave to respond with an

Acknowledge. On the falling edge of the ninth clock, the

master will sample the SDA pin to see if the address

was recognized by a slave. The status of the ACK bit is

loaded into the ACKSTAT status bit (SSPCON2<6>).

Following the falling edge of the ninth clock transmis-

sion of the address, the SSPIF is set, the BF flag is

cleared and the baud rate generator is turned off until

another write to the SSPBUF takes place, holding SCL

low and allowing SDA to float.

15.4.10.1 BF Status Flag

In Transmit mode, the BF bit (SSPSTAT<0>) is set

when the CPU writes to SSPBUF and is cleared when

all 8 bits are shifted out.

15.4.10.2 WCOL Status Flag

If the user writes the SSPBUF when a transmit is

already in progress (i.e., SSPSR is still shifting out a

data byte), the WCOL is set and the contents of the

buffer are unchanged (the write doesn’t occur).

WCOL must be cleared in software.

15.4.10.3 ACKSTAT Status Flag

In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is

cleared when the slave has sent an Acknowledge (ACK

= 0), and is set when the slave does not Acknowledge

(ACK = 1). A slave sends an Acknowledge when it has

recognized its address (including a general call) or

when the slave has properly received its data.

15.4.11 I2C MASTER MODE RECEPTION

Master mode reception is enabled by programming the

receive enable bit, RCEN (SSPCON2<3>).

The baud rate generator begins counting, and on each

rollover, the state of the SCL pin changes (high to low/

low to high) and data is shifted into the SSPSR. After

the falling edge of the eighth clock, the receive enable

flag is automatically cleared, the contents of the

SSPSR are loaded into the SSPBUF, the BF flag bit is

set, the SSPIF flag bit is set and the baud rate genera-

tor is suspended from counting, holding SCL low. The

MSSP is now in IDLE state, awaiting the next com-

mand. When the buffer is read by the CPU, the BF flag

bit is automatically cleared. The user can then send an

Acknowledge bit at the end of reception, by setting the

Acknowledge sequence enable bit, ACKEN

(SSPCON2<4>).

15.4.11.1 BF Status Flag

In receive operation, the BF bit is set when an address

or data byte is loaded into SSPBUF from SSPSR. It is

cleared when the SSPBUF register is read.

15.4.11.2 SSPOV Status Flag

In receive operation, the SSPOV bit is set when 8 bits

are received into the SSPSR and the BF flag bit is

already set from a previous reception.

15.4.11.3 WCOL Status Flag

If the user writes the SSPBUF when a receive is

already in progress (i.e., SSPSR is still shifting in a data

byte), the WCOL bit is set and the contents of the buffer

are unchanged (the write doesn’t occur).

Note: In the MSSP module, the RCEN bit must

be set after the ACK sequence or the

RCEN bit will be disregarded.

PIC18FXX2

FIGURE 15-21: I2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)

SDA

SCL

SSPIF

BF (SSPSTAT<0>)

SEN

A7 A6 A5 A4 A3 A2 A1 ACK = 0 D7D6D5D4D3D2D1D0

ACK

Transmitting Data or Second Half

R/W = 0Transmit Address to Slave

123456789 123456789 P

Cleared in software service routine

SSPBUF is written in software

From SSP interrupt

After START condition, SEN cleared by hardware

SSPBUF written with 7-bit address and R/W

start transmit

SCL held low

while CPU

responds to SSPIF

SEN = 0

of 10-bit Address

Write SSPCON2<0> SEN = 1

START condition begins From slave clear ACKSTAT bit SSPCON2<6>

ACKSTAT in

SSPCON2 = 1

Cleared in software

SSPBUF written

PEN

Cleared in software

R/W

PIC18FXX2

FIGURE 15-22: I2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)

D3D4

D6D7

A7 A6 A5 A4 A3 A2 A1

SDA

SCL 12

345678912345678 9 1234

Bus Master

terminates

transfer

ACK

Receiving Data from Slave

D3D4

D6D7

ACK

R/W = 1

Transmit Address to Slave

SSPIF

ACK is not sent

Write to SSPCON2<0> (SEN = 1)

Write to SSPBUF occurs here ACK from Slave

Master configured as a receiver

by programming SSPCON2<3>, (RCEN = 1)

PEN bit = 1

written here

Data shifted in on falling edge of CLK

Cleared in software

Start XMIT

SEN = 0

SSPOV

SDA = 0, SCL = 1

while CPU

(SSPSTAT<0>)

ACK

Last bit is shifted into SSPSR and

contents are unloaded into SSPBUF

Cleared in software

Set SSPIF interrupt

at end of receive

Set P bit

(SSPSTAT<4>)

and SSPIF

Cleared in

software

ACK from Master

Set SSPIF at end

Set SSPIF interrupt

at end of Acknowledge

sequence

Set SSPIF interrupt

at end of Acknow-

ledge sequence

of receive

Set ACKEN, start Acknowledge sequence

SSPOV is set because

SSPBUF is still full

SDA = ACKDT = 1

RCEN cleared

automatically

RCEN = 1 start

next receive

Write to SSPCON2<4>

to start Acknowledge sequence

SDA = ACKDT (SSPCON2<5>) = 0

RCEN cleared

automatically

responds to SSPIF

ACKEN

Begin START Condition

Cleared in software

SDA = ACKDT = 0

PIC18FXX2

15.4.12 ACKNOWLEDGE SEQUENCE

TIMING

An Acknowledge sequence is enabled by setting the

Acknowledge sequence enable bit, ACKEN

(SSPCON2<4>). When this bit is set, the SCL pin is

pulled low and the contents of the Acknowledge data bit

are presented on the SDA pin. If the user wishes to gen-

erate an Acknowledge, then the ACKDT bit should be

cleared. If not, the user should set the ACKDT bit before

starting an Acknowledge sequence. The baud rate gen-

erator then counts for one rollover period (TBRG) and the

SCL pin is de-asserted (pulled high). When the SCL pin

is sampled high (clock arbitration), the baud rate gener-

ator counts for TBRG. The SCL pin is then pulled low. Fol-

lowing this, the ACKEN bit is automatically cleared, the

baud rate generator is turned off and the MSSP module

then goes into IDLE mode (Figure 15-23).

15.4.12.1 WCOL Status Flag

If the user writes the SSPBUF when an Acknowledge

sequence is in progress, then WCOL is set and the con-

tents of the buffer are unchanged (the write doesn’t occur).

15.4.13 STOP CONDITION TIMING

A STOP bit is asserted on the SDA pin at the end of a

receive/transmit by setting the STOP sequence enable

bit, PEN (SSPCON2<2>). At the end of a receive/trans-

mit the SCL line is held low after the falling edge of the

ninth clock. When the PEN bit is set, the master will

assert the SDA line low. When the SDA line is sampled

low, the baud rate generator is reloaded and counts

down to 0. When the baud rate generator times out, the

SCL pin will be brought high, and one TBRG (baud rate

generator rollover count) later, the SDA pin will be

de-asserted. When the SDA pin is sampled high while

SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG

later, the PEN bit is cleared and the SSPIF bit is set

(Figure 15-24).

15.4.13.1 WCOL Status Flag

If the user writes the SSPBUF when a STOP sequence

is in progress, then the WCOL bit is set and the con-

tents of the buffer are unchanged (the write doesn’t

occur).

FIGURE 15-23: ACKNOWLEDGE SEQUENCE WAVEFORM

FIGURE 15-24: STOP CONDITION RECEIVE OR TRANSMIT MODE

Note: TBRG = one baud rate generator period.

SDA

SCL

Set SSPIF at the end

Acknowledge sequence starts here,

Write to SSPCON2 ACKEN automatically cleared

Cleared in

TBRG TBRG

of receive

ACK

ACKEN = 1, ACKDT = 0

SSPIF

software Set SSPIF at the end

of Acknowledge sequence

Cleared in

software

SCL

SDA

SDA asserted low before rising edge of clock

Write to SSPCON2

Set PEN

Falling edge of

SCL = 1 for TBRG, followed by SDA = 1 for TBRG

9th clock

SCL brought high after TBRG

Note: TBRG = one baud rate generator period.

TBRG TBRG

after SDA sampled high. P bit (SSPSTAT<4>) is set.

TBRG

to setup STOP condition.

ACK

TBRG

PEN bit (SSPCON2<2>) is cleared by

hardware and the SSPIF bit is set

PIC18FXX2

15.4.14 SLEEP OPERATION

While in SLEEP mode, the I2C module can receive

addresses or data, and when an address match or

complete byte transfer occurs, wake the processor

from SLEEP (if the MSSP interrupt is enabled).

15.4.15 EFFECT OF A RESET

A RESET disables the MSSP module and terminates

the current transfer.

15.4.16 MULTI-MASTER MODE

In Multi-Master mode, the interrupt generation on the

detection of the START and STOP conditions allows the

determination of when the bus is free. The STOP (P)

and START (S) bits are cleared from a RESET or when

the MSSP module is disabled. Control of the I2C bus

may be taken when the P bit (SSPSTAT<4>) is set, or

the bus is idle with both the S and P bits clear. When the

bus is busy, enabling the SSP interrupt will generate the

interrupt when the STOP condition occurs.

In multi-master operation, the SDA line must be moni-

tored for arbitration, to see if the signal level is the

expected output level. This check is performed in

hardware, with the result placed in the BCLIF bit.

The states where arbitration can be lost are:

• Address Transfer

• Data Transfer

• A START Condition

• A Repeated START Condition

• An Acknowledge Condition

15.4.17 MULTI -MASTER COMMUNICATION,

BUS COLLISION, AND BUS

ARBITRATION

Multi-Master mode support is achieved by bus arbitra-

tion. When the master outputs address/data bits onto

the SDA pin, arbitration takes place when the master

outputs a '1' on SDA, by letting SDA float high and

another master asserts a '0'. When the SCL pin floats

high, data should be stable. If the expected data on

SDA is a '1' and the data sampled on the SDA pin = '0',

then a bus collision has taken place. The master will set

the Bus Collision Interrupt Flag BCLIF and reset the I2C

port to its IDLE state (Figure 15-25).

If a transmit was in progress when the bus collision

occurred, the transmission is halted, the BF flag is

cleared, the SDA and SCL lines are de-asserted, and

the SSPBUF can be written to. When the user services

the bus collision Interrupt Service Routine, and if the

I2C bus is free, the user can resume communication by

asserting a START condition.

If a START, Repeated START, STOP, or Acknowledge

condition was in progress when the bus collision

occurred, the condition is aborted, the SDA and SCL

lines are de-asserted, and the respective control bits in

the SSPCON2 register are cleared. When the user ser-

vices the bus collision Interrupt Service Routine, and if

the I2C bus is free, the user can resume communication

by asserting a START condition.

The master will continue to monitor the SDA and SCL

pins. If a STOP condition occurs, the SSPIF bit will be set.

A write to the SSPBUF will start the transmission of

data at the first data bit, regardless of where the

transmitter left off when the bus collision occurred.

In Multi-Master mode, the interrupt generation on the

detection of START and STOP conditions allows the

determination of when the bus is free. Control of the I2C

bus can be taken when the P bit is set in the SSPSTAT

cleared.

FIGURE 15-25: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE

SDA

SCL

BCLIF

SDA released

SDA line pulled low

by another source

Sample SDA. While SCL is high,

data doesn’t match what is driven

Bus collision has occurred.

Set bus collision

interrupt (BCLIF)

by the master.

by master

Data changes

while SCL = 0

PIC18FXX2

15.4.17.1 Bus Collision During a START

Condition

During a START condition, a bus collision occurs if:

a) SDA or SCL are sampled low at the beginning of

the START condition (Figure 15-26).

b) SCL is sampled low before SDA is asserted low

(Figure 15-27).

During a START condition, both the SDA and the SCL

pins are monitored.

If the SDA pin is already low, or the SCL pin is already

low, then all of the following occur:

• the START condition is aborted,

• the BCLIF flag is set, and

• the MSSP module is reset to its IDLE state

(Figure 15-26).

The START condition begins with the SDA and SCL

pins de-asserted. When the SDA pin is sampled high,

the baud rate generator is loaded from SSPADD<6:0>

and counts down to 0. If the SCL pin is sampled low

while SDA is high, a bus collision occurs, because it is

assumed that another master is attempting to drive a

data '1' during the START condition.

If the SDA pin is sampled low during this count, the

BRG is reset and the SDA line is asserted early

(Figure 15-28). If, however, a '1' is sampled on the SDA

pin, the SDA pin is asserted low at the end of the BRG

count. The baud rate generator is then reloaded and

counts down to 0, and during this time, if the SCL pins

are sampled as '0', a bus collision does not occur. At

the end of the BRG count, the SCL pin is asserted low.

FIGURE 15-26: BUS COLLISION DURING START CONDITION (SDA ONLY)

Note: The reason that bus collision is not a factor

during a START condition is that no two

bus masters can assert a START condition

at the exact same time. Therefore, one

master will always assert SDA before the

other. This condition does not cause a bus

collision, because the two masters must be

allowed to arbitrate the first address follow-

ing the START condition. If the address is

the same, arbitration must be allowed to

continue into the data portion, Repeated

START or STOP conditions.

SDA

SCL

SEN

SDA sampled low before

SDA goes low before the SEN bit is set.

S bit and SSPIF set because

SSP module reset into IDLE state.

SEN cleared automatically because of bus collision.

S bit and SSPIF set because

Set SEN, enable START

condition if SDA = 1, SCL=1

SDA = 0, SCL = 1.

BCLIF

SSPIF

SDA = 0, SCL = 1.

SSPIF and BCLIF are

cleared in software.

SSPIF and BCLIF are

cleared in software.

Set BCLIF,

Set BCLIF.

START condition.

PIC18FXX2

FIGURE 15-27: BUS COLLISION DURING START CONDITION (SCL = 0)

FIGURE 15-28: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION

SDA

SCL

SEN bus collision occurs. set BCLIF

SCL = 0 before SDA = 0,

Set SEN, enable START

sequence if SDA = 1, SCL = 1

TBRG TBRG

SDA = 0, SCL = 1

BCLIF

SSPIF

Interrupt cleared

in software

bus collision occurs. Set BCLIF.

SCL = 0 before BRG time-out,

'0' '0'

'0''0'

SDA

SCL

SEN

Set S

Set SEN, enable START

sequence if SDA = 1, SCL = 1

Less than TBRG TBRG

SDA = 0, SCL = 1

BCLIF

SSPIF

Interrupts cleared

in software

Set SSPIF

SDA = 0, SCL = 1

SDA pulled low by other master.

Reset BRG and assert SDA.

SCL pulled low after BRG

Time-out

Set SSPIF

'0'

PIC18FXX2

15.4.17.2 Bus Collision During a Repeated

START Condition

During a Repeated START condition, a bus collision

occurs if:

a) A low level is sampled on SDA when SCL goes

from low level to high level.

b) SCL goes low before SDA is asserted low, indi-

cating that another master is attempting to

transmit a data ’1’.

When the user de-asserts SDA and the pin is allowed

to float high, the BRG is loaded with SSPADD<6:0>

and counts down to 0. The SCL pin is then de-asserted,

and when sampled high, the SDA pin is sampled.

If SDA is low, a bus collision has occurred (i.e., another

master is attempting to transmit a data ’0’,

Figure 15-29). If SDA is sampled high, the BRG is

reloaded and begins counting. If SDA goes from high to

low before the BRG times out, no bus collision occurs

because no two masters can assert SDA at exactly the

same time.

If SCL goes from high to low before the BRG times out

and SDA has not already been asserted, a bus collision

occurs. In this case, another master is attempting to

transmit a data ’1’ during the Repeated START

condition, Figure 15-30.

If, at the end of the BRG time-out both SCL and SDA

are still high, the SDA pin is driven low and the BRG is

reloaded and begins counting. At the end of the count,

regardless of the status of the SCL pin, the SCL pin is

driven low and the Repeated START condition is

complete.

FIGURE 15-29: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)

FIGURE 15-30: BUS COLLISION DURING REPEATED START CONDITION (CASE 2)

SDA

SCL

RSEN

BCLIF

SSPIF

Sample SDA when SCL goes high.

If SDA = 0, set BCLIF and release SDA and SCL.

Cleared in software

'0'

SDA

SCL

BCLIF

RSEN

SSPIF

Interrupt cleared

in software

SCL goes low before SDA,

Set BCLIF. Release SDA and SCL.

TBRG TBRG

'0'

PIC18FXX2

15.4.17.3 Bus Collision During a STOP

Condition

Bus collision occurs during a STOP condition if:

a) After the SDA pin has been de-asserted and

allowed to float high, SDA is sampled low after

the BRG has timed out.

b) After the SCL pin is de-asserted, SCL is

sampled low before SDA goes high.

The STOP condition begins with SDA asserted low.

When SDA is sampled low, the SCL pin is allowed to

float. When the pin is sampled high (clock arbitration),

the baud rate generator is loaded with SSPADD<6:0>

and counts down to 0. After the BRG times out, SDA is

sampled. If SDA is sampled low, a bus collision has

occurred. This is due to another master attempting to

drive a data '0' (Figure 15-31). If the SCL pin is sampled

low before SDA is allowed to float high, a bus collision

occurs. This is another case of another master

attempting to drive a data '0' (Figure 15-32).

FIGURE 15-31: BUS COLLISION DURING A STOP CONDITION (CASE 1)

FIGURE 15-32: BUS COLLISION DURING A STOP CONDITION (CASE 2)

SDA

SCL

BCLIF

PEN

SSPIF

TBRG TBRG TBRG

SDA asserted low

SDA sampled

low after TBRG,

Set BCLIF

'0'

SDA

SCL

BCLIF

PEN

SSPIF

TBRG TBRG TBRG

Assert SDA SCL goes low before SDA goes high

Set BCLIF

'0'

PIC18FXX2

NOTES:

PIC18FXX2

16.0 ADDRESSABLE UNIVERSAL

SYNCHRONOUS

ASYNCHRONOUS RECEIVER

TRANSMITTER (USART)

The Universal Synchronous Asynchronous Receiver

Transmitter (USART) module is one of the two serial

I/O modules. (USART is also known as a Serial Com-

munications Interface or SCI.) The USART can be con-

figured as a full duplex asynchronous system that can

communicate with peripheral devices, such as CRT ter-

minals and personal computers, or it can be configured

as a half-duplex synchronous system that can commu-

nicate with peripheral devices, such as A/D or D/A

integrated circuits, serial EEPROMs, etc.

The USART can be configured in the following modes:

• Asynchronous (full-duplex)

• Synchronous - Master (half-duplex)

• Synchronous - Slave (half-duplex)

In order to configure pins RC6/TX/CK and RC7/RX/DT

as the Universal Synchronous Asynchronous Receiver

Transmitter:

• bit SPEN (RCSTA<7>) must be set (= 1),

• bit TRISC<6> must be cleared (= 0), and

• bit TRISC<7> must be set (=1).

Receive Status and Control Register (RCSTA).

PIC18FXX2

R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0

CSRC TX9 TXEN SYNC —BRGHTRMTTX9D

bit 7 bit 0

bit 7 CSRC: Clock Source Select bit

Asynchronous mode:

Don’t care

Synchronous mode:

1 = Master mode (clock generated internally from BRG)

0 = Slave mode (clock from external source)

bit 6 TX9: 9-bit Transmit Enable bit

1 = Selects 9-bit transmission

0 = Selects 8-bit transmission

bit 5 TXEN: Transmit Enable bit

1 = Transmit enabled

0 = Transmit disabled

Note: SREN/CREN overrides TXEN in SYNC mode.

bit 4 SYNC: USART Mode Select bit

1 = Synchronous mode

0 = Asynchronous mode

bit 3 Unimplemented: Read as '0'

bit 2 BRGH: High Baud Rate Select bit

Asynchronous mode:

1 = High speed

0 = Low speed

Synchronous mode:

Unused in this mode

bit 1 TRMT: Transmit Shift Register Status bit

1 = TSR empty

0 = TSR full

bit 0 TX9D: 9th bit of Transmit Data

Can be Address/Data bit or a parity bit.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x

SPEN RX9 SREN CREN ADDEN FERR OERR RX9D

bit 7 bit 0

bit 7 SPEN: Serial Port Enable bit

1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins)

0 = Serial port disabled

bit 6 RX9: 9-bit Receive Enable bit

1 = Selects 9-bit reception

0 = Selects 8-bit reception

bit 5 SREN: Single Receive Enable bit

Asynchronous mode:

Don’t care

Synchronous mode - Master:

1 = Enables single receive

0 = Disables single receive

This bit is cleared after reception is complete.

Synchronous mode - Slave:

Don’t care

bit 4 CREN: Continuous Receive Enable bit

Asynchronous mode:

1 = Enables receiver

0 = Disables receiver

Synchronous mode:

1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)

0 = Disables continuous receive

bit 3 ADDEN: Address Detect Enable bit

Asynchronous mode 9-bit (RX9 = 1):

1 = Enables address detection, enable interrupt and load of the receive buffer

when RSR<8> is set

0 = Disables address detection, all bytes are received, and ninth bit can be used as parity bit

bit 2 FERR: Framing Error bit

1 = Framing error (can be updated by reading RCREG register and receive next valid byte)

0 = No framing error

bit 1 OERR: Overrun Error bit

1 = Overrun error (can be cleared by clearing bit CREN)

0 = No overrun error

bit 0 RX9D: 9th bit of Received Data

This can be Address/Data bit or a parity bit, and must be calculated by user firmware.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

16.1 USART Baud Rate Generator

(BRG)

The BRG supports both the Asynchronous and Syn-

chronous modes of the USART. It is a dedicated 8-bit

baud rate generator. The SPBRG register controls the

period of a free running 8-bit timer. In Asynchronous

mode, bit BRGH (TXSTA<2>) also controls the baud

rate. In Synchronous mode, bit BRGH is ignored.

Table 16-1 shows the formula for computation of the

baud rate for different USART modes, which only apply

in Master mode (internal clock).

Given the desired baud rate and Fosc, the nearest inte-

ger value for the SPBRG register can be calculated

using the formula in Table 16-1. From this, the error in

baud rate can be determined.

Example 16-1 shows the calculation of the baud rate

error for the following conditions:

•F

OSC = 16 MHz

• Desired Baud Rate = 9600

• BRGH = 0

• SYNC = 0

It may be advantageous to use the high baud rate

(BRGH = 1) even for slower baud clocks. This is

because the FOSC/(16(X + 1)) equation can reduce the

baud rate error in some cases.

Writing a new value to the SPBRG register causes the

BRG timer to be reset (or cleared). This ensures the

BRG does not wait for a timer overflow before

outputting the new baud rate.

16.1.1 SAMPLING

The data on the RC7/RX/DT pin is sampled three times

by a majority detect circuit to determine if a high or a

low level is present at the RX pin.

EXAMPLE 16-1: CALCULATING BAUD RATE ERROR

TABLE 16-1: BAUD RATE FORMULA

TABLE 16-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR

Desired Baud Rate = FOSC / (64 (X + 1))

Solving for X:

X = ( (FOSC / Desired Baud Rate) / 64 ) – 1

X = ((1 6000000 / 960 0) / 64) – 1

X = [25. 042] = 25

Calculated Baud Rate = 160000 00 / (64 (2 5 + 1))

= 9615

Error = (Calculated Baud Ra te – Desired Baud Rate)

Desired Baud Rate

= (961 5 – 96 00 ) / 9600

= 0.16%

SYNC BRGH = 0 (Low Speed) BRGH = 1 (High Speed)

(Asynchronous) Baud Rate = FOSC/(64(X+1))

(Synchronous) Baud Rate = FOSC/(4(X+1))

Baud Rate = FOSC/(16(X+1))

N/A

Legend: X = value in SPBRG (0 to 255)

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

TXSTA CSRC TX9 TXEN SYNC —BRGHTRMT TX9D 0000 -010 0000 -010

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG.

PIC18FXX2

TABLE 16-3: BAUD RATES FOR SYNCHRONOUS MODE

BAUD

RATE

(Kbps)

FOSC = 40 MHz SPBRG

value

(decimal)

33 MHz SPBRG

value

(decimal)

25 MHz SPBRG

value

(decimal)

20 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 NA - - NA - - NA - - NA - -

1.2 NA - - NA - - NA - - NA - -

2.4 NA - - NA - - NA - - NA - -

9.6 NA - - NA - - NA - - NA - -

19.2 NA - - NA - - NA - - NA - -

76.8 76.92 +0.16 129 77.10 +0.39 106 77.16 +0.47 80 76.92 +0.16 64

96 96.15 +0.16 103 95.93 -0.07 85 96.15 +0.16 64 96.15 +0.16 51

300 303.03 +1.01 32 294.64 -1.79 27 297.62 -0.79 20 294.12 -1.96 16

500 500 0 19 485.30 -2.94 16 480.77 -3.85 12 500 0 9

HIGH 10000 - 0 8250 - 0 6250 - 0 5000 - 0

LOW 39.06 - 255 32.23 - 255 24.41 - 255 19.53 - 255

BAUD

RATE

(Kbps)

FOSC = 16 MHz SPBRG

value

(decimal)

10 MHz SPBRG

value

(decimal)

7.15909 MHz SPBRG

value

(decimal)

5.0688 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3NA- - NA- - NA - - NA- -

1.2NA- - NA- - NA - - NA- -

2.4NA- - NA- - NA - - NA- -

9.6 NA - - NA - - 9.62 +0.23 185 9.60 0 131

19.2 19.23 +0.16 207 19.23 +0.16 129 19.24 +0.23 92 19.20 0 65

76.8 76.92 +0.16 51 75.76 -1.36 32 77.82 +1.32 22 74.54 -2.94 16

96 95.24 -0.79 41 96.15 +0.16 25 94.20 -1.88 18 97.48 +1.54 12

300 307.70 +2.56 12 312.50 +4.17 7 298.35 -0.57 5 316.80 +5.60 3

500 500 0 7 500 0 4 447.44 -10.51 3 422.40 -15.52 2

HIGH 4000 - 0 2500 - 0 1789.80 - 0 1267.20 - 0

LOW 15.63 - 255 9.77 - 255 6.99 - 255 4.95 - 255

BAUD

RATE

(Kbps)

FOSC = 4 MHz SPBRG

value

(decimal)

3.579545 MHz SPBRG

value

(decimal)

1 MHz SPBRG

value

(decimal)

32.768 kHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 NA - - NA - - NA - - 0.30 +1.14 26

1.2 NA - - NA - - 1.20 +0.16 207 1.17 -2.48 6

2.4 NA - - NA - - 2.40 +0.16 103 2.73 +13.78 2

9.6 9.62 +0.16 103 9.62 +0.23 92 9.62 +0.16 25 8.20 -14.67 0

19.2 19.23 +0.16 51 19.04 -0.83 46 19.23 +0.16 12 NA - -

76.8 76.92 +0.16 12 74.57 -2.90 11 83.33 +8.51 2 NA - -

96 1000 +4.17 9 99.43 +3.57 8 83.33 -13.19 2 NA - -

300 333.33 +11.11 2 298.30 -0.57 2 250 -16.67 0 NA - -

500 500 0 1 447.44 -10.51 1 NA - - NA - -

HIGH 1000 - 0 894.89 - 0 250 - 0 8.20 - 0

LOW 3.91 - 255 3.50 - 255 0.98 - 255 0.03 - 255

PIC18FXX2

TABLE 16-4: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)

BAUD

RATE

(Kbps)

FOSC = 40 MHz SPBRG

value

(decimal)

33 MHz SPBRG

value

(decimal)

25 MHz SPBRG

value

(decimal)

20 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 NA - - NA - - NA - - NA - -

1.2 NA - - NA - - NA - - NA - -

2.4 NA - - 2.40 -0.07 214 2.40 -0.15 162 2.40 +0.16 129

9.6 9.62 +0.16 64 9.55 -0.54 53 9.53 -0.76 40 9.47 -1.36 32

19.2 18.94 -1.36 32 19.10 -0.54 26 19.53 +1.73 19 19.53 +1.73 15

76.8 78.13 +1.73 7 73.66 -4.09 6 78.13 +1.73 4 78.13 +1.73 3

96 89.29 -6.99 6 103.13 +7.42 4 97.66 +1.73 3 104.17 +8.51 2

300 312.50 +4.17 1 257.81 -14.06 1 NA - - 312.50 +4.17 0

500 625 +25.00 0 NA - - NA - - NA - -

HIGH 625 - 0 515.63 - 0 390.63 - 0 312.50 - 0

LOW 2.44 - 255 2.01 - 255 1.53 - 255 1.22 - 255

BAUD

RATE

(Kbps)

FOSC = 16 MHz SPBRG

value

(decimal)

10 MHz SPBRG

value

(decimal)

7.15909 MHz SPBRG

value

(decimal)

5.0688 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 NA - - NA - - NA - - NA - -

1.2 1.20 +0.16 207 1.20 +0.16 129 1.20 +0.23 92 1.20 0 65

2.4 2.40 +0.16 103 2.40 +0.16 64 2.38 -0.83 46 2.40 0 32

9.6 9.62 +0.16 25 9.77 +1.73 15 9.32 -2.90 11 9.90 +3.13 7

19.2 19.23 +0.16 12 19.53 +1.73 7 18.64 -2.90 5 19.80 +3.13 3

76.8 83.33 +8.51 2 78.13 +1.73 1 111.86 +45.65 0 79.20 +3.13 0

96 83.33 -13.19 2 78.13 -18.62 1 NA - - NA - -

300 250 -16.67 0 156.25 -47.92 0 NA - - NA - -

500 NA - - NA - - NA - - NA - -

HIGH 250 - 0 156.25 - 0 111.86 - 0 79.20 - 0

LOW 0.98 - 255 0.61 - 255 0.44 - 255 0.31 - 255

BAUD

RATE

(Kbps)

FOSC = 4 MHz SPBRG

value

(decimal)

3.579545 MHz SPBRG

value

(decimal)

1 MHz SPBRG

value

(decimal)

32.768 kHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 0.30 -0.16 207 0.30 +0.23 185 0.30 +0.16 51 0.26 -14.67 1

1.2 1.20 +1.67 51 1.19 -0.83 46 1.20 +0.16 12 NA - -

2.4 2.40 +1.67 25 2.43 +1.32 22 2.23 -6.99 6 NA - -

9.6 8.93 -6.99 6 9.32 -2.90 5 7.81 -18.62 1 NA - -

19.2 20.83 +8.51 2 18.64 -2.90 2 15.63 -18.62 0 NA - -

76.8 62.50 -18.62 0 55.93 -27.17 0 NA - - NA - -

96 NA - - NA - - NA - - NA - -

300 NA - - NA - - NA - - NA - -

500 NA - - NA - - NA - - NA - -

HIGH 62.50 - 0 55.93 - 0 15.63 - 0 0.51 - 0

LOW 0.24 - 255 0.22 - 255 0.06 - 255 0.002 - 255

PIC18FXX2

TABLE 16-5: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)

BAUD

RATE

(Kbps)

FOSC = 40 MHz SPBRG

value

(decimal)

33 MHz SPBRG

value

(decimal)

25 MHz SPBRG

value

(decimal)

20 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3NA- -NA- -NA- -NA- -

1.2NA- -NA- -NA- -NA- -

2.4NA- -NA- -NA- -NA- -

9.6 NA - - 9.60 -0.07 214 9.59 -0.15 162 9.62 +0.16 129

19.2 19.23 +0.16 129 19.28 +0.39 106 19.30 +0.47 80 19.23 +0.16 64

76.8 75.76 -1.36 32 76.39 -0.54 26 78.13 +1.73 19 78.13 +1.73 15

96 96.15 +0.16 25 98.21 +2.31 20 97.66 +1.73 15 96.15 +0.16 12

300 312.50 +4.17 7 294.64 -1.79 6 312.50 +4.17 4 312.50 +4.17 3

500 500 0 4 515.63 +3.13 3 520.83 +4.17 2 416.67 -16.67 2

HIGH 2500 - 0 2062.50 - 0 1562.50 - 0 1250 - 0

LOW 9.77 - 255 8,06 - 255 6.10 - 255 4.88 - 255

BAUD

RATE

(Kbps)

FOSC = 16 MHz SPBRG

value

(decimal)

10 MHz SPBRG

value

(decimal)

7.15909 MHz SPBRG

value

(decimal)

5.0688 MHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3NA- - NA- - NA- - NA- -

1.2NA- - NA- - NA- - NA- -

2.4 NA - - NA - - 2.41 +0.23 185 2.40 0 131

9.6 9.62 +0.16 103 9.62 +0.16 64 9.52 -0.83 46 9.60 0 32

19.2 19.23 +0.16 51 18.94 -1.36 32 19.45 +1.32 22 18.64 -2.94 16

76.8 76.92 +0.16 12 78.13 +1.73 7 74.57 -2.90 5 79.20 +3.13 3

96 100 +4.17 9 89.29 -6.99 6 89.49 -6.78 4 105.60 +10.00 2

300 333.33 +11.11 2 312.50 +4.17 1 447.44 +49.15 0 316.80 +5.60 0

500 500 0 1 625 +25.00 0 447.44 -10.51 0 NA - -

HIGH 1000 - 0 625 - 0 447.44 - 0 316.80 - 0

LOW 3.91 - 255 2.44 - 255 1.75 - 255 1.24 - 255

BAUD

RATE

(Kbps)

FOSC = 4 MHz SPBRG

value

(decimal)

3.579545 MHz SPBRG

value

(decimal)

1 MHz SPBRG

value

(decimal)

32.768 kHz SPBRG

value

(decimal)

KBAUD

ERROR KBAUD

ERROR

0.3 NA - - NA - - 0.30 +0.16 207 0.29 -2.48 6

1.2 1.20 +0.16 207 1.20 +0.23 185 1.20 +0.16 51 1.02 -14.67 1

2.4 2.40 +0.16 103 2.41 +0.23 92 2.40 +0.16 25 2.05 -14.67 0

9.6 9.62 +0.16 25 9.73 +1.32 22 8.93 -6.99 6 NA - -

19.2 19.23 +0.16 12 18.64 -2.90 11 20.83 +8.51 2 NA - -

76.8 NA - - 74.57 -2.90 2 62.50 -18.62 0 NA - -

96 NA - - 111.86 +16.52 1 NA - - NA - -

300 NA - - 223.72 -25.43 0 NA - - NA - -

500NA- - NA- - NA- - NA- -

HIGH 250 - 0 55.93 - 0 62.50 - 0 2.05 - 0

LOW 0.98 - 255 0.22 - 255 0.24 - 255 0.008 - 255

PIC18FXX2

16.2 USART Asynchronous Mode

In this mode, the USART uses standard non-return-to-

zero (NRZ) format (one START bit, eight or nine data

bits and one STOP bit). The most common data format

is 8-bits. An on-chip dedicated 8-bit baud rate genera-

tor can be used to derive standard baud rate frequen-

cies from the oscillator. The USART transmits and

receives the LSb first. The USART’s transmitter and

receiver are functionally independent, but use the

same data format and baud rate. The baud rate gener-

ator produces a clock, either x16 or x64 of the bit shift

rate, depending on bit BRGH (TXSTA<2>). Parity is not

supported by the hardware, but can be implemented in

software (and stored as the ninth data bit).

Asynchronous mode is stopped during SLEEP.

Asynchronous mode is selected by clearing bit SYNC

(TXSTA<4>).

The USART Asynchronous module consists of the

following important elements:

• Baud Rate Generator

• Sampling Circuit

• Asynchronous Transmitter

• Asynchronous Receiver

16.2.1 USART ASYNCHRONOUS

TRANSMITTER

The USART transmitter block diagram is shown in

Figure 16-1. The heart of the transmitter is the Transmit

(serial) Shift Register (TSR). The shift register obtains

its data from the read/write transmit buffer, TXREG. The

TXREG register is loaded with data in software. The

TSR register is not loaded until the STOP bit has been

transmitted from the previous load. As soon as the

STOP bit is transmitted, the TSR is loaded with new

data from the TXREG register (if available). Once the

TXREG register transfers the data to the TSR register

(occurs in one T

CY), the TXREG register is empty and

flag bit TXIF (PIR1<4>) is set. This interrupt can be

enabled/disabled by setting/clearing enable bit TXIE

( PIE1<4>). Flag bit TXIF will be set, regardless of the

state of enable bit TXIE and cannot be cleared in soft-

ware. It will reset only when new data is loaded into the

TXREG register. While flag bit TXIF indicated the sta-

tus of the TXREG register, another bit, TRMT

(TXSTA<1>), shows the status of the TSR register. Sta-

tus bit TRMT is a read-only bit, which is set when the

TSR register is empty. No interrupt logic is tied to this

bit, so the user has to poll this bit in order to determine

if the TSR register is empty.

To set up an asynchronous transmission:

1. Initialize the SPBRG register for the appropriate

baud rate. If a high speed baud rate is desired,

set bit BRGH (Section 16.1).

2. Enable the asynchronous serial port by clearing

bit SYNC and setting bit SPEN.

3. If interrupts are desired, set enable bit TXIE.

4. If 9-bit transmission is desired, set transmit bit

TX9. Can be used as address/data bit.

5. Enable the transmission by setting bit TXEN,

which will also set bit TXIF.

6. If 9-bit transmission is selected, the ninth bit

should be loaded in bit TX9D.

7. Load data to the TXREG register (starts

transmission).

FIGURE 16-1: USART TRANSMIT BLOCK DIAGRAM

Note 1: The TSR register is not mapped in data

memory, so it is not available to the user.

2: Flag bit TXIF is set when enable bit TXEN

is set.

Note: TXIF is not cleared immediately upon load-

ing data into the transmit buffer TXREG.

The flag bit becomes valid in the second

instruction cycle following the load

instruction.

TXIF

TXIE

Interrupt

TXEN Baud Rate CLK

SPBRG

Baud Rate Generator

TX9D

MSb LSb

Data Bus

TXREG Register

TSR Register

(8) 0

TX9

TRMT SPEN

RC6/TX/CK pin

Pin Buffer

and Control

• • •

PIC18FXX2

FIGURE 16-2: ASYNCHRONOUS TRANSMISSION

FIGURE 16-3: ASYNCHRONOUS TRANSMISSION (BACK TO BACK)

TABLE 16-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION

Word 1

STOP bit

Word 1

Transmit Shift Reg

START bit bit 0 bit 1 bit 7/8

Write to TXREG

Word 1

BRG Output

(Shift Clock)

RC6/TX/CK (pin)

TXIF bit

(Transmit Buffer

Reg. Empty Flag)

TRMT bit

(Transmit Shift

Reg. Empty Flag)

Transmit Shift Reg.

Write to TXREG

BRG Output

(Shift Clock)

RC6/TX/CK (pin)

TXIF bit

(Interrupt Reg. Flag)

TRMT bit

(Transmit Shift

Reg. Empty Flag)

Word 1 Word 2

START bit STOP bit START bit

Transmit Shift Reg.

Word 1 Word 2

bit 0 bit 1 bit 7/8 bit 0

Note: This timing diagram shows two consecutive transmissions.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

TXREG USART Transmit Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC —BRGH TRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented locations read as '0'.

Shaded cells are not used for Asynchronous Transmission.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

PIC18FXX2

16.2.2 USART ASYNCHRONOUS

RECEIVER

The receiver block diagram is shown in Figure 16-4.

The data is received on the RC7/RX/DT pin and drives

the data recovery block. The data recovery block is

actually a high speed shifter operating at x16 times the

baud rate, whereas the main receive serial shifter oper-

ates at the bit rate or at FOSC. This mode would

typically be used in RS-232 systems.

To set up an Asynchronous Reception:

1. Initialize the SPBRG register for the appropriate

baud rate. If a high speed baud rate is desired,

set bit BRGH (Section 16.1).

2. Enable the asynchronous serial port by clearing

bit SYNC and setting bit SPEN.

3. If interrupts are desired, set enable bit RCIE.

4. If 9-bit reception is desired, set bit RX9.

5. Enable the reception by setting bit CREN.

6. Flag bit RCIF will be set when reception is com-

plete and an interrupt will be generated if enable

bit RCIE was set.

7. Read the RCSTA register to get the ninth bit (if

enabled) and determine if any error occurred

during reception.

8. Read the 8-bit received data by reading the

RCREG register.

9. If any error occurred, clear the error by clearing

enable bit CREN.

10. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

16.2.3 SETTING UP 9-BIT MODE WITH

ADDRESS DETECT

This mode would typically be used in RS-485 systems.

To set up an Asynchronous Reception with Address

Detect Enable:

1. Initialize the SPBRG register for the appropriate

baud rate. If a high speed baud rate is required,

set the BRGH bit.

2. Enable the asynchronous serial port by clearing

the SYNC bit and setting the SPEN bit.

3. If interrupts are required, set the RCEN bit and

select the desired priority level with the RCIP bit.

4. Set the RX9 bit to enable 9-bit reception.

5. Set the ADDEN bit to enable address detect.

6. Enable reception by setting the CREN bit.

7. The RCIF bit will be set when reception is com-

plete. The interrupt will be acknowledged if the

RCIE and GIE bits are set.

8. Read the RCSTA register to determine if any

error occurred during reception, as well as read

bit 9 of data (if applicable).

9. Read RCREG to determine if the device is being

addressed.

10. If any error occurred, clear the CREN bit.

11. If the device has been addressed, clear the

ADDEN bit to allow all received data into the

receive buffer and interrupt the CPU.

FIGURE 16-4: USART RECEIVE BLOCK DIAGRAM

x64 Baud Rate CLK

SPBRG

Baud Rate Generator

RC7/RX/DT

Pin Buffer

and Control

SPEN

Data

Recovery

CREN OERR FERR

RSR Register

MSb LSb

RX9D RCREG Register FIFO

Interrupt RCIF

RCIE

Data Bus

÷ 64

÷ 16

STOP START

(8) 710

RX9

• • •

PIC18FXX2

FIGURE 16-5: ASYNCHRONOUS RECEPTION

TABLE 16-7: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION

START

bit bit7/8

bit1bit0 bit7/8 bit0STOP

bit

START

bit

START

bit

bit7/8 STOP

bit

RX (pin)

Reg

Rcv Buffer Reg

Rcv Shift

Read Rcv

Buffer Reg

RCREG

RCIF

(Interrupt Flag)

OERR bit

CREN

Word 1

RCREG

Word 2

RCREG

STOP

bit

Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing

the OERR (overrun) bit to be set.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/GIEH PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

RCREG USART Receive Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC —BRGHTRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented locations read as '0'.

Shaded cells are not used for Asynchronous Reception.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits

clear.

PIC18FXX2

16.3 USART Synchronous Master

Mode

In Synchronous Master mode, the data is transmitted in

a half-duplex manner (i.e., transmission and reception

do not occur at the same time). When transmitting data,

the reception is inhibited and vice versa. Synchronous

mode is entered by setting bit SYNC (TXSTA<4>). In

addition, enable bit SPEN (RCSTA<7>) is set in order

to configure the RC6/TX/CK and RC7/RX/DT I/O pins

to CK (clock) and DT (data) lines, respectively. The

Master mode indicates that the processor transmits the

master clock on the CK line. The Master mode is

entered by setting bit CSRC (TXSTA<7>).

16.3.1 USART SYNCHRONOUS MASTER

TRANSMISSION

The USART transmitter block diagram is shown in

Figure 16-1. The heart of the transmitter is the Transmit

(serial) Shift Register (TSR). The shift register obtains

its data from the read/write transmit buffer register

TXREG. The TXREG register is loaded with data in

software. The TSR register is not loaded until the last

bit has been transmitted from the previous load. As

soon as the last bit is transmitted, the TSR is loaded

with new data from the TXREG (if available). Once the

TXREG register transfers the data to the TSR register

(occurs in one TCYCLE), the TXREG is empty and inter-

rupt bit TXIF (PIR1<4>) is set. The interrupt can be

enabled/disabled by setting/clearing enable bit TXIE

(PIE1<4>). Flag bit TXIF will be set, regardless of the

state of enable bit TXIE, and cannot be cleared in soft-

ware. It will reset only when new data is loaded into the

TXREG register. While flag bit TXIF indicates the status

of the TXREG register, another bit TRMT (TXSTA<1>)

shows the status of the TSR register. TRMT is a read

only bit, which is set when the TSR is empty. No inter-

rupt logic is tied to this bit, so the user has to poll this

bit in order to determine if the TSR register is empty.

The TSR is not mapped in data memory, so it is not

available to the user.

To set up a Synchronous Master Transmission:

1. Initialize the SPBRG register for the appropriate

baud rate (Section 16.1).

2. Enable the synchronous master serial port by

setting bits SYNC, SPEN, and CSRC.

3. If interrupts are desired, set enable bit TXIE.

4. If 9-bit transmission is desired, set bit TX9.

5. Enable the transmission by setting bit TXEN.

6. If 9-bit transmission is selected, the ninth bit

should be loaded in bit TX9D.

7. Start transmission by loading data to the TXREG

TABLE 16-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION

Note: TXIF is not cleared immediately upon load-

ing data into the transmit buffer TXREG.

The flag bit becomes valid in the second

instruction cycle following the load

instruction.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

TXREG USART Transmit Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC —BRGH TRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented, read as '0'.

Shaded cells are not used for Synchronous Master Transmission.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits

clear.

PIC18FXX2

FIGURE 16-6: SYNCHRONOUS TRANSMISSION

FIGURE 16-7: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)

bit 0 bit 1 bit 7

Word 1

Q1Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3Q4 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

bit 2 bit 0 bit 1 bit 7

RC7/RX/DT

RC6/TX/CK

Write to

TXREG Reg

TXIF bit

(Interrupt Flag)

TRMT

TXEN bit '1' '1'

Word 2

TRMT bit

Write Word1 Write Word2

Note: Sync Master mode; SPBRG = '0'. Continuous transmission of two 8-bit words.

RC7/RX/DT pin

RC6/TX/CK pin

Write to

TXREG reg

TXIF bit

TRMT bit

bit0 bit1 bit2 bit6 bit7

TXEN bit

PIC18FXX2

16.3.2 USART SYNCHRONOUS MASTER

RECEPTION

Once Synchronous mode is selected, reception is

enabled by setting either enable bit SREN

(RCSTA<5>), or enable bit CREN (RCSTA<4>). Data is

sampled on the RC7/RX/DT pin on the falling edge of

the clock. If enable bit SREN is set, only a single word

is received. If enable bit CREN is set, the reception is

continuous until CREN is cleared. If both bits are set,

then CREN takes precedence.

To set up a Synchronous Master Reception:

1. Initialize the SPBRG register for the appropriate

baud rate (Section 16.1).

2. Enable the synchronous master serial port by

setting bits SYNC, SPEN and CSRC.

3. Ensure bits CREN and SREN are clear.

4. If interrupts are desired, set enable bit RCIE.

5. If 9-bit reception is desired, set bit RX9.

6. If a single reception is required, set bit SREN.

For continuous reception, set bit CREN.

7. Interrupt flag bit RCIF will be set when reception

is complete and an interrupt will be generated if

the enable bit RCIE was set.

8. Read the RCSTA register to get the ninth bit (if

enabled) and determine if any error occurred

during reception.

9. Read the 8-bit received data by reading the

RCREG register.

10. If any error occurred, clear the error by clearing

bit CREN.

11. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

TABLE 16-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION

FIGURE 16-8: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

RCREG USART Receive Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC —BRGH TRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Reception.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

CREN bit

RC7/RX/DT pin

RC6/TX/CK pin

Write to

bit SREN

SREN bit

RCIF bit

(Interrupt)

Read

RXREG

Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

'0'

bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7

'0'

Q1 Q2 Q3 Q4

Note: Timing diagram demonstrates Sync Master mode with bit SREN = '1' and bit BRGH = '0'.

PIC18FXX2

16.4 USART Synchronous Slave Mode

Synchronous Slave mode differs from the Master mode

in the fact that the shift clock is supplied externally at

the RC6/TX/CK pin (instead of being supplied internally

in Master mode). This allows the device to transfer or

receive data while in SLEEP mode. Slave mode is

entered by clearing bit CSRC (TXSTA<7>).

16.4.1 USART SYNCHRONOUS SLAVE

TRANSMIT

The operation of the Synchronous Master and Slave

modes are identical, except in the case of the SLEEP

mode.

If two words are written to the TXREG and then the

SLEEP instruction is executed, the following will occur:

a) The first word will immediately transfer to the

TSR register and transmit.

b) The second word will remain in TXREG register.

c) Flag bit TXIF will not be set.

d) When the first word has been shifted out of TSR,

the TXREG register will transfer the second

word to the TSR and flag bit TXIF will now be

set.

e) If enable bit TXIE is set, the interrupt will wake

the chip from SLEEP. If the global interrupt is

enabled, the program will branch to the interrupt

vector.

To set up a Synchronous Slave Transmission:

1. Enable the synchronous slave serial port by set-

ting bits SYNC and SPEN and clearing bit

CSRC.

2. Clear bits CREN and SREN.

3. If interrupts are desired, set enable bit TXIE.

4. If 9-bit transmission is desired, set bit TX9.

5. Enable the transmission by setting enable bit

TXEN.

6. If 9-bit transmission is selected, the ninth bit

should be loaded in bit TX9D.

7. Start transmission by loading data to the TXREG

8. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

TXREG USART Transmit Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented, read as '0'.

Shaded cells are not used for Synchronous Slave Transmission.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits

clear.

PIC18FXX2

16.4.2 USART SYNCHRONOUS SLAVE

RECEPTION

The operation of the Synchronous Master and Slave

modes is identical, except in the case of the SLEEP

mode and bit SREN, which is a “don't care” in Slave

mode.

If receive is enabled by setting bit CREN prior to the

SLEEP instruction, then a word may be received during

SLEEP. On completely receiving the word, the RSR

and if enable bit RCIE bit is set, the interrupt generated

will wake the chip from SLEEP. If the global interrupt is

enabled, the program will branch to the interrupt vector.

To set up a Synchronous Slave Reception:

1. Enable the synchronous master serial port by

setting bits SYNC and SPEN and clearing bit

CSRC.

2. If interrupts are desired, set enable bit RCIE.

3. If 9-bit reception is desired, set bit RX9.

4. To enable reception, set enable bit CREN.

5. Flag bit RCIF will be set when reception is com-

plete. An interrupt will be generated if enable bit

RCIE was set.

6. Read the RCSTA register to get the ninth bit (if

enabled) and determine if any error occurred

during reception.

7. Read the 8-bit received data by reading the

RCREG register.

8. If any error occurred, clear the error by clearing

bit CREN.

9. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

TABLE 16-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x

RCREG USART Receive Register 0000 0000 0000 0000

TXSTA CSRC TX9 TXEN SYNC —BRGH TRMT TX9D 0000 -010 0000 -010

SPBRG Baud Rate Generator Register 0000 0000 0000 0000

Legend: x = unknown, - = unimplemented, read as '0'.

Shaded cells are not used for Synchronous Slave Reception.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits

clear.

PIC18FXX2

17.0 COMPATIBLE 10-BIT

ANALOG-TO-DIGITAL

CONVERTER (A/D) MODULE

The Analog-to-Digital (A/D) converter module has five

inputs for the PIC18F2X2 devices and eight for the

PIC18F4X2 devices. This module has the ADCON0

and ADCON1 register definitions that are compatible

with the mid-range A/D module.

The A/D allows conversion of an analog input signal to

a corresponding 10-bit digital number.

The A/D module has four registers. These registers

are:

• A/D Result High Register (ADRESH)

• A/D Result Low Register (ADRESL)

• A/D Control Register 0 (ADCON0)

• A/D Control Register 1 (ADCON1)

The ADCON0 register, shown in Register 17-1, con-

trols the operation of the A/D module. The ADCON1

functions of the port pins.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0

ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE —ADON

bit 7 bit 0

bit 7-6 ADCS1:ADCS0: A/D Conversion Clock Select bits (ADCON0 bits in bold)

bit 5-3 CHS2:CHS0: Analog Channel Select bits

000 = channel 0, (AN0)

001 = channel 1, (AN1)

010 = channel 2, (AN2)

011 = channel 3, (AN3)

100 = channel 4, (AN4)

101 = channel 5, (AN5)

110 = channel 6, (AN6)

111 = channel 7, (AN7)

Note: The PIC18F2X2 devices do not implement the full 8 A/D channels; the unimplemented

selections are reserved. Do not select any unimplemented channel.

bit 2 GO/DONE: A/D Conversion Status bit

When ADON = 1:

1 = A/D conversion in progress (setting this bit starts the A/D conversion which is automatically

cleared by hardware when the A/D conversion is complete)

0 = A/D conversion not in progress

bit 1 Unimplemented: Read as '0'

bit 0 ADON: A/D On bit

1 = A/D converter module is powered up

0 = A/D converter module is shut-off and consumes no operating current

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

ADCON1

<ADCS2>

ADCON0

<ADCS1:ADCS0> Clock Conversion

000 FOSC/2

001 FOSC/8

010 FOSC/32

011 FRC (clock derived from the internal A/D RC oscillator)

100 FOSC/4

101 FOSC/16

110 FOSC/64

111 FRC (clock derived from the internal A/D RC oscillator)

PIC18FXX2

R/W-0 R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0

ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0

bit 7 bit 0

bit 7 ADFM: A/D Result Format Select bit

1 = Right justified. Six (6) Most Significant bits of ADRESH are read as ’0’.

0 = Left justified. Six (6) Least Significant bits of ADRESL are read as ’0’.

bit 6 ADCS2: A/D Conversion Clock Select bit (ADCON1 bits in bold)

bit 5-4 Unimplemented: Read as '0'

bit 3-0 PCFG3:PCFG0: A/D Port Configuration Control bits

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

Note: On any device RESET, the port pins that are multiplexed with analog functions (ANx) are

forced to be an analog input.

ADCON1

<ADCS2>

ADCON0

<ADCS1:ADCS0> Clock Conversion

000 FOSC/2

001 FOSC/8

010 FOSC/32

011 FRC (clock derived from the internal A/D RC oscillator)

100 FOSC/4

101 FOSC/16

110 FOSC/64

111 FRC (clock derived from the internal A/D RC oscillator)

A = Analog input D = Digital I/O

C/R = # of analog input channels / # of A/D voltage references

PCFG

<3:0> AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 VREF+VREF-C / R

0000 AAAA A A AAV

DD VSS 8 / 0

0001 AAAAV

REF+A A AAN3VSS 7 / 1

0010 DDDA A A AAV

DD VSS 5 / 0

0011 DDDAV

REF+A A AAN3VSS 4 / 1

0100 DDDD A D AAV

DD VSS 3 / 0

0101 DDDDV

REF+D A AAN3VSS 2 / 1

011x DDDD D D DD — —0 / 0

1000 AAAAV

REF+VREF-A A AN3AN26 / 2

1001 DDAA A A AAV

DD VSS 6 / 0

1010 DDAAV

REF+A A AAN3VSS 5 / 1

1011 DDAAV

REF+VREF-A A AN3AN24 / 2

1100 DDDAV

REF+VREF-A A AN3AN23 / 2

1101 DDDDV

REF+VREF-A A AN3AN22 / 2

1110 DDDD D D DAV

DD VSS 1 / 0

1111 DDDDV

REF+VREF-D A AN3AN21 / 2

PIC18FXX2

The analog reference voltage is software selectable to

either the device’s positive and negative supply voltage

(VDD and VSS), or the voltage level on the RA3/AN3/

VREF+ pin and RA2/AN2/VREF- pin.

The A/D converter has a unique feature of being able

to operate while the device is in SLEEP mode. To oper-

ate in SLEEP, the A/D conversion clock must be

derived from the A/D’s internal RC oscillator.

The output of the sample and hold is the input into the

converter, which generates the result via successive

approximation.

A device RESET forces all registers to their RESET

state. This forces the A/D module to be turned off and

any conversion is aborted.

Each port pin associated with the A/D converter can be

configured as an analog input (RA3 can also be a

voltage reference) or as a digital I/O.

The ADRESH and ADRESL registers contain the result

of the A/D conversion. When the A/D conversion is

complete, the result is loaded into the ADRESH/

ADRESL registers, the GO/DONE bit (ADCON0<2>) is

cleared, and A/D interrupt flag bit, ADIF is set. The block

diagram of the A/D module is shown in Figure 17-1.

FIGURE 17-1: A/D BLOCK DIAGRAM

(Input Voltage)

VAIN

VREF+

Reference

Voltage

VDD

PCFG<3:0>

CHS<2:0>

AN7*

AN6*

AN5*

AN4

AN3

AN2

AN1

AN0

111

110

101

100

011

010

001

000

10-bit

Converter

VREF-

VSS

A/D

* These channels are implemented only on the PIC18F4X2 devices.

PIC18FXX2

The value that is in the ADRESH/ADRESL registers is

not modified for a Power-on Reset. The ADRESH/

ADRESL registers will contain unknown data after a

Power-on Reset.

After the A/D module has been configured as desired,

the selected channel must be acquired before the con-

version is started. The analog input channels must

have their corresponding TRIS bits selected as an

input. To determine acquisition time, see Section 17.1.

After this acquisition time has elapsed, the A/D conver-

sion can be started. The following steps should be

followed for doing an A/D conversion:

1. Configure the A/D module:

• Configure analog pins, voltage reference and

digital I/O (ADCON1)

• Select A/D input channel (ADCON0)

• Select A/D conversion clock (ADCON0)

• Turn on A/D module (ADCON0)

2. Configure A/D interrupt (if desired):

• Clear ADIF bit

• Set ADIE bit

• Set GIE bit

• Set PEIE bit

3. Wait the required acquisition time.

4. Start conversion:

• Set GO/DONE bit (ADCON0)

5. Wait for A/D conversion to complete, by either:

• Polling for the GO/DONE bit to be cleared

(interrupts disabled)

• Waiting for the A/D interrupt

6. Read A/D Result registers (ADRESH/ADRESL);

clear bit ADIF if required.

7. For next conversion, go to step 1 or step 2 as

required. The A/D conversion time per bit is

defined as T

AD. A minimum wait of 2 TAD is

required before the next acquisition starts.

17.1 A/D Acquisition Requirements

For the A/D converter to meet its specified accuracy,

the charge holding capacitor (CHOLD) must be allowed

to fully charge to the input channel voltage level. The

analog input model is shown in Figure 17-2. The

source impedance (RS) and the internal sampling

switch (RSS) impedance directly affect the time

required to charge the capacitor CHOLD. The sampling

switch (RSS) impedance varies over the device voltage

(VDD). The source impedance affects the offset voltage

at the analog input (due to pin leakage current). The

maximum recommended impedance for analog

sources is 2.5 kΩ. After the analog input channel is

selected (changed), this acquisition must be done

before the conversion can be started.

FIGURE 17-2: ANALOG INPUT MODEL

Note: When the conversion is started, the hold-

ing capacitor is disconnected from the

input pin.

VAIN CPIN

Rs ANx

5 pF

VDD

VT = 0.6V

VT = 0.6V I LEAKAGE

RIC ≤ 1k

Sampling

Switch

SS RSS

CHOLD = 120 pF

VSS

Sampling Switch

567891011

(kΩ)

VDD

± 500 nA

Legend: CPIN

I LEAKAGE

RIC

CHOLD

= input capacitance

= threshold voltage

= leakage current at the pin due to

= interconnect resistance

= sampling switch

= sample/hold capacitance (from DAC)

various junctions

PIC18FXX2

To calculate the minimum acquisition time,

Equation 17-1 may be used. This equation assumes

that 1/2 LSb error is used (1024 steps for the A/D). The

1/2 LSb error is the maximum error allowed for the A/D

to meet its specified resolution.

EQUATION 17-1: ACQUISITION TIME

EQUATION 17-2: A/D MINIMUM CHARGING TIME

Example 17-1 shows the calculation of the minimum

required acquisition time, T

ACQ. This calculation is

based on the following application system assump-

tions:

•C

HOLD = 120 pF

•Rs = 2.5 kΩ

• Conversion Error ≤1/2 LSb

•V

DD = 5V → Rss = 7 kΩ

• Temperature = 50°C (system max.)

•V

HOLD = 0V @ time = 0

EXAMPLE 17-1: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME

TACQ = Amplifier Settlin g Time + Holding Capacit or Charging Time + Temperature Coefficient

AMP + TC + TCOFF

VHOLD = (VREF – (VREF/2048)) • (1 – e(-Tc/CHOLD(RIC + RSS + RS)))

TC = -(120 pF)(1 kΩ + RSS + RS) ln(1/2048)

TACQ =TAMP + TC + TCOFF

Temperature coefficient is only required for temperatures > 25°C.

TACQ =2 μs + TC + [(Temp – 25°C)(0.05 μs/°C)]

TC=-CHOLD (RIC + RSS + RS) ln(1/2048)

-120 pF (1 kΩ + 7 kΩ + 2.5 kΩ) ln(0.0004883)

-120 pF (10.5 kΩ) ln(0.000 4883)

-1.26 μs (-7.6246)

9.61 μs

TACQ =2 μs + 9.61 μs + [(50°C – 25°C)(0.05 μs/°C)]

11.61 μs + 1.25 μs

12.86 μs

PIC18FXX2

17.2 Selecting the A/D Conversion Clock

The A/D conversion time per bit is defined as TAD. The

A/D conversion requires 12 TAD per 10-bit conversion.

The source of the A/D conversion clock is software

selectable. The seven possible options for TAD are:

•2 T

OSC

•4 TOSC

•8 TOSC

•16 TOSC

•32 TOSC

•64 T

OSC

• Internal A/D module RC oscillator (2-6 μs)

For correct A/D conversions, the A/D conversion clock

(TAD) must be selected to ensure a minimum TAD time

of 1.6 μs.

Table 17-1 shows the resultant TAD times derived from

the device operating frequencies and the A/D clock

source selected.

17.3 Configuring Analog Port Pins

The ADCON1, TRISA and TRISE registers control the

operation of the A/D port pins. The port pins that are

desired as analog inputs, must have their corresponding

TRIS bits set (input). If the TRIS bit is cleared (output),

the digital output level (VOH or VOL) will be converted.

The A/D operation is independent of the state of the

CHS2:CHS0 bits and the TRIS bits.

TABLE 17-1: TAD vs. DEVICE OPERATING FREQUENCIES

Note 1: When reading the port register, all pins con-

figured as analog input channels will read

as cleared (a low level). Pins configured as

digital inputs will convert an analog input.

Analog levels on a digitally configured input

will not affect the conversion accuracy.

2: Analog levels on any pin that is defined as

a digital input (including the AN4:AN0

pins) may cause the input buffer to con-

sume current that is out of the device’s

specification.

AD Clock Source (TAD) Maximum Device Frequency

Operation ADCS2:ADCS0 PIC18FXX2 PIC18LFXX2

2 T

OSC 000 1.25 MHz 666 kHz

4 TOSC 100 2.50 MHz 1.33 MHz

8 T

OSC 001 5.00 MHz 2.67 MHz

16 TOSC 101 10.00 MHz 5.33 MHz

32 TOSC 010 20.00 MHz 10.67 MHz

64 TOSC 110 40.00 MHz 21.33 MHz

RC 011 ——

PIC18FXX2

17.4 A/D Conversions

Figure 17-3 shows the operation of the A/D converter

after the GO bit has been set. Clearing the GO/DONE

bit during a conversion will abort the current conver-

sion. The A/D result register pair will NOT be updated

with the partially completed A/D conversion sample.

That is, the ADRESH:ADRESL registers will continue

to contain the value of the last completed conversion

(or the last value written to the ADRESH:ADRESL reg-

isters). After the A/D conversion is aborted, a 2 TAD wait

is required before the next acquisition is started. After

this 2 TAD wait, acquisition on the selected channel is

automatically started. The GO/DONE bit can then be

set to start the conversion.

FIGURE 17-3: A/D CONVERSION TAD CYCLES

17.4.1 A/D RESULT REGISTERS

The ADRESH:ADRESL register pair is the location

where the 10-bit A/D result is loaded at the completion

of the A/D conversion. This register pair is 16-bits wide.

The A/D module gives the flexibility to left or right justify

the 10-bit result in the 16-bit result register. The A/D

Format Select bit (ADFM) controls this justification.

Figure 17-4 shows the operation of the A/D result justi-

fication. The extra bits are loaded with ’0’s. When an

A/D result will not overwrite these locations (A/D

disable), these registers may be used as two general

purpose 8-bit registers.

FIGURE 17-4: A/D RESULT JUSTIFICATION

Note: The GO/DONE bit should NOT be set in

the same instruction that turns on the A/D.

TAD1TAD2TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD11

Set GO bit

Holding capacitor is disconnected from analog input (typically 100 ns)

b9 b8 b7 b6 b5 b4 b3 b2

TAD9TAD10

b1 b0

TCY - TAD

Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared,

ADIF bit is set, holding capacitor is connected to analog input.

Conversion Starts

10-bit Result

ADRESH ADRESL

0000 00

ADFM = 0

2 1 0 77

10-bit Result

ADRESH ADRESL

10-bit Result

0000 00

70 7 6 5 0

ADFM = 1

Right Justified Left Justified

PIC18FXX2

17.5 Use of the CCP2 Trigger

An A/D conversion can be started by the “special event

trigger” of the CCP2 module. This requires that the

CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be pro-

grammed as 1011 and that the A/D module is enabled

(ADON bit is set). When the trigger occurs, the GO/

DONE bit will be set, starting the A/D conversion, and

the Timer1 (or Timer3) counter will be reset to zero.

Timer1 (or Timer3) is reset to automatically repeat the

A/D acquisition period with minimal software overhead

(moving ADRESH/ADRESL to the desired location).

The appropriate analog input channel must be selected

and the minimum acquisition done before the “special

event trigger” sets the GO/DONE bit (starts a

conversion).

If the A/D module is not enabled (ADON is cleared), the

“special event trigger” will be ignored by the A/D

module, but will still reset the Timer1 (or Timer3)

counter.

TABLE 17-2: SUMMARY OF A/D REGISTERS

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on

POR, BOR

Value on

All Other

RESETS

INTCON GIE/

GIEH

PEIE/

GIEL

TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u

PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000

PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000

IPR1 PSPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000

PIR2 — — — EEIF BCLIF LVDIF TMR3IF CCP2IF ---0 0000 ---0 0000

PIE2 — — — EEIE BCLIE LVDIE TMR3IE CCP2IE ---0 0000 ---0 0000

IPR2 — — — EEIP BCLIP LVDIP TMR3IP CCP2IP ---1 1111 ---1 0000

ADRESH A/D Result Register xxxx xxxx uuuu uuuu

ADRESL A/D Result Register xxxx xxxx uuuu uuuu

ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE —ADON0000 00-0 0000 00-0

ADCON1 ADFM ADCS2 —— PCFG3 PCFG2 PCFG1 PCFG0 ---- -000 ---- -000

PORTA —RA6 RA5 RA4 RA3 RA2 RA1 RA0 --0x 0000 --0u 0000

TRISA — PORTA Data Direction Register --11 1111 --11 1111

PORTE — — — — —RE2RE1RE0---- -000 ---- -000

LATE — — — — — LATE2 LATE1 LATE0 ---- -xxx ---- -uuu

TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 -111 0000 -111

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion.

Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.

PIC18FXX2

18.0 LOW VOLTAGE DETECT

In many applications, the ability to determine if the

device voltage (VDD) is below a specified voltage level

is a desirable feature. A window of operation for the

application can be created, where the application soft-

ware can do “housekeeping tasks” before the device

voltage exits the valid operating range. This can be

done using the Low Voltage Detect module.

This module is a software programmable circuitry,

where a device voltage trip point can be specified.

When the voltage of the device becomes lower then the

specified point, an interrupt flag is set. If the interrupt is

enabled, the program execution will branch to the inter-

rupt vector address and the software can then respond

to that interrupt source.

The Low Voltage Detect circuitry is completely under

software control. This allows the circuitry to be “turned

off” by the software, which minimizes the current

consumption for the device.

Figure 18-1 shows a possible application voltage curve

(typically for batteries). Over time, the device voltage

decreases. When the device voltage equals voltage VA,

the LVD logic generates an interrupt. This occurs at

time T

A. The application software then has the time,

until the device voltage is no longer in valid operating

range, to shutdown the system. Voltage point VB is the

minimum valid operating voltage specification. This

occurs at time TB. The difference TB - TA is the total

time for shutdown.

FIGURE 18-1: TYPICAL LOW VOLTAGE DETECT APPLICATION

The block diagram for the LVD module is shown in

Figure 18-2. A comparator uses an internally gener-

ated reference voltage as the set point. When the

selected tap output of the device voltage crosses the

set point (is lower than), the LVDIF bit is set.

Each node in the resistor divider represents a “trip

point” voltage. The “trip point” voltage is the minimum

supply voltage level at which the device can operate

before the LVD module asserts an interrupt. When the

supply voltage is equal to the trip point, the voltage

tapped off of the resistor array is equal to the 1.2V

internal reference voltage generated by the voltage

reference module. The comparator then generates an

interrupt signal setting the LVDIF bit. This voltage is

software programmable to any one of 16 values (see

Figure 18-2). The trip point is selected by

programming the LVDL3:LVDL0 bits (LVDCON<3:0>).

Time

Voltage

TATB

VA = LVD trip point

VB = Minimum valid device

operating voltage

Legend:

PIC18FXX2

FIGURE 18-2: LOW VOLTAGE DETECT (LVD) BLOCK DIAGRAM

The LVD module has an additional feature that allows

the user to supply the trip voltage to the module from

an external source. This mode is enabled when bits

LVDL3:LVDL0 are set to 1111. In this state, the com-

parator input is multiplexed from the external input pin,

LVDIN (Figure 18-3). This gives users flexibility,

because it allows them to configure the Low Voltage

Detect interrupt to occur at any voltage in the valid

operating range.

FIGURE 18-3: LOW VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM

LVDIF

VDD

16 to 1 MUX

LVDEN

LVD Control

Internally Generated

Reference Voltage

LVDIN

1.2V Typical

–

LVD

LVD Control

16 to 1 MUX

BGAP

BODEN

LVDEN

VxEN

LVDIN

VDD

Externally Generated

Trip Point –

PIC18FXX2

18.1 Control Register

The Low Voltage Detect Control register controls the

operation of the Low Voltage Detect circuitry.

U-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1

—— IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0

bit 7 bit 0

bit 7-6 Unimplemented: Read as '0'

bit 5 IRVST: Internal Reference Voltage Stable Flag bit

1 = Indicates that the Low Voltage Detect logic will generate the interrupt flag at the

specified voltage range

0 = Indicates that the Low Voltage Detect logic will not generate the interrupt flag at the

specified voltage range and the LVD interrupt should not be enabled

bit 4 LVDEN: Low Voltage Detect Power Enable bit

1 = Enables LVD, powers up LVD circuit

0 = Disables LVD, powers down LVD circuit

bit 3-0 LVDL3:LVDL0: Low Voltage Detection Limit bits

1111 = External analog input is used (input comes from the LVDIN pin)

1110 = 4.5V - 4.77V

1101 = 4.2V - 4.45V

1100 = 4.0V - 4.24V

1011 = 3.8V - 4.03V

1010 = 3.6V - 3.82V

1001 = 3.5V - 3.71V

1000 = 3.3V - 3.50V

0111 = 3.0V - 3.18V

0110 = 2.8V - 2.97V

0101 = 2.7V - 2.86V

0100 = 2.5V - 2.65V

0011 = 2.4V - 2.54V

0010 = 2.2V - 2.33V

0001 = 2.0V - 2.12V

0000 = Reserved

Note: LVDL3:LVDL0 modes which result in a trip point below the valid operating voltage

of the device are not tested.

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

PIC18FXX2

18.2 Operation

Depending on the power source for the device voltage,

the voltage normally decreases relatively slowly. This

means that the LVD module does not need to be con-

stantly operating. To decrease the current require-

ments, the LVD circuitry only needs to be enabled for

short periods, where the voltage is checked. After

doing the check, the LVD module may be disabled.

Each time that the LVD module is enabled, the circuitry

requires some time to stabilize. After the circuitry has

stabilized, all status flags may be cleared. The module

will then indicate the proper state of the system.

The following steps are needed to set up the LVD

module:

1. Write the value to the LVDL3:LVDL0 bits

(LVDCON register), which selects the desired

LVD Trip Point.

2. Ensure that LVD interrupts are disabled (the

LVDIE bit is cleared or the GIE bit is cleared).

3. Enable the LVD module (set the LVDEN bit in

the LVDCON register).

4. Wait for the LVD module to stabilize (the IRVST

bit to become set).

5. Clear the LVD interrupt flag, which may have

falsely become set until the LVD module has

stabilized (clear the LVDIF bit).

6. Enable the LVD interrupt (set the LVDIE and the

GIE bits).

Figure 18-4 shows typical waveforms that the LVD

module may be used to detect.

FIGURE 18-4: LOW VOLTAGE DETECT WAVEFORMS

VLVD

VDD

LVDIF

VLVD

VDD

Enable LVD

Internally Generated TIVRST

LVDIF may not be set

Enable LVD

LVDIF

LVDIF cleared in software

LVDIF cleared in software,

CASE 1:

CASE 2:

LVDIF remains set since LVD condition still exists

Reference Stable

Internally Generated

Reference Stable

TIVRST

PIC18FXX2

18.2.1 REFERENCE VOLTAGE SET POINT

The Internal Reference Voltage of the LVD module may

be used by other internal circuitry (the Programmable

Brown-out Reset). If these circuits are disabled (lower

current consumption), the reference voltage circuit

requires a time to become stable before a low voltage

condition can be reliably detected. This time is invariant

of system clock speed. This start-up time is specified in

electrical specification parameter 36. The low voltage

interrupt flag will not be enabled until a stable reference

voltage is reached. Refer to the waveform in Figure 18-4.

18.2.2 CURRENT CONSUMPTION

When the module is enabled, the LVD comparator and

voltage divider are enabled and will consume static cur-

rent. The voltage divider can be tapped from multiple

places in the resistor array. Total current consumption,

when enabled, is specified in electrical specification

parameter #D022B.

18.3 Operation During SLEEP

When enabled, the LVD circuitry continues to operate

during SLEEP. If the device voltage crosses the trip

point, the LVDIF bit will be set and the device will wake-

up from SLEEP. Device execution will continue from

the interrupt vector address if interrupts have been

globally enabled.

18.4 Effects of a RESET

A device RESET forces all registers to their RESET

state. This forces the LVD module to be turned off.

PIC18FXX2

NOTES:

PIC18FXX2

19.0 SPECIAL FEATURES OF THE

CPU

There are several features intended to maximize sys-

tem reliability, minimize cost through elimination of

external components, provide power saving Operating

modes and offer code protection. These are:

• OSC Selection

• RESET

- Power-on Reset (POR)

- Power-up Timer (PWRT)

- Oscillator Start-up Timer (OST)

- Brown-out Reset (BOR)

• Interrupts

• Watchdog Timer (WDT)

• SLEEP

• Code Protection

• ID Locations

• In-Circuit Serial Programming

All PIC18FXX2 devices have a Watchdog Timer, which

is permanently enabled via the configuration bits or

software controlled. It runs off its own RC oscillator for

added reliability. There are two timers that offer neces-

sary delays on power-up. One is the Oscillator Start-up

Timer (OST), intended to keep the chip in RESET until

the crystal oscillator is stable. The other is the Power-

up Timer (PWRT), which provides a fixed delay on

power-up only, designed to keep the part in RESET

while the power supply stabilizes. With these two tim-

ers on-chip, most applications need no external

RESET circuitry.

SLEEP mode is designed to offer a very low current

Power-down mode. The user can wake-up from

SLEEP through external RESET, Watchdog Timer

Wake-up or through an interrupt. Several oscillator

options are also made available to allow the part to fit

the application. The RC oscillator option saves system

cost, while the LP crystal option saves power. A set of

configuration bits are used to select various options.

19.1 Configuration Bits

The configuration bits can be programmed (read as '0'),

or left unprogrammed (read as '1'), to select various

device configurations. These bits are mapped starting

at program memory location 300000h.

The user will note that address 300000h is beyond the

user program memory space. In fact, it belongs to the

configuration memory space (300000h - 3FFFFFh),

which can only be accessed using Table Reads and

Table Writes.

Programming the configuration registers is done in a

manner similar to programming the FLASH memory

(see Section 5.5.1). The only difference is the configu-

ration registers are written a byte at a time. The

sequence of events for programming configuration

registers is:

1. Load table pointer with address of configuration

2. Write a single byte using the TBLWT instruction.

3. Set EEPGD to point to program memory, set the

CFGS bit to access configuration registers, and

set WREN to enable byte writes.

4. Disable interrupts.

5. Write 55h to EECON2.

6. Write AAh to EECON2.

7. Set the WR bit. This will begin the write cycle.

8. CPU will stall for duration of write (approximately

2 ms using internal timer).

9. Execute a NOP.

10. Re-enable interrupts.

PIC18FXX2

TABLE 19-1: CONFIGURATION BITS AND DEVICE IDS

File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Default/

Unprogrammed

Value

300001h CONFIG1H —— OSCSEN —— FOSC2 FOSC1 FOSC0 --1- -111

300002h CONFIG2L — — — — BORV1 BORV0 BOREN PWRTEN ---- 1111

300003h CONFIG2H — — — — WDTPS2 WDTPS1 WDTPS0 WDTEN ---- 1111

300005h CONFIG3H — — — — — — — CCP2MX ---- ---1

300006h CONFIG4L DEBUG — — — —LVP—STVREN

1--- -1-1

300008h CONFIG5L — — — —CP3CP2CP1CP0

---- 1111

300009h CONFIG5H CPD CPB — — — — — — 11-- ----

30000Ah CONFIG6L — — — — WRT3 WRT2 WRT1 WRT0 ---- 1111

30000Bh CONFIG6H WRTD WRTB WRTC —————111- ----

30000Ch CONFIG7L — — — — EBTR3 EBTR2 EBTR1 EBTR0 ---- 1111

30000Dh CONFIG7H — EBTRB — — — — — — -1-- ----

3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 (1)

3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0000 0100

Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition.

Shaded cells are unimplemented, read as ‘0’.

Note 1: See Register 19-12 for DEVID1 values.

U-0 U-0 R/P-1 U-0 U-0 R/P-1 R/P-1 R/P-1

—— OSCSEN —— FOSC2 FOSC1 FOSC0

bit 7 bit 0

bit 7-6 Unimplemented: Read as ‘0’

bit 5 OSCSEN: Oscillator System Clock Switch Enable bit

1 = Oscillator system clock switch option is disabled (main oscillator is source)

0 = Oscillator system clock switch option is enabled (oscillator switching is enabled)

bit 4-3 Unimplemented: Read as ‘0’

bit 2-0 FOSC2:FOSC0: Oscillator Selection bits

111 = RC oscillator w/ OSC2 configured as RA6

110 = HS oscillator with PLL enabled/Clock frequency = (4 x FOSC)

101 = EC oscillator w/ OSC2 configured as RA6

100 = EC oscillator w/ OSC2 configured as divide-by-4 clock output

011 = RC oscillator

010 = HS oscillator

001 = XT oscillator

000 = LP oscillator

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1

— — — — BORV1 BORV0 BOREN PWRTEN

bit 7 bit 0

bit 7-4 Unimplemented: Read as ‘0’

bit 3-2 BORV1:BORV0: Brown-out Reset Voltage bits

11 = VBOR set to 2.5V

10 = VBOR set to 2.7V

01 = VBOR set to 4.2V

00 = VBOR set to 4.5V

bit 1 BOREN: Brown-out Reset Enable bit

1 = Brown-out Reset enabled

0 = Brown-out Reset disabled

bit 0 PWRTEN: Power-up Timer Enable bit

1 = PWRT disabled

0 = PWRT enabled

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1

— — — — WDTPS2 WDTPS1 WDTPS0 WDTEN

bit 7 bit 0

bit 7-4 Unimplemented: Read as ‘0’

bit 3-1 WDTPS2:WDTPS0: Watchdog Timer Postscale Select bits

111 = 1:128

110 = 1:64

101 = 1:32

100 = 1:16

011 = 1:8

010 = 1:4

001 = 1:2

000 = 1:1

bit 0 WDTEN: Watchdog Timer Enable bit

1 = WDT enabled

0 = WDT disabled (control is placed on the SWDTEN bit)

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/P-1

— — — — — — — CCP2MX

bit 7 bit 0

bit 7-1 Unimplemented: Read as ‘0’

bit 0 CCP2MX: CCP2 Mux bit

1 = CCP2 input/output is multiplexed with RC1

0 = CCP2 input/output is multiplexed with RB3

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

R/P-1 U-0 U-0 U-0 U-0 R/P-1 U-0 R/P-1

BKBUG — — — —LVP —STVREN

bit 7 bit 0

bit 7 DEBUG: Background Debugger Enable bit

1 = Background Debugger disabled. RB6 and RB7 configured as general purpose I/O pins.

0 = Background Debugger enabled. RB6 and RB7 are dedicated to In-Circuit Debug.

bit 6-3 Unimplemented: Read as ‘0’

bit 2 LVP: Low Voltage ICSP Enable bit

1 = Low Voltage ICSP enabled

0 = Low Voltage ICSP disabled

bit 1 Unimplemented: Read as ‘0’

bit 0 STVREN: Stack Full/Underflow Reset Enable bit

1 = Stack Full/Underflow will cause RESET

0 = Stack Full/Underflow will not cause RESET

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1

— — — —CP3

(1) CP2(1) CP1 CP0

bit 7 bit 0

bit 7-4 Unimplemented: Read as ‘0’

bit 3 CP3: Code Protection bit(1)

1 = Block 3 (006000-007FFFh) not code protected

0 = Block 3 (006000-007FFFh) code protected

bit 2 CP2: Code Protection bit(1)

1 = Block 2 (004000-005FFFh) not code protected

0 = Block 2 (004000-005FFFh) code protected

bit 1 CP1: Code Protection bit

1 = Block 1 (002000-003FFFh) not code protected

0 = Block 1 (002000-003FFFh) code protected

bit 0 CP0: Code Protection bit

1 = Block 0 (000200-001FFFh) not code protected

0 = Block 0 (000200-001FFFh) code protected

Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0

CPD CPB — — — — — —

bit 7 bit 0

bit 7 CPD: Data EEPROM Code Protection bit

1 = Data EEPROM not code protected

0 = Data EEPROM code protected

bit 6 CPB: Boot Block Code Protection bit

1 = Boot Block (000000-0001FFh) not code protected

0 = Boot Block (000000-0001FFh) code protected

bit 5-0 Unimplemented: Read as ‘0’

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1

— — — —WRT3

(1) WRT2(1) WRT1 WRT0

bit 7 bit 0

bit 7-4 Unimplemented: Read as ‘0’

bit 3 WRT3: Write Protection bit(1)

1 = Block 3 (006000-007FFFh) not write protected

0 = Block 3 (006000-007FFFh) write protected

bit 2 WRT2: Write Protection bit(1)

1 = Block 2 (004000-005FFFh) not write protected

0 = Block 2 (004000-005FFFh) write protected

bit 1 WRT1: Write Protection bit

1 = Block 1 (002000-003FFFh) not write protected

0 = Block 1 (002000-003FFFh) write protected

bit 0 WRT0: Write Protection bit

1 = Block 0 (000200h-001FFFh) not write protected

0 = Block 0 (000200h-001FFFh) write protected

Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

R/C-1 R/C-1 C-1 U-0 U-0 U-0 U-0 U-0

WRTD WRTB WRTC — — — — —

bit 7 bit 0

bit 7 WRTD: Data EEPROM Write Protection bit

1 = Data EEPROM not write protected

0 = Data EEPROM write protected

bit 6 WRTB: Boot Block Write Protection bit

1 = Boot Block (000000-0001FFh) not write protected

0 = Boot Block (000000-0001FFh) write protected

bit 5 WRTC: Configuration Register Write Protection bit

1 = Configuration registers (300000-3000FFh) not write protected

0 = Configuration registers (300000-3000FFh) write protected

Note: This bit is read only, and cannot be changed in User mode.

bit 4-0 Unimplemented: Read as ‘0’

Legend:

R = Readable bit C =Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

U-0 U-0 U-0 U-0 R/C-1 R/C-1 R/C-1 R/C-1

— — — — EBTR3(1) EBTR2(1) EBTR1 EBTR0

bit 7 bit 0

bit 7-4 Unimplemented: Read as ‘0’

bit 3 EBTR3: Table Read Protection bit(1)

1 = Block 3 (006000-007FFFh) not protected from Table Reads executed in other blocks

0 = Block 3 (006000-007FFFh) protected from Table Reads executed in other blocks

bit 2 EBTR2: Table Read Protection bit(1)

1 = Block 2 (004000-005FFFh) not protected from Table Reads executed in other blocks

0 = Block 2 (004000-005FFFh) protected from Table Reads executed in other blocks

bit 1 EBTR1: Table Read Protection bit

1 = Block 1 (002000-003FFFh) not protected from Table Reads executed in other blocks

0 = Block 1 (002000-003FFFh) protected from Table Reads executed in other blocks

bit 0 EBTR0: Table Read Protection bit

1 = Block 0 (000200h-001FFFh) not protected from Table Reads executed in other blocks

0 = Block 0 (000200h-001FFFh) protected from Table Reads executed in other blocks

Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

U-0 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0

— EBTRB — — — — — —

bit 7 bit 0

bit 7 Unimplemented: Read as ‘0’

bit 6 EBTRB: Boot Block Table Read Protection bit

1 = Boot Block (000000-0001FFh) not protected from Table Reads executed in other blocks

0 = Boot Block (000000-0001FFh) protected from Table Reads executed in other blocks

bit 5-0 Unimplemented: Read as ‘0’

Legend:

R = Readable bit C =Clearable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

R EG I S T E R 1 9 - 12 : D EV I C E I D R E G I ST E R 1 F OR P I C 1 8F X X 2 (D E V I D 1: B Y T E A D D R E SS 3 F F FF E h )

RRRRRRRR

DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0

bit 7 bit 0

bit 7-5 DEV2:DEV0: Device ID bits

000 = PIC18F252

001 = PIC18F452

100 = PIC18F242

101 = PIC18F442

bit 4-0 REV4:REV0: Revision ID bits

These bits are used to indicate the device revision.

Legend:

R = Readable bit P =Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

RRRRRRRR

DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3

bit 7 bit 0

bit 7-0 DEV10:DEV3: Device ID bits

These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the

part number.

Legend:

R = Readable bit P =Programmable bit U = Unimplemented bit, read as ‘0’

- n = Value when device is unprogrammed u = Unchanged from programmed state

PIC18FXX2

19.2 Watchdog Timer (WDT)

The Watchdog Timer is a free running on-chip RC oscil-

lator, which does not require any external components.

This RC oscillator is separate from the RC oscillator of

the OSC1/CLKI pin. That means that the WDT will run,

even if the clock on the OSC1/CLKI and OSC2/CLKO/

RA6 pins of the device has been stopped, for example,

by execution of a SLEEP instruction.

During normal operation, a WDT time-out generates a

device RESET (Watchdog Timer Reset). If the device is

in SLEEP mode, a WDT time-out causes the device to

wake-up and continue with normal operation (Watch-

dog Timer Wake-up). The TO bit in the RCON register

will be cleared upon a WDT time-out.

The Watchdog Timer is enabled/disabled by a device

configuration bit. If the WDT is enabled, software exe-

cution may not disable this function. When the WDTEN

configuration bit is cleared, the SWDTEN bit enables/

disables the operation of the WDT.

The WDT time-out period values may be found in the

Electrical Specifications (Section 22.0) under parame-

ter D031. Values for the WDT postscaler may be

assigned using the configuration bits.

19.2.1 CONTROL REGISTER

readable and writable register, which contains a control

bit that allows software to override the WDT enable

configuration bit, only when the configuration bit has

disabled the WDT.

Note: The CLRWDT and SLEEP instructions clear

the WDT and the postscaler, if assigned to

the WDT and prevent it from timing out and

generating a device RESET condition.

Note: When a CLRWDT instruction is executed

and the postscaler is assigned to the WDT,

the postscaler count will be cleared, but the

postscaler assignment is not changed.

U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0

— — — — — — —SWDTEN

bit 7 bit 0

bit 7-1 Unimplemented: Read as ’0’

bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit

1 = Watchdog Timer is on

0 = Watchdog Timer is turned off if the WDTEN configuration bit in the configuration

Legend:

R = Readable bit W = Writable bit

U = Unimplemented bit, read as ‘0’ - n = Value at POR

PIC18FXX2

19.2.2 WDT POSTSCALER

The WDT has a postscaler that can extend the WDT

Reset period. The postscaler is selected at the time of

the device programming, by the value written to the

CONFIG2H configuration register.

FIGURE 19-1: WATCHDOG TIMER BLOCK DIAGRAM

TABLE 19-2: SUMMARY OF WATCHDOG TIMER REGISTERS

Postscaler

WDT Timer

WDTEN

8 - to - 1 MUX WDTPS2:WDTPS0

WDT

Time-out

SWDTEN bit

Configuration bit

Note: WDPS2:WDPS0 are bits in register CONFIG2H.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

CONFIG2H ———— WDTPS2 WDTPS2 WDTPS0 WDTEN

RCON IPEN ——RI TO PD POR BOR

WDTCON ———————SWDTEN

Legend: Shaded cells are not used by the Watchdog Timer.

PIC18FXX2

19.3 Power-down Mode (SLEEP)

Power-down mode is entered by executing a SLEEP

instruction.

If enabled, the Watchdog Timer will be cleared, but

keeps running, the PD bit (RCON<3>) is cleared, the

TO (RCON<4>) bit is set, and the oscillator driver is

turned off. The I/O ports maintain the status they had

before the SLEEP instruction was executed (driving

high, low or hi-impedance).

For lowest current consumption in this mode, place all

I/O pins at either VDD or VSS, ensure no external cir-

cuitry is drawing current from the I/O pin, power-down

the A/D and disable external clocks. Pull all I/O pins

that are hi-impedance inputs, high or low externally, to

avoid switching currents caused by floating inputs. The

T0CKI input should also be at VDD or VSS for lowest

current consumption. The contribution from on-chip

pull-ups on PORTB should be considered.

The MCLR pin must be at a logic high level (VIHMC).

19.3.1 WAKE-UP FROM SLEEP

The device can wake-up from SLEEP through one of

the following events:

1. External RESET input on MCLR pin.

2. Watchdog Timer Wake-up (if WDT was

enabled).

3. Interrupt from INT pin, RB port change or a

Peripheral Interrupt.

The following peripheral interrupts can wake the device

from SLEEP:

1. PSP read or write.

2. TMR1 interrupt. Timer1 must be operating as

an asynchronous counter.

3. TMR3 interrupt. Timer3 must be operating as

an asynchronous counter.

4. CCP Capture mode interrupt.

5. Special event trigger (Timer1 in Asynchronous

mode using an external clock).

6. MSSP (START/STOP) bit detect interrupt.

7. MSSP transmit or receive in Slave mode

(SPI/I2C).

8. USART RX or TX (Synchronous Slave mode).

9. A/D conversion (when A/D clock source is RC).

10. EEPROM write operation complete.

11. LVD interrupt.

Other peripherals cannot generate interrupts, since

during SLEEP, no on-chip clocks are present.

External MCLR Reset will cause a device RESET. All

other events are considered a continuation of program

execution and will cause a “wake-up”. The TO and PD

bits in the RCON register can be used to determine the

cause of the device RESET. The PD bit, which is set on

power-up, is cleared when SLEEP is invoked. The TO

bit is cleared, if a WDT time-out occurred (and caused

wake-up).

When the SLEEP instruction is being executed, the next

instruction (PC + 2) is pre-fetched. For the device to

wake-up through an interrupt event, the corresponding

interrupt enable bit must be set (enabled). Wake-up is

regardless of the state of the GIE bit. If the GIE bit is

clear (disabled), the device continues execution at the

instruction after the SLEEP instruction. If the GIE bit is

set (enabled), the device executes the instruction after

the SLEEP instruction and then branches to the inter-

rupt address. In cases where the execution of the

instruction following SLEEP is not desirable, the user

should have a NOP after the SLEEP instruction.

19.3.2 WAKE-UP USING INTERRUPTS

When global interrupts are disabled (GIE cleared) and

any interrupt source has both its interrupt enable bit

and interrupt flag bit set, one of the following will occur:

• If an interrupt condition (interrupt flag bit and inter-

rupt enable bits are set) occurs before the execu-

tion of a SLEEP instruction, the SLEEP instruction

will complete as a NOP. Therefore, the WDT and

WDT postscaler will not be cleared, the TO bit will

not be set and PD bits will not be cleared.

• If the interrupt condition occurs during or after

the execution of a SLEEP instruction, the device

will immediately wake-up from SLEEP. The

SLEEP instruction will be completely executed

before the wake-up. Therefore, the WDT and

WDT postscaler will be cleared, the TO bit will be

set and the PD bit will be cleared.

Even if the flag bits were checked before executing a

SLEEP instruction, it may be possible for flag bits to

become set before the SLEEP instruction completes. To

determine whether a SLEEP instruction executed, test

the PD bit. If the PD bit is set, the SLEEP instruction

was executed as a NOP.

To ensure that the WDT is cleared, a CLRWDT instruction

should be executed before a SLEEP instruction.

PIC18FXX2

FIGURE 19-2: WAKE-UP FROM SLEEP THROUGH INTERRUPT(1,2)

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

OSC1

CLKO(4)

INT pin

INTF flag

(INTCON<1>)

GIEH bit

(INTCON<7>)

INSTRUCTION FLOW

Instruction

Fetched

Instruction

Executed

PC PC+2 PC+4

Inst(PC) = SLEEP

Inst(PC - 1)

Inst(PC + 2)

SLEEP

Processor in

SLEEP

Interrupt Latency(3)

Inst(PC + 4)

Inst(PC + 2)

Inst(0008h) Inst(000Ah)

Inst(0008h)

Dummy Cycle

PC + 4 0008h 000Ah

Dummy Cycle

TOST(2)

PC+4

Note 1: XT, HS or LP Oscillator mode assumed.

2: GIE = '1' assumed. In this case, after wake-up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line.

3: TOST = 1024 TOSC (drawing not to scale). This delay will not occur for RC and EC Osc modes.

4: CLKO is not available in these Osc modes, but shown here for timing reference.

PIC18FXX2

19.4 Program Verification and

Code Protection

The overall structure of the code protection on the

PIC18 FLASH devices differs significantly from other

PICmicro devices.

The user program memory is divided into five blocks.

One of these is a boot block of 512 bytes. The remain-

der of the memory is divided into four blocks on binary

boundaries.

Each of the five blocks has three code protection bits

associated with them. They are:

• Code Protect bit (CPn)

• Write Protect bit (WRTn)

• External Block Table Read bit (EBTRn)

Figure 19-3 shows the program memory organization

for 16- and 32-Kbyte devices, and the specific code

protection bit associated with each block. The actual

locations of the bits are summarized in Table 19-3.

FIGURE 19-3: CODE PROTECTED PROGRAM MEMORY FOR PIC18F2XX/4XX

TABLE 19-3: SUMMARY OF CODE PROTECTION REGISTERS

MEMORY SIZE/DEVICE

Block Code Protection

Controlled By:

16 Kbytes

(PIC18FX42)

32 Kbytes

(PIC18FX52)

Address

Range

Boot Block Boot Block 000000h

0001FFh CPB, WRTB, EBTRB

Block 0 Block 0

000200h

001FFFh

CP0, WRT0, EBTR0

Block 1 Block 1

002000h

003FFFh

CP1, WRT1, EBTR1

Unimplemented

Read 0’s Block 2

004000h

005FFFh

CP2, WRT2, EBTR2

Unimplemented

Read 0’s Block 3

006000h

007FFFh

CP3, WRT3, EBTR3

Unimplemented

Read 0’s

Unimplemented

Read 0’s

008000h

1FFFFFh

(Unimplemented Memory Space)

File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

300008h CONFIG5L ———— CP3 CP2 CP1 CP0

300009h CONFIG5H CPD CPB ——————

30000Ah CONFIG6L ———— WRT3 WRT2 WRT1 WRT0

30000Bh CONFIG6H WRTD WRTB WRTC —————

30000Ch CONFIG7L ———— EBTR3 EBTR2 EBTR1 EBTR0

30000Dh CONFIG7H — EBTRB ——————

Legend: Shaded cells are unimplemented.

PIC18FXX2

19.4.1 PROGRAM MEMORY

CODE PROTECTION

The user memory may be read to or written from any

location using the Table Read and Table Write instruc-

tions. The device ID may be read with Table Reads.

The configuration registers may be read and written

with the Table Read and Table Write instructions.

In User mode, the CPn bits have no direct effect. CPn

bits inhibit external reads and writes. A block of user

memory may be protected from Table Writes if the

WRTn configuration bit is ‘0’. The EBTRn bits control

Table Reads. For a block of user memory with the

EBTRn bit set to ‘0’, a Table Read instruction that

executes from within that block is allowed to read. A

Table Read instruction that executes from a location

outside of that block is not allowed to read, and will

result in reading ‘0’s. Figures 19-4 through 19-6

illustrate Table Write and Table Read protection.

FIGURE 19-4: TABLE WRITE (WRTn) DISALLOWED

Note: Code protection bits may only be written to

a ‘0’ from a ‘1’ state. It is not possible to

write a ‘1’ to a bit in the ‘0’ state. Code pro-

tection bits are only set to ‘1’ by a full chip

erase or block erase function. The full chip

erase and block erase functions can only

be initiated via ICSP or an external

programmer.

000000h

0001FFh

000200h

001FFFh

002000h

003FFFh

004000h

005FFFh

006000h

007FFFh

WRTB,EBTRB = 11

WRT0,EBTR0 = 01

WRT1,EBTR1 = 11

WRT2,EBTR2 = 11

WRT3,EBTR3 = 11

TBLWT *

TBLPTR = 000FFF

PC = 001FFE

TBLWT *

PC = 004FFE

Results: All Table Writes disabled to Blockn whenever WRTn = ‘0’.

PIC18FXX2

FIGURE 19-5: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED

FIGURE 19-6: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED

000000h

0001FFh

000200h

001FFFh

002000h

003FFFh

004000h

005FFFh

006000h

007FFFh

WRTB,EBTRB = 11

WRT0,EBTR0 = 10

WRT1,EBTR1 = 11

WRT2,EBTR2 = 11

WRT3,EBTR3 = 11

TBLRD *

TBLPTR = 000FFF

PC = 002FFE

Results: All Table Reads from external blocks to Blockn are disabled whenever EBTRn = ‘0’.

TABLAT register returns a value of “0”.

000000h

0001FFh

000200h

001FFFh

002000h

003FFFh

004000h

005FFFh

006000h

007FFFh

WRTB,EBTRB = 11

WRT0,EBTR0 = 10

WRT1,EBTR1 = 11

WRT2,EBTR2 = 11

WRT3,EBTR3 = 11

TBLRD *

TBLPTR = 000FFF

PC = 001FFE

Results: Table Reads permitted within Blockn, even when EBTRBn = ‘0’.

TABLAT register returns the value of the data at the location TBLPTR.

PIC18FXX2

19.4.2 DATA EEPROM

CODE PROTECTION

The entire Data EEPROM is protected from external

reads and writes by two bits: CPD and WRTD. CPD

inhibits external reads and writes of Data EEPROM.

WRTD inhibits external writes to Data EEPROM. The

CPU can continue to read and write Data EEPROM

regardless of the protection bit settings.

19.4.3 CONFIGURATION REGISTER

PROTECTION

The configuration registers can be write protected. The

WRTC bit controls protection of the configuration regis-

ters. In User mode, the WRTC bit is readable only. WRTC

can only be written via ICSP or an external programmer.

19.5 ID Locations

Eight memory locations (200000h - 200007h) are des-

ignated as ID locations, where the user can store

checksum or other code identification numbers. These

locations are accessible during normal execution

through the TBLRD and TBLWT instructions, or during

program/verify. The ID locations can be read when the

device is code protected.

The sequence for programming the ID locations is sim-

ilar to programming the FLASH memory (see

Section 5.5.1).

19.6 In-Circuit Serial Programming

PIC18FXXX microcontrollers can be serially pro-

grammed while in the end application circuit. This is

simply done with two lines for clock and data, and three

other lines for power, ground and the programming

voltage. This allows customers to manufacture boards

with unprogrammed devices, and then program the

microcontroller just before shipping the product. This

also allows the most recent firmware or a custom

firmware to be programmed.

19.7 In-Circuit Debugger

When the DEBUG bit in configuration register

CONFIG4L is programmed to a '0', the In-Circuit

Debugger functionality is enabled. This function allows

simple debugging functions when used with MPLAB®

IDE. When the microcontroller has this feature

enabled, some of the resources are not available for

general use. Table 19-4 shows which features are

consumed by the background debugger.

TABLE 19-4: DEBUGGER RESOURCES

To use the In-Circuit Debugger function of the micro-

controller, the design must implement In-Circuit Serial

Programming connections to MCLR/VPP, VDD, GND,

RB7 and RB6. This will interface to the In-Circuit

Debugger module available from Microchip or one of

the third party development tool companies.

19.8 Low Voltage ICSP Programming

The LVP bit configuration register CONFIG4L enables

low voltage ICSP programming. This mode allows the

microcontroller to be programmed via ICSP using a

VDD source in the operating voltage range. This only

means that VPP does not have to be brought to VIHH,

but can instead be left at the normal operating voltage.

In this mode, the RB5/PGM pin is dedicated to the pro-

gramming function and ceases to be a general purpose

I/O pin. During programming, VDD is applied to the

MCLR/VPP pin. To enter Programming mode, VDD must

be applied to the RB5/PGM, provided the LVP bit is set.

The LVP bit defaults to a (‘1’) from the factory.

If Low Voltage Programming mode is not used, the LVP

bit can be programmed to a '0' and RB5/PGM becomes

a digital I/O pin. However, the LVP bit may only be pro-

grammed when programming is entered with VIHH on

MCLR/VPP.

It should be noted that once the LVP bit is programmed

to 0, only the High Voltage Programming mode is avail-

able and only High Voltage Programming mode can be

used to program the device.

When using low voltage ICSP, the part must be sup-

plied 4.5V to 5.5V, if a bulk erase will be executed. This

includes reprogramming of the code protect bits from

an on-state to off-state. For all other cases of low volt-

age ICSP, the part may be programmed at the normal

operating voltage. This means unique user IDs, or user

code can be reprogrammed or added.

I/O pins RB6, RB7

Stack 2 levels

Program Memory 512 bytes

Data Memory 10 bytes

Note 1: The High Voltage Programming mode is

always available, regardless of the state

of the LVP bit, by applying VIHH to the

MCLR pin.

2: While in low voltage ICSP mode, the RB5

pin can no longer be used as a general

purpose I/O pin, and should be held low

during normal operation to protect

against inadvertent ICSP mode entry.

3: When using low voltage ICSP program-

ming (LVP), the pull-up on RB5 becomes

disabled. If TRISB bit 5 is cleared,

thereby setting RB5 as an output, LATB

bit 5 must also be cleared for proper

operation.

PIC18FXX2

20.0 INSTRUCTION SET SUMMARY

The PIC18FXXX instruction set adds many enhance-

ments to the previous PICmicro instruction sets, while

maintaining an easy migration from these PICmicro

instruction sets.

Most instructions are a single program memory word

(16-bits), but there are three instructions that require

two program memory locations.

Each single word instruction is a 16-bit word divided

into an OPCODE, which specifies the instruction type

and one or more operands, which further specify the

operation of the instruction.

The instruction set is highly orthogonal and is grouped

into four basic categories:

•Byte-oriented operations

•Bit-oriented operations

•Literal operations

•Control operations

The PIC18FXXX instruction set summary in Table 20-2

lists byte-oriented, bit-oriented, literal and control

operations. Table 20-1 shows the opcode field

descriptions.

Most byte-oriented instructions have three operands:

1. The file register (specified by ‘f’)

2. The destination of the result

(specified by ‘d’)

3. The accessed memory

(specified by ‘a’)

The file register designator 'f' specifies which file

The destination designator ‘d’ specifies where the

result of the operation is to be placed. If 'd' is zero, the

result is placed in the WREG register. If 'd' is one, the

result is placed in the file register specified in the

instruction.

All bit-oriented instructions have three operands:

1. The file register (specified by ‘f’)

2. The bit in the file register

(specified by ‘b’)

3. The accessed memory

(specified by ‘a’)

The bit field designator 'b' selects the number of the bit

affected by the operation, while the file register desig-

nator 'f' represents the number of the file in which the

bit is located.

The literal instructions may use some of the following

operands:

• A literal value to be loaded into a file register

(specified by ‘k’)

• The desired FSR register to load the literal value

into (specified by ‘f’)

• No operand required

(specified by ‘—’)

The control instructions may use some of the following

operands:

• A program memory address (specified by ‘n’)

• The mode of the Call or Return instructions

(specified by ‘s’)

• The mode of the Table Read and Table Write

instructions (specified by ‘m’)

• No operand required

(specified by ‘—’)

All instructions are a single word, except for three dou-

ble-word instructions. These three instructions were

made double-word instructions so that all the required

information is available in these 32 bits. In the second

word, the 4-MSbs are 1’s. If this second word is exe-

cuted as an instruction (by itself), it will execute as a

NOP.

All single word instructions are executed in a single

instruction cycle, unless a conditional test is true or the

program counter is changed as a result of the instruc-

tion. In these cases, the execution takes two instruction

cycles with the additional instruction cycle(s) executed

as a NOP.

The double-word instructions execute in two instruction

cycles.

One instruction cycle consists of four oscillator periods.

Thus, for an oscillator frequency of 4 MHz, the normal

instruction execution time is 1 μs. If a conditional test is

true or the program counter is changed as a result of an

instruction, the instruction execution time is 2 μs.

Two-word branch instructions (if true) would take 3 μs.

Figure 20-1 shows the general formats that the

instructions can have.

All examples use the format ‘nnh’ to represent a

hexadecimal number, where ‘h’ signifies a

hexadecimal digit.

The Instruction Set Summary, shown in Table 20-2,

lists the instructions recognized by the Microchip

Assembler (MPASMTM).

Section 20.1 provides a description of each instruction.

PIC18FXX2

TABLE 20-1: OPCODE FIELD DESCRIPTIONS

Field Description

aRAM access bit

a = 0: RAM location in Access RAM (BSR register is ignored)

a = 1: RAM bank is specified by BSR register

bbb Bit address within an 8-bit file register (0 to 7)

BSR Bank Select Register. Used to select the current RAM bank.

dDestination select bit;

d = 0: store result in WREG,

d = 1: store result in file register f.

dest Destination either the WREG register or the specified register file location

f8-bit Register file address (0x00 to 0xFF)

fs 12-bit Register file address (0x000 to 0xFFF). This is the source address.

fd 12-bit Register file address (0x000 to 0xFFF). This is the destination address.

kLiteral field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value)

label Label name

mm The mode of the TBLPTR register for the Table Read and Table Write instructions.

Only used with Table Read and Table Write instructions:

*No Change to register (such as TBLPTR with Table reads and writes)

*+ Post-Increment register (such as TBLPTR with Table reads and writes)

*- Post-Decrement register (such as TBLPTR with Table reads and writes)

+* Pre-Increment register (such as TBLPTR with Table reads and writes)

nThe relative address (2’s complement number) for relative branch instructions, or the direct address for

Call/Branch and Return instructions

PRODH Product of Multiply high byte

PRODL Product of Multiply low byte

sFast Call/Return mode select bit.

s = 0: do not update into/from shadow registers

s = 1: certain registers loaded into/from shadow registers (Fast mode)

uUnused or Unchanged

WREG Working register (accumulator)

xDon't care (0 or 1)

The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all

Microchip software tools.

TBLPTR 21-bit Table Pointer (points to a Program Memory location)

TABLAT 8-bit Table Latch

TOS Top-of-Stack

PC Program Counter

PCL Program Counter Low Byte

PCH Program Counter High Byte

PCLATH Program Counter High Byte Latch

PCLATU Program Counter Upper Byte Latch

GIE Global Interrupt Enable bit

WDT Watchdog Timer

TO Time-out bit

PD Power-down bit

C, DC, Z, OV, N ALU status bits Carry, Digit Carry, Zero, Overflow, Negative

[ ] Optional

( ) Contents

→Assigned to

< > Register bit field

∈In the set of

italics User defined term (font is courier)

PIC18FXX2

FIGURE 20-1: GENERAL FORMAT FOR INSTRUCTIONS

Byte-oriented file register operations

15 10 9 8 7 0

d = 0 for result destination to be WREG register

OPCODE d a f (FILE #)

d = 1 for result destination to be file register (f)

a = 0 to force Access Bank

Bit-oriented file register operations

15 12 11 9 8 7 0

OPCODE b (BIT #) a f (FILE #)

b = 3-bit position of bit in file register (f)

Literal operations

15 8 7 0

OPCODE k (literal)

k = 8-bit immediate value

Byte to Byte move operations (2-word)

15 12 11 0

OPCODE f (Source FILE #)

CALL, GOTO and Branch operations

15 8 7 0

OPCODE n<7:0> (literal)

n = 20-bit immediate value

a = 1 for BSR to select bank

f = 8-bit file register address

a = 0 to force Access Bank

a = 1 for BSR to select bank

f = 8-bit file register address

15 12 11 0

1111 n<19:8> (literal)

15 12 11 0

1111 f (Destination FILE #)

f = 12-bit file register address

Control operations

Example Instruction

ADDWF MYREG, W, B

MOVFF MYREG1, MYREG2

BSF MYREG, bit, B

MOVLW 0x7F

GOTO Label

15 8 7 0

OPCODE n<7:0> (literal)

15 12 11 0

n<19:8> (literal)

CALL MYFUNC

15 11 10 0

OPCODE n<10:0> (literal)

S = Fast bit

BRA MYFUNC

15 8 7 0

OPCODE n<7:0> (literal) BC MYFUNC

PIC18FXX2

TABLE 20-2: PIC18FXXX INSTRUCTION SET

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

BYTE-ORIENTED FILE REGISTER OPERATIONS

ADDWF

ADDWFC

ANDWF

CLRF

COMF

CPFSEQ

CPFSGT

CPFSLT

DECF

DECFSZ

DCFSNZ

INCF

INCFSZ

INFSNZ

IORWF

MOVF

MOVFF

MOVWF

MULWF

NEGF

RLCF

RLNCF

RRCF

RRNCF

SETF

SUBFWB

SUBWF

SUBWFB

SWAPF

TSTFSZ

XORWF

f, d, a

f, a

f, d, a

f, a

f, d, a

fs, fd

f, a

f, d, a

f, a

f, d, a

f, a

f, d, a

Add WREG and f

Add WREG and Carry bit to f

AND WREG with f

Clear f

Complement f

Compare f with WREG, skip =

Compare f with WREG, skip >

Compare f with WREG, skip <

Decrement f

Decrement f, Skip if 0

Decrement f, Skip if Not 0

Increment f

Increment f, Skip if 0

Increment f, Skip if Not 0

Inclusive OR WREG with f

Move f

Move fs (source) to 1st word

fd (destination) 2nd word

Move WREG to f

Multiply WREG with f

Negate f

Rotate Left f through Carry

Rotate Left f (No Carry)

Rotate Right f through Carry

Rotate Right f (No Carry)

Set f

Subtract f from WREG with

borrow

Subtract WREG from f

Subtract WREG from f with

borrow

Swap nibbles in f

Test f, skip if 0

Exclusive OR WREG with f

1 (2 or 3)

0010

0001

0110

0001

0110

0000

0010

0100

0010

0011

0100

0001

0101

1100

1111

0110

0000

0110

0011

0100

0011

0100

0110

0101

0011

0110

0001

01da0

0da

01da

101a

11da

001a

010a

000a

01da

11da

10da

11da

10da

00da

ffff

111a

001a

110a

01da

00da

100a

01da

11da

10da

011a

10da

ffff

C, DC, Z, OV, N

Z, N

None

C, DC, Z, OV, N

None

C, DC, Z, OV, N

None

Z, N

None

C, DC, Z, OV, N

C, Z, N

Z, N

C, Z, N

Z, N

None

C, DC, Z, OV, N

None

Z, N

1, 2

1,2

1, 2

1, 2, 3, 4

1, 2

1, 2, 3, 4

1, 2

BIT-ORIENTED FILE REGISTER OPERATIONS

BCF

BSF

BTFSC

BTFSS

BTG

f, b, a

f, d, a

Bit Clear f

Bit Set f

Bit Test f, Skip if Clear

Bit Test f, Skip if Set

Bit Toggle f

1 (2 or 3)

1001

1000

1011

1010

0111

bbba

ffff

None

1, 2

3, 4

1, 2

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an

external device, the data will be written back with a '0'.

2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned.

3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is

executed as a NOP.

4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the

first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory

locations have a valid instruction.

5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.

PIC18FXX2

CONTROL OPERATIONS

BNC

BNN

BNOV

BNZ

BOV

BRA

CALL

CLRWDT

DAW

GOTO

NOP

POP

PUSH

RCALL

RESET

RETFIE

RETLW

RETURN

SLEEP

n, s

—

Branch if Carry

Branch if Negative

Branch if Not Carry

Branch if Not Negative

Branch if Not Overflow

Branch if Not Zero

Branch if Overflow

Branch Unconditionally

Branch if Zero

Call subroutine1st word

2nd word

Clear Watchdog Timer

Decimal Adjust WREG

Go to address1st word

2nd word

No Operation

Pop top of return stack (TOS)

Push top of return stack (TOS)

Relative Call

Software device RESET

Return from interrupt enable

Return with literal in WREG

Return from Subroutine

Go into Standby mode

1 (2)

1110

1101

1110

1111

0000

1110

1111

0000

1111

0000

1101

0000

0010

0110

0011

0111

0101

0001

0100

0nnn

0000

110s

kkkk

0000

1111

kkkk

0000

xxxx

0000

1nnn

0000

1100

0000

nnnn

kkkk

0000

kkkk

0000

xxxx

0000

nnnn

1111

0001

kkkk

0001

0000

nnnn

kkkk

0100

0111

kkkk

0000

xxxx

0110

0101

nnnn

1111

000s

kkkk

001s

0011

None

TO, PD

None

All

GIE/GIEH,

PEIE/GIEL

None

TO, PD

TABLE 20-2: PIC18FXXX INSTRUCTION SET (CONTINUED)

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an

external device, the data will be written back with a '0'.

2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned.

3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is

executed as a NOP.

4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the

first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory

locations have a valid instruction.

5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.

PIC18FXX2

LITERAL OPERATIONS

ADDLW

ANDLW

IORLW

LFSR

MOVLB

MOVLW

MULLW

RETLW

SUBLW

XORLW

f, k

Add literal and WREG

AND literal with WREG

Inclusive OR literal with WREG

Move literal (12-bit) 2nd word

to FSRx 1st word

Move literal to BSR<3:0>

Move literal to WREG

Multiply literal with WREG

Return with literal in WREG

Subtract WREG from literal

Exclusive OR literal with WREG

0000

1110

1111

0000

1111

1011

1001

1110

0000

0001

1110

1101

1100

1000

1010

kkkk

00ff

kkkk

0000

kkkk

C, DC, Z, OV, N

Z, N

None

C, DC, Z, OV, N

Z, N

DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS

TBLRD*

TBLRD*+

TBLRD*-

TBLRD+*

TBLWT*

TBLWT*+

TBLWT*-

TBLWT+*

Table Read

Table Read with post-increment

Table Read with post-decrement

Table Read with pre-increment

Table Write

Table Write with post-increment

Table Write with post-decrement

Table Write with pre-increment

2 (5)

0000

1000

1001

1010

1011

1100

1101

1110

1111

None

TABLE 20-2: PIC18FXXX INSTRUCTION SET (CONTINUED)

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an

external device, the data will be written back with a '0'.

2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned.

3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is

executed as a NOP.

4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the

first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory

locations have a valid instruction.

5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.

PIC18FXX2

20.1 Instruction Set

ADDLW ADD literal to W

Syntax: [

label

] ADDLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) + k → W

Status Affected: N, OV, C, DC, Z

Encoding: 0000 1111 kkkk kkkk

Description: The contents of W are added to the

8-bit literal 'k' and the result is

placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write to W

Example:ADDLW 0x15

Before Instruction

W = 0x10

After Instruction

W = 0x25

ADDWF ADD W to f

Syntax: [

label

] ADDWF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) + (f) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0010 01da ffff ffff

Description: Add W to register 'f'. If 'd' is 0, the

result is stored in W. If 'd' is 1, the

result is stored back in register 'f'

(default). If ‘a’ is 0, the Access

Bank will be selected. If ‘a’ is 1, the

BSR is used.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:ADDWF REG, 0, 0

Before Instruction

W = 0x17

REG = 0xC2

After Instruction

W=0xD9

REG = 0xC2

PIC18FXX2

ADDWFC ADD W and Carry bit to f

Syntax: [

label

] ADDWFC f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) + (f) + (C) → dest

Status Affected: N,OV, C, DC, Z

Encoding: 0010 00da ffff ffff

Description: Add W, the Carry Flag and data

memory location 'f'. If 'd' is 0, the

result is placed in W. If 'd' is 1, the

result is placed in data memory loca-

tion 'f'. If ‘a’ is 0, the Access Bank

will be selected. If ‘a’ is 1, the BSR

will not be overridden.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:ADDWFC REG, 0, 1

Before Instruction

Carry bit = 1

REG = 0x02

W = 0x4D

After Instruction

Carry bit = 0

REG = 0x02

W = 0x50

ANDLW AND literal with W

Syntax: [

label

] ANDLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .AND. k → W

Status Affected: N,Z

Encoding: 0000 1011 kkkk kkkk

Description: The contents of W are ANDed with

the 8-bit literal 'k'. The result is

placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'k'

Process

Data

Write to W

Example:ANDLW 0x5F

Before Instruction

W=0xA3

After Instruction

W = 0x03

PIC18FXX2

ANDWF AND W with f

Syntax: [

label

] ANDWF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .AND. (f) → dest

Status Affected: N,Z

Encoding: 0001 01da ffff ffff

Description: The contents of W are AND’ed with

stored in W. If 'd' is 1, the result is

stored back in register 'f' (default). If

‘a’ is 0, the Access Bank will be

selected. If ‘a’ is 1, the BSR will not

be overridden (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:ANDWF REG, 0, 0

Before Instruction

W = 0x17

REG = 0xC2

After Instruction

W = 0x02

REG = 0xC2

BC Branch if Carry

Syntax: [

label

] BC n

Operands: -128 ≤ n ≤ 127

Operation: if carry bit is ’1’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0010 nnnn nnnn

Description: If the Carry bit is ’1’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BC 5

Before Instruction

PC = address (HERE)

After Instruction

If Carry = 1;

PC = address (HERE+12)

If Carry = 0;

PC = address (HERE+2)

PIC18FXX2

BCF Bit Clear f

Syntax: [

label

] BCF f,b[,a]

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: 0 → f

Status Affected: None

Encoding: 1001 bbba ffff ffff

Description: Bit 'b' in register 'f' is cleared. If ‘a’

is 0, the Access Bank will be

selected, overriding the BSR value.

If ‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:BCF FLAG_REG, 7, 0

Before Instruction

FLAG_REG = 0xC7

After Instruction

FLAG_REG = 0x47

BN Branch if Negative

Syntax: [

label

] BN n

Operands: -128 ≤ n ≤ 127

Operation: if negative bit is ’1’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0110 nnnn nnnn

Description: If the Negative bit is ’1’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BN Jump

Before Instruction

PC = address (HERE)

After Instruction

If Negative = 1;

PC = address (Jump)

If Negative = 0;

PC = address (HERE+2)

PIC18FXX2

BNC Branch if Not Carry

Syntax: [

label

] BNC n

Operands: -128 ≤ n ≤ 127

Operation: if carry bit is ’0’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0011 nnnn nnnn

Description: If the Carry bit is ’0’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BNC Jump

Before Instruction

PC = address (HERE)

After Instruction

If Carry = 0;

PC = address (Jump)

If Carry = 1;

PC = address (HERE+2)

BNN Branch if Not Negative

Syntax: [

label

] BNN n

Operands: -128 ≤ n ≤ 127

Operation: if negative bit is ’0’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0111 nnnn nnnn

Description: If the Negative bit is ’0’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BNN Jump

Before Instruction

PC = address (HERE)

After Instruction

If Negative = 0;

PC = address (Jump)

If Negative = 1;

PC = address (HERE+2)

PIC18FXX2

BNOV Branch if Not Overflow

Syntax: [

label

] BNOV n

Operands: -128 ≤ n ≤ 127

Operation: if overflow bit is ’0’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0101 nnnn nnnn

Description: If the Overflow bit is ’0’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BNOV Jump

Before Instruction

PC = address (HERE)

After Instruction

If Overflow = 0;

PC = address (Jump)

If Overflow = 1;

PC = address (HERE+2)

BNZ Branch if Not Zero

Syntax: [

label

] BNZ n

Operands: -128 ≤ n ≤ 127

Operation: if zero bit is ’0’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0001 nnnn nnnn

Description: If the Zero bit is ’0’, then the pro-

gram will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BNZ Jump

Before Instruction

PC = address (HERE)

After Instruction

If Zero = 0;

PC = address (Jump)

If Zero = 1;

PC = address (HERE+2)

PIC18FXX2

BRA Unconditional Branch

Syntax: [

label

] BRA n

Operands: -1024 ≤ n ≤ 1023

Operation: (PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1101 0nnn nnnn nnnn

Description: Add the 2’s complement number

’2n’ to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is a

two-cycle instruction.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

Example:HERE BRA Jump

Before Instruction

PC = address (HERE)

After Instruction

PC = address (Jump)

BSF Bit Set f

Syntax: [

label

] BSF f,b[,a]

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: 1 → f

Status Affected: None

Encoding: 1000 bbba ffff ffff

Description: Bit 'b' in register 'f' is set. If ‘a’ is 0

Access Bank will be selected, over-

riding the BSR value. If ‘a’ = 1, then

the bank will be selected as per the

BSR value.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:BSF FLAG_REG, 7, 1

Before Instruction

FLAG_REG = 0x0A

After Instruction

FLAG_REG = 0x8A

PIC18FXX2

BTFSC Bit Test File, Skip if Clear

Syntax: [

label

] BTFSC f,b[,a]

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: skip if (f) = 0

Status Affected: None

Encoding: 1011 bbba ffff ffff

Description: If bit 'b' in register ’f' is 0, then the

next instruction is skipped.

If bit 'b' is 0, then the next instruction

fetched during the current instruction

execution is discarded, and a NOP is

executed instead, making this a two-

cycle instruction. If ‘a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ‘a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process Data No

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE

FALSE

TRUE

BTFSC

FLAG, 1, 0

Before Instruction

PC = address (HERE)

After Instruction

If FLAG<1> = 0;

PC = address (TRUE)

If FLAG<1> = 1;

PC = address (FALSE)

BTFSS Bit Test File, Skip if Set

Syntax: [

label

] BTFSS f,b[,a]

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: skip if (f) = 1

Status Affected: None

Encoding: 1010 bbba ffff ffff

Description: If bit 'b' in register 'f' is 1, then the

next instruction is skipped.

If bit 'b' is 1, then the next instruction

fetched during the current instruc-

tion execution, is discarded and a

NOP is executed instead, making this

a two-cycle instruction. If ‘a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ‘a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process Data No

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE

FALSE

TRUE

BTFSS

FLAG, 1, 0

Before Instruction

PC = address (HERE)

After Instruction

If FLAG<1> = 0;

PC = address (FALSE)

If FLAG<1> = 1;

PC = address (TRUE)

PIC18FXX2

BTG Bit Toggle f

Syntax: [

label

] BTG f,b[,a]

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: (f) → f

Status Affected: None

Encoding: 0111 bbba ffff ffff

Description: Bit 'b' in data memory location 'f' is

inverted. If ‘a’ is 0, the Access Bank

will be selected, overriding the BSR

value. If ‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:BTG PORTC, 4, 0

Before Instruction:

PORTC = 0111 0101 [0x75]

After Instruction:

PORTC = 0110 0101 [0x65]

BOV Branch if Overflow

Syntax: [

label

] BOV n

Operands: -128 ≤ n ≤ 127

Operation: if overflow bit is ’1’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0100 nnnn nnnn

Description: If the Overflow bit is ’1’, then the

program will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BOV Jump

Before Instruction

PC = address (HERE)

After Instruction

If Overflow = 1;

PC = address (Jump)

If Overflow = 0;

PC = address (HERE+2)

PIC18FXX2

BZ Branch if Zero

Syntax: [

label

] BZ n

Operands: -128 ≤ n ≤ 127

Operation: if Zero bit is ’1’

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0000 nnnn nnnn

Description: If the Zero bit is ’1’, then the pro-

gram will branch.

The 2’s complement number ’2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC+2+2n. This instruction is then

a two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

Write to PC

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Process

Data

operation

Example:HERE BZ Jump

Before Instruction

PC = address (HERE)

After Instruction

If Zero = 1;

PC = address (Jump)

If Zero = 0;

PC = address (HERE+2)

CALL Subroutine Call

Syntax: [

label

] CALL k [,s]

Operands: 0 ≤ k ≤ 1048575

s ∈ [0,1]

Operation: (PC) + 4 → TOS,

k → PC<20:1>,

if s = 1

(W) → WS,

(STATUS) → STATUSS,

(BSR) → BSRS

Status Affected: None

Encoding:

1st word (k<7:0>)

2nd word(k<19:8>)

1110

1111

110s

k19kkk

k7kkk

kkkk

kkkk0

kkkk8

Description: Subroutine call of entire 2 Mbyte

memory range. First, return

address (PC+ 4) is pushed onto the

return stack. If ’s’ = 1, the W,

STATUS and BSR registers are

also pushed into their respective

shadow registers, WS, STATUSS

and BSRS. If 's' = 0, no update

occurs (default). Then, the 20-bit

value ’k’ is loaded into PC<20:1>.

CALL is a two-cycle instruction.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'k'<7:0>,

Push PC to

stack

Read literal

’k’<19:8>,

Write to PC

operation

Example:HERE CALL THERE,1

Before Instruction

PC = address (HERE)

After Instruction

PC = address (THERE)

TOS = address (HERE + 4)

WS = W

BSRS = BSR

STATUSS= STATUS

PIC18FXX2

CLRF Clear f

Syntax: [

label

] CLRF f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: 000h → f

1 → Z

Status Affected: Z

Encoding: 0110 101a ffff ffff

Description: Clears the contents of the specified

will be selected, overriding the BSR

value. If ‘a’ = 1, then the bank will

be selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:CLRF FLAG_REG,1

Before Instruction

FLAG_REG = 0x5A

After Instruction

FLAG_REG = 0x00

CLRWDT Clear Watchdog Timer

Syntax: [

label

] CLRWDT

Operands: None

Operation: 000h → WDT,

000h → WDT postscaler,

1 → TO,

1 → PD

Status Affected: TO, PD

Encoding: 0000 0000 0000 0100

Description: CLRWDT instruction resets the

Watchdog Timer. It also resets the

postscaler of the WDT. Status bits

TO and PD are set.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

operation

Example:CLRWDT

Before Instruction

WDT Counter = ?

After Instruction

WDT Counter = 0x00

WDT Postscaler = 0

TO =1

PD =1

PIC18FXX2

COMF Complement f

Syntax: [

label

] COMF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: → dest

Status Affected: N, Z

Encoding: 0001 11da ffff ffff

Description: The contents of register 'f' are com-

plemented. If 'd' is 0, the result is

stored in W. If 'd' is 1, the result is

stored back in register 'f' (default). If

‘a’ is 0, the Access Bank will be

selected, overriding the BSR value.

If ‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:COMF REG, 0, 0

Before Instruction

REG = 0x13

After Instruction

REG = 0x13

W=0xEC

(f)

CPFSEQ Compare f with W, skip if f = W

Syntax: [

label

] CPFSEQ f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) – (W),

skip if (f) = (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 001a ffff ffff

Description: Compares the contents of data

memory location 'f' to the contents

of W by performing an unsigned

subtraction.

If 'f' = W, then the fetched instruc-

tion is discarded and a NOP is exe-

cuted instead, making this a two-

cycle instruction. If ‘a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ‘a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE CPFSEQ REG, 0

NEQUAL :

EQUAL :

Before Instruction

PC Address = HERE

W=?

REG = ?

After Instruction

If REG = W;

PC = Address (EQUAL)

If REG ≠ W;

PC = Address (NEQUAL)

PIC18FXX2

CPFSGT Compare f with W, skip if f > W

Syntax: [

label

] CPFSGT f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) − (W),

skip if (f) > (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 010a ffff ffff

Description: Compares the contents of data

memory location 'f' to the contents

of the W by performing an

unsigned subtraction.

If the contents of 'f' are greater than

the contents of WREG, then the

fetched instruction is discarded and

a NOP is executed instead, making

this a two-cycle instruction. If ‘a’ is

0, the Access Bank will be

selected, overriding the BSR value.

If ‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE CPFSGT REG, 0

NGREATER :

GREATER :

Before Instruction

PC = Address (HERE)

W= ?

After Instruction

If REG > W;

PC = Address (GREATER)

If REG ≤ W;

PC = Address (NGREATER)

CPFSLT Compare f with W, skip if f < W

Syntax: [

label

] CPFSLT f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) – (W),

skip if (f) < (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 000a ffff ffff

Description: Compares the contents of data

memory location 'f' to the contents

of W by performing an unsigned

subtraction.

If the contents of 'f' are less than

the contents of W, then the fetched

instruction is discarded and a NOP

is executed instead, making this a

two-cycle instruction. If ‘a’ is 0, the

Access Bank will be selected. If ’a’

is 1, the BSR will not be overridden

(default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE CPFSLT REG, 1

NLESS :

LESS :

Before Instruction

PC = Address (HERE)

W= ?

After Instruction

If REG < W;

PC = Address (LESS)

If REG ≥ W;

PC = Address (NLESS)

PIC18FXX2

DAW Decimal Adjust W Register

Syntax: [

label

] DAW

Operands: None

Operation: If [W<3:0> >9] or [DC = 1] then

(W<3:0>) + 6 → W<3:0>;

else

(W<3:0>) → W<3:0>;

If [W<7:4> >9] or [C = 1] then

(W<7:4>) + 6 → W<7:4>;

else

(W<7:4>) → W<7:4>;

Status Affected: C

Encoding: 0000 0000 0000 0111

Description: DAW adjusts the eight-bit value in

W, resulting from the earlier addi-

tion of two variables (each in

packed BCD format) and produces

a correct packed BCD result.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example1:DAW

Before Instruction

W=0xA5

C=0

DC = 0

After Instruction

W = 0x05

C=1

DC = 0

Example 2:

Before Instruction

W=0xCE

C=0

DC = 0

After Instruction

W = 0x34

C=1

DC = 0

DECF Decrement f

Syntax: [

label

] DECF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest

Status Affected: C, DC, N, OV, Z

Encoding: 0000 01da ffff ffff

Description: Decrement register 'f'. If 'd' is 0, the

result is stored in W. If 'd' is 1, the

result is stored back in register 'f'

(default). If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ = 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:DECF CNT, 1, 0

Before Instruction

CNT = 0x01

Z=0

After Instruction

CNT = 0x00

Z=1

PIC18FXX2

DECFSZ Decrement f, skip if 0

Syntax: [

label

] DECFSZ f [,d [,a]]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest,

skip if result = 0

Status Affected: None

Encoding: 0010 11da ffff ffff

Description: The contents of register 'f' are dec-

remented. If 'd' is 0, the result is

placed in W. If 'd' is 1, the result is

placed back in register 'f' (default).

If the result is 0, the next instruc-

tion, which is already fetched, is

discarded, and a NOP is executed

instead, making it a two-cycle

instruction. If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ = 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE DECFSZ CNT, 1, 1

GOTO LOOP

CONTINUE

Before Instruction

PC = Address (HERE)

After Instruction

CNT = CNT - 1

If CNT = 0;

PC = Address (CONTINUE)

If CNT ≠0;

PC = Address (HERE+2)

DCFSNZ Decrement f, skip if not 0

Syntax: [

label

] DCFSNZ f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest,

skip if result ≠ 0

Status Affected: None

Encoding: 0100 11da ffff ffff

Description: The contents of register 'f' are dec-

remented. If 'd' is 0, the result is

placed in W. If 'd' is 1, the result is

placed back in register 'f' (default).

If the result is not 0, the next

instruction, which is already

fetched, is discarded, and a NOP is

executed instead, making it a two-

cycle instruction. If ’a’ is 0, the

Access Bank will be selected,

overriding the BSR value. If ’a’ = 1,

then the bank will be selected as

per the BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE DCFSNZ TEMP, 1, 0

ZERO :

NZERO :

Before Instruction

TEMP = ?

After Instruction

TEMP = TEMP - 1,

If TEMP = 0;

PC = Address (ZERO)

If TEMP ≠0;

PC = Address (NZERO)

PIC18FXX2

GOTO Unconditional Branch

Syntax: [

label

] GOTO k

Operands: 0 ≤ k ≤ 1048575

Operation: k → PC<20:1>

Status Affected: None

Encoding:

1st word (k<7:0>)

2nd word(k<19:8>)

1110

1111

k19kkk

k7kkk

kkkk

kkkk0

kkkk8

Description: GOTO allows an unconditional

branch anywhere within entire

2 Mbyte memory range. The 20-bit

value ’k’ is loaded into PC<20:1>.

GOTO is always a two-cycle

instruction.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'k'<7:0>,

operation

Read literal

’k’<19:8>,

Write to PC

operation

Example:GOTO THERE

After Instruction

PC = Address (THERE)

INCF Increment f

Syntax: [

label

] INCF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest

Status Affected: C, DC, N, OV, Z

Encoding: 0010 10da ffff ffff

Description: The contents of register 'f' are

incremented. If 'd' is 0, the result is

placed in W. If 'd' is 1, the result is

placed back in register 'f' (default).

If ’a’ is 0, the Access Bank will be

selected, overriding the BSR value.

If ’a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:INCF CNT, 1, 0

Before Instruction

CNT = 0xFF

Z=0

C=?

DC = ?

After Instruction

CNT = 0x00

Z=1

C=1

DC = 1

PIC18FXX2

INCFSZ Increment f, skip if 0

Syntax: [

label

] INCFSZ f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest,

skip if result = 0

Status Affected: None

Encoding: 0011 11da ffff ffff

Description: The contents of register 'f' are

incremented. If 'd' is 0, the result is

placed in W. If 'd' is 1, the result is

placed back in register 'f'. (default)

If the result is 0, the next instruc-

tion, which is already fetched, is

discarded, and a NOP is executed

instead, making it a two-cycle

instruction. If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ = 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE INCFSZ CNT, 1, 0

NZERO :

ZERO :

Before Instruction

PC = Address (HERE)

After Instruction

CNT = CNT + 1

If CNT = 0;

PC = Address (ZERO)

If CNT ≠0;

PC = Address (NZERO)

INFSNZ Increment f, skip if not 0

Syntax: [

label

] INFSNZ f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest,

skip if result ≠ 0

Status Affected: None

Encoding: 0100 10da ffff ffff

Description: The contents of register 'f' are

incremented. If 'd' is 0, the result is

placed in W. If 'd' is 1, the result is

placed back in register 'f' (default).

If the result is not 0, the next

instruction, which is already

fetched, is discarded, and a NOP is

executed instead, making it a two-

cycle instruction. If ’a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ’a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE INFSNZ REG, 1, 0

ZERO

NZERO

Before Instruction

PC = Address (HERE)

After Instruction

REG = REG + 1

If REG ≠0;

PC = Address (NZERO)

If REG = 0;

PC = Address (ZERO)

PIC18FXX2

IORLW Inclusive OR literal with W

Syntax: [

label

] IORLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .OR. k → W

Status Affected: N, Z

Encoding: 0000 1001 kkkk kkkk

Description: The contents of W are OR’ed with

the eight-bit literal 'k'. The result is

placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write to W

Example:IORLW 0x35

Before Instruction

W = 0x9A

After Instruction

W=0xBF

IORWF Inclusive OR W with f

Syntax: [

label

] IORWF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .OR. (f) → dest

Status Affected: N, Z

Encoding: 0001 00da ffff ffff

Description: Inclusive OR W with register 'f'. If 'd'

is 0, the result is placed in W. If 'd'

is 1, the result is placed back in

Access Bank will be selected, over-

riding the BSR value. If ’a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:IORWF RESULT, 0, 1

Before Instruction

RESULT = 0x13

W = 0x91

After Instruction

RESULT = 0x13

W = 0x93

PIC18FXX2

LFSR Load FSR

Syntax: [

label

] LFSR f,k

Operands: 0 ≤ f ≤ 2

0 ≤ k ≤ 4095

Operation: k → FSRf

Status Affected: None

Encoding: 1110

1111

1110

0000

00ff

k7kkk

k11kkk

kkkk

Description: The 12-bit literal 'k' is loaded into

the file select register pointed to

by 'f'.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'k' MSB

Process

Data

Write

literal 'k'

MSB to

FSRfH

Decode Read literal

'k' LSB

Process

Data

Write literal

'k' to FSRfL

Example:LFSR 2, 0x3AB

After Instruction

FSR2H = 0x03

FSR2L = 0xAB

MOVF Move f

Syntax: [

label

] MOVF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: f → dest

Status Affected: N, Z

Encoding: 0101 00da ffff ffff

Description: The contents of register 'f' are

moved to a destination dependent

upon the status of ’d’. If 'd' is 0, the

result is placed in W. If 'd' is 1, the

result is placed back in register 'f'

(default). Location 'f' can be any-

where in the 256 byte bank. If ’a’ is

0, the Access Bank will be

selected, overriding the BSR value.

If ‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write W

Example:MOVF REG, 0, 0

Before Instruction

REG = 0x22

W=0xFF

After Instruction

REG = 0x22

W = 0x22

PIC18FXX2

MOVFF Move f to f

Syntax: [

label

] MOVFF fs,fd

Operands: 0 ≤ fs ≤ 4095

0 ≤ fd ≤ 4095

Operation: (fs) → fd

Status Affected: None

Encoding:

1st word (source)

2nd word (destin.)

1100

1111

ffff

ffffs

ffffd

Description: The contents of source register 'fs'

are moved to destination register

'fd'. Location of source 'fs' can be

anywhere in the 4096 byte data

space (000h to FFFh), and location

of destination 'fd' can also be any-

where from 000h to FFFh.

Either source or destination can be

W (a useful special situation).

MOVFF is particularly useful for

transferring a data memory location

to a peripheral register (such as the

transmit buffer or an I/O port).

The MOVFF instruction cannot use

the PCL, TOSU, TOSH or TOSL as

the destination register.

Note: The MOVFF instruction

should not be used to mod-

ify interrupt settings while

any interrupt is enabled.

See Section 8.0 for more

information.

Words: 2

Cycles: 2 (3)

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

(src)

Process

Data

operation

Decode No

operation

No dummy

read

operation

Write

(dest)

Example:MOVFF REG1, REG2

Before Instruction

REG1 = 0x33

REG2 = 0x11

After Instruction

REG1 = 0x33,

REG2 = 0x33

MOVLB Move literal to low nibble in BSR

Syntax: [

label

] MOVLB k

Operands: 0 ≤ k ≤ 255

Operation: k → BSR

Status Affected: None

Encoding: 0000 0001 kkkk kkkk

Description: The 8-bit literal 'k' is loaded into

the Bank Select Register (BSR).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'k'

Process

Data

Write

literal 'k' to

BSR

Example:MOVLB 5

Before Instruction

BSR register = 0x02

After Instruction

BSR register = 0x05

PIC18FXX2

MOVLW Move literal to W

Syntax: [

label

] MOVLW k

Operands: 0 ≤ k ≤ 255

Operation: k → W

Status Affected: None

Encoding: 0000 1110 kkkk kkkk

Description: The eight-bit literal 'k' is loaded

into W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write to W

Example:MOVLW 0x5A

After Instruction

W = 0x5A

MOVWF Move W to f

Syntax: [

label

] MOVWF f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (W) → f

Status Affected: None

Encoding: 0110 111a ffff ffff

Description: Move data from W to register 'f'.

Location 'f' can be anywhere in the

256 byte bank. If ‘a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ‘a’ = 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:MOVWF REG, 0

Before Instruction

W = 0x4F

REG = 0xFF

After Instruction

W = 0x4F

REG = 0x4F

PIC18FXX2

MULLW Multiply Literal with W

Syntax: [

label

] MULLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) x k → PRODH:PRODL

Status Affected: None

Encoding: 0000 1101 kkkk kkkk

Description: An unsigned multiplication is car-

ried out between the contents of

W and the 8-bit literal 'k'. The

16-bit result is placed in

PRODH:PRODL register pair.

PRODH contains the high byte.

W is unchanged.

None of the status flags are

affected.

Note that neither overflow nor

carry is possible in this opera-

tion. A zero result is possible but

not detected.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write

registers

PRODH:

PRODL

Example:MULLW 0xC4

Before Instruction

W=0xE2

PRODH = ?

PRODL = ?

After Instruction

W=0xE2

PRODH = 0xAD

PRODL = 0x08

MULWF Multiply W with f

Syntax: [

label

] MULWF f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (W) x (f) → PRODH:PRODL

Status Affected: None

Encoding: 0000 001a ffff ffff

Description: An unsigned multiplication is car-

ried out between the contents of

W and the register file location 'f'.

The 16-bit result is stored in the

PRODH:PRODL register pair.

PRODH contains the high byte.

Both W and 'f' are unchanged.

None of the status flags are

affected.

Note that neither overflow nor

carry is possible in this opera-

tion. A zero result is possible but

not detected. If ‘a’ is 0, the

Access Bank will be selected,

overriding the BSR value. If

‘a’ = 1, then the bank will be

selected as per the BSR value

(default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

registers

PRODH:

PRODL

Example:MULWF REG, 1

Before Instruction

W=0xC4

REG = 0xB5

PRODH = ?

PRODL = ?

After Instruction

W=0xC4

REG = 0xB5

PRODH = 0x8A

PRODL = 0x94

PIC18FXX2

NEGF Negate f

Syntax: [

label

] NEGF f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: ( f ) + 1 → f

Status Affected: N, OV, C, DC, Z

Encoding: 0110 110a ffff ffff

Description: Location ‘f’ is negated using two’s

complement. The result is placed in

the data memory location 'f'. If ’a’ is

0, the Access Bank will be

selected, overriding the BSR value.

If ’a’ = 1, then the bank will be

selected as per the BSR value.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:NEGF REG, 1

Before Instruction

REG = 0011 1010 [0x3A]

After Instruction

REG = 1100 0110 [0xC6]

NOP No Operation

Syntax: [

label

] NOP

Operands: None

Operation: No operation

Status Affected: None

Encoding: 0000

1111

0000

xxxx

0000

xxxx

0000

xxxx

Description: No operation.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Example:

None.

PIC18FXX2

POP Pop Top of Return Stack

Syntax: [

label

] POP

Operands: None

Operation: (TOS) → bit bucket

Status Affected: None

Encoding: 0000 0000 0000 0110

Description: The TOS value is pulled off the

return stack and is discarded. The

TOS value then becomes the previ-

ous value that was pushed onto the

return stack.

This instruction is provided to

enable the user to properly manage

the return stack to incorporate a

software stack.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

POP TOS

value

operation

Example:POP

GOTO NEW

Before Instruction

TOS = 0031A2h

Stack (1 level down) = 014332h

After Instruction

TOS = 014332h

PC = NEW

PUSH Push Top of Return Stack

Syntax: [

label

] PUSH

Operands: None

Operation: (PC+2) → TOS

Status Affected: None

Encoding: 0000 0000 0000 0101

Description: The PC+2 is pushed onto the top of

the return stack. The previous TOS

value is pushed down on the stack.

This instruction allows to implement

a software stack by modifying TOS,

and then push it onto the return

stack.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode PUSH PC+2

onto return

stack

operation

Example:PUSH

Before Instruction

TOS = 00345Ah

PC = 000124h

After Instruction

PC = 000126h

TOS = 000126h

Stack (1 level down) = 00345Ah

PIC18FXX2

RCALL Relative Call

Syntax: [

label

] RCALL n

Operands: -1024 ≤ n ≤ 1023

Operation: (PC) + 2 → TOS,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1101 1nnn nnnn nnnn

Description: Subroutine call with a jump up to

1K from the current location. First,

return address (PC+2) is pushed

onto the stack. Then, add the 2’s

complement number ’2n’ to the PC.

Since the PC will have incremented

to fetch the next instruction, the

new address will be PC+2+2n.

This instruction is a two-cycle

instruction.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

'n'

Push PC to

stack

Process

Data

Write to PC

operation

Example:HERE RCALL Jump

Before Instruction

PC = Address (HERE)

After Instruction

PC = Address (Jump)

TOS = Address (HERE+2)

RESET Reset

Syntax: [

label

] RESET

Operands: None

Operation: Reset all registers and flags that

are affected by a MCLR Reset.

Status Affected: All

Encoding: 0000 0000 1111 1111

Description: This instruction provides a way to

execute a MCLR Reset in software.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Start

reset

operation

Example:RESET

After Instruction

Registers = Reset Value

Flags* = Reset Value

PIC18FXX2

RETFIE Return from Interrupt

Syntax: [

label

] RETFIE [s]

Operands: s ∈ [0,1]

Operation: (TOS) → PC,

1 → GIE/GIEH or PEIE/GIEL,

if s = 1

(WS) → W,

(STATUSS) → STATUS,

(BSRS) → BSR,

PCLATU, PCLATH are unchanged.

Status Affected: GIE/GIEH, PEIE/GIEL.

Encoding: 0000 0000 0001 000s

Description: Return from Interrupt. Stack is

popped and Top-of-Stack (TOS) is

loaded into the PC. Interrupts are

enabled by setting either the high

or low priority global interrupt

enable bit. If ‘s’ = 1, the contents of

the shadow registers WS,

STATUSS and BSRS are loaded

into their corresponding registers,

W, STATUS and BSR. If ‘s’ = 0, no

update of these registers occurs

(default).

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

pop PC from

stack

Set GIEH or

GIEL

operation

Example:RETFIE 1

After Interrupt

PC = TOS

W=WS

BSR = BSRS

STATUS = STATUSS

GIE/GIEH, PEIE/GIEL = 1

RETLW Return Literal to W

Syntax: [

label

] RETLW k

Operands: 0 ≤ k ≤ 255

Operation: k → W,

(TOS) → PC,

PCLATU, PCLATH are unchanged

Status Affected: None

Encoding: 0000 1100 kkkk kkkk

Description: W is loaded with the eight-bit literal

'k'. The program counter is loaded

from the top of the stack (the return

address). The high address latch

(PCLATH) remains unchanged.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

pop PC from

stack, Write

to W

operation

Example:

CALL TABLE ; W contains table

; offset value

; W now has

; table value

TABLE

ADDWF PCL ; W = offset

RETLW k0 ; Begin table

RETLW k1 ;

RETLW kn ; End of table

Before Instruction

W = 0x07

After Instruction

W = value of kn

PIC18FXX2

RETURN Return from Subroutine

Syntax: [

label

] RETURN [s]

Operands: s ∈ [0,1]

Operation: (TOS) → PC,

if s = 1

(WS) → W,

(STATUSS) → STATUS,

(BSRS) → BSR,

PCLATU, PCLATH are unchanged

Status Affected: None

Encoding: 0000 0000 0001 001s

Description: Return from subroutine. The stack

is popped and the top of the stack

(TOS) is loaded into the program

counter. If ‘s’= 1, the contents of the

shadow registers WS, STATUSS

and BSRS are loaded into their cor-

responding registers, W, STATUS

and BSR. If ‘s’ = 0, no update of

these registers occurs (default).

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

pop PC from

stack

operation

Example:RETURN

After Interrupt

PC = TOS

RLCF Rotate Left f through Carry

Syntax: [

label

] RLCF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n+1>,

(f<7>) → C,

Status Affected: C, N, Z

Encoding: 0011 01da ffff ffff

Description: The contents of register 'f' are

rotated one bit to the left through

the Carry Flag. If 'd' is 0, the result

is placed in W. If 'd' is 1, the result

is stored back in register 'f'

(default). If ‘a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ = 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:RLCF REG, 0, 0

Before Instruction

REG = 1110 0110

C=0

After Instruction

REG = 1110 0110

W=1100 1100

C=1

Cregister f

PIC18FXX2

RLNCF Rotate Left f (no carry)

Syntax: [

label

] RLNCF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n+1>,

(f<7>) → dest<0>

Status Affected: N, Z

Encoding: 0100 01da ffff ffff

Description: The contents of register 'f' are

rotated one bit to the left. If 'd' is 0,

the result is placed in W. If 'd' is 1,

the result is stored back in register

'f' (default). If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ is 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:RLNCF REG, 1, 0

Before Instruction

REG = 1010 1011

After Instruction

REG = 0101 0111

RRCF Rotate Right f through Carry

Syntax: [

label

] RRCF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n-1>,

(f<0>) → C,

Status Affected: C, N, Z

Encoding: 0011 00da ffff ffff

Description: The contents of register 'f' are

rotated one bit to the right through

the Carry Flag. If 'd' is 0, the result

is placed in W. If 'd' is 1, the result

is placed back in register 'f'

(default). If ‘a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ is 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:RRCF REG, 0, 0

Before Instruction

REG = 1110 0110

C=0

After Instruction

REG = 1110 0110

W=0111 0011

C=0

Cregister f

PIC18FXX2

RRNCF Rotate Right f (no carry)

Syntax: [

label

] RRNCF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n-1>,

(f<0>) → dest<7>

Status Affected: N, Z

Encoding: 0100 00da ffff ffff

Description: The contents of register 'f' are

rotated one bit to the right. If 'd' is 0,

the result is placed in W. If 'd' is 1,

the result is placed back in register

'f' (default). If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ is 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1:RRNCF REG, 1, 0

Before Instruction

REG = 1101 0111

After Instruction

REG = 1110 1011

Example 2:RRNCF REG, 0, 0

Before Instruction

W=?

REG = 1101 0111

After Instruction

W=1110 1011

REG = 1101 0111

SETF Set f

Syntax: [

label

] SETF f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: FFh → f

Status Affected: None

Encoding: 0110 100a ffff ffff

Description: The contents of the specified regis-

ter are set to FFh. If ’a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ’a’ is 1, then

the bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example:SETF REG,1

Before Instruction

REG = 0x5A

After Instruction

REG = 0xFF

PIC18FXX2

SLEEP Enter SLEEP mode

Syntax: [

label

] SLEEP

Operands: None

Operation: 00h → WDT,

0 → WDT postscaler,

1 → TO,

0 → PD

Status Affected: TO, PD

Encoding: 0000 0000 0000 0011

Description: The power-down status bit (PD) is

cleared. The time-out status bit

(TO) is set. Watchdog Timer and

its postscaler are cleared.

The processor is put into SLEEP

mode with the oscillator stopped.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

Go to

sleep

Example:SLEEP

Before Instruction

TO =?

PD =?

After Instruction

TO =1 †

PD =0

† If WDT causes wake-up, this bit is cleared.

SUBFWB Subtract f from W with borrow

Syntax: [

label

] SUBFWB f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) – (f) – (C) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 01da ffff ffff

Description: Subtract register 'f' and carry flag

(borrow) from W (2’s complement

method). If 'd' is 0, the result is

stored in W. If 'd' is 1, the result is

stored in register 'f' (default). If ’a’ is

0, the Access Bank will be selected,

overriding the BSR value. If ’a’ is 1,

then the bank will be selected as

per the BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1:SUBFWB REG, 1, 0

Before Instruction

REG = 3

W=2

C=1

After Instruction

REG = FF

W=2

C=0

Z=0

N = 1 ; result is negative

Example 2:SUBFWB REG, 0, 0

Before Instruction

REG = 2

W=5

C=1

After Instruction

REG = 2

W=3

C=1

Z=0

N = 0 ; result is positive

Example 3:SUBFWB REG, 1, 0

Before Instruction

REG = 1

W=2

C=0

After Instruction

REG = 0

W=2

C=1

Z = 1 ; result is zero

N=0

PIC18FXX2

SUBLW Subtract W from literal

Syntax: [

label

]SUBLW k

Operands: 0 ≤ k ≤ 255

Operation: k – (W) → W

Status Affected: N, OV, C, DC, Z

Encoding: 0000 1000 kkkk kkkk

Description: W is subtracted from the eight-bit

literal 'k'. The result is placed

in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write to W

Example 1: SUBLW 0x02

Before Instruction

W=1

C=?

After Instruction

W=1

C = 1 ; result is positive

Z=0

N=0

Example 2:SUBLW 0x02

Before Instruction

W=2

C=?

After Instruction

W=0

C = 1 ; result is zero

Z=1

N=0

Example 3:SUBLW 0x02

Before Instruction

W=3

C=?

After Instruction

W = FF ; (2’s complement)

C = 0 ; result is negative

Z=0

N=1

SUBWF Subtract W from f

Syntax: [

label

] SUBWF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – (W) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 11da ffff ffff

Description: Subtract W from register 'f' (2’s

complement method). If 'd' is 0,

the result is stored in W. If 'd' is 1,

the result is stored back in regis-

ter 'f' (default). If ’a’ is 0, the

Access Bank will be selected,

overriding the BSR value. If ’a’ is

1, then the bank will be selected

as per the BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1:SUBWF REG, 1, 0

Before Instruction

REG = 3

W=2

C=?

After Instruction

REG = 1

W=2

C = 1 ; result is positive

Z=0

N=0

Example 2:SUBWF REG, 0, 0

Before Instruction

REG = 2

W=2

C=?

After Instruction

REG = 2

W=0

C = 1 ; result is zero

Z=1

N=0

Example 3:SUBWF REG, 1, 0

Before Instruction

REG = 1

W=2

C=?

After Instruction

REG = FFh ;(2’s complement)

W=2

C = 0 ; result is negative

Z=0

N=1

PIC18FXX2

SUBWFB Subtract W from f with Borrow

Syntax: [

label

] SUBWFB f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – (W) – (C) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 10da ffff ffff

Description: Subtract W and the carry flag (bor-

row) from register 'f' (2’s complement

method). If 'd' is 0, the result is stored

in W. If 'd' is 1, the result is stored

back in register 'f' (default). If ’a’ is 0,

the Access Bank will be selected,

overriding the BSR value. If ’a’ is 1,

then the bank will be selected as per

the BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1:SUBWFB REG, 1, 0

Before Instruction

REG = 0x19 (0001 1001)

W= 0x0D (0000 1101)

C=1

After Instruction

REG = 0x0C (0000 1011)

W= 0x0D (0000 1101)

C=1

Z=0

N = 0 ; result is positive

Example 2: SUBWFB REG, 0, 0

Before Instruction

REG = 0x1B (0001 1011)

W= 0x1A (0001 1010)

C=0

After Instruction

REG = 0x1B (0001 1011)

W = 0x00

C=1

Z = 1 ; result is zero

N=0

Example 3: SUBWFB REG, 1, 0

Before Instruction

REG = 0x03 (0000 0011)

W= 0x0E (0000 1101)

C=1

After Instruction

REG = 0xF5 (1111 0100)

; [2’s comp]

W= 0x0E (0000 1101)

C=0

Z=0

N = 1 ; result is negative

SWAPF Swap f

Syntax: [

label

] SWAPF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<3:0>) → dest<7:4>,

(f<7:4>) → dest<3:0>

Status Affected: None

Encoding: 0011 10da ffff ffff

Description: The upper and lower nibbles of reg-

ister 'f' are exchanged. If 'd' is 0, the

result is placed in W. If 'd' is 1, the

result is placed in register 'f'

(default). If ’a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ is 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:SWAPF REG, 1, 0

Before Instruction

REG = 0x53

After Instruction

REG = 0x35

PIC18FXX2

TBLRD Table Read

Syntax: [

label

] TBLRD ( *; *+; *-; +*)

Operands: None

Operation: if TBLRD *,

(Prog Mem (TBLPTR)) → TABLAT;

TBLPTR - No Change;

if TBLRD *+,

(Prog Mem (TBLPTR)) → TABLAT;

(TBLPTR) +1 → TBLPTR;

if TBLRD *-,

(Prog Mem (TBLPTR)) → TABLAT;

(TBLPTR) -1 → TBLPTR;

if TBLRD +*,

(TBLPTR) +1 → TBLPTR;

(Prog Mem (TBLPTR)) → TABLAT;

Status Affected:None

Encoding: 0000 0000 0000 10nn

nn=0 *

=1 *+

=2 *-

=3 +*

Description: This instruction is used to read the con-

tents of Program Memory (P.M.). To

address the program memory, a pointer

called Table Pointer (TBLPTR) is used.

The TBLPTR (a 21-bit pointer) points

to each byte in the program memory.

TBLPTR has a 2 Mbyte address range.

TBLPTR[0] = 0: Least Significant

Byte of Program

Memory Word

TBLPTR[0] = 1: Most Significant

Byte of Program

Memory Word

The TBLRD instruction can modify the

value of TBLPTR as follows:

• no change

• post-increment

• post-decrement

• pre-increment

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

No operation

(Read Program

Memory)

operation

No operation

(Write TABLAT)

TBLRD Table Read (cont’d)

Example1:TBLRD *+ ;

Before Instruction

TABLAT = 0x55

TBLPTR = 0x00A356

MEMORY(0x00A356) = 0x34

After Instruction

TABLAT = 0x34

TBLPTR = 0x00A357

Example2:TBLRD +* ;

Before Instruction

TABLAT = 0xAA

TBLPTR = 0x01A357

MEMORY(0x01A357) = 0x12

MEMORY(0x01A358) = 0x34

After Instruction

TABLAT = 0x34

TBLPTR = 0x01A358

PIC18FXX2

TBLWT Table Write

Syntax: [

label

] TBLWT ( *; *+; *-; +*)

Operands: None

Operation: if TBLWT*,

(TABLAT) → Holding Register;

TBLPTR - No Change;

if TBLWT*+,

(TABLAT) → Holding Register;

(TBLPTR) +1 → TBLPTR;

if TBLWT*-,

(TABLAT) → Holding Register;

(TBLPTR) -1 → TBLPTR;

if TBLWT+*,

(TBLPTR) +1 → TBLPTR;

(TABLAT) → Holding Register;

Status Affected: None

Encoding: 0000 0000 0000 11nn

nn=0 *

=1 *+

=2 *-

=3 +*

Description: This instruction uses the 3 LSbs of the

TBLPTR to determine which of the 8

holding registers the TABLAT data is

written to. The 8 holding registers are

used to program the contents of Pro-

gram Memory (P.M.). See Section 5.0

for information on writing to FLASH

memory.

The TBLPTR (a 21-bit pointer) points

to each byte in the program memory.

TBLPTR has a 2 MBtye address

range. The LSb of the TBLPTR selects

which byte of the program memory

location to access.

TBLPTR[0] = 0: Least Significant

Byte of Program

Memory Word

TBLPTR[0] = 1: Most Significant

Byte of Program

Memory Word

The TBLWT instruction can modify the

value of TBLPTR as follows:

• no change

• post-increment

• post-decrement

• pre-increment

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

(Read

TABLAT)

operation

(Write to Holding

TBLWT Table Write (Continued)

Example1:TBLWT *+;

Before Instruction

TABLAT = 0x55

TBLPTR = 0x00A356

HOLDING REGISTER

(0x00A356) = 0xFF

After Instructions (table write completion)

TABLAT = 0x55

TBLPTR = 0x00A357

HOLDING REGISTER

(0x00A356) = 0x55

Example 2:TBLWT +*;

Before Instruction

TABLAT = 0x34

TBLPTR = 0x01389A

HOLDING REGISTER

(0x01389A) = 0xFF

HOLDING REGISTER

(0x01389B) = 0xFF

After Instruction (table write completion)

TABLAT = 0x34

TBLPTR = 0x01389B

HOLDING REGISTER

(0x01389A) = 0xFF

HOLDING REGISTER

(0x01389B) = 0x34

PIC18FXX2

TSTFSZ Test f, skip if 0

Syntax: [

label

] TSTFSZ f [,a]

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: skip if f = 0

Status Affected: None

Encoding: 0110 011a ffff ffff

Description: If 'f' = 0, the next instruction,

fetched during the current instruc-

tion execution, is discarded and a

NOP is executed, making this a two-

cycle instruction. If ’a’ is 0, the

Access Bank will be selected, over-

riding the BSR value. If ’a’ is 1,

then the bank will be selected as

per the BSR value (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example:HERE TSTFSZ CNT, 1

NZERO :

ZERO :

Before Instruction

PC = Address (HERE)

After Instruction

If CNT = 0x00,

PC = Address (ZERO)

If CNT ≠0x00,

PC = Address (NZERO)

XORLW Exclusive OR literal with W

Syntax: [

label

] XORLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .XOR. k → W

Status Affected: N, Z

Encoding: 0000 1010 kkkk kkkk

Description: The contents of W are XORed

with the 8-bit literal 'k'. The result

is placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal 'k'

Process

Data

Write to W

Example:XORLW 0xAF

Before Instruction

W=0xB5

After Instruction

W = 0x1A

PIC18FXX2

XORWF Exclusive OR W with f

Syntax: [

label

] XORWF f [,d [,a]

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .XOR. (f) → dest

Status Affected: N, Z

Encoding: 0001 10da ffff ffff

Description: Exclusive OR the contents of W

with register 'f'. If 'd' is 0, the result

is stored in W. If 'd' is 1, the result is

stored back in the register 'f'

(default). If ‘a’ is 0, the Access

Bank will be selected, overriding

the BSR value. If ’a’ is 1, then the

bank will be selected as per the

BSR value (default).

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example:XORWF REG, 1, 0

Before Instruction

REG = 0xAF

W=0xB5

After Instruction

REG = 0x1A

W=0xB5

PIC18FXX2

21.0 DEVELOPMENT SUPPORT

The PICmicro® microcontrollers are supported with a

full range of hardware and software development tools:

• Integrated Development Environment

- MPLAB® IDE Software

• Assemblers/Compilers/Linkers

- MPASMTM Assembler

- MPLAB C17 and MPLAB C18 C Compilers

-MPLINK

TM Object Linker/

MPLIBTM Object Librarian

• Simulators

- MPLAB SIM Software Simulator

•Emulators

- MPLAB ICE 2000 In-Circuit Emulator

- ICEPIC™ In-Circuit Emulator

• In-Circuit Debugger

- MPLAB ICD

• Device Programmers

-PRO MATE

® II Universal Device Programmer

- PICSTART® Plus Entry-Level Development

Programmer

• Low Cost Demonstration Boards

- PICDEMTM 1 Demonstration Board

- PICDEM 2 Demonstration Board

- PICDEM 3 Demonstration Board

- PICDEM 17 Demonstration Board

-K

EELOQ® Demonstration Board

21.1 MPLAB Integrated Development

Environment Software

The MPLAB IDE software brings an ease of software

development previously unseen in the 8-bit microcon-

troller market. The MPLAB IDE is a Windows® based

application that contains:

• An interface to debugging tools

- simulator

- programmer (sold separately)

- emulator (sold separately)

- in-circuit debugger (sold separately)

• A full-featured editor

• A project manager

• Customizable toolbar and key mapping

• A status bar

• On-line help

The MPLAB IDE allows you to:

• Edit your source files (either assembly or ‘C’)

• One touch assemble (or compile) and download

to PICmicro emulator and simulator tools (auto-

matically updates all project information)

• Debug using:

- source files

- absolute listing file

- machine code

The ability to use MPLAB IDE with multiple debugging

tools allows users to easily switch from the cost-

effective simulator to a full-featured emulator with

minimal retraining.

21.2 MPASM Assembler

The MPASM assembler is a full-featured universal

macro assembler for all PICmicro MCU’s.

The MPASM assembler has a command line interface

and a Windows shell. It can be used as a stand-alone

application on a Windows 3.x or greater system, or it

can be used through MPLAB IDE. The MPASM assem-

bler generates relocatable object files for the MPLINK

object linker, Intel® standard HEX files, MAP files to

detail memory usage and symbol reference, an abso-

lute LST file that contains source lines and generated

machine code, and a COD file for debugging.

The MPASM assembler features include:

• Integration into MPLAB IDE projects.

• User-defined macros to streamline assembly

code.

• Conditional assembly for multi-purpose source

files.

• Directives that allow complete control over the

assembly process.

21.3 MPLAB C17 and MPLAB C18

C Compilers

The MPLAB C17 and MPLAB C18 Code Development

Systems are complete ANSI ‘C’ compilers for

Microchip’s PIC17CXXX and PIC18CXXX family of

microcontrollers, respectively. These compilers provide

powerful integration capabilities and ease of use not

found with other compilers.

For easier source level debugging, the compilers pro-

vide symbol information that is compatible with the

MPLAB IDE memory display.

PIC18FXX2

21.4 MPLINK Object Linker/

MPLIB Object Librarian

The MPLINK object linker combines relocatable

objects created by the MPASM assembler and the

MPLAB C17 and MPLAB C18 C compilers. It can also

link relocatable objects from pre-compiled libraries,

using directives from a linker script.

The MPLIB object librarian is a librarian for pre-

compiled code to be used with the MPLINK object

linker. When a routine from a library is called from

another source file, only the modules that contain that

routine will be linked in with the application. This allows

large libraries to be used efficiently in many different

applications. The MPLIB object librarian manages the

creation and modification of library files.

The MPLINK object linker features include:

• Integration with MPASM assembler and MPLAB

C17 and MPLAB C18 C compilers.

• Allows all memory areas to be defined as sections

to provide link-time flexibility.

The MPLIB object librarian features include:

• Easier linking because single libraries can be

included instead of many smaller files.

• Helps keep code maintainable by grouping

related modules together.

• Allows libraries to be created and modules to be

added, listed, replaced, deleted or extracted.

21.5 MPLAB SIM Software Simulator

The MPLAB SIM software simulator allows code devel-

opment in a PC-hosted environment by simulating the

PICmicro series microcontrollers on an instruction

level. On any given instruction, the data areas can be

examined or modified and stimuli can be applied from

a file, or user-defined key press, to any of the pins. The

execution can be performed in single step, execute

until break, or trace mode.

The MPLAB SIM simulator fully supports symbolic debug-

ging using the MPLAB C17 and the MPLAB C18 C com-

pilers and the MPASM assembler. The software simulator

offers the flexibility to develop and debug code outside of

the laboratory environment, making it an excellent multi-

project software development tool.

21.6 MPLAB ICE High Performance

Universal In-Circuit Emulator with

MPLAB IDE

The MPLAB ICE universal in-circuit emulator is intended

to provide the product development engineer with a

complete microcontroller design tool set for PICmicro

microcontrollers (MCUs). Software control of the

MPLAB ICE in-circuit emulator is provided by the

MPLAB Integrated Development Environment (IDE),

which allows editing, building, downloading and source

debugging from a single environment.

The MPLAB ICE 2000 is a full-featured emulator sys-

tem with enhanced trace, trigger and data monitoring

features. Interchangeable processor modules allow the

system to be easily reconfigured for emulation of differ-

ent processors. The universal architecture of the

MPLAB ICE in-circuit emulator allows expansion to

support new PICmicro microcontrollers.

The MPLAB ICE in-circuit emulator system has been

designed as a real-time emulation system, with

advanced features that are generally found on more

expensive development tools. The PC platform and

Microsoft® Windows environment were chosen to best

make these features available to you, the end user.

21.7 ICEPIC In-Circuit Emulator

The ICEPIC low cost, in-circuit emulator is a solution

for the Microchip Technology PIC16C5X, PIC16C6X,

PIC16C7X and PIC16CXXX families of 8-bit One-

Time-Programmable (OTP) microcontrollers. The mod-

ular system can support different subsets of PIC16C5X

or PIC16CXXX products through the use of inter-

changeable personality modules, or daughter boards.

The emulator is capable of emulating without target

application circuitry being present.

PIC18FXX2

21.8 MPLAB ICD In-Circuit Debugger

Microchip's In-Circuit Debugger, MPLAB ICD, is a pow-

erful, low cost, run-time development tool. This tool is

based on the FLASH PICmicro MCUs and can be used

to develop for this and other PICmicro microcontrollers.

The MPLAB ICD utilizes the in-circuit debugging capa-

bility built into the FLASH devices. This feature, along

with Microchip's In-Circuit Serial ProgrammingTM proto-

col, offers cost-effective in-circuit FLASH debugging

from the graphical user interface of the MPLAB

Integrated Development Environment. This enables a

designer to develop and debug source code by watch-

ing variables, single-stepping and setting break points.

Running at full speed enables testing hardware in real-

time.

21.9 PRO MATE II Universal Device

Programmer

The PRO MATE II universal device programmer is a

full-featured programmer, capable of operating in

stand-alone mode, as well as PC-hosted mode. The

PRO MATE II device programmer is CE compliant.

The PRO MATE II device programmer has program-

mable VDD and VPP supplies, which allow it to verify

programmed memory at VDD min and VDD max for max-

imum reliability. It has an LCD display for instructions

and error messages, keys to enter commands and a

modular detachable socket assembly to support various

package types. In stand-alone mode, the PRO MATE II

device programmer can read, verify, or program

PICmicro devices. It can also set code protection in this

mode.

21.10 PICSTART Plus Entry Level

Development Programmer

The PICSTART Plus development programmer is an

easy-to-use, low cost, prototype programmer. It con-

nects to the PC via a COM (RS-232) port. MPLAB

Integrated Development Environment software makes

using the programmer simple and efficient.

The PICSTART Plus development programmer sup-

ports all PICmicro devices with up to 40 pins. Larger pin

count devices, such as the PIC16C92X and

PIC17C76X, may be supported with an adapter socket.

The PICSTART Plus development programmer is CE

compliant.

21.11 PICDEM 1 Low Cost PICmicro

Demonstration Board

The PICDEM 1 demonstration board is a simple board

which demonstrates the capabilities of several of

Microchip’s microcontrollers. The microcontrollers sup-

ported are: PIC16C5X (PIC16C54 to PIC16C58A),

PIC16C61, PIC16C62X, PIC16C71, PIC16C8X,

PIC17C42, PIC17C43 and PIC17C44. All necessary

hardware and software is included to run basic demo

programs. The user can program the sample microcon-

trollers provided with the PICDEM 1 demonstration

board on a PRO MATE II device programmer, or a

PICSTART Plus development programmer, and easily

test firmware. The user can also connect the

PICDEM 1 demonstration board to the MPLAB ICE in-

circuit emulator and download the firmware to the emu-

lator for testing. A prototype area is available for the

user to build some additional hardware and connect it

to the microcontroller socket(s). Some of the features

include an RS-232 interface, a potentiometer for simu-

lated analog input, push button switches and eight

LEDs connected to PORTB.

21.12 PICDEM 2 Low Cost PIC16CXX

Demonstration Board

The PICDEM 2 demonstration board is a simple dem-

onstration board that supports the PIC16C62,

PIC16C64, PIC16C65, PIC16C73 and PIC16C74

microcontrollers. All the necessary hardware and soft-

ware is included to run the basic demonstration pro-

grams. The user can program the sample

microcontrollers provided with the PICDEM 2 demon-

stration board on a PRO MATE II device programmer,

or a PICSTART Plus development programmer, and

easily test firmware. The MPLAB ICE in-circuit emula-

tor may also be used with the PICDEM 2 demonstration

board to test firmware. A prototype area has been pro-

vided to the user for adding additional hardware and

connecting it to the microcontroller socket(s). Some of

the features include a RS-232 interface, push button

switches, a potentiometer for simulated analog input, a

serial EEPROM to demonstrate usage of the I2CTM bus

and separate headers for connection to an LCD

module and a keypad.

PIC18FXX2

21.13 PICDEM 3 Low Cost PIC16CXXX

Demonstration Board

The PICDEM 3 demonstration board is a simple dem-

onstration board that supports the PIC16C923 and

PIC16C924 in the PLCC package. It will also support

future 44-pin PLCC microcontrollers with an LCD Mod-

ule. All the necessary hardware and software is

included to run the basic demonstration programs. The

user can program the sample microcontrollers pro-

vided with the PICDEM 3 demonstration board on a

PRO MATE II device programmer, or a PICSTART Plus

development programmer with an adapter socket, and

easily test firmware. The MPLAB ICE in-circuit emula-

tor may also be used with the PICDEM 3 demonstration

board to test firmware. A prototype area has been pro-

vided to the user for adding hardware and connecting it

to the microcontroller socket(s). Some of the features

include a RS-232 interface, push button switches, a

potentiometer for simulated analog input, a thermistor

and separate headers for connection to an external

LCD module and a keypad. Also provided on the

PICDEM 3 demonstration board is a LCD panel, with 4

commons and 12 segments, that is capable of display-

ing time, temperature and day of the week. The

PICDEM 3 demonstration board provides an additional

RS-232 interface and Windows software for showing

the demultiplexed LCD signals on a PC. A simple serial

interface allows the user to construct a hardware

demultiplexer for the LCD signals.

21.14 PICDEM 17 Demonstration Board

The PICDEM 17 demonstration board is an evaluation

board that demonstrates the capabilities of several

Microchip microcontrollers, including PIC17C752,

PIC17C756A, PIC17C762 and PIC17C766. All neces-

sary hardware is included to run basic demo programs,

which are supplied on a 3.5-inch disk. A programmed

sample is included and the user may erase it and

program it with the other sample programs using the

PRO MATE II device programmer, or the PICSTART

Plus development programmer, and easily debug and

test the sample code. In addition, the PICDEM 17 dem-

onstration board supports downloading of programs to

and executing out of external FLASH memory on board.

The PICDEM 17 demonstration board is also usable

with the MPLAB ICE in-circuit emulator, or the

PICMASTER emulator and all of the sample programs

can be run and modified using either emulator. Addition-

ally, a generous prototype area is available for user

hardware.

21.15 KEELOQ Evaluation and

Programming Tools

KEELOQ evaluation and programming tools support

Microchip’s HCS Secure Data Products. The HCS eval-

uation kit includes a LCD display to show changing

codes, a decoder to decode transmissions and a

programming interface to program test transmitters.

PIC18FXX2

TABLE 21-1: DEVELOPMENT TOOLS FROM MICROCHIP

PIC12CXXX

PIC14000

PIC16C5X

PIC16C6X

PIC16CXXX

PIC16F62X

PIC16C7X

PIC16C7XX

PIC16C8X/

PIC16F8X

PIC16F8XX

PIC16C9XX

PIC17C4X

PIC17C7XX

PIC18CXX2

PIC18FXXX

24CXX/

25CXX/

93CXX

HCSXXX

MCRFXXX

MCP2510

Software Tools

MPLAB® Integrated

Development Environment !!!!!!!!!!!!!!!

MPLAB® C17 C Compiler !!

MPLAB® C18 C Compiler !!

MPASMTM Assembler/

MPLINKTM Object Linker !!!!!!!!!!!!!!! ! !

Emulators

MPLAB® ICE In-Circuit Emulator !!! ! !!

** !!!!!!!!!

ICEPICTM In-Circuit Emulator ! !!! !!! !

Debugger

MPLAB® ICD In-Circuit

Debugger !*!*!!

Programmers

PICSTART® Plus Entry Level

Development Programmer !!! ! !!

** !!!!!!!!!

PRO MATE® II

Universal Device Programmer !!! ! !!

** !!!!!!!!! ! !

Demo Boards and Eval Kits

PICDEMTM 1 Demonstration

Board !!!

†!!

PICDEMTM 2 Demonstration

Board !†!†!!

PICDEMTM 3 Demonstration

Board !

PICDEMTM 14A Demonstration

Board !

PICDEMTM 17 Demonstration

Board !

KEELOQ® Evaluation Kit !

KEELOQ® Transponder Kit !

microIDTM Programmer’s Kit !

125 kHz microIDTM

Developer’s Kit !

125 kHz Anticollision microIDTM

Developer’s Kit !

13.56 MHz Anticollision

microIDTM Developer’s Kit !

MCP2510 CAN Developer’s Kit !

* Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB® ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77.

** Contact Microchip Technology Inc. for availability date.

†Development tool is available on select devices.

PIC18FXX2

NOTES:

PIC18FXX2

22.0 ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings (†)

Ambient temperature under bias.............................................................................................................-55°C to +125°C

Storage temperature .............................................................................................................................. -65°C to +150°C

Voltage on any pin with respect to VSS (except VDD, MCLR, and RA4) ......................................... -0.3V to (VDD + 0.3V)

Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V

Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V

Voltage on RA4 with respect to Vss ............................................................................................................... 0V to +8.5V

Total power dissipation (Note 1) ...............................................................................................................................1.0W

Maximum current out of VSS pin ...........................................................................................................................300 mA

Maximum current into VDD pin ..............................................................................................................................250 mA

Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA

Output clamp current, IOK (VO < 0 or VO > VDD).............................................................................................................. ±20 mA

Maximum output current sunk by any I/O pin..........................................................................................................25 mA

Maximum output current sourced by any I/O pin ....................................................................................................25 mA

Maximum current sunk by PORTA, PORTB, and PORTE (Note 3) (combined)...................................................200 mA

Maximum current sourced by PORTA, PORTB, and PORTE (Note 3) (combined)..............................................200 mA

Maximum current sunk by PORTC and PORTD (Note 3) (combined)..................................................................200 mA

Maximum current sourced by PORTC and PORTD (Note 3) (combined).............................................................200 mA

Note 1: Power dissipation is calculated as follows:

Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD-VOH) x IOH} + ∑(VOl x IOL)

2: Voltage spikes below VSS at the MCLR/VPP pin, inducing currents greater than 80 mA, may cause latchup.

Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP pin, rather

than pulling this pin directly to VSS.

3: PORTD and PORTE not available on the PIC18F2X2 devices.

† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the

device. This is a stress rating only and functional operation of the device at those or any other conditions above those

indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for

extended periods may affect device reliability.

PIC18FXX2

FIGURE 22-1: PIC18FXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)

FIGURE 22-2: PIC18LFXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)

Frequency

Voltage

6.0V

5.5V

4.5V

4.0V

2.0V

40 MHz

5.0V

3.5V

3.0V

2.5V

PIC18FXXX

4.2V

Frequency

Voltage

6.0V

5.5V

4.5V

4.0V

2.0V

40 MHz

5.0V

3.5V

3.0V

2.5V

PIC18LFXXX

FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz

Note: VDDAPPMIN is the minimum voltage of the PICmicro® device in the application.

4 MHz

4.2V

PIC18FXX2

22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial)

PIC18LFXX2

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18FXX2

(Industrial, Extended)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

VDD Supply Voltage

D001 PIC18LFXX2 2.0 — 5.5 V HS, XT, RC and LP Osc mode

D001 PIC18FXX2 4.2 —5.5 V

D002 VDR RAM Data Retention

Voltage(1)

1.5 — — V

D003 VPOR VDD Start Voltage

to ensure internal

Power-on Reset signal

— — 0.7 V See Section 3.1 (Power-on Reset) for details

D004 SVDD VDD Rise Rate

to ensure internal

Power-on Reset signal

0.05 — — V/ms See Section 3.1 (Power-on Reset) for details

VBOR Brown-out Reset Voltage

D005 PIC18LFXX2

BORV1:BORV0 = 11 1.98 — 2.14 V 85°C ≥ T ≥ 25°C

BORV1:BORV0 = 10 2.67 — 2.89 V

BORV1:BORV0 = 01 4.16 — 4.5 V

BORV1:BORV0 = 00 4.45 — 4.83 V

D005 PIC18FXX2

BORV1:BORV0 = 1x N.A. —N.A. VNot in operating voltage range of device

BORV1:BORV0 = 01 4.16 —4.5 V

BORV1:BORV0 = 00 4.45 —4.83 V

Legend: Shading of rows is to assist in readability of the table.

Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.

2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin

loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an

impact on the current consumption.

The test conditions for all IDD measurements in active Operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD

MCLR = VDD; WDT enabled/disabled as specified.

3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is

measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all

features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).

4: For RC osc configuration, current through REXT is not included. The current through the resistor can be

estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.

5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.

Once one of these modules is enabled, the other may also be enabled without further penalty.

PIC18FXX2

IDD Supply Current(2,4)

D010 PIC18LFXX2

—

1.2

1.5

.75

1.25

XT osc configuration

VDD = 2.0V, +25°C, FOSC = 4 MHz

VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

RC osc configuration

VDD = 2.0V, +25°C, FOSC = 4 MHz

VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

RCIO osc configuration

VDD = 2.0V, +25°C, FOSC = 4 MHz

VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

D010 PIC18FXX2

—

1.2

1.5

1.6

.75

1.5

XT osc configuration

VDD = 4.2V, +25°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz

RC osc configuration

VDD = 4.2V, +25°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz

RCIO osc configuration

VDD = 4.2V, +25°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz

VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz

D010A PIC18LFXX2

—1430μA

LP osc, FOSC = 32 kHz, WDT disabled

VDD = 2.0V, -40°C to +85°C

D010A PIC18FXX2

—

100

μA

LP osc, FOSC = 32 kHz, WDT disabled

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial) (Continued)

PIC18LFXX2

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18FXX2

(Industrial, Extended)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

Legend: Shading of rows is to assist in readability of the table.

Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.

2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin

loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an

impact on the current consumption.

The test conditions for all IDD measurements in active Operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD

MCLR = VDD; WDT enabled/disabled as specified.

3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is

measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all

features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).

4: For RC osc configuration, current through REXT is not included. The current through the resistor can be

estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.

5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.

Once one of these modules is enabled, the other may also be enabled without further penalty.

PIC18FXX2

IDD Supply Current(2,4) (Continued)

D010C PIC18LFXX2

—1025mA

EC, ECIO osc configurations

VDD = 4.2V, -40°C to +85°C

D010C PIC18FXX2

—10 25 mA

EC, ECIO osc configurations

VDD = 4.2V, -40°C to +125°C

D013 PIC18LFXX2

—

HS osc configuration

FOSC = 4 MHz, VDD = 2.0V

FOSC = 25 MHz, VDD = 5.5V

HS + PLL osc configurations

FOSC = 10 MHz, VDD = 5.5V

D013 PIC18FXX2

—

HS osc configuration

FOSC = 25 MHz, VDD = 5.5V

HS + PLL osc configurations

FOSC = 10 MHz, VDD = 5.5V

D014 PIC18LFXX2

—1555μA

Timer1 osc configuration

FOSC = 32 kHz, VDD = 2.0V

D014 PIC18FXX2

—

200

250

μA

Timer1 osc configuration

FOSC = 32 kHz, VDD = 4.2V, -40°C to +85°C

FOSC = 32 kHz, VDD = 4.2V, -40°C to +125°C

IPD Power-down Current(3)

D020 PIC18LFXX2 —

—

.08

μA

VDD = 2.0V, +25°C

VDD = 2.0V, -40°C to +85°C

VDD = 4.2V, -40°C to +85°C

D020

D021B

PIC18FXX2 —

—

μA

VDD = 4.2V, +25°C

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial) (Continued)

PIC18LFXX2

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18FXX2

(Industrial, Extended)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

Legend: Shading of rows is to assist in readability of the table.

Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.

2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin

loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an

impact on the current consumption.

The test conditions for all IDD measurements in active Operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD

MCLR = VDD; WDT enabled/disabled as specified.

3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is

measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all

features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).

4: For RC osc configuration, current through REXT is not included. The current through the resistor can be

estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.

5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.

Once one of these modules is enabled, the other may also be enabled without further penalty.

PIC18FXX2

Module Differential Current

D022 ΔIWDT Watchdog Timer

PIC18LFXX2

—

.75

1.5

μA

VDD = 2.0V, +25°C

VDD = 2.0V, -40°C to +85°C

VDD = 4.2V, -40°C to +85°C

D022 Watchdog Timer

PIC18FXX2

—

μA

VDD = 4.2V, +25°C

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

D022A ΔIBOR Brown-out Reset(5)

PIC18LFXX2

—

μA

VDD = 2.0V, +25°C

VDD = 2.0V, -40°C to +85°C

VDD = 4.2V, -40°C to +85°C

D022A Brown-out Reset(5)

PIC18FXX2

—

μA

VDD = 4.2V, +25°C

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

D022B ΔILVD Low Voltage Detect(5)

PIC18LFXX2

—

μA

VDD = 2.0V, +25°C

VDD = 2.0V, -40°C to +85°C

VDD = 4.2V, -40°C to +85°C

D022B Low Voltage Detect(5)

PIC18FXX2

—

μA

VDD = 4.2V, +25°C

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

D025 ΔITMR1Timer1 Oscillator

PIC18LFXX2

—

5.2

6.5

μA

VDD = 2.0V, +25°C

VDD = 2.0V, -40°C to +85°C

VDD = 4.2V, -40°C to +85°C

D025 Timer1 Oscillator

PIC18FXX2

—

6.5

μA

VDD = 4.2V, +25°C

VDD = 4.2V, -40°C to +85°C

VDD = 4.2V, -40°C to +125°C

22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial) (Continued)

PIC18LFXX2

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18FXX2

(Industrial, Extended)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

Legend: Shading of rows is to assist in readability of the table.

Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.

2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin

loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an

impact on the current consumption.

The test conditions for all IDD measurements in active Operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD

MCLR = VDD; WDT enabled/disabled as specified.

3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is

measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all

features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).

4: For RC osc configuration, current through REXT is not included. The current through the resistor can be

estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.

5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.

Once one of these modules is enabled, the other may also be enabled without further penalty.

PIC18FXX2

22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial)

DC CHARACTERISTICS

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Max Units Conditions

VIL Input Low Voltage

I/O ports:

D030 with TTL buffer Vss 0.15 VDD VVDD < 4.5V

D030A — 0.8 V 4.5V ≤ VDD ≤ 5.5V

D031 with Schmitt Trigger buffer

RC3 and RC4

Vss

0.2 VDD

0.3 VDD

D032 MCLR VSS 0.2 VDD V

D032A OSC1 (in XT, HS and LP modes)

and T1OSI

VSS 0.3 VDD V

D033 OSC1 (in RC and EC mode)(1) VSS 0.2 VDD V

VIH Input High Voltage

I/O ports:

D040 with TTL buffer 0.25 VDD +

0.8V

VDD VVDD < 4.5V

D040A 2.0 VDD V4.5V ≤ VDD ≤ 5.5V

D041 with Schmitt Trigger buffer

RC3 and RC4

0.8 VDD

0.7 VDD

VDD

D042 MCLR, OSC1 (EC mode) 0.8 VDD VDD V

D042A OSC1 (in XT, HS and LP modes)

and T1OSI

0.7 VDD VDD V

D043 OSC1 (RC mode)(1) 0.9 VDD VDD V

IIL Input Leakage Current(2,3)

D060 I/O ports .02 ±1μAVSS ≤ VPIN ≤ VDD,

Pin at hi-impedance

D061 MCLR —±1μA Vss ≤ VPIN ≤ VDD

D063 OSC1 — ±1μA Vss ≤ VPIN ≤ VDD

IPU Weak Pull-up Current

D070 IPURB PORTB weak pull-up current 50 450 μAVDD = 5V, VPIN = VSS

Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the

PICmicro device be driven with an external clock while in RC mode.

2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified

levels represent normal operating conditions. Higher leakage current may be measured at different input

voltages.

3: Negative current is defined as current sourced by the pin.

4: Parameter is characterized but not tested.

PIC18FXX2

VOL Output Low Voltage

D080 I/O ports — 0.6 V IOL = 8.5 mA, VDD = 4.5V,

-40°C to +85°C

D080A — 0.6 V IOL = 7.0 mA, VDD = 4.5V,

-40°C to +125°C

D083 OSC2/CLKO

(RC mode)

—0.6VI

OL = 1.6 mA, VDD = 4.5V,

-40°C to +85°C

D083A — 0.6 V IOL = 1.2 mA, VDD = 4.5V,

-40°C to +125°C

VOH Output High Voltage(3)

D090 I/O ports VDD – 0.7 — V IOH = -3.0 mA, VDD = 4.5V,

-40°C to +85°C

D090A VDD – 0.7 — V IOH = -2.5 mA, VDD = 4.5V,

-40°C to +125°C

D092 OSC2/CLKO

(RC mode)

VDD – 0.7 — V IOH = -1.3 mA, VDD = 4.5V,

-40°C to +85°C

D092A VDD – 0.7 — V IOH = -1.0 mA, VDD = 4.5V,

-40°C to +125°C

D150 VOD Open Drain High Voltage — 8.5 V RA4 pin

Capacitive Loading Specs

on Output Pins

D100(4) COSC2 OSC2 pin —15 pF In XT, HS and LP modes

when external clock is used

to drive OSC1

D101 CIO All I/O pins and OSC2

(in RC mode)

— 50 pF To meet the AC Timing

Specifications

D102 CBSCL, SDA — 400 pF In I2C mode

22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended)

PIC18LFXX2 (Industrial) (Continued)

DC CHARACTERISTICS

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Max Units Conditions

Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the

PICmicro device be driven with an external clock while in RC mode.

2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified

levels represent normal operating conditions. Higher leakage current may be measured at different input

voltages.

3: Negative current is defined as current sourced by the pin.

4: Parameter is characterized but not tested.

PIC18FXX2

FIGURE 22-3: LOW VOLTAGE DETECT CHARACTERISTICS

TABLE 22-1: LOW VOLTAGE DETECT CHARACTERISTICS

VLVD

LVDIF

VDD

(LVDIF set by hardware)

(LVDIF can be

cleared in software)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ T

A ≤ +85°C for industrial

-40°C ≤ T

A ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

D420 VLVD LVD Voltage on VDD

transition high to

low

LVV = 0001 1.98 2.06 2.14 V T ≥ 25°C

LVV = 0010 2.18 2.27 2.36 V T ≥ 25°C

LVV = 0011 2.37 2.47 2.57 V T ≥ 25°C

LVV = 0100 2.48 2.58 2.68 V

LVV = 0101 2.67 2.78 2.89 V

LVV = 0110 2.77 2.89 3.01 V

LVV = 0111 2.98 3.1 3.22 V

LVV = 1000 3.27 3.41 3.55 V

LVV = 1001 3.47 3.61 3.75 V

LVV = 1010 3.57 3.72 3.87 V

LVV = 1011 3.76 3.92 4.08 V

LVV = 1100 3.96 4.13 4.3 V

LVV = 1101 4.16 4.33 4.5 V

LVV = 1110 4.45 4.64 4.83 V

PIC18FXX2

TABLE 22-2: MEMORY PROGRAMMING REQUIREMENTS

DC Characteristics

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Sym Characteristic Min Typ† Max Units Conditions

Internal Program Memory

Programming Specifications

D110 VPP Voltage on MCLR/VPP pin 9.00 — 13.25 V

D113 IDDP Supply Current during

Programming

——10mA

Data EEPROM Memory

D120 EDCell Endurance 100K 1M — E/W -40°C to +85°C

D121 VDRW VDD for Read/Write VMIN —5.5 V Using EECON to read/write

VMIN = Minimum operating

voltage

D122 TDEW Erase/Write Cycle Time —4—ms

D123 TRETD Characteristic Retention 40 — — Year Provided no other

specifications are violated

D124 TREF Number of Total Erase/Write

Cycles before Refresh(1)

1M 10M — E/W -40°C to +85°C

Program FLASH Memory

D130 EPCell Endurance 10K 100K —E/W -40°C to +85°C

D131 VPR VDD for Read VMIN —5.5 V VMIN = Minimum operating

voltage

D132 VIE VDD for Block Erase 4.5 —5.5 V Using ICSP port

D132A VIW VDD for Externally Timed Erase

or Write

4.5 —5.5 V Using ICSP port

D132B VPEW VDD for Self-timed Write VMIN —5.5 V VMIN = Minimum operating

voltage

D133 TIE ICSP Block Erase Cycle Time —4—ms VDD ≥ 4.5V

D133A TIW ICSP Erase or Write Cycle Time

(externally timed)

1——

ms VDD ≥ 4.5V

D133A TIW Self-timed Write Cycle Time —2—ms

D134 TRETD Characteristic Retention 40 — — Year Provided no other

specifications are violated

† Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance

only and are not tested.

Note 1: Refer to Section 6.8 for a more detailed discussion on data EEPROM endurance.

PIC18FXX2

22.3 AC (Timing) Characteristics

22.3.1 TIMING PARAMETER SYMBOLOGY

The timing parameter symbols have been created

following one of the following formats:

1. TppS2ppS 3. TCC:ST (I2C specifications only)

2. TppS 4. Ts (I2C specifications only)

F Frequency T Time

Lowercase letters (pp) and their meanings:

cc CCP1 osc OSC1

ck CLKO rd RD

cs CS rw RD or WR

di SDI sc SCK

do SDO ss SS

dt Data in t0 T0CKI

io I/O port t1 T1CKI

mc MCLR wr WR

Uppercase letters and their meanings:

F Fall P Period

HHigh RRise

I Invalid (Hi-impedance) V Valid

L Low Z Hi-impedance

I2C only

AA output access High High

BUF Bus free Low Low

TCC:ST (I2C specifications only)

HD Hold SU Setup

DAT DATA input hold STO STOP condition

STA START condition

PIC18FXX2

22.3.2 TIMING CONDITIONS

The temperature and voltages specified in Table 22-3

apply to all timing specifications unless otherwise

noted. Figure 22-4 specifies the load conditions for the

timing specifications.

TABLE 22-3: TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC

FIGURE 22-4: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS

AC CHARACTERISTICS

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Operating voltage VDD range as described in DC spec Section 22.1 and

Section 22.2.

LC parts operate for industrial temperatures only.

VDD/2

VSS

RL=464Ω

CL= 50 pF for all pins except OSC2/CLKO

and including D and E outputs as ports

Load condition 1 Load condition 2

PIC18FXX2

22.3.3 TIMING DIAGRAMS AND SPECIFICATIONS

FIGURE 22-5: EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)

TABLE 22-4: EXTERNAL CLOCK TIMING REQUIREMENTS

OSC1

CLKO

Q4 Q1 Q2 Q3 Q4 Q1

3344

Param.

No. Symbol Characteristic Min Max Units Conditions

1A FOSC External CLKI Frequency(1) DC 40 MHz EC, ECIO, -40°C to +85°C

Oscillator Frequency(1) DC 25 MHz EC, ECIO, +85°C to +125°C

DC 4 MHz RC osc

0.1 4 MHz XT osc

4 25 MHz HS osc

4 10 MHz HS + PLL osc, -40°C to +85°C

4 6.25 MHz HS + PLL osc, +85°C to +125°C

5 200 kHz LP Osc mode

1TOSC External CLKI Period(1) 25 — ns EC, ECIO, -40°C to +85°C

Oscillator Period(1) 40 — ns EC, ECIO, +85°C to +125°C

250 — ns RC osc

250 10,000 ns XT osc

40 250 ns HS osc

100 250 ns HS + PLL osc, -40°C to +85°C

160 250 ns HS + PLL osc, +85°C to +125°C

25 — μsLP osc

2TCY Instruction Cycle Time(1) 100 — ns TCY = 4/FOSC, -40°C to +85°C

160 — ns TCY = 4/FOSC, +85°C to +125°C

3 TosL,

To s H

External Clock in (OSC1)

High or Low Time

30 — ns XT osc

2.5 — μsLP osc

10 — ns HS osc

4TosR,

To s F

External Clock in (OSC1)

Rise or Fall Time

— 20 ns XT osc

— 50 ns LP osc

—7.5nsHS osc

Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period for all configurations

except PLL. All specified values are based on characterization data for that particular oscillator type under

standard operating conditions with the device executing code. Exceeding these specified limits may result in

an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to

operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock input

is used, the “max.” cycle time limit is “DC” (no clock) for all devices.

PIC18FXX2

TABLE 22-5: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2 TO 5.5V)

FIGURE 22-6: CLKO AND I/O TIMING

Param

No. Sym Characteristic Min Typ† Max Units Conditions

—F

OSC Oscillator Frequency Range 4 — 10 MHz HS mode only

—F

SYS On-chip VCO System Frequency 16 — 40 MHz HS mode only

—t

rc PLL Start-up Time (Lock Time) — — 2 ms

—ΔCLK CLKO Stability (Jitter) -2 — +2 %

† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only

and are not tested.

Note: Refer to Figure 22-4 for load conditions.

OSC1

CLKO

I/O Pin

(input)

I/O Pin

(output)

Q4 Q1 Q2 Q3

20, 21

19 18

Old Value New Value

PIC18FXX2

TABLE 22-6: CLKO AND I/O TIMING REQUIREMENTS

FIGURE 22-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP

TIMER TIMING

Param.

No. Symbol Characteristic Min Typ Max Units Conditions

10 TosH2ckL OSC1↑ to CLKO↓ —75200ns(Note 1)

11 TosH2ckH OSC1↑ to CLKO↑ —75200ns(Note 1)

12 TckR CLKO rise time — 35 100 ns (Note 1)

13 TckF CLKO fall time — 35 100 ns (Note 1)

14 TckL2ioV CLKO↓ to Port out valid — — 0.5 T

CY + 20 ns (Note 1)

15 TioV2ckH Port in valid before CLKO ↑ 0.25 TCY + 25 — — ns (Note 1)

16 TckH2ioI Port in hold after CLKO ↑ 0——ns(Note 1)

17 TosH2ioV OSC1↑ (Q1 cycle) to Port out valid — 50 150 ns

18 TosH2ioI OSC1↑ (Q2 cycle) to Port

input invalid (I/O in hold time)

PIC18FXXX 100 — — ns

18A PIC18LFXXX 200 — — ns

19 TioV2osH Port input valid to OSC1↑ (I/O in setup time) 0 — — ns

20 TioR Port output rise time PIC18FXXX — 10 25 ns

20A PIC18LFXXX — — 60 ns VDD = 2V

21 TioF Port output fall time PIC18FXXX — 10 25 ns

21A PIC18LFXXX — — 60 ns VDD = 2V

22†† TINP INT pin high or low time TCY ——ns

23†† TRBP RB7:RB4 change INT high or low time TCY ——ns

24†† TRCP RC7:RC4 change INT high or low time 20 ns

†† These parameters are asynchronous events not related to any internal clock edges.

Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.

VDD

MCLR

Internal

POR

PWRT

Time-out

OSC

Time-out

Internal

Reset

Watchdog

Timer

Reset

I/O Pins

Note: Refer to Figure 22-4 for load conditions.

PIC18FXX2

FIGURE 22-8: BROWN-OUT RESET TIMING

TABLE 22-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER

AND BROWN-OUT RESET REQUIREMENTS

VDD

BVDD

VBGAP = 1.2V

VIRVST

Enable Internal Reference Voltage

Internal Reference Voltage stable 36

Typical

Param.

No. Symbol Characteristic Min Typ Max Units Conditions

30 TmcL MCLR Pulse Width (low) 2 — — μs

31 TWDT Watchdog Timer Time-out Period

(No Postscaler)

71833ms

32 T

OST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC —TOSC = OSC1 period

33 TPWRT Power up Timer Period 28 72 132 ms

34 TIOZ I/O Hi-impedance from MCLR Low

or Watchdog Timer Reset

—2—μs

35 TBOR Brown-out Reset Pulse Width 200 — — μsVDD ≤ BVDD (see

D005)

36 TIVRST Time for Internal Reference

Voltage to become stable

—20500μs

37 TLVD Low Voltage Detect Pulse Width 200 — — μsVDD ≤ VLVD (see

D420)

PIC18FXX2

FIGURE 22-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS

TABLE 22-8: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS

Note: Refer to Figure 22-4 for load conditions.

T0CKI

T1OSO/T1CKI

TMR0 or

TMR1

Param

No. Symbol Characteristic Min Max Units Conditions

40 Tt0H T0CKI High Pulse Width No Prescaler 0.5TCY + 20 — ns

With Prescaler 10 — ns

41 Tt0L T0CKI Low Pulse Width No Prescaler 0.5TCY + 20 — ns

With Prescaler 10 — ns

42 Tt0P T0CKI Period No Prescaler T

CY + 10 — ns

With Prescaler Greater of:

20 nS or TCY + 40

— ns N = prescale

value

(1, 2, 4,..., 256)

45 Tt1H T1CKI High

Time

Synchronous, no prescaler 0.5TCY + 20 — ns

Synchronous,

with prescaler

PIC18FXXX 10 — ns

PIC18LFXXX 25 — ns

Asynchronous PIC18FXXX 30 — ns

PIC18LFXXX 50 — ns

46 Tt1L T1CKI Low

Time

Synchronous, no prescaler 0.5TCY + 5 — ns

Synchronous,

with prescaler

PIC18FXXX 10 — ns

PIC18LFXXX 25 — ns

Asynchronous PIC18FXXX 30 — ns

PIC18LFXXX 50 — ns

47 Tt1P T1CKI input

period

Synchronous Greater of:

20 nS or TCY + 40

— ns N = prescale

value

(1, 2, 4, 8)

Asynchronous 60 — ns

Ft1 T1CKI oscillator input frequency range DC 50 kHz

48 Tcke2tmrI Delay from external T1CKI clock edge to timer

increment

2 TOSC 7 TOSC —

PIC18FXX2

FIGURE 22-10: CAPTURE/COMPARE/PWM TIMINGS (CCP1 AND CCP2)

TABLE 22-9: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1 AND CCP2)

Note: Refer to Figure 22-4 for load conditions.

CCPx

(Capture Mode)

50 51

CCPx

53 54

(Compare or PWM Mode)

Param.

No. Symbol Characteristic Min Max Units Conditions

50 TccL CCPx input low

time

No Prescaler 0.5 TCY + 20 — ns

With

Prescaler

PIC18FXXX 10 — ns

PIC18LFXXX 20 — ns

51 TccH CCPx input

high time

No Prescaler 0.5 TCY + 20 — ns

With

Prescaler

PIC18FXXX 10 — ns

PIC18LFXXX 20 — ns

52 TccP CCPx input period 3 TCY + 40

—nsN = prescale

value (1,4 or 16)

53 TccR CCPx output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

54 TccF CCPx output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

PIC18FXX2

FIGURE 22-11: PARALLEL SLAVE PORT TIMING (PIC18F4X2)

TABLE 22-10: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F4X2)

Note: Refer to Figure 22-4 for load conditions.

RE2/CS

RE0/RD

RE1/WR

RD7:RD0

Param.

No. Symbol Characteristic Min Max Units Conditions

62 TdtV2wrH Data in valid before WR↑ or CS↑

(setup time)

—

ns Extended Temp. Range

63 TwrH2dtI WR↑ or CS↑ to data–in invalid

(hold time)

PIC18FXXX 20 — ns

PIC18LFXXX 35 — ns VDD = 2V

64 TrdL2dtV RD↓ and CS↓ to data–out valid —

—

ns Extended Temp. Range

65 TrdH2dtI RD↑ or CS↓ to data–out invalid 10 30 ns

66 TibfINH Inhibit of the IBF flag bit being cleared from

WR↑ or CS↑

—3 T

PIC18FXX2

FIGURE 22-12: EXAMPLE SPI MASTER MODE TIMING (CKE = 0)

TABLE 22-11: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)

Param.

No. Symbol Characteristic Min Max Units Conditions

70 TssL2scH,

TssL2 scL

SS↓ to SCK↓ or SCK↑ input TCY —ns

71 TscH SCK input high time

(Slave mode)

Continuous 1.25 T

CY + 30 — ns

71A Single Byte 40 — ns (Note 1)

72 TscL SCK input low time

(Slave mode)

Continuous 1.25 T

CY + 30 — ns

72A Single Byte 40 — ns (Note 1)

73 TdiV2scH,

TdiV2scL

Setup time of SDI data input to SCK edge 100 — ns

73A TB2BLast clock edge of Byte1 to the 1st clock edge of Byte2 1.5 TCY + 40 — ns (Note 2)

74 TscH2diL,

TscL2diL

Hold time of SDI data input to SCK edge 100 — ns

75 TdoR SDO data output rise time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

76 TdoF SDO data output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

78 TscR SCK output rise time

(Master mode)

PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

80 TscH2doV,

TscL2doV

SDO data output valid after SCK

edge

PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

Note 1: Requires the use of Parameter # 73A.

2: Only if Parameter # 71A and # 72A are used.

SCK

(CKP = 0)

SCK

(CKP = 1)

SDO

SDI

71 72

75, 76

MSb LSb

bit6 - - - - - -1

MSb In LSb In

bit6 - - - -1

Note: Refer to Figure 22-4 for load conditions.

PIC18FXX2

FIGURE 22-13: EXAMPLE SPI MASTER MODE TIMING (CKE = 1)

TABLE 22-12: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)

Param.

No. Symbol Characteristic Min Max Units Conditions

71 TscH SCK input high time

(Slave mode)

Continuous 1.25 TCY + 30 — ns

71A Single Byte 40 — ns (Note 1)

72 TscL SCK input low time

(Slave mode)

Continuous 1.25 TCY + 30 — ns

72A Single Byte 40 — ns (Note 1)

73 TdiV2scH,

TdiV2scL

Setup time of SDI data input to SCK edge 100 — ns

73A TB2BLast clock edge of Byte1 to the 1st clock edge of Byte2 1.5 TCY + 40 — ns (Note 2)

74 TscH2diL,

TscL2diL

Hold time of SDI data input to SCK edge 100 — ns

75 TdoR SDO data output rise time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

76 TdoF SDO data output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

80 TscH2doV,

TscL2doV

SDO data output valid after SCK

edge

PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

81 TdoV2scH,

TdoV2scL

SDO data output setup to SCK edge TCY —ns

Note 1: Requires the use of Parameter # 73A.

2: Only if Parameter # 71A and # 72A are used.

SCK

(CKP = 0)

SCK

(CKP = 1)

SDO

SDI

71 72

75, 76

MSb

MSb In

bit6 - - - - - -1

LSb In

bit6 - - - -1

LSb

Note: Refer to Figure 22-4 for load conditions.

PIC18FXX2

FIGURE 22-14: EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)

TABLE 22-13: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING (CKE = 0))

Param. No. Symbol Characteristic Min Max Units Conditions

70 TssL2scH,

Ts s L 2 sc L

SS↓ to SCK↓ or SCK↑ input TCY —ns

71 TscH SCK input high time (Slave mode) Continuous 1.25 TCY + 30 — ns

71A Single Byte 40 — ns (Note 1)

72 TscL SCK input low time (Slave mode) Continuous 1.25 TCY + 30 — ns

72A Single Byte 40 — ns (Note 1)

73 TdiV2scH,

TdiV2scL

Setup time of SDI data input to SCK edge 100 — ns

73A TB2BLast clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40 — ns (Note 2)

74 TscH2diL,

TscL2diL

Hold time of SDI data input to SCK edge 100 — ns

75 TdoR SDO data output rise time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

76 TdoF SDO data output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

77 TssH2doZ SS↑ to SDO output hi-impedance 10 50 ns

78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

80 TscH2doV,

TscL2doV

SDO data output valid after SCK edge PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

83 TscH2ssH,

Ts c L 2 ss H

SS ↑ after SCK edge 1.5 TCY + 40 — ns

Note 1: Requires the use of Parameter # 73A.

2: Only if Parameter # 71A and # 72A are used.

SCK

(CKP = 0)

SCK

(CKP = 1)

SDO

SDI

71 72

73 74

75, 76 77

SDI

MSb LSb

bit6 - - - - - -1

MSb In bit6 - - - -1 LSb In

Note: Refer to Figure 22-4 for load conditions.

PIC18FXX2

FIGURE 22-15: EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)

TABLE 22-14: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)

Param. No. Symbol Characteristic Min Max Units Conditions

70 TssL2scH,

Ts s L 2 sc L

SS↓ to SCK↓ or SCK↑ input TCY —ns

71 TscH SCK input high time

(Slave mode)

Continuous 1.25 TCY + 30 — ns

71A Single Byte 40 — ns (Note 1)

72 TscL SCK input low time

(Slave mode)

Continuous 1.25 TCY + 30 — ns

72A Single Byte 40 — ns (Note 1)

73A TB2BLast clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40 — ns (Note 2)

74 TscH2diL,

TscL2diL

Hold time of SDI data input to SCK edge 100 — ns

75 TdoR SDO data output rise time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

76 TdoF SDO data output fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

77 TssH2doZ SS↑ to SDO output hi-impedance 10 50 ns

78 TscR SCK output rise time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

79 TscF SCK output fall time (Master mode) PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

80 TscH2doV,

TscL2doV

SDO data output valid after SCK

edge

PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

82 TssL2doV SDO data output valid after SS↓ edge PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

83 TscH2ssH,

Ts c L 2 ss H

SS ↑ after SCK edge 1.5 TCY + 40 — ns

Note 1: Requires the use of Parameter # 73A.

2: Only if Parameter # 71A and # 72A are used.

SCK

(CKP = 0)

SCK

(CKP = 1)

SDO

SDI

71 72

75, 76

MSb bit6 - - - - - -1 LSb

MSb In bit6 - - - -1 LSb In

Note: Refer to Figure 22-4 for load conditions.

PIC18FXX2

FIGURE 22-16: I2C BUS START/STOP BITS TIMING

TABLE 22-15: I2C BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)

FIGURE 22-17: I2C BUS DATA TIMING

Note: Refer to Figure 22-4 for load conditions.

SCL

SDA

START

Condition

STOP

Condition

Param.

No. Symbol Characteristic Min Max Units Conditions

90 TSU:STA START condition 100 kHz mode 4700 — ns Only relevant for Repeated

START condition

Setup time 400 kHz mode 600 —

91 THD:STA START condition 100 kHz mode 4000 — ns After this period, the first

clock pulse is generated

Hold time 400 kHz mode 600 —

92 TSU:STO STOP condition 100 kHz mode 4700 — ns

Setup time 400 kHz mode 600 —

93 THD:STO STOP condition 100 kHz mode 4000 — ns

Hold time 400 kHz mode 600 —

Note: Refer to Figure 22-4 for load conditions.

91 92

100

101

103

106 107

109 109

110

102

SCL

SDA

Out

PIC18FXX2

TABLE 22-16: I2C BUS DATA REQUIREMENTS (SLAVE MODE)

Param.

No. Symbol Characteristic Min Max Units Conditions

100 THIGH Clock high time 100 kHz mode 4.0 — μs PIC18FXXX must operate at a

minimum of 1.5 MHz

400 kHz mode 0.6 — μs PIC18FXXX must operate at a

minimum of 10 MHz

SSP Module 1.5 TCY —

101 TLOW Clock low time 100 kHz mode 4.7 — μs PIC18FXXX must operate at a

minimum of 1.5 MHz

400 kHz mode 1.3 — μs PIC18FXXX must operate at a

minimum of 10 MHz

SSP Module 1.5 TCY —

102 TRSDA and SCL rise

time

100 kHz mode — 1000 ns

400 kHz mode 20 + 0.1 CB300 ns CB is specified to be from

10 to 400 pF

103 TFSDA and SCL fall

time

100 kHz mode — 1000 ns VDD ≥ 4.2V

400 kHz mode 20 + 0.1 CB300 ns VDD ≥ 4.2V

90 TSU:STA START condition

setup time

100 kHz mode 4.7 — μs Only relevant for Repeated

START condition

400 kHz mode 0.6 — μs

91 THD:STA START condition hold

time

100 kHz mode 4.0 — μs After this period, the first clock

pulse is generated

400 kHz mode 0.6 — μs

106 THD:DAT Data input hold time 100 kHz mode 0 — ns

400 kHz mode 0 0.9 μs

107 TSU:DAT Data input setup time 100 kHz mode 250 — ns (Note 2)

400 kHz mode 100 — ns

92 TSU:STO STOP condition

setup time

100 kHz mode 4.7 — μs

400 kHz mode 0.6 — μs

109 TAA Output valid from

clock

100 kHz mode — 3500 ns (Note 1)

400 kHz mode — — ns

110 TBUF Bus free time 100 kHz mode 4.7 — μs Time the bus must be free

before a new transmission can

start

400 kHz mode 1.3 — μs

D102 CBBus capacitive loading — 400 pF

Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of

the falling edge of SCL to avoid unintended generation of START or STOP conditions.

2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but the requirement TSU:DAT ≥250 ns

must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If

such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line.

TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification) before the SCL line is

released.

PIC18FXX2

FIGURE 22-18: MASTER SSP I2C BUS START/STOP BITS TIMING WAVEFORMS

TABLE 22-17: MASTER SSP I2C BUS START/STOP BITS REQUIREMENTS

FIGURE 22-19: MASTER SSP I2C BUS DATA TIMING

Note: Refer to Figure 22-4 for load conditions.

91 93

SCL

SDA

START

Condition

STOP

Condition

90 92

Param.

No. Symbol Characteristic Min Max Units Conditions

90 TSU:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) — ns Only relevant for

Repeated START

condition

Setup time 400 kHz mode 2(TOSC)(BRG + 1) —

1 MHz mode(1) 2(TOSC)(BRG + 1) —

91 THD:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) — ns After this period, the

first clock pulse is

generated

Hold time 400 kHz mode 2(TOSC)(BRG + 1) —

1 MHz mode(1) 2(TOSC)(BRG + 1) —

92 TSU:STO STOP condition 100 kHz mode 2(TOSC)(BRG + 1) — ns

Setup time 400 kHz mode 2(TOSC)(BRG + 1) —

1 MHz mode(1) 2(TOSC)(BRG + 1) —

93 THD:STO STOP condition 100 kHz mode 2(TOSC)(BRG + 1) — ns

Hold time 400 kHz mode 2(TOSC)(BRG + 1) —

1 MHz mode(1) 2(TOSC)(BRG + 1) —

Note 1: Maximum pin capacitance = 10 pF for all I2C pins.

Note: Refer to Figure 22-4 for load conditions.

90 91 92

100

101

103

106 107

109 109 110

102

SCL

SDA

Out

PIC18FXX2

TABLE 22-18: MASTER SSP I2C BUS DATA REQUIREMENTS

Param.

No. Symbol Characteristic Min Max Units Conditions

100 THIGH Clock high time 100 kHz mode 2(TOSC)(BRG + 1) — ms

400 kHz mode 2(T

OSC)(BRG + 1) — ms

1 MHz mode(1) 2(TOSC)(BRG + 1) — ms

101 TLOW Clock low time 100 kHz mode 2(TOSC)(BRG + 1) — ms

400 kHz mode 2(T

OSC)(BRG + 1) — ms

1 MHz mode(1) 2(TOSC)(BRG + 1) — ms

102 TRSDA and SCL

rise time

100 kHz mode — 1000 ns CB is specified to be from

10 to 400 pF

400 kHz mode 20 + 0.1 CB300 ns

1 MHz mode(1) — 300 ns

103 TFSDA and SCL

fall time

100 kHz mode — 1000 ns VDD ≥ 4.2V

400 kHz mode 20 + 0.1 CB 300 ns VDD ≥ 4.2V

90 TSU:STA START condition

setup time

100 kHz mode 2(TOSC)(BRG + 1) — ms Only relevant for

Repeated START

condition

400 kHz mode 2(TOSC)(BRG + 1) — ms

1 MHz mode(1) 2(TOSC)(BRG + 1) — ms

91 THD:STA START condition

hold time

100 kHz mode 2(TOSC)(BRG + 1) — ms After this period, the first

clock pulse is generated

400 kHz mode 2(TOSC)(BRG + 1) — ms

1 MHz mode(1) 2(TOSC)(BRG + 1) — ms

106 THD:DAT Data input

hold time

100 kHz mode 0 — ns

400 kHz mode 0 0.9 ms

107 T

SU:DAT Data input

setup time

100 kHz mode 250 — ns (Note 2)

400 kHz mode 100 — ns

92 T

SU:STO STOP condition

setup time

100 kHz mode 2(TOSC)(BRG + 1) — ms

400 kHz mode 2(TOSC)(BRG + 1) — ms

1 MHz mode(1) 2(TOSC)(BRG + 1) — ms

109 TAA Output valid from

clock

100 kHz mode — 3500 ns

400 kHz mode — 1000 ns

1 MHz mode(1) ——ns

110 TBUF Bus free time 100 kHz mode 4.7 — ms Time the bus must be free

before a new transmission

can start

400 kHz mode 1.3 — ms

D102 CBBus capacitive loading — 400 pF

Note 1: Maximum pin capacitance = 10 pF for all I2C pins.

2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 ≥250 ns

must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL

signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the

SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line

is released.

PIC18FXX2

FIGURE 22-20: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING

TABLE 22-19: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS

FIGURE 22-21: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING

TABLE 22-20: USART SYNCHRONOUS RECEIVE REQUIREMENTS

121 121

120 122

RC6/TX/CK

RC7/RX/DT

Note: Refer to Figure 22-4 for load conditions.

Param.

No. Symbol Characteristic Min Max Units Conditions

120 TckH2dtV SYNC XMIT (MASTER & SLAVE)

Clock high to data out valid PIC18FXXX — 50 ns

PIC18LFXXX — 150 ns VDD = 2V

121 Tckr Clock out rise time and fall time

(Master mode)

PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

122 Tdtr Data out rise time and fall time PIC18FXXX — 25 ns

PIC18LFXXX — 60 ns VDD = 2V

125

126

RC6/TX/CK

RC7/RX/DT

Note: Refer to Figure 22-4 for load conditions.

Param.

No. Symbol Characteristic Min Max Units Conditions

125 TdtV2ckl SYNC RCV (MASTER & SLAVE)

Data hold before CK ↓ (DT hold time) 10 — ns

126 TckL2dtl Data hold after CK ↓ (DT hold time) PIC18FXXX 15 — ns

PIC18LFXXX 20 — ns VDD = 2V

PIC18FXX2

TABLE 22-21: A/D CONVERTER CHARACTERISTICS: PIC18FXX2 (INDUSTRIAL, EXTENDED)

PIC18LFXX2 (INDUSTRIAL)

FIGURE 22-22: A/D CONVERSION TIMING

Param

No. Symbol Characteristic Min Typ Max Units Conditions

A01 NRResolution — — 10 bit

A03 EIL Integral linearity error — — <±1 LSb VREF = VDD = 5.0V

A04 EDL Differential linearity error — — <±1 LSb VREF = VDD = 5.0V

A05 EGGain error — — <±1 LSb VREF = VDD = 5.0V

A06 EOFF Offset error — — <±1.5 LSb VREF = VDD = 5.0V

A10 — Monotonicity guaranteed(2) —VSS ≤ VAIN ≤ VREF

A20

A20A

VREF Reference Voltage

(VREFH – VREFL)

1.8V

—

VDD < 3.0V

VDD ≥ 3.0V

A21 VREFH Reference voltage High AVSS —AVDD + 0.3V V

A22 VREFL Reference voltage Low AVSS – 0.3V — VREFH V

A25 VAIN Analog input voltage AVSS – 0.3V — AVDD + 0.3V V VDD ≥ 2.5V (Note 3)

A30 ZAIN Recommended impedance of

analog voltage source

—— 2.5kΩ(Note 4)

A50 IREF VREF input current (Note 1) —

—

150

μA

During VAIN acquisition

During A/D conversion cycle

Note 1: Vss ≤ VAIN ≤ VREF

2: The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes.

3: For VDD < 2.5V, VAIN should be limited to < .5 VDD.

4: Maximum allowed impedance for analog voltage source is 10 kΩ. This requires higher acquisition times.

131

130

132

BSF ADCON0, GO

A/D CLK

A/D DATA

ADRES

ADIF

SAMPLE

OLD_DATA

SAMPLING STOPPED

DONE

NEW_DATA

(Note 2)

987 21 0

Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts.

This allows the SLEEP instruction to be executed.

2: This is a minimal RC delay (typically 100 nS), which also disconnects the holding capacitor from the analog input.

. . . . . .

TCY

PIC18FXX2

TABLE 22-22: A/D CONVERSION REQUIREMENTS

Param

No. Symbol Characteristic Min Max Units Conditions

130 TAD A/D clock period PIC18FXXX 1.6 20(4) μsTOSC based

PIC18FXXX 2.0 6.0 μs A/D RC mode

131 TCNV Conversion time

(not including acquisition time) (Note 1)

11 12 TAD

132 TACQ Acquisition time (Note 2) 5

—

μs

VREF = VDD = 5.0V

VREF = VDD = 2.5V

135 TSWC Switching Time from convert → sample — (Note 3)

Note 1: ADRES register may be read on the following TCY cycle.

2: The time for the holding capacitor to acquire the “New” input voltage, when the new input value has not

changed by more than 1 LSB from the last sampled voltage. The source impedance (

) on the input channels

is 50Ω. See Section 17.0 for more information on acquisition time consideration.

3: On the next Q4 cycle of the device clock.

4: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.

PIC18FXX2

23.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES

“Typical” represents the mean of the distribution at 25°C. “Maximum” or “minimum” represents (mean + 3σ) or (mean - 3σ)

respectively, where σ is a standard deviation, over the whole temperature range.

FIGURE 23-1: TYPICAL IDD vs. FOSC OVER VDD (HS MODE)

FIGURE 23-2: MAXIMUM IDD vs. FOSC OVER VDD (HS MODE)

Note: The graphs and tables provided following this note are a statistical summary based on a limited number of

samples and are provided for informational purposes only. The performance characteristics listed herein are

not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified

operating range (e.g., outside specified power supply range) and therefore, outside the warranted range.

4 6 8 101214161820222426

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

4 6 8 101214161820222426

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-3: TYPICAL IDD vs. FOSC OVER VDD (HS/PLL MODE)

FIGURE 23-4: MAXIMUM IDD vs. FOSC OVER VDD (HS/PLL MODE)

45678910

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.2V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

45678910

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.2V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-5: TYPICAL IDD vs. FOSC OVER VDD (XT MODE)

FIGURE 23-6: MAXIMUM IDD vs. FOSC OVER VDD (XT MODE)

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

FOSC (MHz)

IDD (uA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

IDD (μA)

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

FOSC (MHz)

IDD (μA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-7: TYPICAL IDD vs. FOSC OVER VDD (LP MODE)

FIGURE 23-8: MAXIMUM IDD vs. FOSC OVER VDD (LP MODE)

100

20 30 40 50 60 70 80 90 100

FOSC (kHz)

IDD (uA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

100

120

140

20 30 40 50 60 70 80 90 100

FOSC (kHz)

IDD (uA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-9: TYPICAL IDD vs. FOSC OVER VDD (EC MODE)

FIGURE 23-10: MAXIMUM IDD vs. FOSC OVER VDD (EC MODE)

4 8 12 16 20 24 28 32 36 40

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

4.2V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

4 8 12 16 20 24 28 32 36 40

FOSC (MHz)

IDD (mA)

5.5V

5.0V

4.5V

4.0V

3.5V

3.0V

2.5V

2.0V

4.2V

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-11: TYPICAL AND MAXIMUM IDD vs. VDD

(TIMER1 AS MAIN OSCILLATOR, 32.768 kHz, C1 AND C2 = 47 pF)

FIGURE 23-12: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R

(RC MODE, C = 20 pF, +25°C)

100

120

140

160

180

2.02.53.03.54.04.55.05.5

VDD (V)

IPD (uA)

Typ (25C)

Max (70C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-10°C to 70°C)

Minimum: mean – 3σ (-10°C to 70°C)

IDD (μA)

Max (+70°C)

Typ (+25°C)

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

2.02.53.03.54.04.55.05.5

VDD (V)

Freq (kHz)

3.3kΩ

5.1kΩ

10kΩ

100kΩ

Operation above 4 MHz is not recommended.

PIC18FXX2

FIGURE 23-13: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R

(RC MODE, C = 100 pF, +25°C)

FIGURE 23-14: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R

(RC MODE, C = 300 pF, +25°C)

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

2.02.53.03.54.04.55.05.5

VDD (V)

Freq (kHz)

3.3kΩ

5.1kΩ

10kΩ

100kΩ

100

200

300

400

500

600

700

800

2.02.53.03.54.04.55.05.5

VDD (V)

Freq (MHz)

3.3kΩ

5.1kΩ

10kΩ

100kΩ

PIC18FXX2

FIGURE 23-15: IPD vs. VDD, -40°C TO +125°C (SLEEP MODE, ALL PERIPHERALS DISABLED)

FIGURE 23-16: ΔIBOR vs. VDD OVER TEMPERATURE (BOR ENABLED, VBOR = 2.00 - 2.16V)

0.01

0.1

100

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

IPD (uA)

Typ (+25°C)

Max

(+85°C)

Max

(-40°C to +125°C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

IDD (μA)

Max (125C)

Max (85C)

Typ (25C)

Device

Held in

Reset

Device

Sleep

Max (+125°C)

Max (+85°C)

Typ (+25°C)

Device

Held in

RESET

Device

SLEEP

PIC18FXX2

FIGURE 23-17: TYPICAL AND MAXIMUM ΔITMR1 vs. VDD OVER TEMPERATURE (-10°C TO +70°C,

TIMER1 WITH OSCILLATOR, XTAL = 32 kHz, C1 AND C2 = 47 pF)

FIGURE 23-18: TYPICAL AND MAXIMUM ΔIWDT vs. VDD OVER TEMPERATURE (WDT ENABLED)

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

IPD (uA)

Typ (25C)

Max (70C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-10°C to 70°C)

Minimum: mean – 3σ (-10°C to 70°C)

IPD (μA)

Max (+70°C)

Typ (+25°C)

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

IPD (μA)

Max (125C)

Max (85C)

Typ (25C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

Max (+125°C)

Max (+85°C)

Typ (+25°C)

PIC18FXX2

FIGURE 23-19: TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40°C TO +125°C)

FIGURE 23-20: ΔILVD vs. VDD OVER TEMPERATURE (LVD ENABLED, VLVD = 4.5 - 4.78V)

2.02.53.03.54.04.55.05.5

VDD (V)

WDT Period (ms)

Max

(125C)

MAX

(85C)

Typ

(25C)

Min

(-40C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

Max

(+125°C)

Max

(+85°C)

Typ

(+25°C)

Min

(-40°C)

2.02.53.03.54.04.55.05.5

VDD (V)

IDD (μA)

Max (125C)

Typ (25C)

Max (125C)

Typ (25C)

LVDIF is set

hardware

LVDIF can be

cleared by

firmware

LVDIF state

is unknown

Max (+125°C)

Typ (+25°C)

PIC18FXX2

FIGURE 23-21: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40°C TO +125°C)

FIGURE 23-22: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40°C TO +125°C)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

0 5 10 15 20 25

IOH (-mA)

VOH (V)

Typ (25C)

Max

Min

Max

Typ (+25°C)

Min

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 5 10 15 20 25

IOH (-mA)

VOH (V)

Typ (25C)

Max

Min

Typ (+25°C)

Min

Max

PIC18FXX2

FIGURE 23-23: TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 5V, -40°C TO +125°C)

FIGURE 23-24: TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 3V, -40°C TO +125°C)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 5 10 15 20 25

IOL (-mA)

VOL (V)

Max

Typ (25C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

Typ (+25°C)

Max

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15 20 25

IOL (-mA)

VOL (V)

Max

Typ (25C)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

Typ (+25°C)

Max

PIC18FXX2

FIGURE 23-25: MINIMUM AND MAXIMUM VIN vs. VDD (ST INPUT, -40°C TO +125°C)

FIGURE 23-26: MINIMUM AND MAXIMUM VIN vs. VDD (TTL INPUT, -40°C TO +125°C)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

VIN (V)

VIH Max

VIH Min

VIL Max

VIL Min

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

VIN (V)

VTH (Max)

VTH (Min)

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

PIC18FXX2

FIGURE 23-27: MINIMUM AND MAXIMUM VIN vs. VDD (I2C INPUT, -40°C TO +125°C)

FIGURE 23-28: A/D NON-LINEARITY vs. VREFH (VDD = VREFH, -40°C TO +125°C)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

VDD (V)

VIN (V)

VIH Max

VIH Min

VILMax

VIL Min

Typical: statistical mean @ 25°C

Maximum: mean + 3σ (-40°C to 125°C)

Minimum: mean – 3σ (-40°C to 125°C)

0.5

1.5

2.5

3.5

22.533.544.555.5

VDD and VREFH (V)

Differential or Integral Nonlinearity (LSB)

-40C

25C

85C

125C

-40°C

+25°C

+85°C

+125°C

PIC18FXX2

FIGURE 23-29: A/D NON-LINEARITY vs. VREFH (VDD = 5V, -40°C TO +125°C)

0.5

1.5

2.5

22.533.544.555.5

VREFH (V)

Differential or Integral Nonlinearilty (LSB)

Max (-40C to 125C)

Typ (25C)

Typ (+25°C)

Max (-40°C to +125°C)

PIC18FXX2

NOTES:

PIC18FXX2

24.0 PACKAGING INFORMATION

24.1 Package Marking Information

28-Lead SPDIP

XXXXXXXXXXXXXXXXX

YYWWNNN

Example

PIC18F242-I/SP

0610017

28-Lead SOIC

XXXXXXXXXXXXXXXXXXXX

YYWWNNN

Example

PIC18F242-E/SO

0610017

40-Lead PDIP

XXXXXXXXXXXXXXXXXX

YYWWNNN

Example

PIC18F442-I/P

0610017

Legend: XX...X Customer-specific information

Y Year code (last digit of calendar year)

YY Year code (last 2 digits of calendar year)

WW Week code (week of January 1 is week ‘01’)

NNN Alphanumeric traceability code

Pb-free JEDEC designator for Matte Tin (Sn)

*This package is Pb-free. The Pb-free JEDEC designator ( )

can be found on the outer packaging for this package.

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line, thus limiting the number of available

characters for customer-specific information.

PIC18FXX2

Package Marking Information (Cont’d)

44-Lead TQFP

XXXXXXXXXX

YYWWNNN

Example

PIC18F452

-E/PT

0610017

44-Lead PLCC

XXXXXXXXXX

YYWWNNN

Example

PIC18F442

-I/L

0610017

PIC18FXX2

24.2 Package Details

The following sections give the technical details of the packages.

28-Lead Skinny Plastic Dual In-line (SP) – 300 mil Body (PDIP)

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

1510515105

Mold Draft Angle Bottom

1510515105

Mold Draft Angle Top

10.928.898.13.430.350.320

Overall Row Spacing

0.560.480.41.022.019.016BLower Lead Width

1.651.331.02.065.053.040B1Upper Lead Width

0.380.290.20.015.012.008

Lead Thickness

3.433.303.18.135.130.125LTip to Seating Plane

35.1834.6734.161.3851.3651.345DOverall Length

7.497.246.99.295.285.275E1Molded Package Width

8.267.877.62.325.310.300EShoulder to Shoulder Width

0.38.015A1Base to Seating Plane

3.433.303.18.135.130.125A2Molded Package Thickness

4.063.813.56.160.150.140ATop to Seating Plane

2.54.100

Pitch

2828

Number of Pins

MAXNOMMINMAXNOMMINDimension Limits

MILLIMETERSINCHES

Units

Notes:

JEDEC Equivalent: MO-095

Drawing No. C04-070

Controlling Parameter

Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.

Significant Characteristic

PIC18FXX2

28-Lead Plastic Small Outline (SO) – Wide, 300 mil Body (SOIC)

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Foot Angle Top φ048048

1512015120

Mold Draft Angle Bottom

1512015120

Mold Draft Angle Top

0.510.420.36.020.017.014BLead Width

0.330.280.23.013.011.009

Lead Thickness

1.270.840.41.050.033.016LFoot Length

0.740.500.25.029.020.010hChamfer Distance

18.0817.8717.65.712.704.695DOverall Length

7.597.497.32.299.295.288

Molded Package Width

10.6710.3410.01.420.407.394EOverall Width

0.300.200.10.012.008.004A1Standoff §

2.392.312.24.094.091.088A2Molded Package Thickness

2.642.502.36.104.099.093AOverall Height

1.27.050

Pitch

2828

Number of Pins

MAXNOMMINMAXNOMMINDimension Limits

MILLIMETERSINCHES*Units

45°

* Controlling Parameter

Notes:

Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.

JEDEC Equivalent: MS-013

Drawing No. C04-052

§ Significant Characteristic

PIC18FXX2

40-Lead Plastic Dual In-line (P) – 600 mil Body (PDIP)

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

1510515105

Mold Draft Angle Bottom

1510515105

Mold Draft Angle Top

17.2716.5115.75.680.650.620eBOverall Row Spacing §

0.560.460.36.022.018.014BLower Lead Width

1.781.270.76.070.050.030B1Upper Lead Width

0.380.290.20.015.012.008

Lead Thickness

3.433.303.05.135.130.120LTip to Seating Plane

52.4552.2651.942.0652.0582.045DOverall Length

14.2213.8413.46.560.545.530E1Molded Package Width

15.8815.2415.11.625.600.595EShoulder to Shoulder Width

0.38.015A1Base to Seating Plane

4.063.813.56.160.150.140A2Molded Package Thickness

4.834.454.06.190.175.160ATop to Seating Plane

2.54.100

Pitch

4040

Number of Pins

MAXNOMMINMAXNOMMINDimension Limits

MILLIMETERSINCHES*Units

* Controlling Parameter

Notes:

Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.

JEDEC Equivalent: MO-011

Drawing No. C04-016

§ Significant Characteristic

PIC18FXX2

44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

A1 A2

#leads=n1

D1 D

CH x 45°

1.140.890.64.045.035.025CH

Pin 1 Corner Chamfer

1.00 REF..039 REF.F

Footprint (Reference)

Units INCHES MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX

Number of Pins n44 44

Pitch p.031 0.80

Overall Height A .039 .043 .047 1.00 1.10 1.20

Molded Package Thickness A2 .037 .039 .041 0.95 1.00 1.05

Standoff A1 .002 .004 .006 0.05 0.10 0.15

Foot Length L .018 .024 .030 0.45 0.60 0.75

Foot Angle

03.5 7 03.5 7

Overall Width E .463 .472 .482 11.75 12.00 12.25

Overall Length D .463 .472 .482 11.75 12.00 12.25

Molded Package Width E1 .390 .394 .398 9.90 10.00 10.10

Molded Package Length D1 .390 .394 .398 9.90 10.00 10.10

Pins per Side n1 11 11

Lead Thickness c.004 .006 .008 0.09 0.15 0.20

Lead Width B .012 .015 .017 0.30 0.38 0.44

Mold Draft Angle Top

5 10 15 5 10 15

Mold Draft Angle Bottom

5 10 15 5 10 15

Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side.

Notes:

JEDEC Equivalent: MS-026

Revised 07-22-05

Controlling Parameter

REF: Reference Dimension, usually without tolerance, for information purposes only.

See ASME Y14.5M

Drawing No. C04-076

PIC18FXX2

44-Lead Plastic Leaded Chip Carrier (L) – Square (PLCC)

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

CH2 x 45°CH1 x 45°

10501050

Mold Draft Angle Bottom

10501050

Mold Draft Angle Top

0.530.510.33.021.020.013B

0.810.740.66.032.029.026B1Upper Lead Width

0.330.270.20.013.011.008

Lead Thickness

1111n1Pins per Side

16.0015.7514.99.630.620.590D2Footprint Length

16.0015.7514.99.630.620.590

Footprint Width

16.6616.5916.51.656.653.650D1Molded Package Length

16.6616.5916.51.656.653.650E1Molded Package Width

17.6517.5317.40.695.690.685DOverall Length

17.6517.5317.40.695.690.685EOverall Width

0.250.130.00.010.005.000

CH2Corner Chamfer (others)

1.271.141.02.050.045.040CH1Corner Chamfer 1

0.860.740.61.034.029.024A3Side 1 Chamfer Height

0.51.020A1Standoff §

A2Molded Package Thickness

4.574.394.19.180.173.165AOverall Height

1.27.050

Pitch

4444

Number of Pins

MAXNOMMINMAXNOMMINDimension Limits

MILLIMETERSINCHES*Units

#leads=n1

35°

.145 .153 .160 3.68 3.87 4.06

.028 .035 0.71 0.89

Lower Lead Width

* Controlling Parameter

Notes:

Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.

JEDEC Equivalent: MO-047

Drawing No. C04-048

§ Significant Characteristic

PIC18FXX2

NOTES:

PIC18FXX2

APPENDIX A: REVISION HISTORY

Revision A (June 2001)

Original data sheet for the PIC18FXX2 family.

Revision B (August 2002)

This revision includes the DC and AC Characteristics

Graphs and Tables. The Electrical Specifications in

Section 22.0 have been updated and there have been

minor corrections to the data sheet text.

Revision C (October 2006)

Packaging diagrams updated.

APPENDIX B: DEVICE

DIFFERENCES

The differences between the devices listed in this data

sheet are shown in Table B-1.

TABLE B-1: DEVICE DIFFERENCES

Feature PIC18F242 PIC18F252 PIC18F442 PIC18F452

Program Memory (Kbytes) 16 32 16 32

Data Memory (Bytes) 768 1536 768 1536

A/D Channels 5 5 8 8

Parallel Slave Port (PSP) No No Yes Yes

Package Types 28-pin DIP

28-pin SOIC

28-pin DIP

28-pin SOIC

40-pin DIP

44-pin PLCC

44-pin TQFP

40-pin DIP

44-pin PLCC

44-pin TQFP

PIC18FXX2

APPENDIX C: CONVERSION

CONSIDERATIONS

This appendix discusses the considerations for con-

verting from previous versions of a device to the ones

listed in this data sheet. Typically, these changes are

due to the differences in the process technology used.

An example of this type of conversion is from a

PIC16C74A to a PIC16C74B.

Not Applicable

APPENDIX D: MIGRATION FROM

BASELINE TO

ENHANCED DEVICES

This section discusses how to migrate from a Baseline

device (i.e., PIC16C5X) to an Enhanced MCU device

(i.e., PIC18FXXX).

The following are the list of modifications over the

PIC16C5X microcontroller family:

Not Currently Available

PIC18FXX2

APPENDIX E: MIGRATION FROM

MID-RANGE TO

ENHANCED DEVICES

A detailed discussion of the differences between the

mid-range MCU devices (i.e., PIC16CXXX) and the

enhanced devices (i.e., PIC18FXXX) is provided in

AN716, “Migrating Designs from PIC16C74A/74B to

PIC18F442”. The changes discussed, while device

specific, are generally applicable to all mid-range to

enhanced device migrations.

This Application Note is available as Literature Number

DS00716.

APPENDIX F: MIGRATION FROM

HIGH-END TO

ENHANCED DEVICES

A detailed discussion of the migration pathway and dif-

ferences between the high-end MCU devices (i.e.,

PIC17CXXX) and the enhanced devices (i.e.,

PIC18FXXX) is provided in AN726, “PIC17CXXX to

PIC18FXXX Migration”. This Application Note is

available as Literature Number DS00726.

PIC18FXX2

NOTES:

© 2006 Microchip Technology Inc. DS39564C-page 317
PIC18FXX2
INDEX
A
A/D ................................................................................... 181
A/D Converter Flag (ADIF Bit) ................................. 183
A/D Converter Interrupt, Configuring ....................... 184
Acquisition Requirements ........................................ 184
ADCON0 Register .................................................... 181
ADCON1 Register .................................................... 181
ADRESH Register .................................................... 181
ADRESH/ADRESL Registers .................................. 183
ADRESL Register .................................................... 181
Analog Port Pins ................................................ 99, 100
Analog Port Pins, Configuring .................................. 186
Associated Registers ............................................... 188
Configuring the Module ............................................ 184
Conversion Clock (TAD) ........................................... 186
Conversion Status (GO/DONE Bit) .......................... 183
Conversions ............................................................. 187
Converter Characteristics ........................................ 287
Equations
Acquisition Time ............................................... 185
Minimum Charging Time .................................. 185
Examples
Calculating the Minimum Required 
Acquisition Time ...................................... 185
Result Registers ....................................................... 187
Special Event Trigger (CCP) ............................ 120, 188
TAD vs. Device Operating Frequencies .................... 186
Use of the CCP2 Trigger .......................................... 188
Absolute Maximum Ratings ............................................. 259
AC (Timing) Characteristics ............................................. 269
Load Conditions for Device Timing 
Specifications ................................................... 270
Parameter Symbology ............................................. 269
Temperature and Voltage Specifications - AC ......... 270
Timing Conditions .................................................... 270
ACKSTAT Status Flag ..................................................... 155
ADCON0 Register ............................................................ 181
GO/DONE Bit ........................................................... 183
ADCON1 Register ............................................................ 181
ADDLW ............................................................................ 217
ADDWF ............................................................................ 217
ADDWFC ......................................................................... 218
ADRESH Register ............................................................ 181
ADRESH/ADRESL Registers ........................................... 183
ADRESL Register ............................................................ 181
Analog-to-Digital Converter. 
See
 A/D
ANDLW ............................................................................ 218
ANDWF ............................................................................ 219
Assembler
MPASM Assembler .................................................. 253
B
Baud Rate Generator ....................................................... 151
BC .................................................................................... 219
BCF .................................................................................. 220
BF Status Flag ................................................................. 155
Block Diagrams
A/D Converter .......................................................... 183
Analog Input Model .................................................. 184
Baud Rate Generator .............................................. 151
Capture Mode Operation ......................................... 119
Compare Mode Operation ....................................... 120
Low Voltage Detect
External Reference Source ............................. 190
Internal Reference Source ............................... 190
MSSP
I2C Mode ......................................................... 134
MSSP (SPI Mode) ................................................... 125
On-Chip Reset Circuit ................................................ 25
Parallel Slave Port (PORTD and PORTE) ............... 100
PIC18F2X2 .................................................................. 8
PIC18F4X2 .................................................................. 9
PLL ............................................................................ 19
PORTC (Peripheral Output Override) ........................ 93
PORTD (I/O Mode) .................................................... 95
PORTE (I/O Mode) .................................................... 97
PWM Operation (Simplified) .................................... 122
RA3:RA0 and RA5 Port Pins ..................................... 87
RA4/T0CKI Pin .......................................................... 88
RA6 Pin ..................................................................... 88
RB2:RB0 Port Pins .................................................... 91
RB3 Pin ..................................................................... 91
RB7:RB4 Port Pins .................................................... 90
Table Read Operation ............................................... 55
Table Write Operation ................................................ 56
Table Writes to FLASH Program Memory ................. 61
Timer0 in 16-bit Mode .............................................. 104
Timer0 in 8-bit Mode ................................................ 104
Timer1 ..................................................................... 108
Timer1 (16-bit R/W Mode) ....................................... 108
Timer2 ..................................................................... 112
Timer3 ..................................................................... 114
Timer3 (16-bit R/W Mode) ....................................... 114
USART
Asynchronous Receive .................................... 174
Asynchronous Transmit ................................... 172
Watchdog Timer ...................................................... 204
BN .................................................................................... 220
BNC ................................................................................. 221
BNN ................................................................................. 221
BNOV ............................................................................... 222
BNZ .................................................................................. 222
BOR. 
See
 Brown-out Reset
BOV ................................................................................. 225
BRA ................................................................................. 223
BRG. 
See 
Baud Rate Generator
Brown-out Reset (BOR) ..................................................... 26
BSF .................................................................................. 223
BTFSC ............................................................................. 224
BTFSS ............................................................................. 224
BTG ................................................................................. 225
Bus Collision During a STOP Condition .......................... 163
BZ .................................................................................... 226

PIC18FXX2
DS39564C-page 318 © 2006 Microchip Technology Inc.
C
CALL ................................................................................ 226
Capture (CCP Module) ..................................................... 119
Associated Registers ............................................... 121
CCP Pin Configuration ............................................. 119
CCPR1H:CCPR1L Registers ................................... 119
Software Interrupt ..................................................... 119
Timer1/Timer3 Mode Selection ................................ 119
Capture/Compare/PWM (CCP) ........................................ 117
Capture Mode. 
See
 Capture
CCP1 ........................................................................ 118
CCPR1H Register ............................................ 118
CCPR1L Register ............................................ 118
CCP2 ........................................................................ 118
CCPR2H Register ............................................ 118
CCPR2L Register ............................................ 118
Compare Mode. 
See
 Compare
Interaction of Two CCP Modules ............................. 118
PWM Mode. 
See
 PWM
Timer Resources ...................................................... 118
Clocking Scheme/Instruction Cycle .................................... 39
CLRF ................................................................................ 227
CLRWDT .......................................................................... 227
Code Examples
16 x 16 Signed Multiply Routine ................................. 72
16 x 16 Unsigned Multiply Routine ............................. 72
8 x 8 Signed Multiply Routine ..................................... 71
8 x 8 Unsigned Multiply Routine ................................. 71
Changing Between Capture Prescalers ................... 119
Data EEPROM Read ................................................. 67
Data EEPROM Refresh Routine ................................ 68
Data EEPROM Write .................................................. 67
Erasing a FLASH Program Memory Row .................. 60
Fast Register Stack .................................................... 39
How to Clear RAM (Bank1) Using 
Indirect Addressing ............................................ 50
Initializing PORTA ...................................................... 87
Initializing PORTB ...................................................... 90
Initializing PORTC ...................................................... 93
Initializing PORTD ...................................................... 95
Initializing PORTE ...................................................... 97
Loading the SSPBUF (SSPSR) Register ................. 128
Reading a FLASH Program Memory Word ................ 59
Saving STATUS, WREG and BSR 
Registers in RAM ............................................... 85
Writing to FLASH Program Memory ..................... 62–63
Code Protection ............................................................... 195
COMF ............................................................................... 228
Compare (CCP Module) ................................................... 120
Associated Registers ............................................... 121
CCP Pin Configuration ............................................. 120
CCPR1 Register ....................................................... 120
Software Interrupt ..................................................... 120
Special Event Trigger ........................109, 115, 120, 188
Timer1/Timer3 Mode Selection ................................ 120
Configuration Bits ............................................................. 195
Context Saving During Interrupts ....................................... 85
Conversion Considerations .............................................. 314
CPFSEQ .......................................................................... 228
CPFSGT ........................................................................... 229
CPFSLT ........................................................................... 229
D
Data EEPROM Memory
Associated Registers ................................................. 69
EEADR Register ........................................................ 65
EECON1 Register ...................................................... 65
EECON2 Register ...................................................... 65
Operation During Code Protect ................................. 68
Protection Against Spurious Write ............................. 68
Reading ..................................................................... 67
Using .......................................................................... 68
Write Verify ................................................................ 68
Writing ........................................................................ 67
Data Memory ..................................................................... 42
General Purpose Registers ....................................... 42
Map for PIC18F242/442 ............................................ 43
Map for PIC18F252/452 ............................................ 44
Special Function Registers ........................................ 42
DAW ................................................................................ 230
DC and AC Characteristics
Graphs and Tables .................................................. 289
DC Characteristics ....................................................261, 265
DCFSNZ .......................................................................... 231
DECF ............................................................................... 230
DECFSZ .......................................................................... 231
Development Support ...................................................... 253
Device Differences ........................................................... 313
Device Overview .................................................................. 7
Features ....................................................................... 7
Direct Addressing ............................................................... 51
Example ..................................................................... 49
E
Electrical Characteristics .................................................. 259
Errata ................................................................................... 5
F
Firmware Instructions ....................................................... 211
FLASH Program Memory ................................................... 55
Associated Registers ................................................. 63
Control Registers ....................................................... 56
Erase Sequence ........................................................ 60
Erasing ....................................................................... 60
Operation During Code Protect ................................. 63
Reading ..................................................................... 59
TABLAT Register ....................................................... 58
Table Pointer ............................................................. 58
Boundaries Based on Operation ........................ 58
Table Pointer Boundaries .......................................... 58
Table Reads and Table Writes .................................. 55
Block Diagrams
Reads from FLASH Program Memory ....... 59
Writing to .................................................................... 61
Protection Against Spurious Writes ................... 63
Unexpected Termination .................................... 63
Write Verify ........................................................ 63
G
General Call Address Support ......................................... 148
GOTO .............................................................................. 232

© 2006 Microchip Technology Inc. DS39564C-page 319
PIC18FXX2
I
I/O Ports ............................................................................. 87
I2C (MSSP Module)
ACK Pulse ................................................................ 139
Read/Write Bit Information (R/W Bit) ....................... 139
I2C (SSP Module)
ACK Pulse ................................................................ 138
I2C Master Mode Reception ............................................. 155
I2C Mode
Clock Stretching ....................................................... 144
I2C Mode (MSSP Module) ................................................ 134
Registers .................................................................. 134
I2C Module
ACK Pulse ........................................................ 138, 139
Acknowledge Sequence Timing ............................... 158
Baud Rate Generator ............................................... 151
Bus Collision
Repeated START Condition ............................ 162
START Condition ............................................. 160
Clock Arbitration ....................................................... 152
Effect of a RESET .................................................... 159
General Call Address Support ................................. 148
Master Mode ............................................................ 149
Operation ......................................................... 150
Repeated START Condition Timing ................. 154
Master Mode START Condition ............................... 153
Master Mode Transmission ...................................... 155
Multi-Master Communication, Bus Collision 
and Arbitration .................................................. 159
Multi-Master Mode ................................................... 159
Operation ................................................................. 138
Read/Write Bit Information (R/W Bit) ............... 138, 139
Serial Clock (RC3/SCK/SCL) ................................... 139
Slave Mode .............................................................. 138
Addressing ....................................................... 138
Reception ......................................................... 139
Transmission .................................................... 139
Slave Mode Timing (10-bit Reception, 
SEN = 0) .......................................................... 142
Slave Mode Timing (10-bit Reception, 
SEN = 1) .......................................................... 147
Slave Mode Timing (10-bit Transmission) ................ 143
Slave Mode Timing (7-bit Reception, 
SEN = 0) .......................................................... 140
Slave Mode Timing (7-bit Reception, 
SEN = 1) .......................................................... 146
Slave Mode Timing (7-bit Transmission) .................. 141
SLEEP Operation ..................................................... 159
STOP Condition Timing ........................................... 158
ICEPIC In-Circuit Emulator .............................................. 254
ID Locations ............................................................. 195, 210
INCF ................................................................................. 232
INCFSZ ............................................................................ 233
In-Circuit Debugger .......................................................... 210
In-Circuit Serial Programming (ICSP) ...................... 195, 210
Indirect Addressing ............................................................ 51
INDF and FSR Registers ........................................... 50
Indirect Addressing Operation ............................................ 51
Indirect File Operand .......................................................... 42
INFSNZ ............................................................................ 233
Instruction Cycle ................................................................. 39
Instruction Flow/Pipelining ................................................. 40
Instruction Format ............................................................ 213
Instruction Set .................................................................. 211
ADDLW .................................................................... 217
ADDWF .................................................................... 217
ADDWFC ................................................................. 218
ANDLW .................................................................... 218
ANDWF .................................................................... 219
BC ............................................................................ 219
BCF ......................................................................... 220
BN ............................................................................ 220
BNC ......................................................................... 221
BNN ......................................................................... 221
BNOV ...................................................................... 222
BNZ ......................................................................... 222
BOV ......................................................................... 225
BRA ......................................................................... 223
BSF .......................................................................... 223
BTFSC ..................................................................... 224
BTFSS ..................................................................... 224
BTG ......................................................................... 225
BZ ............................................................................ 226
CALL ........................................................................ 226
CLRF ....................................................................... 227
CLRWDT ................................................................. 227
COMF ...................................................................... 228
CPFSEQ .................................................................. 228
CPFSGT .................................................................. 229
CPFSLT ................................................................... 229
DAW ........................................................................ 230
DCFSNZ .................................................................. 231
DECF ....................................................................... 230
DECFSZ .................................................................. 231
GOTO ...................................................................... 232
INCF ........................................................................ 232
INCFSZ .................................................................... 233
INFSNZ .................................................................... 233
IORLW ..................................................................... 234
IORWF ..................................................................... 234
LFSR ....................................................................... 235
MOVF ...................................................................... 235
MOVFF .................................................................... 236
MOVLB .................................................................... 236
MOVLW ................................................................... 237
MOVWF ................................................................... 237
MULLW .................................................................... 238
MULWF .................................................................... 238
NEGF ....................................................................... 239
NOP ......................................................................... 239
POP ......................................................................... 240
PUSH ....................................................................... 240
RCALL ..................................................................... 241
RESET ..................................................................... 241
RETFIE .................................................................... 242
RETLW .................................................................... 242
RETURN .................................................................. 243
RLCF ....................................................................... 243
RLNCF ..................................................................... 244
RRCF ....................................................................... 244
RRNCF .................................................................... 245
SETF ....................................................................... 245
SLEEP ..................................................................... 246
SUBFWB ................................................................. 246
SUBLW .................................................................... 247
SUBWF .................................................................... 247
SUBWFB ................................................................. 248
SWAPF .................................................................... 248

PIC18FXX2
DS39564C-page 320 © 2006 Microchip Technology Inc.
TBLRD ..................................................................... 249
TBLWT ..................................................................... 250
TSTFSZ .................................................................... 251
XORLW .................................................................... 251
XORWF .................................................................... 252
Summary Table ........................................................ 214
Instructions in Program Memory ........................................ 40
Two-Word Instructions ............................................... 41
INT Interrupt (RB0/INT). 
See
 Interrupt Sources
INTCON Register
RBIF Bit ...................................................................... 90
INTCON Registers ....................................................... 75–77
Inter-Integrated Circuit. 
See
 I2C
Interrupt Sources .............................................................. 195
A/D Conversion Complete ........................................ 184
Capture Complete (CCP) ......................................... 119
Compare Complete (CCP) ....................................... 120
INT0 ........................................................................... 85
Interrupt-on-Change (RB7:RB4 ) ............................... 90
PORTB, Interrupt-on-Change .................................... 85
RB0/INT Pin, External ................................................ 85
TMR0 ......................................................................... 85
TMR0 Overflow ........................................................ 105
TMR1 Overflow ................................................ 107, 109
TMR2 to PR2 Match ................................................. 112
TMR2 to PR2 Match (PWM) ............................ 111, 122
TMR3 Overflow ................................................ 113, 115
USART Receive/Transmit Complete ........................ 165
Interrupts ............................................................................ 73
Logic ........................................................................... 74
Interrupts, Enable Bits
CCP1 Enable (CCP1IE Bit) ...................................... 119
Interrupts, Flag Bits
A/D Converter Flag (ADIF Bit) .................................. 183
CCP1 Flag (CCP1IF Bit) .......................................... 119
CCP1IF Flag (CCP1IF Bit) ....................................... 120
Interrupt-on-Change (RB7:RB4) Flag 
(RBIF Bit) ........................................................... 90
IORLW ............................................................................. 234
IORWF ............................................................................. 234
IPR Registers ............................................................... 82–83
K
KEELOQ Evaluation and Programming Tools ................... 256
L
LFSR ................................................................................ 235
Lookup Tables
Computed GOTO ....................................................... 41
Table Reads, Table Writes ......................................... 41
Low Voltage Detect .......................................................... 189
Converter Characteristics ......................................... 267
Effects of a RESET .................................................. 193
Operation ................................................................. 192
Current Consumption ....................................... 193
During SLEEP .................................................. 193
Reference Voltage Set Point ............................ 193
Typical Application ................................................... 189
LVD. 
See
 Low Voltage Detect. ......................................... 189
M
Master SSP (MSSP) Module Overview ........................... 125
Master Synchronous Serial Port (MSSP). 
See
 MSSP.
Master Synchronous Serial Port. 
See
 MSSP
Memory Organization
Data Memory ............................................................. 42
Program Memory ....................................................... 35
Memory Programming Requirements .............................. 268
Migration from Baseline to Enhanced Devices ................ 314
Migration from High-End to Enhanced Devices ............... 315
Migration from Mid-Range to Enhanced Devices ............ 315
MOVF .............................................................................. 235
MOVFF ............................................................................ 236
MOVLB ............................................................................ 236
MOVLW ........................................................................... 237
MOVWF ........................................................................... 237
MPLAB C17 and MPLAB C18 C Compilers ..................... 253
MPLAB ICD In-Circuit Debugger ..................................... 255
MPLAB ICE High Performance Universal In-Circuit 
Emulator with MPLAB IDE ....................................... 254
MPLAB Integrated Development 
Environment Software ............................................. 253
MPLINK Object Linker/MPLIB Object Librarian ............... 254
MSSP ............................................................................... 125
Control Registers (general) ...................................... 125
Enabling SPI I/O ...................................................... 129
Operation ................................................................. 128
Typical Connection .................................................. 129
MSSP Module
SPI Master Mode ..................................................... 130
SPI Master./Slave Connection ................................. 129
SPI Slave Mode ....................................................... 131
MULLW ............................................................................ 238
MULWF ............................................................................ 238
N
NEGF ............................................................................... 239
NOP ................................................................................. 239
O
Opcode Field Descriptions ............................................... 212
OPTION_REG Register
PSA Bit .................................................................... 105
T0CS Bit .................................................................. 105
T0PS2:T0PS0 Bits ................................................... 105
T0SE Bit ................................................................... 105
Oscillator Configuration ...................................................... 17
EC .............................................................................. 17
ECIO .......................................................................... 17
HS .............................................................................. 17
HS + PLL ................................................................... 17
LP .............................................................................. 17
RC .............................................................................. 17
RCIO .......................................................................... 17
XT .............................................................................. 17
Oscillator Selection .......................................................... 195
Oscillator, Timer1 ..............................................107, 109, 115
Oscillator, Timer3 ............................................................. 113
Oscillator, WDT ................................................................ 203

© 2006 Microchip Technology Inc. DS39564C-page 321
PIC18FXX2
P
Packaging ........................................................................ 305
Details ...................................................................... 307
Marking Information ................................................. 305
Parallel Slave Port
PORTD .................................................................... 100
Parallel Slave Port (PSP) ........................................... 95, 100
Associated Registers ............................................... 101
RE0/RD/AN5 Pin ................................................ 99, 100
RE1/WR/AN6 Pin ............................................... 99, 100
RE2/CS/AN7 Pin ................................................ 99, 100
Select (PSPMODE Bit) ...................................... 95, 100
PIC18F2X2 Pin Functions
MCLR/VPP .................................................................. 10
OSC1/CLKI ................................................................ 10
OSC2/CLKO/RA6 ...................................................... 10
RA0/AN0 .................................................................... 10
RA1/AN1 .................................................................... 10
RA2/AN2/VREF- .......................................................... 10
RA3/AN3/VREF+ ......................................................... 10
RA4/T0CKI ................................................................. 10
RA5/AN4/SS/LVDIN ................................................... 10
RB0/INT0 ................................................................... 11
RB1/INT1 ................................................................... 11
RB2/INT2 ................................................................... 11
RB3/CCP2 ................................................................. 11
RB4 ............................................................................ 11
RB5/PGM ................................................................... 11
RB6/PGC ................................................................... 11
RB7/PGD ................................................................... 11
RC0/T1OSO/T1CKI ................................................... 12
RC1/T1OSI/CCP2 ...................................................... 12
RC2/CCP1 ................................................................. 12
RC3/SCK/SCL ........................................................... 12
RC4/SDI/SDA ............................................................ 12
RC5/SDO ................................................................... 12
RC6/TX/CK ................................................................ 12
RC7/RX/DT ................................................................ 12
VDD ............................................................................. 12
VSS ............................................................................. 12
PIC18F4X2 Pin Functions
MCLR/VPP .................................................................. 13
OSC1/CLKI ................................................................ 13
OSC2/CLKO .............................................................. 13
RA0/AN0 .................................................................... 13
RA1/AN1 .................................................................... 13
RA2/AN2/VREF- .......................................................... 13
RA3/AN3/VREF+ ......................................................... 13
RA4/T0CKI ................................................................. 13
RA5/AN4/SS/LVDIN ................................................... 13
RB0/INT ..................................................................... 14
RB1 ............................................................................ 14
RB2 ............................................................................ 14
RB3 ............................................................................ 14
RB4 ............................................................................ 14
RB5/PGM ................................................................... 14
RB6/PGC ................................................................... 14
RB7/PGD ................................................................... 14
RC0/T1OSO/T1CKI ................................................... 15
RC1/T1OSI/CCP2 ...................................................... 15
RC2/CCP1 ................................................................. 15
RC3/SCK/SCL ........................................................... 15
RC4/SDI/SDA ............................................................ 15
RC5/SDO ................................................................... 15
RC6/TX/CK ................................................................ 15
RC7/RX/DT ................................................................ 15
RD0/PSP0 ................................................................. 16
RD1/PSP1 ................................................................. 16
RD2/PSP2 ................................................................. 16
RD3/PSP3 ................................................................. 16
RD4/PSP4 ................................................................. 16
RD5/PSP5 ................................................................. 16
RD6/PSP6 ................................................................. 16
RD7/PSP7 ................................................................. 16
RE0/RD/AN5 .............................................................. 16
RE1/WR/AN6 ............................................................. 16
RE2/CS/AN7 .............................................................. 16
VDD ............................................................................ 16
VSS ............................................................................ 16
PIC18FXX2 Voltage-Frequency Graph 
(Industrial) ................................................................ 260
PIC18LFXX2 Voltage-Frequency Graph 
(Industrial) ................................................................ 260
PICDEM 1 Low Cost PICmicro 
Demonstration Board ............................................... 255
PICDEM 17 Demonstration Board ................................... 256
PICDEM 2 Low Cost PIC16CXX 
Demonstration Board ............................................... 255
PICDEM 3 Low Cost PIC16CXXX 
Demonstration Board ............................................... 256
PICSTART Plus Entry Level Development 
Programmer ............................................................. 255
PIE Registers ................................................................80–81
Pinout I/O Descriptions
PIC18F2X2 ................................................................ 10
PIR Registers ................................................................78–79
PLL Lock Time-out ............................................................. 26
Pointer, FSR ...................................................................... 50
POP ................................................................................. 240
POR. 
See
 Power-on Reset
PORTA
Associated Registers ................................................. 89
LATA Register ........................................................... 87
PORTA Register ........................................................ 87
TRISA Register .......................................................... 87
PORTB
Associated Registers ................................................. 92
LATB Register ........................................................... 90
PORTB Register ........................................................ 90
RB0/INT Pin, External ................................................ 85
RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) .......... 90
TRISB Register .......................................................... 90
PORTC
Associated Registers ................................................. 94
LATC Register ........................................................... 93
PORTC Register ........................................................ 93
RC3/SCK/SCL Pin ................................................... 139
RC7/RX/DT Pin ........................................................ 168
TRISC Register ...................................................93, 165
PORTD
Associated Registers ................................................. 96
LATD Register ........................................................... 95
Parallel Slave Port (PSP) Function ............................ 95
PORTD Register ........................................................ 95
TRISD Register .......................................................... 95

PIC18FXX2
DS39564C-page 322 © 2006 Microchip Technology Inc.
PORTE
Analog Port Pins ................................................ 99, 100
Associated Registers ................................................. 99
LATE Register ............................................................ 97
PORTE Register ........................................................ 97
PSP Mode Select (PSPMODE Bit) .................... 95, 100
RE0/RD/AN5 Pin ................................................ 99, 100
RE1/WR/AN6 Pin ............................................... 99, 100
RE2/CS/AN7 Pin ................................................ 99, 100
TRISE Register .......................................................... 97
Postscaler, WDT
Assignment (PSA Bit) ............................................... 105
Rate Select (T0PS2:T0PS0 Bits) ............................. 105
Switching Between Timer0 and WDT ...................... 105
Power-down Mode. 
See
 SLEEP
Power-on Reset (POR) ...................................................... 26
Oscillator Start-up Timer (OST) ................................. 26
Power-up Timer (PWRT) ............................................ 26
Prescaler, Capture ........................................................... 119
Prescaler, Timer0 ............................................................. 105
Assignment (PSA Bit) ............................................... 105
Rate Select (T0PS2:T0PS0 Bits) ............................. 105
Switching Between Timer0 and WDT ...................... 105
Prescaler, Timer2 ............................................................. 122
PRO MATE II Universal Device Programmer ................... 255
Product Identification System ........................................... 327
Program Counter
PCL Register .............................................................. 39
PCLATH Register ....................................................... 39
PCLATU Register ....................................................... 39
Program Memory
Interrupt Vector .......................................................... 35
Map and Stack for PIC18F442/242 ............................ 36
Map and Stack for PIC18F452/252 ............................ 36
RESET Vector ............................................................ 35
Program Verification and Code Protection ....................... 207
Associated Registers ............................................... 207
Programming, Device Instructions ................................... 211
PSP.
See 
Parallel Slave Port.
Pulse Width Modulation. 
See 
PWM (CCP Module).
PUSH ............................................................................... 240
PWM (CCP Module) ......................................................... 122
Associated Registers ............................................... 123
CCPR1H:CCPR1L Registers ................................... 122
Duty Cycle ................................................................ 122
Example Frequencies/Resolutions ........................... 123
Period ....................................................................... 122
Setup for PWM Operation ........................................ 123
TMR2 to PR2 Match ......................................... 111, 122
Q
Q Clock ............................................................................ 122
R
RAM. 
See
 Data Memory
RC Oscillator ...................................................................... 18
RCALL .............................................................................. 241
RCSTA Register
SPEN Bit .................................................................. 165
Register File ....................................................................... 42
Registers
ADCON0 (A/D Control 0) ......................................... 181
ADCON1 (A/D Control 1) ......................................... 182
CCP1CON and CCP2CON 
(Capture/Compare/PWM Control) ................... 117
CONFIG1H (Configuration 1 High) .......................... 196
CONFIG2H (Configuration 2 High) .......................... 197
CONFIG2L (Configuration 2 Low) ........................... 197
CONFIG3H (Configuration 3 High) .......................... 198
CONFIG4L (Configuration 4 Low) ........................... 198
CONFIG5H (Configuration 5 High) .......................... 199
CONFIG5L (Configuration 5 Low) ........................... 199
CONFIG6H (Configuration 6 High) .......................... 200
CONFIG6L (Configuration 6 Low) ........................... 200
CONFIG7H (Configuration 7 High) .......................... 201
CONFIG7L (Configuration 7 Low) ........................... 201
DEVID1 (Device ID Register 1) ............................... 202
DEVID2 (Device ID Register 2) ............................... 202
EECON1 (Data EEPROM Control 1) ....................57, 66
File Summary ........................................................46–48
INTCON (Interrupt Control) ........................................ 75
INTCON2 (Interrupt Control 2) ................................... 76
INTCON3 (Interrupt Control 3) ................................... 77
IPR1 (Peripheral Interrupt Priority 1) ......................... 82
IPR2 (Peripheral Interrupt Priority 2) ......................... 83
LVDCON (LVD Control) ........................................... 191
OSCCON (Oscillator Control) .................................... 21
PIE1 (Peripheral Interrupt Enable 1) .......................... 80
PIE2 (Peripheral Interrupt Enable 2) .......................... 81
PIR1 (Peripheral Interrupt Request 1) ....................... 78
PIR2 (Peripheral Interrupt Request 2) ....................... 79
RCON (Register Control) ........................................... 84
RCON (RESET Control) ............................................ 53
RCSTA (Receive Status and Control) ..................... 167
SSPCON1 (MSSP Control 1)
I2C Mode ......................................................... 136
SPI Mode ......................................................... 127
SSPCON2 (MSSP Control 2)
I2C Mode ......................................................... 137
SSPSTAT (MSSP Status)
I2C Mode ......................................................... 135
SPI Mode ......................................................... 126
STATUS ..................................................................... 52
STKPTR (Stack Pointer) ............................................ 38
T0CON (Timer0 Control) ......................................... 103
T1CON (Timer 1 Control) ........................................ 107
T2CON (Timer 2 Control) ........................................ 111
T3CON (Timer3 Control) ......................................... 113
TRISE ........................................................................ 98
TXSTA (Transmit Status and Control) ..................... 166
WDTCON (Watchdog Timer Control) ...................... 203
RESET ................................................................25, 195, 241
Brown-out Reset (BOR) ........................................... 195
MCLR Reset (During SLEEP) .................................... 25
MCLR Reset (Normal Operation) .............................. 25
Oscillator Start-up Timer (OST) ............................... 195
Power-on Reset (POR) .......................................25, 195
Power-up Timer (PWRT) ......................................... 195
Programmable Brown-out Reset (BOR) .................... 25
RESET Instruction ..................................................... 25
Stack Full Reset ......................................................... 25
Stack Underflow Reset .............................................. 25
Watchdog Timer (WDT) Reset .................................. 25

© 2006 Microchip Technology Inc. DS39564C-page 323
PIC18FXX2
RETFIE ............................................................................ 242
RETLW ............................................................................. 242
RETURN .......................................................................... 243
Revision History ............................................................... 313
RLCF ................................................................................ 243
RLNCF ............................................................................. 244
RRCF ............................................................................... 244
RRNCF ............................................................................. 245
S
SCI. 
See
 USART
SCK .................................................................................. 125
SDI ................................................................................... 125
SDO ................................................................................. 125
Serial Clock, SCK ............................................................. 125
Serial Communication Interface. 
See
 USART
Serial Data In, SDI ........................................................... 125
Serial Data Out, SDO ....................................................... 125
Serial Peripheral Interface. 
See
 SPI
SETF ................................................................................ 245
Slave Select Synchronization ........................................... 131
Slave Select, SS .............................................................. 125
SLEEP ...............................................................195, 205, 246
Software Simulator (MPLAB SIM) .................................... 254
Special Event Trigger. 
See
 Compare
Special Features of the CPU ............................................ 195
Configuration Registers ................................... 196–201
Special Function Registers ................................................ 42
Map ............................................................................ 45
SPI
Master Mode ............................................................ 130
Serial Clock .............................................................. 125
Serial Data In ........................................................... 125
Serial Data Out ........................................................ 125
Slave Select ............................................................. 125
SPI Clock ................................................................. 130
SPI Mode ................................................................. 125
SPI Master/Slave Connection .......................................... 129
SPI Module
Associated Registers ............................................... 133
Bus Mode Compatibility ........................................... 133
Effects of a RESET .................................................. 133
Master/Slave Connection ......................................... 129
Slave Mode .............................................................. 131
Slave Select Synchronization .................................. 131
Slave Synch Timing ................................................. 131
SLEEP Operation ..................................................... 133
SS .................................................................................... 125
SSP
I2C Mode. 
See
 I2C
SPI Mode ................................................................. 125
SPI Mode. 
See
 SPI
SSPBUF Register .................................................... 130
SSPSR Register ...................................................... 130
TMR2 Output for Clock Shift ............................ 111, 112
SSPOV Status Flag .......................................................... 155
SSPSTAT Register
R/W Bit ............................................................. 138, 139
Status Bits
Significance and the Initialization Condition 
for RCON Register ............................................. 27
SUBFWB .......................................................................... 246
SUBLW ............................................................................ 247
SUBWF ............................................................................ 247
SUBWFB .......................................................................... 248
SWAPF ............................................................................ 248
T
TABLAT Register ............................................................... 58
Table Pointer Operations (table) ........................................ 58
TBLPTR Register ............................................................... 58
TBLRD ............................................................................. 249
TBLWT ............................................................................. 250
Time-out Sequence ........................................................... 26
Time-out in Various Situations ................................... 27
Timer0 .............................................................................. 103
16-bit Mode Timer Reads and Writes ...................... 105
Associated Registers ............................................... 105
Clock Source Edge Select (T0SE Bit) ..................... 105
Clock Source Select (T0CS Bit) ............................... 105
Operation ................................................................. 105
Overflow Interrupt .................................................... 105
Prescaler. 
See
 Prescaler, Timer0
Timer1 .............................................................................. 107
16-bit Read/Write Mode ........................................... 109
Associated Registers ............................................... 110
Operation ................................................................. 108
Oscillator ...........................................................107, 109
Overflow Interrupt .............................................107, 109
Special Event Trigger (CCP) ............................109, 120
TMR1H Register ...................................................... 107
TMR1L Register ....................................................... 107
Timer2 .............................................................................. 111
Associated Registers ............................................... 112
Operation ................................................................. 111
Postscaler. 
See
 Postscaler, Timer2
PR2 Register ....................................................111, 122
Prescaler. 
See
 Prescaler, Timer2
SSP Clock Shift ................................................111, 112
TMR2 Register ......................................................... 111
TMR2 to PR2 Match Interrupt ................... 111, 112, 122
Timer3 .............................................................................. 113
Associated Registers ............................................... 115
Operation ................................................................. 114
Oscillator ...........................................................113, 115
Overflow Interrupt .............................................113, 115
Special Event Trigger (CCP) ................................... 115
TMR3H Register ...................................................... 113
TMR3L Register ....................................................... 113
Timing Diagrams
Bus Collision
Transmit and Acknowledge ..................... 159
A/D Conversion ........................................................ 287
Acknowledge Sequence .......................................... 158
Baud Rate Generator with Clock Arbitration ............ 152
BRG Reset Due to SDA Arbitration During 
START Condition ............................................. 161
Brown-out Reset (BOR) ........................................... 274
Bus Collision
Start Condition (SDA Only) .............................. 160
Bus Collision During a Repeated 
START Condition (Case 1) .............................. 162
Bus Collision During a Repeated 
START Condition (Case 2) .............................. 162
Bus Collision During a START Condition 
(SCL = 0) ......................................................... 161
Bus Collision During a STOP Condition 
(Case 1) ........................................................... 163
Bus Collision During a STOP Condition 
(Case 2) ........................................................... 163
Capture/Compare/PWM (CCP1 and CCP2) ............ 276
CLKO and I/O .......................................................... 272
Clock Synchronization ............................................. 145

PIC18FXX2
DS39564C-page 324 © 2006 Microchip Technology Inc.
Example SPI Master Mode (CKE = 0) ..................... 278
Example SPI Master Mode (CKE = 1) ..................... 279
Example SPI Slave Mode (CKE = 0) ....................... 280
Example SPI Slave Mode (CKE = 1) ....................... 281
External Clock (All Modes except PLL) .................... 271
First START Bit Timing ............................................ 153
I2C Bus Data ............................................................ 282
I2C Bus START/STOP Bits ...................................... 282
I2C Master Mode (Reception, 7-bit Address) ........... 157
I2C Master Mode (Transmission, 
7 or 10-bit Address) ......................................... 156
I2C Slave Mode Timing (10-bit Reception, 
SEN = 0) .......................................................... 142
I2C Slave Mode Timing (10-bit Transmission) ......... 143
I2C Slave Mode Timing (7-bit Reception, 
SEN = 0) .......................................................... 140
I2C Slave Mode Timing (7-bit Reception, 
SEN = 1) .................................................. 146, 147
I2C Slave Mode Timing (7-bit Transmission) ........... 141
Low Voltage Detect .................................................. 192
Master SSP I2C Bus Data ........................................ 284
Master SSP I2C Bus START/STOP Bits .................. 284
Parallel Slave Port (PIC18F4X2) .............................. 277
Parallel Slave Port (Read) ........................................ 101
Parallel Slave Port (Write) ........................................ 100
PWM Output ............................................................. 122
Repeat START Condition ......................................... 154
RESET, Watchdog Timer (WDT), 
Oscillator Start-up Timer (OST) and 
Power-up Timer (PWRT) ................................. 273
Slave Synchronization .............................................. 131
Slaver Mode General Call Address Sequence 
(7 or 10-bit Address Mode) .............................. 148
Slow Rise Time (MCLR Tied to VDD) ......................... 33
SPI Mode (Master Mode) ......................................... 130
SPI Mode (Slave Mode with CKE = 0) ..................... 132
SPI Mode (Slave Mode with CKE = 1) ..................... 132
Stop Condition Receive or Transmit Mode .............. 158
Time-out Sequence on POR w/PLL Enabled 
(MCLR Tied to VDD) ........................................... 33
Time-out Sequence on Power-up 
(MCLR Not Tied to VDD)
Case 1 ................................................................ 32
Case 2 ................................................................ 32
Time-out Sequence on Power-up 
(MCLR Tied to VDD) ........................................... 32
Timer0 and Timer1 External Clock ........................... 275
Timing for Transition Between Timer1 and 
OSC1 (HS with PLL) .......................................... 23
Transition Between Timer1 and OSC1 
(HS, XT, LP) ....................................................... 22
Transition Between Timer1 and OSC1 
(RC, EC) ............................................................ 23
Transition from OSC1 to Timer1 Oscillator ................ 22
USART Asynchronous Master Transmission ........... 173
USART Asynchronous Master Transmission 
(Back to Back) .................................................. 173
USART Asynchronous Reception ............................ 175
USART Synchronous Receive (Master/Slave) ......... 286
USART Synchronous Reception 
(Master Mode, SREN) ...................................... 178
USART Synchronous Transmission ......................... 177
USART Synchronous Transmission 
(Master/Slave) .................................................. 286
USART Synchronous Transmission 
(Through TXEN) .............................................. 177
Wake-up from SLEEP via Interrupt .......................... 206
Timing Diagrams Requirements
Master SSP I2C Bus START/STOP Bits .................. 284
Timing Requirements
A/D Conversion ........................................................ 288
Capture/Compare/PWM (CCP1 and CCP2) ............ 276
CLKO and I/O .......................................................... 273
Example SPI Mode (Master Mode, CKE = 0) .......... 278
Example SPI Mode (Master Mode, CKE = 1) .......... 279
Example SPI Mode (Slave Mode, CKE = 0) ............ 280
Example SPI Slave Mode (CKE = 1) ....................... 281
External Clock .......................................................... 271
I2C Bus Data (Slave Mode) ..................................... 283
Master SSP I2C Bus Data ........................................ 285
Parallel Slave Port (PIC18F4X2) ............................. 277
RESET, Watchdog Timer, Oscillator Start-up 
Timer, Power-up Timer and 
Brown-out Reset Requirements ....................... 274
Timer0 and Timer1 External Clock .......................... 275
USART Synchronous Receive ................................. 286
USART Synchronous Transmission ........................ 286
Timing Specifications
PLL Clock ................................................................ 272
TRISE Register
PSPMODE Bit .....................................................95, 100
TSTFSZ ........................................................................... 251
Two-Word Instructions
Example Cases .......................................................... 41
TXSTA Register
BRGH Bit ................................................................. 168
U
Universal Synchronous Asynchronous 
Receiver Transmitter. 
See
 USART
USART ............................................................................. 165
Asynchronous Mode ................................................ 172
Associated Registers, Receive ........................ 175
Associated Registers, Transmit ....................... 173
Receiver .......................................................... 174
Transmitter ....................................................... 172
Baud Rate Generator (BRG) ................................... 168
Associated Registers ....................................... 168
Baud Rate Error, Calculating ........................... 168
Baud Rate Formula .......................................... 168
Baud Rates for Asynchronous Mode 
(BRGH = 0) .............................................. 170
Baud Rates for Asynchronous Mode 
(BRGH = 1) .............................................. 171
Baud Rates for Synchronous Mode ................. 169
High Baud Rate Select (BRGH Bit) ................. 168
Sampling .......................................................... 168
Serial Port Enable (SPEN Bit) ................................. 165
Synchronous Master Mode ...................................... 176
Associated Registers, Reception ..................... 178
Associated Registers, Transmit ....................... 176
Reception ........................................................ 178
Transmission ................................................... 176
Synchronous Slave Mode ........................................ 179
Associated Registers, Receive ........................ 180
Associated Registers, Transmit ....................... 179
Reception ........................................................ 180
Transmission ................................................... 179

© 2006 Microchip Technology Inc. DS39564C-page 325
PIC18FXX2
W
Wake-up from SLEEP .............................................. 195, 205
Using Interrupts ........................................................ 205
Watchdog Timer (WDT) ........................................... 195, 203
Associated Registers ............................................... 204
Control Register ....................................................... 203
Postscaler ........................................................ 203, 204
Programming Considerations .................................. 203
RC Oscillator ............................................................ 203
Time-out Period ....................................................... 203
WCOL .............................................................................. 153
WCOL Status Flag ............................................153, 155, 158
WWW, On-Line Support ....................................................... 5
X
XORLW ............................................................................ 251
XORWF ........................................................................... 252

PIC18FXX2

NOTES:

PIC18FXX2

THE MICROCHIP WEB SITE

Microchip provides online support via our WWW site at

www.microchip.com. This web site is used as a means

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Customers should contact their distributor,

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support. Local sales offices are also available to help

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Technical support is available through the web site

at: http://support.microchip.com

PIC18FXX2

READER RESPONSE

It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-

uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation

can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.

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DS39564CPIC18FXX2

1. What are the best features of this document?

2. How does this document meet your hardware and software development needs?

3. Do you find the organization of this document easy to follow? If not, why?

4. What additions to the document do you think would enhance the structure and subject?

5. What deletions from the document could be made without affecting the overall usefulness?

6. Is there any incorrect or misleading information (what and where)?

7. How would you improve this document?

PIC18FXX2

PIC18FXX2 PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

PART NO. −X/XX XXX

PatternPackageTemperature

Range

Device

Device PIC18FXX2(1), PIC18FXX2T(2);

VDD range 4.2V to 5.5V

PIC18LFXX2(1), PIC18LFXX2T(2);

VDD range 2.5V to 5.5V

Temperature

Range

I= -40°C to +85°C (Industrial)

E= -40°C to +125°C (Extended)

Package PT = TQFP (Thin Quad Flatpack)

SO = SOIC

SP = Skinny Plastic DIP

P=PDIP

L=PLCC

Pattern QTP, SQTP, Code or Special Requirements

(blank otherwise)

Examples:

a) PIC18LF452 - I/P 301 = Industrial temp.,

PDIP package, Extended VDD limits,

QTP pattern #301.

b) PIC18LF242 - I/SO = Industrial temp.,

SOIC package, Extended VDD limits.

c) PIC18F442 - E/P = Extended temp.,

PDIP package, normal VDD limits.

Note 1: F = Standard Voltage range

LF = Wide Voltage Range

2: T = in tape and reel - SOIC,

PLCC, and TQFP

packages only.

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08/29/06