Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SOIC 28 8-Bit 40 MHz I/O number 22

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Table Of Contents

High-Performance RISC CPU:
Peripheral Features:
Advanced Analog Features:
CAN bus Module Features:
Special Microcontroller Features:
Flash Technology:
Pin Diagrams
Table of Contents
Most Current Data Sheet
Errata
Customer Notification System
1.0 Device Overview
- TABLE 1-1: PIC18FXX8 Device Features
- FIGURE 1-1: PIC18F248/258 Block Diagram
- FIGURE 1-2: PIC18F448/458 Block Diagram
- TABLE 1-2: PIC18FXX8 Pinout I/O Descriptions
2.0 Oscillator Configurations
- 2.1 Oscillator Types
- 2.2 Crystal Oscillator/Ceramic Resonators
- 2.3 RC Oscillator
  - FIGURE 2-2: RC Oscillator Mode
- 2.4 External Clock Input
  - FIGURE 2-3: External Clock Input Operation (EC Osc Configuration)
  - FIGURE 2-4: External Clock Input Operation (ECIO Configuration)
- 2.5 HS4 (PLL)
  - FIGURE 2-5: PLL Block Diagram
- 2.6 Oscillator Switching Feature
  - 2.6.1 System Clock Switch Bit
    - FIGURE 2-6: Device Clock Sources
    - Register 2-1: OSCCON: Oscillator Control Register
  - 2.6.2 Oscillator Transitions
- 2.7 Effects of Sleep Mode on the OnChip Oscillator
- 2.8 Power-up Delays
  - TABLE 2-3: OSC1 and OSC2 Pin States in Sleep Mode
3.0 Reset
- FIGURE 3-1: Simplified Block Diagram of On-Chip Reset Circuit
- 3.1 Power-on Reset (POR)
- 3.2 MCLR
  - FIGURE 3-2: External Power-on Reset Circuit (for Slow Vdd Power-up)
- 3.3 Power-up Timer (PWRT)
- 3.4 Oscillator Start-up Timer (OST)
- 3.5 PLL Lock Time-out
- 3.6 Brown-out Reset (BOR)
- 3.7 Time-out Sequence
4.0 Memory Organization
- 4.1 Program Memory Organization
  - FIGURE 4-1: Program Memory Map and Stack for PIC18F248/448
  - 4.1.1 Internal Program Memory Operation
    - FIGURE 4-2: Program Memory Map and Stack for PIC18F258/458
- 4.2 Return Address Stack
- 4.3 Fast Register Stack
  - EXAMPLE 4-1: Fast Register Stack Code Example
- 4.4 PCL, PCLATH and PCLATU
- 4.5 Clocking Scheme/Instruction Cycle
  - FIGURE 4-4: Clock/Instruction Cycle
- 4.6 Instruction Flow/Pipelining
- 4.7 Instructions in Program Memory
- 4.8 Look-up Tables
  - 4.8.1 Computed GOTO
  - 4.8.2 Table Reads/Table Writes
    - EXAMPLE 4-4: Two-Word Instructions
- 4.9 Data Memory Organization
  - 4.9.1 General Purpose Register File
  - 4.9.2 Special Function Registers
- 4.10 Access Bank
- 4.11 Bank Select Register (BSR)
  - FIGURE 4-7: Direct Addressing
- 4.12 Indirect Addressing, INDF and FSR Registers
  - EXAMPLE 4-5: How to Clear RAM (Bank 1) Using Indirect Addressing
  - 4.12.1 Indirect Addressing Operation
    - FIGURE 4-8: Indirect Addressing
- 4.13 Status Register
  - Register 4-2: Status Register
- 4.14 RCON Register
  - Register 4-3: RCON: Reset Control Register
5.0 Data EEPROM Memory
- 5.1 EEADR Register
- 5.2 EECON1 and EECON2 Registers
  - Register 5-1: EECON1: EEPROM Control Register 1
- 5.3 Reading the Data EEPROM Memory
  - EXAMPLE 5-1: Data EEPROM Read
- 5.4 Writing to the Data EEPROM Memory
  - EXAMPLE 5-2: Data EEPROM Write
- 5.5 Write Verify
- 5.6 Protection Against Spurious Write
- 5.7 Operation During Code-Protect
- 5.8 Using the Data EEPROM
  - EXAMPLE 5-3: Data EEPROM Refresh Routine
  - TABLE 5-1: Registers Associated with Data EEPROM Memory
6.0 Flash Program Memory
- 6.1 Table Reads and Table Writes
  - FIGURE 6-1: Table Read Operation
  - FIGURE 6-2: Table Write Operation
- 6.2 Control Registers
- 6.3 Reading the Flash Program Memory
  - FIGURE 6-4: Reads From Flash Program Memory
  - EXAMPLE 6-1: Reading a Flash Program Memory Word
- 6.4 Erasing Flash Program Memory
  - 6.4.1 Flash Program Memory Erase Sequence
    - EXAMPLE 6-2: Erasing a Flash Program Memory Row
- 6.5 Writing to Flash Program Memory
- 6.6 Flash Program Operation During Code Protection
  - TABLE 6-2: Registers Associated with Program Flash Memory
7.0 8 x 8 Hardware Multiplier
- 7.1 Introduction
- 7.2 Operation
8.0 Interrupts
- FIGURE 8-1: Interrupt Logic
- 8.1 INTCON Registers
- 8.2 PIR Registers
- 8.3 PIE Registers
- 8.4 IPR Registers
- 8.5 RCON Register
  - Register 8-13: RCON: Reset Control Register
- 8.6 INT Interrupts
- 8.7 TMR0 Interrupt
- 8.8 PORTB Interrupt-on-Change
- 8.9 Context Saving During Interrupts
  - EXAMPLE 8-1: Saving Status, WREG and BSR Registers in RAM
9.0 I/O Ports
- 9.1 PORTA, TRISA and LATA Registers
- 9.2 PORTB, TRISB and LATB Registers
- 9.3 PORTC, TRISC and LATC Registers
- 9.4 PORTD, TRISD and LATD Registers
- 9.5 PORTE, TRISE and LATE Registers
10.0 Parallel Slave Port
- FIGURE 10-1: PORTD and PORTE Block Diagram (Parallel Slave Port)
- FIGURE 10-2: Parallel Slave Port Write Waveforms
- FIGURE 10-3: Parallel Slave Port Read Waveforms
- TABLE 10-1: Registers Associated with Parallel Slave Port
11.0 Timer0 Module
- Register 11-1: T0CON: Timer0 Control Register
- FIGURE 11-1: Timer0 Block Diagram in 8-bit Mode
- FIGURE 11-2: Timer0 Block Diagram in 16-bit Mode
- 11.1 Timer0 Operation
- 11.2 Prescaler
  - 11.2.1 Switching Prescaler Assignment
- 11.3 Timer0 Interrupt
- 11.4 16-Bit Mode Timer Reads and Writes
  - TABLE 11-1: Registers Associated with Timer0
12.0 Timer1 Module
- Register 12-1: T1CON: Timer1 Control Register
- 12.1 Timer1 Operation
  - FIGURE 12-1: Timer1 Block Diagram
  - FIGURE 12-2: Timer1 Block Diagram: 16-bit Read/Write Mode
- 12.2 Timer1 Oscillator
  - TABLE 12-1: Capacitor Selection for the Alternate Oscillator
- 12.3 Timer1 Interrupt
- 12.4 Resetting Timer1 Using a CCP Trigger Output
- 12.5 Timer1 16-Bit Read/Write Mode
  - TABLE 12-2: Registers Associated with Timer1 as a Timer/Counter
13.0 Timer2 Module
- 13.1 Timer2 Operation
  - Register 13-1: T2CON: Timer2 Control Register
- 13.2 Timer2 Interrupt
- 13.3 Output of TMR2
  - FIGURE 13-1: Timer2 Block Diagram
  - TABLE 13-1: Registers Associated with Timer2 as a Timer/Counter
14.0 Timer3 Module
- Register 14-1: T3CON:Timer3 Control Register
- 14.1 Timer3 Operation
  - FIGURE 14-1: Timer3 Block Diagram
  - FIGURE 14-2: Timer3 Block Diagram Configured in 16-bit Read/Write Mode
- 14.2 Timer1 Oscillator
- 14.3 Timer3 Interrupt
- 14.4 Resetting Timer3 Using a CCP Trigger Output
  - TABLE 14-1: Registers Associated with Timer3 as a Timer/Counter
15.0 Capture/Compare/PWM (CCP) Modules
- Register 15-1: CCP1CON: CCP1 Control Register
- 15.1 CCP1 Module
  - TABLE 15-1: CCP1 Mode – Timer Resource
- 15.2 Capture Mode
- 15.3 Compare Mode
- 15.4 PWM Mode
16.0 Enhanced Capture/ Compare/PWM (ECCP) Module
- Register 16-1: ECCP1Con: ECCP1 Control Register
- 16.1 ECCP1 Module
- 16.2 Capture Mode
  - 16.2.1 CAN Message TIME-STAMP
- 16.3 Compare Mode
  - 16.3.1 Special Event Trigger
    - TABLE 16-4: Registers Associated with Enhanced Capture, Compare, Timer1 and Timer3
- 16.4 Standard PWM Mode
- 16.5 Enhanced PWM Mode
- 16.6 Enhanced CCP Auto-Shutdown
  - Register 16-3: ECCPAS: Enhanced Capture/Compare/PWM Auto-Shutdown Control Register
17.0 Master Synchronous Serial Port (MSSP) Module
- 17.1 Master SSP (MSSP) Module Overview
- 17.2 Control Registers
- 17.3 SPI Mode
- 17.4 I2C Mode
18.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART)
- Register 18-1: TXSTA: Transmit Status and Control Register
- Register 18-2: RCSTA: Receive Status and Control Register
- 18.1 USART Baud Rate Generator (BRG)
  - 18.1.1 Sampling
- 18.2 USART Asynchronous Mode
- 18.3 USART Synchronous Master Mode
  - 18.3.1 USART Synchronous Master Transmission
  - 18.3.2 USART Synchronous Master Reception
    - TABLE 18-9: Registers Associated with Synchronous Master Reception
    - FIGURE 18-8: Synchronous Reception (Master Mode, SREN)
- 18.4 USART Synchronous Slave Mode
  - 18.4.1 USART Synchronous Slave Transmit
  - 18.4.2 USART Synchronous Slave Reception
    - TABLE 18-10: Registers Associated with Synchronous Slave Transmission
    - TABLE 18-11: Registers Associated with Synchronous Slave Reception
19.0 CAN Module
- 19.1 Overview
  - 19.1.1 Overview of the Module
  - 19.1.2 Transmit/Receive Buffers
    - FIGURE 19-1: CAN Buffers and Protocol Engine Block Diagram
- 19.2 CAN Module Registers
- 19.3 CAN Modes of Operation
- 19.4 CAN Message Transmission
- 19.5 Message Reception
- 19.6 Message Acceptance Filters and Masks
  - TABLE 19-2: Filter/Mask Truth Table
  - FIGURE 19-6: Message Acceptance Mask and Filter Operation
- 19.7 Baud Rate Setting
- 19.8 Synchronization
- 19.9 Programming Time Segments
- 19.10 Oscillator Tolerance
- 19.11 Bit Timing Configuration Registers
- 19.12 Error Detection
- 19.13 CAN Interrupts
20.0 Compatible 10-Bit Analog- to-Digital Converter (A/D) Module
- Register 20-1: ADCON0: A/D Control Register 0
- Register 20-2: ADCON1: A/D Control Register 1
- FIGURE 20-1: A/D Block Diagram
- 20.1 A/D Acquisition Requirements
- 20.2 Selecting the A/D Conversion Clock
- 20.3 Configuring Analog Port Pins
  - TABLE 20-1: Tad vs. Device Operating Frequencies
  - TABLE 20-2: Tad vs. Device Operating Frequencies (for Extended, LF Devices)
- 20.4 A/D Conversions
  - 20.4.1 A/D Result Registers
    - FIGURE 20-3: A/D Result Justification
- 20.5 Use of the ECCP Trigger
  - FIGURE 20-4: A/D Conversion Tad Cycles
  - TABLE 20-3: Summary of A/D Registers
21.0 Comparator Module
- Register 21-1: CMCON: Comparator Control Register
- 21.1 Comparator Configuration
  - FIGURE 21-1: Comparator I/O Operating Modes
- 21.2 Comparator Operation
- 21.3 Comparator Reference
- 21.4 Comparator Response Time
- 21.5 Comparator Outputs
  - FIGURE 21-3: Comparator Output Block Diagram
- 21.6 Comparator Interrupts
- 21.7 Comparator Operation During Sleep
- 21.8 Effects of a Reset
- 21.9 Analog Input Connection Considerations
  - FIGURE 21-4: Analog Input Model
  - TABLE 21-1: Registers Associated with Comparator Module
22.0 Comparator Voltage Reference Module
- 22.1 Configuring the Comparator Voltage Reference
- 22.2 Voltage Reference Accuracy/Error
- 22.3 Operation During Sleep
- 22.4 Effects of a Reset
- 22.5 Connection Considerations
  - FIGURE 22-2: Voltage Reference Output Buffer Example
  - TABLE 22-1: Registers Associated with Comparator Voltage Reference
23.0 Low-Voltage Detect
- FIGURE 23-1: Typical Low-Voltage Detect Application
- FIGURE 23-2: Low-Voltage Detect (LVD) Block Diagram
- FIGURE 23-3: Low-Voltage Detect (LVD) with External Input Block Diagram
- 23.1 Control Register
  - Register 23-1: LVDCON: Low-Voltage Detect Control Register
- 23.2 Operation
- 23.3 Operation During Sleep
- 23.4 Effects of a Reset
24.0 Special Features of the CPU
- 24.1 Configuration Bits
- 24.2 Watchdog Timer (WDT)
  - 24.2.1 Control Register
    - Register 24-13: WDTCON: Watchdog Timer Control Register
  - 24.2.2 WDT Postscaler
    - FIGURE 24-1: Watchdog Timer Block Diagram
    - TABLE 24-2: Summary of Watchdog Timer Registers
- 24.3 Power-Down Mode (Sleep)
  - 24.3.1 Wake-up From Sleep
  - 24.3.2 Wake-up Using Interrupts
    - FIGURE 24-2: Wake-up From Sleep Through Interrupt(1,2)
- 24.4 Program Verification and Code Protection
- 24.5 ID Locations
- 24.6 In-Circuit Serial Programming
- 24.7 In-Circuit Debugger
- 24.8 Low-Voltage ICSP Programming
25.0 Instruction Set Summary
- 25.1 ReadModify-Write Operations
- 25.2 Instruction Set
26.0 Development Support
- 26.1 MPLAB Integrated Development Environment Software
- 26.2 MPASM Assembler
- 26.3 MPLAB C17 and MPLAB C18 C Compilers
- 26.4 MPLINK Object Linker/ MPLIB Object Librarian
- 26.5 MPLAB C30 C Compiler
- 26.6 MPLAB ASM30 Assembler, Linker and Librarian
- 26.7 MPLAB SIM Software Simulator
- 26.8 MPLAB SIM30 Software Simulator
- 26.9 MPLAB ICE 2000 High-Performance Universal In-Circuit Emulator
- 26.10 MPLAB ICE 4000 High-Performance Universal In-Circuit Emulator
- 26.11 MPLAB ICD 2 In-Circuit Debugger
- 26.12 PRO MATE II Universal Device Programmer
- 26.13 MPLAB PM3 Device Programmer
- 26.14 PICSTART Plus Development Programmer
- 26.15 PICDEM 1 PICmicro Demonstration Board
- 26.16 PICDEM.net Internet/Ethernet Demonstration Board
- 26.17 PICDEM 2 Plus Demonstration Board
- 26.18 PICDEM 3 PIC16C92X Demonstration Board
- 26.19 PICDEM 4 8/14/18-Pin Demonstration Board
- 26.20 PICDEM 17 Demonstration Board
- 26.21 PICDEM 18R PIC18C601/801 Demonstration Board
- 26.22 PICDEM LIN PIC16C43X Demonstration Board
- 26.23 PICkitTM 1 Flash Starter Kit
- 26.24 PICDEM USB PIC16C7X5 Demonstration Board
- 26.25 Evaluation and Programming Tools
27.0 Electrical Characteristics
- Absolute Maximum Ratings(†)
- 27.1 DC Characteristics
- 27.2 DC Characteristics: PIC18FXX8 (Industrial, Extended) PIC18LFXX8 (Industrial)
- 27.3 AC (Timing) Characteristics
28.0 DC and AC Characteristics Graphs and Tables
- FIGURE 28-1: Typical Idd vs. Fosc Over Vdd (Hs Mode)
- FIGURE 28-2: Maximum Idd vs. Fosc Over Vdd (Hs Mode)
- FIGURE 28-3: Typical Idd vs. Fosc Over Vdd (HS/PLL Mode)
- FIGURE 28-4: Maximum Idd vs. Fosc Over Vdd (HS/PLL Mode)
- FIGURE 28-5: Typical Idd vs. Fosc Over Vdd (XT Mode)
- FIGURE 28-6: Maximum Idd vs. Fosc Over Vdd (XT Mode)
- FIGURE 28-7: Typical Idd vs. Fosc Over Vdd (LP Mode)
- FIGURE 28-8: Maximum Idd vs. Fosc Over Vdd (LP Mode)
- FIGURE 28-9: Typical Idd vs. Fosc Over Vdd (EC Mode)
- FIGURE 28-10: Maximum Idd vs. Fosc Over Vdd (EC Mode)
- FIGURE 28-11: Typical and Maximum Idd vs. Vdd (Timer1 as Main Oscillator 32.768kHz, C1 and C2 = ...
- FIGURE 28-12: Average Fosc vs. Vdd for Various Values of R (RC Mode, C = 20 pF, +25°C)
- FIGURE 28-13: Average Fosc vs. Vdd for Various Values of R (RC Mode, C = 100pF, +25°C)
- FIGURE 28-14: Average Fosc vs. Vdd for Various Values of R (RC Mode, C = 300pF, +25°C)
- FIGURE 28-15: Ipd vs. Vdd, -40°C to +125°C (Sleep Mode, All Peripherals Disabled)
- FIGURE 28-16: DIbor vs. Vdd Over Temperature (BOR Enabled, Vbor = 2.00-2.16V)
- FIGURE 28-17: Typical and Maximum DItmr1 vs. Vdd Over Temperature (-10°C to +70°C, Timer1 with Os...
- FIGURE 28-18: Typical and Maximum DIwdt vs. Vdd Over Temperature (WDT Enabled)
- FIGURE 28-19: Typical, Minimum and Maximum WDT Period vs. Vdd (-40°C to +125°C)
- FIGURE 28-20: DIlvd vs. Vdd Over Temperature (LVD Enabled, Vlvd = 4.5 - 4.78V)
- FIGURE 28-21: Typical, Minimum and Maximum Voh vs. Ioh (Vdd = 5V, -40°C to +125°C)
- FIGURE 28-22: Typical, Minimum and Maximum Voh vs. Ioh (Vdd = 3V, -40°C to +125°C)
- FIGURE 28-23: Typical and Maximum Vol vs. Iol (Vdd = 5V, -40°C to +125°C)
- FIGURE 28-24: Typical and Maximum Vol vs. Iol (Vdd = 3V, -40°C to +125°C)
- FIGURE 28-25: Minimum and Maximum Vin vs. Vdd (ST Input, -40°C to +125°C)
- FIGURE 28-26: Minimum and Maximum Vin vs. Vdd (TTL Input, -40°C to +125°C)
- FIGURE 28-27: Minimum and Maximum Vin vs. Vdd (I2C™ Input, -40°C to +125°C)
- FIGURE 28-28: A/D Nonlinearity vs. Vrefh (Vdd = Vrefh, -40°C to +125°C)
- FIGURE 28-29: A/D Nonlinearity vs. Vrefh (Vdd = 5V, -40°C to +125°C)
29.0 Packaging Information
- 29.1 Package Marking Information
- 29.1 Package Marking Information (Continued)
- 29.2 Package Details
- 28-Lead Skinny Plastic Dual In-line (SP) – 300 mil Body (PDIP)
- 28-Lead Plastic Small Outline (SO) –Wide, 300 mil Body (SOIC)
- 40-Lead Plastic Dual In-line (P) – 600 mil Body (PDIP)
- 44-Lead Plastic Leaded Chip Carrier (L) – Square (PLCC)
- 44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)
Appendix A: Data Sheet Revision History
- Revision A (June 2001)
- Revision B (May 2002)
- Revision C (January 2003)
- Revision D (September 2004)
- Revision E (October 2006)
Appendix B: Device Differences
- TABLE B-1: Device Differences
Appendix C: Device Migrations
Appendix D: Migrating From Other PICmicro® Devices
INDEX
The Microchip Web Site
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PIC18FXX8 Product Identification System
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PIC18FXX8

24.2.2 WDT POSTSCALER

The WDT has a postscaler that can extend the WDT

Reset period. The postscaler is selected at the time of

device programming by the value written to the

CONFIG2H Configuration register.

FIGURE 24-1: WATCHDOG TIMER BLOCK DIAGRAM

TABLE 24-2: SUMMARY OF WATCHDOG TIMER REGISTERS

Postscaler

WDT Timer

WDTEN

8-to-1 MUX

WDTPS2:WDTPS0

WDT

Time-out

SWDTEN bit

Configuration bit

Note: WDTPS2:WDTPS0 are bits in register CONFIG2H.

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

CONFIG2H — — — — WDTPS2 WDTPS1 WDTPS0 WDTEN

RCON

IPEN — — RI TO PD POR BOR

WDTCON — — — — — — —SWDTEN

Legend: Shaded cells are not used by the Watchdog Timer.