PIC18F/LF1XK50 Data Sheet 20-Pin USB Flash Microcontrollers with nanoWatt XLP Technology 2010 Microchip Technology Inc. Preliminary DS41350D 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. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, PIC32 logo, rfPIC and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor, MXDEV, MXLAB, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Octopus, Omniscient Code Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, REAL ICE, rfLAB, Select Mode, Total Endurance, TSHARC, UniWinDriver, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2010, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. ISBN: 978-1-60932-214-4 Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, 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. DS41350D-page 2 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 20-Pin USB Flash Microcontrollers with nanoWatt XLP Technology Universal Serial Bus Features: Extreme Low-Power Management PIC18LF1XK50 with nanoWatt XLP: • USB V2.0 Compliant SIE • Full Speed (12 Mb/s) and Low Speed (1.5 Mb/s) • Supports Control, Interrupt, Isochronous and Bulk Transfers • Supports up to 16 Endpoints (8 bidirectional) • 256-byte Dual Access RAM for USB • Input-change interrupt on D+/D- for detecting physical connection to USB host • Sleep mode: 24 nA • Watchdog Timer: 450 nA • Timer1 Oscillator: 790 nA @ 32 kHz Analog Features: High Performance RISC CPU: • C Compiler Optimized Architecture: - Optional extended instruction set designed to optimize re-entrant code - 256 bytes, data EEPROM - Up to 16 Kbytes linear program memory addressing - Up to 768 bytes linear data memory addressing • Priority levels for Interrupts • 8 x 8 Single-Cycle Hardware Multiplier Flexible Oscillator Structure: • CPU divider to run the core slower than the USB peripheral • 16 MHz Internal Oscillator Block: - Software selectable frequencies, 31 kHz to 16 MHz - Provides a complete range of clock speeds from 31 kHz to 32 MHz when used with PLL - User tunable to compensate for frequency drift • Four Crystal modes, up to 48 MHz • External Clock modes, up to 48 MHz • 4X Phase Lock Loop (PLL) • Secondary oscillator using Timer1 at 32 kHz • Fail-Safe Clock Monitor: - Allows for safe shutdown if primary or secondary oscillator stops • Two-speed Oscillator Start-up Special Microcontroller Features: • • • • Full 5.5V Operation – PIC18F1XK50 1.8V-3.6V Operation – PIC18LF1XK50 Self-programmable under Software Control Programmable Brown-out Reset (BOR) - With software enable option • Extended Watchdog Timer (WDT) - Programmable period from 4ms to 131s • Single-supply 3V In-Circuit Serial Programming™ (ICSP™) via two pins 2010 Microchip Technology Inc. • Analog-to-Digital Converter (ADC) module: - 10-bit resolution, 9 external channels - Auto acquisition capability - Conversion available during Sleep - Internal 1.024V Fixed Voltage Reference (FVR) channel - Independent input multiplexing • Dual Analog Comparators - Rail-to-rail operation - Independent input multiplexing • Voltage Reference module: - Programmable (% of VDD), 16 steps - Two 16-level voltage ranges using VREF pins - Programmable Fixed Voltage Reference (FVR), 3 levels • On-chip 3.2V LDO Regulator – (PIC18F1XK50) Peripheral Highlights: • 14 I/O Pins plus 1 Input-only pin: - High-current sink/source 25 mA/25 mA - 7 Programmable weak pull-ups - 7 Programmable Interrupt-on-change pins - 3 programmable external interrupts - Programmable slew rate • Enhanced Capture/Compare/PWM (ECCP) module: - One, two, three, or four PWM outputs - Selectable polarity - Programmable dead time - Auto-shutdown and Auto-restart • Master Synchronous Serial Port (MSSP) module: - 3-wire SPI (supports all 4 modes) - I2C™ Master and Slave modes (Slave mode address masking) • Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module: - Supports RS-485, RS-232 and LIN 2.0 - RS-232 operation using internal oscillator - Auto-Baud Detect - Auto-Wake-up on Break • SR Latch mode Preliminary DS41350D-page 3 PIC18F/LF1XK50 - Data Memory MSSP EUSART Program Memory Comp. PIC18F13K50/ PIC18LF13K50 8K 4096 512(3) 256 15 11 1 Y Y 1 2 1/3 Y PIC18F14K50/ PIC18LF14K50 16K 8192 768(3) 256 15 11 1 Y Y 1 2 1/3 Y Device Note 1: 2: 3: 10-bit (1) A/D Flash # Single-Word SRAM EEPROM I/O (ch)(2) (bytes) Instructions (bytes) (bytes) ECCP (PWM) SPI Master I2C™ Timers USB 8/16-bit One pin is input only. Channel count includes internal Fixed Voltage Reference (FVR) and Programmable Voltage Reference (CVREF) channels. Includes the dual port RAM used by the USB module which is shared with the data memory. Pin Diagrams VDD RA5/IOCA5/OSC1/CLKIN RA4/AN3/IOCA3/OSC2/CLKOUT RA3/IOCA3/MCLR/VPP RC5/CCP1/P1A/T0CKI RC4/P1B/C12OUT/SRQ RC3/AN7/P1C/C12IN3-/PGM RC6/AN8/SS/T13CKI/T1OSCI RC7/AN9/SDO/T1OSCO RB7/IOCB7/TX/CK 1 2 3 4 5 6 7 8 9 10 PIC18F/LF1XK50 20-pin PDIP, SSOP, SOIC (300 MIL) 20 19 18 17 16 15 14 13 12 11 VSS RA0/IOCA0/D+/PGD RA1/IOCA1/D-/PGC VUSB RC0/AN4/C12IN+/INT0/VREF+ RC1/AN5/C12IN1-/INT1/VREFRC2/AN6/P1D/C12IN2-/CVREF/INT2 RB4/AN10/IOCB4/SDI/SDA RB5/AN11/IOCB5/RX/DT RB6/IOCB6/SCK/SCL Pin Diagrams RA4/AN3/OSC2/CLKO RA5/OSC1/CLKI VDD Vss RA0/D+/PGD 20-pin QFN (5x5) 20 19 18 17 16 RA3/MCLR/VPP RC5/CCP1/P1A/T0CKI RC4/P1B/C12OUT/SRQ RC3/AN7/P1C/C12IN3-/PGM RC6/AN8/SS/T13CKI/T1OSCI 1 2 3 PIC18F1XK50/ 4 PIC18LF1XK50 5 15 14 13 12 11 RA1/D-/PGC VUSB RC0/AN4/C12IN+/INT0/VREF+ RC1/AN1/C12IN1-/INT1/VREFRC2/AN6/P1D/C12IN2-/CVREF/INT2 RC7/AN9/SDO/T1OSCO RB7/TX/CK RB6/SCK/SCL RB5/AN11/RX/DT RB4/AN10/SDI/SDA 6 7 8 9 10 DS41350D-page 4 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 Basic RA0 IOCA0 D+ PGD RA1 IOCA1 D- 4 RA3(1) IOCA3 Y MCLR/VPP 3 RA4 2 RA5 13 RB4 AN10 12 RB5 AN11 11 RB6 10 RB7 16 RC0 AN4 C12IN+ VREF+ INT0 15 RC1 AN5 C12IN1- VREF- INT1 14 RC2 AN6 C12IN2- CVREF 7 RC3 AN7 C12IN3- P1C 6 RC4 C12OUT P1B 5 RC5 8 RC6 AN8 SS T13CKI/T1OSCI 9 RC7 AN9 SDO T1OSCO I/O 19 18 Pin USB Pull-up Interrupts Timers MSSP EUSART ECCP Reference Comparator PIC18F/LF1XK50 PIN SUMMARY Analog TABLE 1: AN3 IOCA4 Y OSC2/CLKOUT IOCA5 Y OSC1/CLKIN SDI/SDA IOCB4 Y IOCB5 Y SCL/SCK IOCB6 Y IOCB7 Y RX/DT TX/CK P1D INT2 PGM SRQ CCP1/P1A T0CKI 17 VUSB 1 VDD 20 Note PGC VSS 1: Input only. 2010 Microchip Technology Inc. Preliminary DS41350D-page 5 PIC18F/LF1XK50 Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 9 2.0 Oscillator Module (With Fail-Safe Clock Monitor)....................................................................................................................... 15 3.0 Memory Organization ................................................................................................................................................................. 29 4.0 Flash Program Memory .............................................................................................................................................................. 51 5.0 Data EEPROM Memory ............................................................................................................................................................. 61 6.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 65 7.0 Interrupts .................................................................................................................................................................................... 67 8.0 Low Dropout (LDO) Voltage Regulator ...................................................................................................................................... 81 9.0 I/O Ports ..................................................................................................................................................................................... 83 10.0 Timer0 Module ......................................................................................................................................................................... 101 11.0 Timer1 Module ......................................................................................................................................................................... 105 12.0 Timer2 Module ......................................................................................................................................................................... 111 13.0 Timer3 Module ......................................................................................................................................................................... 113 14.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 117 15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 139 16.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 183 17.0 Analog-to-Digital Converter (ADC) Module .............................................................................................................................. 211 18.0 Comparator Module.................................................................................................................................................................. 225 19.0 Power-Managed Modes ........................................................................................................................................................... 237 20.0 SR Latch................................................................................................................................................................................... 243 21.0 Voltage References .................................................................................................................................................................. 247 22.0 Universal Serial Bus (USB) ...................................................................................................................................................... 253 23.0 Reset ........................................................................................................................................................................................ 279 24.0 Special Features of the CPU .................................................................................................................................................... 293 25.0 Instruction Set Summary .......................................................................................................................................................... 311 26.0 Development Support............................................................................................................................................................... 361 27.0 Electrical Specifications............................................................................................................................................................ 365 28.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 399 29.0 Packaging Information.............................................................................................................................................................. 401 Appendix A: Revision History............................................................................................................................................................. 407 Appendix B: Device Differences......................................................................................................................................................... 407 Index .................................................................................................................................................................................................. 409 The Microchip Web Site ..................................................................................................................................................................... 419 Customer Change Notification Service .............................................................................................................................................. 419 Customer Support .............................................................................................................................................................................. 419 Reader Response .............................................................................................................................................................................. 420 Product Identification System............................................................................................................................................................. 421 DS41350D-page 6 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at [email protected] or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: • Microchip’s Worldwide Web site; http://www.microchip.com • Your local Microchip sales office (see last page) • The Microchip Corporate Literature Center; U.S. FAX: (480) 792-7277 When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at www.microchip.com/cn to receive the most current information on all of our products. 2010 Microchip Technology Inc. Preliminary DS41350D-page 7 PIC18F/LF1XK50 NOTES: DS41350D-page 8 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 1.0 DEVICE OVERVIEW 1.1.2 This document contains device specific information for the following devices: • PIC18F13K50 • PIC18F14K50 • PIC18LF13K50 • PIC18LF14K50 This family offers the advantages of all PIC18 microcontrollers – namely, high computational performance at an economical price – with the addition of high-endurance, Flash program memory. On top of these features, the PIC18F/LF1XK50 family introduces design enhancements that make these microcontrollers a logical choice for many highperformance, power sensitive applications. 1.1 1.1.1 New Core Features nanoWatt XLP TECHNOLOGY All of the devices in the PIC18F/LF1XK50 family incorporate a range of features that can significantly reduce power consumption during operation. Key items include: • Alternate Run Modes: By clocking the controller from the Timer1 source or the internal oscillator block, power consumption during code execution can be reduced by as much as 90%. • Multiple Idle Modes: The controller can also run with its CPU core disabled but the peripherals still active. In these states, power consumption can be reduced even further, to as little as 4% of normal operation requirements. • On-the-fly Mode Switching: The powermanaged modes are invoked by user code during operation, allowing the user to incorporate powersaving ideas into their application’s software design. • Low Consumption in Key Modules: The power requirements for both Timer1 and the Watchdog Timer are minimized. See Section 27.0 “Electrical Specifications” for values. 2010 Microchip Technology Inc. MULTIPLE OSCILLATOR OPTIONS AND FEATURES All of the devices in the PIC18F/LF1XK50 family offer ten different oscillator options, allowing users a wide range of choices in developing application hardware. These include: • Four Crystal modes, using crystals or ceramic resonators • External Clock modes, offering the option of using two pins (oscillator input and a divide-by-4 clock output) or one pin (oscillator input, with the second pin reassigned as general I/O) • External RC Oscillator modes with the same pin options as the External Clock modes • An internal oscillator block which contains a 16 MHz HFINTOSC oscillator and a 31 kHz LFINTOSC oscillator which together provide 8 user selectable clock frequencies, from 31 kHz to 16 MHz. This option frees the two oscillator pins for use as additional general purpose I/O. • A Phase Lock Loop (PLL) frequency multiplier, available to both the high-speed crystal and internal oscillator modes, which allows clock speeds of up to 48 MHz. Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 32 MHz – all without using an external crystal or clock circuit. Besides its availability as a clock source, the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: • Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the LFINTOSC. If a clock failure occurs, the controller is switched to the internal oscillator block, allowing for continued operation or a safe application shutdown. • Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Power-on Reset, or wake-up from Sleep mode, until the primary clock source is available. Preliminary DS41350D-page 9 PIC18F/LF1XK50 1.2 Other Special Features 1.3 • Memory Endurance: The Flash cells for both program memory and data EEPROM are rated to last for many thousands of erase/write cycles – up to 1K for program memory and 100K for EEPROM. Data retention without refresh is conservatively estimated to be greater than 40 years. • Self-programmability: These devices can write to their own program memory spaces under internal software control. Using a bootloader routine located in the code protected Boot Block, it is possible to create an application that can update itself in the field. • Extended Instruction Set: The PIC18F/ LF1XK50 family introduces an optional extension to the PIC18 instruction set, which adds 8 new instructions and an Indexed Addressing mode. This extension has been specifically designed to optimize re-entrant application code originally developed in high-level languages, such as C. • Enhanced CCP module: In PWM mode, this module provides 1, 2 or 4 modulated outputs for controlling half-bridge and full-bridge drivers. Other features include: - Auto-Shutdown, for disabling PWM outputs on interrupt or other select conditions - Auto-Restart, to reactivate outputs once the condition has cleared - Output steering to selectively enable one or more of 4 outputs to provide the PWM signal. • Enhanced Addressable USART: This serial communication module is capable of standard RS-232 operation and provides support for the LIN bus protocol. Other enhancements include automatic baud rate detection and a 16-bit Baud Rate Generator for improved resolution. • 10-bit A/D Converter: This module incorporates programmable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period and thus, reduce code overhead. • Extended Watchdog Timer (WDT): This enhanced version incorporates a 16-bit postscaler, allowing an extended time-out range that is stable across operating voltage and temperature. See Section 27.0 “Electrical Specifications” for time-out periods. DS41350D-page 10 Details on Individual Family Members Devices in the PIC18F/LF1XK50 family are available in 20-pin packages. Block diagrams for the two groups are shown in Figure 1-1. The devices are differentiated from each other in the following ways: 1. 2. Flash program memory: • 8 Kbytes for PIC18F13K50/PIC18LF13K50 • 16 Kbytes for PIC18F14K50/PIC18LF14K50 On-chip 3.2V LDO regulator for PIC18F13K50 and PIC18F14K50. All other features for devices in this family are identical. These are summarized in Table 1-1. The pinouts for all devices are listed in Table 1 and I/O description are in Table 1-2. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 1-1: DEVICE FEATURES FOR THE PIC18F/LF1XK50 (20-PIN DEVICES) Features LDO Regulator Program Memory (Bytes) PIC18F13K50 PIC18LF13K50 PIC18F14K50 PIC18LF14K50 No Yes No Yes 8K 16K Program Memory (Instructions) 4096 8192 Data Memory (Bytes) 512 768 Operating Frequency DC – 48 MHz Interrupt Sources 30 I/O Ports Ports A, B, C Timers 4 Enhanced Capture/ Compare/PWM Modules Serial Communications 1 MSSP, Enhanced USART, USB 10-Bit Analog-to-Digital Module Resets (and Delays) Instruction Set Packages 2010 Microchip Technology Inc. 9 Input Channels POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT (PWRT, OST) 75 Instructions, 83 with Extended Instruction Set Enabled 20-Pin PDIP, SSOP, SOIC (300 mil) and QFN (5x5) Preliminary DS41350D-page 11 PIC18F/LF1XK50 FIGURE 1-1: PIC18F/LF1XK50 BLOCK DIAGRAM Data Bus<8> Table Pointer<21> Data Latch 8 8 inc/dec logic PCLATU PCLATH 21 PORTA Data Memory (512/768 bytes) Address Latch 20 PCU PCH PCL Program Counter 12 Data Address<12> 31-Level Stack 4 BSR Address Latch STKPTR Program Memory 12 FSR0 FSR1 FSR2 Data Latch 4 Access Bank 12 PORTB 8 inc/dec logic Table Latch Instruction Bus <16> RA0 RA1 RA3 RA4 RA5 RB4 RB5 RB6 RB7 Address Decode ROM Latch IR Instruction Decode and Control 8 State machine control signals PRODH PRODL PORTC 8 x 8 Multiply 3 Internal Oscillator Block OSC1(2) OSC2(2) T1OSI LFINTOSC Oscillator T1OSO 16 MHz Oscillator MCLR(1) 8 8 8 8 Oscillator Start-up Timer RC0 RC1 RC2 RC3 RC4 RC5 RC6 RC7 ALU<8> Power-on Reset 8 Watchdog Timer Single-Supply Programming VDD, VSS W BITOP 8 Power-up Timer USB Module VUSB 8 Fail-Safe Clock Monitor Precision Band Gap Reference FVR LDO(3) Regulator BOR FVR CVREF Comparator Note Data EEPROM Timer0 Timer1 Timer2 Timer3 ECCP1 USB MSSP EUSART ADC 10-bit FVR CVREF 1: RA3 is only available when MCLR functionality is disabled. 2: OSC1/CLKIN and OSC2/CLKOUT are only available in select oscillator modes and when these pins are not being used as digital I/O. Refer to Section 2.0 “Oscillator Module” for additional information. 3: PIC18F13K50/PIC18F14K50 only. DS41350D-page 12 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 1-2: PIC18F/LF1XK50 PINOUT I/O DESCRIPTIONS Pin Name Pin Pin Number Type RA0/D+/PGD RA0 D+ PGD 19 RA1/D-/PGC RA1 DPGC 18 RA3/MCLR/VPP RA3 MCLR VPP 4 RA4/AN3/OSC2/CLKOUT RA4 AN3 OSC2 3 CLKOUT RA5/OSC1/CLKIN RA5 OSC1 Description I I/O I/O TTL XCVR ST Digital input USB differential plus line (input/output) ICSP™ programming data pin I I/O I/O TTL XCVR ST Digital input USB differential minus line (input/output) ICSP™ programming clock pin I I P ST ST — I/O I O TTL Analog XTAL O CMOS I/O I TTL XTAL I CMOS I/O I I I/O TTL Analog ST ST Digital I/O ADC channel 10 SPI data in I2C™ data I/O I/O I I I/O TLL Analog ST ST Digital I/O ADC channel 11 EUSART asynchronous receive EUSART synchronous data (see related RX/TX) I/O I/O I/O TLL ST ST I/O O I/O TLL CMOS ST Master Clear (input) or programming voltage (input) Digital input Active-low Master Clear with internal pull-up High voltage programming input Digital I/O ADC channel 3 Oscillator crystal output. Connect to crystal or resonator in Crystal Oscillator mode In RC mode, OSC2 pin outputs CLKOUT which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate 2 CLKIN RB4/AN10/SDI/SDA RB4 AN10 SDI SDA 13 RB5/AN11/RX/DT RB5 AN11 RX DT 12 RB6/SCK/SCI RB6 SCK SCI 11 RB7/TX/CK RB7 TX CK 10 Legend: TTL = ST = O = XTAL= Buffer Type TTL compatible input Schmitt Trigger input Output Crystal Oscillator 2010 Microchip Technology Inc. Digital I/O Oscillator crystal input or external clock input ST buffer when configured in RC mode; analog other wise External clock source input. Always associated with the pin function OSC1 (See related OSC1/CLKIN, OSC2, CLKOUT pins Digital I/O Synchronous serial clock input/output for SPI mode Synchronous serial clock input/output for I2C™ mode Digital I/O EUSART asynchronous transmit EUSART synchronous clock (see related RX/DT) CMOS I P XCVR Preliminary = = = = CMOS compatible input or output Input Power USB Differential Transceiver DS41350D-page 13 PIC18F/LF1XK50 TABLE 1-2: PIC18F/LF1XK50 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Pin Number Type RC0/AN4/C12IN+/INT0/VREF+ RC0 AN4 C12IN+ INT0 VREF+ 16 RC1/AN5/C12IN-/INT1/VREFRC1 AN5 C12ININT1 VREF- 15 RC2/AN6/P1D/C12IN2-/CVREF/INT2 RC2 AN6 P1D C12IN2CVREF INT2 14 RC3/AN7/P1C/C12IN3-/PGM RC3 AN7 P1C C12IN3PGM 7 RC4/P1B/C12OUT/SRQ RC4 P1B C12OUT SRQ 6 RC5/CCP1/P1A/T0CKI RC5 CCP1 P1A T0CKI 5 RC6/AN8/SS/T13CKI/T1OSCI RC6 AN8 SS T13CKI T1OSCI 8 RC7/AN9/SDO/T1OSCO RC7 AN9 SDO T1OSCO 9 VSS 20 Buffer Type Description I/O I I I I ST Analog Analog ST Analog Digital I/O ADC channel 4 Comparator C1 and C2 non-inverting input External interrupt 0 Comparator reference voltage (high) input I/O I I I I ST Analog Analog ST Analog Digital I/O ADC channel 5 Comparator C1 and C2 non-inverting input External interrupt 0 Comparator reference voltage (low) input I/O I O I O I ST Analog CMOS Analog Analog ST Digital I/O ADC channel 6 Enhanced CCP1 PWM output Comparator C1 and C2 inverting input Comparator reference voltage output External interrupt 0 I/O I O I I/O ST Analog CMOS Analog ST Digital I/O ADC channel 7 Enhanced CCP1 PWM output Comparator C1 and C2 inverting input Low-Voltage ICSP Programming enable pin I/O O O O ST CMOS CMOS CMOS Digital I/O Enhanced CCP1 PWM output Comparator C1 and C2 output SR Latch output I/O I/O O I ST ST CMOS ST Digital I/O Capture 1 input/Compare 1 output/PWM 1 output Enhanced CCP1 PWM output Timer0 external clock input I/O I I I I ST Analog TTL ST XTAL Digital I/O ADC channel 8 SPI slave select input Timer0 and Timer3 external clock input Timer1 oscillator input I/O I O O ST Analog CMOS XTAL Digital I/O ADC channel 9 SPI data out Timer1 oscillator output P — Ground reference for logic and I/O pins VDD 1 P — Positive supply for logic and I/O pins VUSB 17 P — Positive supply for USB transceiver Legend: TTL = ST = O = XTAL= TTL compatible input Schmitt Trigger input Output Crystal Oscillator DS41350D-page 14 CMOS I P XCVR Preliminary = = = = CMOS compatible input or output Input Power USB Differential Transceiver 2010 Microchip Technology Inc. PIC18F/LF1XK50 2.0 OSCILLATOR MODULE 2.2 2.1 Overview The SCS bits of the OSCCON register select between the following clock sources: The oscillator module has a variety of clock sources and features that allow it to be used in a wide range of applications, maximizing performance and minimizing power consumption. Figure 2-1 illustrates a block diagram of the oscillator module. • Primary External Oscillator • Secondary External Oscillator • Internal Oscillator Note: Key features of the oscillator module include: • System Clock Selection - Primary External Oscillator - Secondary External Oscillator - Internal Oscillator • Oscillator Start-up Timer • System Clock Selection • Clock Switching • 4x Phase Lock Loop Frequency Multiplier • CPU Clock Divider • USB Operation - Low Speed - Full Speed • Two-Speed Start-up Mode • Fail-Safe Clock Monitoring System Clock Selection The frequency of the system clock will be referred to as FOSC throughout this document. TABLE 2-1: SYSTEM CLOCK SELECTION Configuration Selection SCS <1:0> System Clock 1x Internal Oscillator 01 Secondary External Oscillator 00 (Default after Reset) Oscillator defined by FOSC<3:0> The default state of the SCS bits sets the system clock to be the oscillator defined by the FOSC bits of the CONFIG1H Configuration register. The system clock will always be defined by the FOSC bits until the SCS bits are modified in software. When the Internal Oscillator is selected as the system clock, the IRCF bits of the OSCCON register and the INTSRC bit of the OSCTUNE register will select either the LFINTOSC or the HFINTOSC. The LFINTOSC is selected when the IRCF<2:0> = 000 and the INTSRC bit is clear. All other combinations of the IRCF bits and the INTSRC bit will select the HFINTOSC as the system clock. 2.3 Primary External Oscillator The Primary External Oscillator’s mode of operation is selected by setting the FOSC<3:0> bits of the CONFIG1H Configuration register. The oscillator can be set to the following modes: • • • • • LP: Low-Power Crystal XT: Crystal/Ceramic Resonator HS: High-Speed Crystal Resonator RC: External RC Oscillator EC: External Clock Additionally, the Primary External Oscillator may be shut-down under firmware control to save power. 2010 Microchip Technology Inc. Preliminary DS41350D-page 15 PIC18F/LF1XK50 PIC® MCU CLOCK SOURCE BLOCK DIAGRAM FIGURE 2-1: PIC18F/LF1XK50 2 Low Speed USB 1 0 Primary Oscillator High Speed USB USBDIV OSC1 Sleep OSC2 IDLEN PCLKEN PRI_SD 4 x PLL 1 0 FOSC<3:0> CPU Divider Peripherals PLLEN SPLLEN MUX 1x IRCF<2:0> 31 kHz LFINTOSC 8 MHz 4 MHz Postscaler Internal Oscillator Block 16 MHz HFINTOSC 2 MHz 1 MHz 500 kHz System Clock 01 CPU Sleep 111 110 101 100 011 MUX 16 MHz Sleep 00 Clock Control FOSC<3:0> SCS<1:0> 010 250 kHz 001 1 31 kHz 000 0 INTSRC Secondary Oscillator T1OSI T1OSO T1OSCEN Enable Oscillator Fail-Safe Clock Watchdog Timer DS41350D-page 16 Preliminary Two-Speed Start-up 2010 Microchip Technology Inc. PIC18F/LF1XK50 2.3.1 PRIMARY EXTERNAL OSCILLATOR SHUT-DOWN FIGURE 2-2: The Primary External Oscillator can be enabled or disabled via software. To enable software control of the Primary External Oscillator, the PCLKEN bit of the CONFIG1H Configuration register must be set. With the PCLKEN bit set, the Primary External Oscillator is controlled by the PRI_SD bit of the OSCCON2 register. The Primary External Oscillator will be enabled when the PRI_SD bit is set, and disabled when the PRI_SD bit is clear. Note: 2.3.2 The Primary External Oscillator cannot be shut down when it is selected as the System Clock. To shut down the oscillator, the system clock source must be either the Secondary Oscillator or the Internal Oscillator. QUARTZ CRYSTAL OPERATION (LP, XT OR HS MODE) PIC® MCU OSC1/CLKIN C1 To Internal Logic Quartz Crystal C2 RS(1) RF(2) Sleep OSC2/CLKOUT Note 1: A series resistor (RS) may be required for quartz crystals with low drive level. 2: The value of RF varies with the Oscillator mode selected (typically between 2 M to 10 M. LP, XT AND HS OSCILLATOR MODES The LP, XT and HS modes support the use of quartz crystal resonators or ceramic resonators connected to OSC1 and OSC2 (Figure 2-2). The mode selects a low, medium or high gain setting of the internal inverteramplifier to support various resonator types and speed. Note 1: Quartz crystal characteristics vary according to type, package and manufacturer. The user should consult the manufacturer data sheets for specifications and recommended application. LP Oscillator mode selects the lowest gain setting of the internal inverter-amplifier. LP mode current consumption is the least of the three modes. This mode is best suited to drive resonators with a low drive level specification, for example, tuning fork type crystals. 2: Always verify oscillator performance over the VDD and temperature range that is expected for the application. XT Oscillator mode selects the intermediate gain setting of the internal inverter-amplifier. XT mode current consumption is the medium of the three modes. This mode is best suited to drive resonators with a medium drive level specification. • AN826, “Crystal Oscillator Basics and Crystal Selection for rfPIC® and PIC® Devices” (DS00826) • AN849, “Basic PIC® Oscillator Design” (DS00849) • AN943, “Practical PIC® Oscillator Analysis and Design” (DS00943) • AN949, “Making Your Oscillator Work” (DS00949) HS Oscillator mode selects the highest gain setting of the internal inverter-amplifier. HS mode current consumption is the highest of the three modes. This mode is best suited for resonators that require a high drive setting. 3: For oscillator design assistance, reference the following Microchip Applications Notes: Figure 2-2 and Figure 2-3 show typical circuits for quartz crystal and ceramic resonators, respectively. 2010 Microchip Technology Inc. Preliminary DS41350D-page 17 PIC18F/LF1XK50 FIGURE 2-3: CERAMIC RESONATOR OPERATION (XT OR HS MODE) • Input threshold voltage variation • Component tolerances • Variation in capacitance due to packaging PIC® MCU OSC1/CLKIN C1 To Internal Logic RP(3) RF(2) C2 Ceramic RS(1) Resonator Sleep OSC2/CLKOUT Note 1: A series resistor (RS) may be required for ceramic resonators with low drive level. 2: The value of RF varies with the Oscillator mode selected (typically between 2 M to 10 M. 3: An additional parallel feedback resistor (RP) may be required for proper ceramic resonator operation. 2.3.3 EXTERNAL RC The External Resistor-Capacitor (RC) mode supports the use of an external RC circuit. This allows the designer maximum flexibility in frequency choice while keeping costs to a minimum when clock accuracy is not required. In RC mode, the RC circuit connects to OSC1, allowing OSC2 to be configured as an IO or as CLKOUT. The CLKOUT function is selected by the FOSC bits of the CONFIG1H Configuration register. When OSC2 is configured as CLKOUT, the frequency at the pin is the frequency of the RC oscillator divided by 4. Figure 2-4 shows the external RC mode connections. FIGURE 2-4: VDD The RC oscillator frequency is a function of the supply voltage, the resistor REXT, the capacitor CEXT and the operating temperature. Other factors affecting the oscillator frequency are: 2.3.4 EXTERNAL CLOCK The External Clock (EC) mode allows an externally generated logic level clock to be used as the system’s clock source. When operating in this mode, the external clock source is connected to the OSC1 allowing OSC2 to be configured as an I/O or as CLKOUT. The CLKOUT function is selected by the FOSC bits of the CONFIG1H Configuration register. When OSC2 is configured as CLKOUT, the frequency at the pin is the frequency of the EC oscillator divided by 4. Three different power settings are available for EC mode. The power settings allow for a reduced IDD of the device, if the EC clock is known to be in a specific range. If there is an expected range of frequencies for the EC clock, select the power mode for the highest frequency. EC Low power 0 – 250 kHz EC Medium power 250 kHz – 4 MHz EC High power 4 – 48 MHz 2.4 Secondary External Oscillator The Secondary External Oscillator is designed to drive an external 32.768 kHz crystal. This oscillator is enabled or disabled by the T1OSCEN bit of the T1CON register. See Section 11.0 “Timer1 Module” for more information. EXTERNAL RC MODES PIC® MCU REXT OSC1/CLKIN Internal Clock CEXT VSS FOSC/4 or I/O(2) OSC2/CLKOUT(1) Recommended values: 10 k REXT 100 k CEXT > 20 pF Note 1: 2: Alternate pin functions are listed in Section 1.0 “Device Overview”. Output depends upon RC or RCIO clock mode. DS41350D-page 18 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 2.5 Internal Oscillator The internal oscillator module contains two independent oscillators which are: • LFINTOSC: Low-Frequency Internal Oscillator • HFINTOSC: High-Frequency Internal Oscillator When operating with either oscillator, OSC1 will be an I/O and OSC2 will be either an I/O or CLKOUT. The CLKOUT function is selected by the FOSC bits of the CONFIG1H Configuration register. When OSC2 is configured as CLKOUT, the frequency at the pin is the frequency of the Internal Oscillator divided by 4. 2.5.1 LFINTOSC The Low-Frequency Internal Oscillator (LFINTOSC) is a 31 kHz internal clock source. The LFINTOSC oscillator is the clock source for: • Power-up Timer • Watchdog Timer • Fail-Safe Clock Monitor The LFINTOSC is enabled when any of the following conditions are true: • Power-up Timer is enabled (PWRTEN = 0) • Watchdog Timer is enabled (WDTEN = 1) • Watchdog Timer is enabled by software (WDTEN = 0 and SWDTEN = 1) • Fail-Safe Clock Monitor is enabled (FCMEM = 1) • SCS1 = 1 and IRCF<2:0> = 000 and INTSRC = 0 • FOSC<3:0> selects the internal oscillator as the primary clock and IRCF<2:0> = 000 and INTSRC = 0 • IESO = 1 (Two-Speed Start-up) and IRCF<2:0> = 000 and INTSRC = 0 2.5.2 The HFIOFS bit of the OSCCON register indicates whether the HFINTOSC is stable. Note 1: Selecting 31 kHz from the HFINTOSC oscillator requires IRCF<2:0> = 000 and the INTSRC bit of the OSCTUNE register to be set. If the INTSRC bit is clear, the system clock will come from the LFINTOSC. 2: Additional adjustments to the frequency of the HFINTOSC can made via the OSCTUNE registers. See Register 2-3 for more details The HFINTOSC is enabled if any of the following conditions are true: • SCS1 = 1 and IRCF<2:0> 000 • SCS1 = 1 and IRCF<2:0> = 000 and INTSRC = 1 • FOSC<3:0> selects the internal oscillator as the primary clock and - IRCF<2:0> 000 or - IRCF<2:0> = 000 and INTSRC = 1 • IESO = 1 (Two-Speed Start-up) and - IRCF<2:0> 000 or - IRCF<2:0> = 000 and INTSRC = 1 • FCMEM = 1 (Fail Safe Clock Monitoring) and - IRCF<2:0> 000 or - IRCF<2:0> = 000 and INTSRC = 1 HFINTOSC The High-Frequency Internal Oscillator (HFINTOSC) is a precision oscillator that is factory-calibrated to operate at 16 MHz. The output of the HFINTOSC connects to a postscaler and a multiplexer (see Figure 2-1). One of eight frequencies can be selected using the IRCF<2:0> bits of the OSCCON register. The following frequencies are available from the HFINTOSC: • • • • • • • • 16 MHZ 8 MHZ 4 MHZ 2 MHZ 1 MHZ (Default after Reset) 500 kHz 250 kHz 31 kHz 2010 Microchip Technology Inc. Preliminary DS41350D-page 19 PIC18F/LF1XK50 2.6 Oscillator Control The Oscillator Control (OSCCON) (Register 2-1) and the Oscillator Control 2 (OSCCON2) (Register 2-2) registers control the system clock and frequency selection options. REGISTER 2-1: OSCCON: OSCILLATOR CONTROL REGISTER R/W-0 R/W-0 R/W-1 R/W-1 R-q R-0 R/W-0 R/W-0 IDLEN IRCF2 IRCF1 IRCF0 OSTS(1) HFIOFS SCS1 SCS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ q = depends on condition -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 IDLEN: Idle Enable bit 1 = Device enters Idle mode on SLEEP instruction 0 = Device enters Sleep mode on SLEEP instruction bit 6-4 IRCF<2:0>: Internal Oscillator Frequency Select bits 111 = 16 MHz 110 = 8 MHz 101 = 4 MHz 100 = 2 MHz 011 = 1 MHz(3) 010 = 500 kHz 001 = 250 kHz 000 = 31 kHz(2) bit 3 OSTS: Oscillator Start-up Time-out Status bit(1) 1 = Device is running from the clock defined by FOSC<2:0> of the CONFIG1 register 0 = Device is running from the internal oscillator (HFINTOSC or LFINTOSC) bit 2 HFIOFS: HFINTOSC Frequency Stable bit 1 = HFINTOSC frequency is stable 0 = HFINTOSC frequency is not stable bit 1-0 SCS<1:0>: System Clock Select bits 1x = Internal oscillator block 01 = Secondary (Timer1) oscillator 00 = Primary clock (determined by CONFIG1H[FOSC<3:0>]). Note 1: 2: 3: Reset state depends on state of the IESO Configuration bit. Source selected by the INTSRC bit of the OSCTUNE register, see text. Default output frequency of HFINTOSC on Reset. DS41350D-page 20 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 2-2: OSCCON2: OSCILLATOR CONTROL REGISTER 2 U-0 U-0 U-0 U-0 U-0 R/W-1 R/W-0 R-x — — — — — PRI_SD HFIOFL LFIOFS bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ q = depends on condition -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-3 Unimplemented: Read as ‘0’ bit 2 PRI_SD: Primary Oscillator Drive Circuit shutdown bit 1 = Oscillator drive circuit on 0 = Oscillator drive circuit off (zero power) bit 1 HFIOFL: HFINTOSC Frequency Locked bit 1 = HFINTOSC is in lock 0 = HFINTOSC has not yet locked bit 0 LFIOFS: LFINTOSC Frequency Stable bit 1 = LFINTOSC is stable 0 = LFINTOSC is not stable 2010 Microchip Technology Inc. Preliminary DS41350D-page 21 PIC18F/LF1XK50 2.6.1 OSCTUNE REGISTER The HFINTOSC is factory calibrated, but can be adjusted in software by writing to the TUN<5:0> bits of the OSCTUNE register (Register 2-3). The default value of the TUN<5:0> is ‘000000’. The value is a 6-bit two’s complement number. When the OSCTUNE register is modified, the HFINTOSC frequency will begin shifting to the new frequency. Code execution continues during this shift, while giving no indication that the shift has occurred. OSCTUNE does not affect the LFINTOSC frequency. The operation of features that depend on the LFINTOSC clock source frequency, such as the Power-up Timer REGISTER 2-3: (PWRT), Watchdog Timer (WDT), Fail-Safe Clock Monitor (FSCM) and peripherals, are not affected by the change in frequency. The OSCTUNE register also implements the INTSRC and SPLLEN bits, which control certain features of the internal oscillator block. The INTSRC bit allows users to select which internal oscillator provides the clock source when the 31 kHz frequency option is selected. This is covered in greater detail in Section 2.5.1 “LFINTOSC”. The SPLLEN bit controls the operation of the frequency multiplier. For more details about the function of the SPLLEN bit see Section 2.9 “4x Phase Lock Loop Frequency Multiplier” OSCTUNE: OSCILLATOR TUNING REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 INTSRC SPLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 bit 7 bit 0 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 bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit 1 = 31.25 kHz device clock derived from 16 MHz HFINTOSC source (divide-by-512 enabled) 0 = 31 kHz device clock derived directly from LFINTOSC internal oscillator bit 6 SPLLEN: Software Controlled Frequency Multiplier PLL bit 1 = PLL enabled (for HFINTOSC 8 MHz only) 0 = PLL disabled bit 5-0 TUN<5:0>: Frequency Tuning bits 011111 = Maximum frequency 011110 = ••• 000001 = 000000 = Oscillator module is running at the factory calibrated frequency. 111111 = ••• 100000 = Minimum frequency DS41350D-page 22 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 2.7 Oscillator Start-up Timer 2.8 Clock Switching The Primary External Oscillator, when configured for LP, XT or HS modes, incorporates an Oscillator Startup Timer (OST). The OST ensures that the oscillator starts and provides a stable clock to the oscillator module. The OST times out when 1024 oscillations on OSC1 have occurred. During the OST period, with the system clock set to the Primary External Oscillator, the program counter does not increment suspending program execution. The OST period will occur following: The device contains circuitry to prevent clock “glitches” due to a change of the system clock source. To accomplish this, a short pause in the system clock occurs during the clock switch. If the new clock source is not stable (e.g., OST is active), the device will continue to execute from the old clock source until the new clock source becomes stable. The timing of a clock switch is as follows: • • • • • 2. Power-on Reset (POR) Brown-out Reset (BOR) Wake-up from Sleep Oscillator being enabled Expiration of Power-up Timer (PWRT) 1. 3. In order to minimize latency between external oscillator start-up and code execution, the Two-Speed Start-up mode can be selected. See Section 2.12 “Two-Speed Start-up Mode” for more information. 4. 5. 6. 7. SCS<1:0> bits of the OSCCON register are modified. The system clock will continue to operate from the old clock until the new clock is ready. Clock switch circuitry waits for two consecutive rising edges of the old clock after the new clock is ready. The system clock is held low, starting at the next falling edge of the old clock. Clock switch circuitry waits for an additional two rising edges of the new clock. On the next falling edge of the new clock, the low hold on the system clock is release and the new clock is switched in as the system clock. Clock switch is complete. Refer to Figure 2-5 for more details. FIGURE 2-5: High Speed CLOCK SWITCH TIMING Low Speed Old Clock Start-up Time(1) Clock Sync Running New Clock New Clk Ready IRCF <2:0> Select Old Select New System Clock Low Speed High Speed Old Clock Start-up Time(1) Clock Sync Running New Clock New Clk Ready IRCF <2:0> Select Old Select New System Clock Note 1: Start-up time includes TOST (1024 TOSC) for external clocks, plus TPLL (approx. 2 ms) for HSPLL mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 23 PIC18F/LF1XK50 TABLE 2-2: EXAMPLES OF DELAYS DUE TO CLOCK SWITCHING Switch From Switch To Oscillator Delay Sleep/POR LFINTOSC HFINTOSC Oscillator Warm-up Delay (TWARM) Sleep/POR LP, XT, HS 1024 clock cycles Sleep/POR EC, RC 8 clock cycles 2.9 4x Phase Lock Loop Frequency Multiplier 2.11 A Phase Locked Loop (PLL) circuit is provided as an option for users who wish to use a lower-frequency external oscillator or to operate at 32 MHz with the HFINTOSC. The PLL is designed for an input frequency from 4 MHz to 12 MHz. The PLL multiplies its input frequency by a factor of four when the PLL is enabled. This may be useful for customers who are concerned with EMI, due to high-frequency crystals. Two bits control the PLL: the PLLEN bit of the CONFIG1H Configuration register and the SPLLEN bit of the OSCTUNE register. The PLL is enabled when the PLLEN bit is set and it is under software control when the PLLEN bit is cleared. TABLE 2-3: PLL CONFIGURATION PLLEN SPLLEN PLL Status 1 x PLL enabled 0 1 PLL enabled 0 0 PLL disabled The USB module is designed to operate in two different modes: • Low Speed • Full Speed Because of timing requirements imposed by the USB specifications, the Primary External Oscillator is required for the USB module. The FOSC bits of the CONFIG1H Configuration register must be set to either External Clock (EC) High-power or HS mode with a clock frequency of 6, 12 or 48 MHz. 2.11.1 2.10 • EC High-power mode • HS mode Table 2-4 shows the recommended Clock mode for low-speed operation. The HFINTOSC may use the PLL when the postscaler is set to 8 MHz and the FOSC<3:0> bits of the CONFIG1H Configuration register are selected for Internal Oscillator operation. 2.11.2 CPU Clock Divider The CPU Clock Divider allows the system clock to run at a slower speed than the Low/Full Speed USB module clock while sharing the same clock source. Only the oscillator defined by the settings of the FOSC bits of the CONFIG1H Configuration register may be used with the CPU Clock Divider. The CPU Clock Divider is controlled by the CPUDIV bits of the CONFIG1L Configuration register. Setting the CPUDIV bits will set the system clock to: • • • • LOW SPEED OPERATION For Low Speed USB operation, a 6 MHz clock is required for the USB module. To generate the 6 MHz clock, only 2 Oscillator modes are allowed: Note: Note: USB Operation Users must run USB low speed operation using a CPU clock frequency of 24 MHz or slower (64 MHz is optimal). If anything higher than 24 MHz is used, a firmware delay of at least 14 instruction cycles is required. FULL-SPEED OPERATION For full-speed USB operation, a 48 MHz clock is required for the USB module. To generate the 48 MHz clock, only 2 Oscillator modes are allowed: • EC High-power mode • HS mode Table 2-5 shows the recommended Clock mode for fullspeed operation. Equal the clock speed of the USB module Half the clock speed of the USB module One third the clock speed of the USB module One fourth the clock speed of the USB module For more information on the CPU Clock Divider, see Figure 2-1 and Register 24-1 CONFIG1L. DS41350D-page 24 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 2-4: Clock Mode LOW SPEED USB CLOCK SETTINGS Clock Frequency 4x PLL Enabled USBDIV CPUDIV<1:0> System Clock Frequency (MHz) 00 48 01 24 10 16 11 12 00 12 01 6 10 4 11 3 00 24 01 12 10 8 11 6 00 6 01 3 10 2 11 1.5 Yes 12 MHz 1 No EC High/HS Yes 6 MHz 0 No Note: The system clock frequency in Table 2-4 only applies if the OSCCON register bits SCS<1:0> = 00. By changing these bits, the system clock can operate down to 31 kHz. TABLE 2-5: Clock Mode EC High Clock Frequency 4x PLL Enabled 48 MHz EC High/HS Note: FULL-SPEED USB CLOCK SETTINGS No 12 MHz Yes CPUDIV<1:0> System Clock Frequency (MHz) 00 48 01 24 10 16 11 12 00 48 01 24 10 16 11 12 The system clock frequency in the above table only applies if the OSCCON register bits SCS<1:0> = 00. By changing these bits, the system clock can operate down to 31 kHz. 2010 Microchip Technology Inc. Preliminary DS41350D-page 25 PIC18F/LF1XK50 2.12 Two-Speed Start-up Mode FIGURE 2-6: Two-Speed Start-up mode provides additional power savings by minimizing the latency between external Oscillator Start-up Timer (OST) and code execution. In applications that make heavy use of the Sleep mode, Two-Speed Start-up will remove the OST period, which can reduce the overall power consumption of the device. Two-speed Start-up will become active after: • Power-on Reset (POR) • Power-up Timer (PWRT), if enabled • Wake-up from Sleep The OSTS bit of the OSCCON register reports which oscillator the device is currently using for operation. The device is running from the oscillator defined by the FOSC bits of the CONFIG1H Configuration register when the OSTS bit is set. The device is running from the internal oscillator when the OSTS bit is clear. 2.13 Fail-Safe Clock Monitor The Fail-Safe Clock Monitor (FSCM) allows the device to continue operating should the external oscillator fail. The FSCM can detect oscillator failure any time after the Oscillator Start-up Timer (OST) has expired. The FSCM is enabled by setting the FCMEN bit in the CONFIG1H Configuration register. The FSCM is applicable to all external oscillator modes (LP, XT, HS, EC and RC). DS41350D-page 26 Clock Monitor Latch External Clock Two-Speed Start-up mode is enabled by setting the IESO bit of the CONFIG1H Configuration register. With Two-Speed Start-up enabled, the device will execute instructions using the internal oscillator during the Primary External Oscillator OST period. When the system clock is set to the Primary External Oscillator and the oscillator is configured for LP, XT or HS modes, the device will not execute code during the OST period. The OST will suspend program execution until 1024 oscillations are counted. Two-Speed Startup mode minimizes the delay in code execution by operating from the internal oscillator while the OST is active. The system clock will switch back to the Primary External Oscillator after the OST period has expired. FSCM BLOCK DIAGRAM LFINTOSC Oscillator ÷ 64 31 kHz (~32 s) 488 Hz (~2 ms) S Q R Q Sample Clock 2.13.1 Clock Failure Detected FAIL-SAFE DETECTION The FSCM module detects a failed oscillator by comparing the external oscillator to the FSCM sample clock. The sample clock is generated by dividing the LFINTOSC by 64. See Figure 2-6. Inside the fail detector block is a latch. The external clock sets the latch on each falling edge of the external clock. The sample clock clears the latch on each rising edge of the sample clock. A failure is detected when an entire halfcycle of the sample clock elapses before the primary clock goes low. 2.13.2 FAIL-SAFE OPERATION When the external clock fails, the FSCM switches the device clock to an internal clock source and sets the bit flag OSCFIF of the PIR2 register. The OSCFIF flag will generate an interrupt if the OSCFIE bit of the PIE2 register is also set. The device firmware can then take steps to mitigate the problems that may arise from a failed clock. The system clock will continue to be sourced from the internal clock source until the device firmware successfully restarts the external oscillator and switches back to external operation. An automatic transition back to the failed clock source will not occur. The internal clock source chosen by the FSCM is determined by the IRCF<2:0> bits of the OSCCON register. This allows the internal oscillator to be configured before a failure occurs. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 2.13.3 FAIL-SAFE CONDITION CLEARING The Fail-Safe condition is cleared by either one of the following: • Any Reset • By toggling the SCS1 bit of the OSCCON register Both of these conditions restart the OST. While the OST is running, the device continues to operate from the INTOSC selected in OSCCON. When the OST times out, the Fail-Safe condition is cleared and the device automatically switches over to the external clock source. The Fail-Safe condition need not be cleared before the OSCFIF flag is cleared. 2.13.4 any type of Reset. The OST is not used with the EC or RC Clock modes so that the FSCM will be active as soon as the Reset or wake-up has completed. When the FSCM is enabled, the Two-Speed Start-up is also enabled. Therefore, the device will always be executing code while the OST is operating. Note: Due to the wide range of oscillator start-up times, the Fail-Safe circuit is not active during oscillator start-up (i.e., after exiting Reset or Sleep). After an appropriate amount of time, the user should check the OSTS bit of the OSCCON register to verify the oscillator start-up and that the system clock switchover has successfully completed. RESET OR WAKE-UP FROM SLEEP The FSCM is designed to detect an oscillator failure after the Oscillator Start-up Timer (OST) has expired. The OST is used after waking up from Sleep and after FIGURE 2-7: FSCM TIMING DIAGRAM Sample Clock Oscillator Failure System Clock Output Clock Monitor Output (Q) Failure Detected OSCFIF Test Note: TABLE 2-6: Test Test The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in this example have been chosen for clarity. SUMMARY OF REGISTERS ASSOCIATED WITH CLOCK SOURCES Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page CONFIG1H IESO FCMEN PCLKEN PLLEN FOSC3 FOSC2 FOSC1 FOSC0 296 TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS HFIOFS SCS1 SCS0 288 OSCTUNE INTSRC SPLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — 290 PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — 290 RD16 T1RUN T1CKPS1 INTCON T1CON Legend: Note 1: GIE/GIEH PEIE/GIEL T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 105 x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by oscillators. Other (non Power-up) Resets include MCLR Reset and Watchdog Timer Reset during normal operation. 2010 Microchip Technology Inc. Preliminary DS41350D-page 27 PIC18F/LF1XK50 NOTES: DS41350D-page 28 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.0 MEMORY ORGANIZATION 3.1 There are three types of memory in PIC18 Enhanced microcontroller devices: • Program Memory • Data RAM • Data EEPROM Program Memory Organization PIC18 microcontrollers implement a 21-bit program counter, which is capable of addressing a 2-Mbyte program memory space. Accessing a location between the upper boundary of the physically implemented memory and the 2-Mbyte address will return all ‘0’s (a NOP instruction). As Harvard architecture devices, the data and program memories use separate busses; this allows for concurrent access of the two memory spaces. The data EEPROM, for practical purposes, can be regarded as a peripheral device, since it is addressed and accessed through a set of control registers. This family of devices contain the following: Additional detailed information on the operation of the Flash program memory is provided in Section 4.0 “Flash Program Memory”. Data EEPROM is discussed separately in Section 5.0 “Data EEPROM Memory”. PIC18 devices have two interrupt vectors and one Reset vector. The Reset vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. FIGURE 3-1: • PIC18F13K50: 8 Kbytes of Flash Memory, up to 4,096 single-word instructions • PIC18F14K50: 16 Kbytes of Flash Memory, up to 8,192 single-word instructions The program memory map for PIC18F/LF1XK50 devices is shown in Figure 3-1. Memory block details are shown in Figure 24-2. PROGRAM MEMORY MAP AND STACK FOR PIC18F/LF1XK50 DEVICES PC<20:0> 21 CALL,RCALL,RETURN RETFIE,RETLW Stack Level 1 Stack Level 31 2000h 0000h High Priority Interrupt Vector 0008h Low Priority Interrupt Vector 0018h On-Chip Program Memory 3FFFh 4000h PIC18F13K50 User Memory Space On-Chip Program Memory 1FFFh Reset Vector PIC18F14K50 Read ‘0’ Read ‘0’ 1FFFFFh 200000h 2010 Microchip Technology Inc. Preliminary DS41350D-page 29 PIC18F/LF1XK50 3.1.1 PROGRAM COUNTER The Program Counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21 bits wide and is contained in three separate 8-bit registers. The low byte, known as the PCL register, is both readable and writable. The high byte, or PCH register, contains the PC<15:8> bits; it is not directly readable or writable. Updates to the PCH register are performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits; it is also not directly readable or writable. Updates to the PCU register are performed through the PCLATU register. The contents of PCLATH and PCLATU are transferred to the program counter by any operation that writes PCL. Similarly, the upper two bytes of the program counter are transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 3.1.4.1 “Computed GOTO”). The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the Least Significant bit (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. 3.1.2 RETURN ADDRESS STACK The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC 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. FIGURE 3-2: The stack operates as a 31-word by 21-bit RAM and a 5-bit Stack Pointer, STKPTR. 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 writable through the Top-ofStack (TOS) Special File Registers. Data can also be pushed to, or popped from the stack, using these registers. A CALL type instruction causes a push onto the stack; the Stack Pointer is first incremented and the location pointed to by the Stack Pointer is written with the contents of the PC (already pointing to the instruction following the CALL). A RETURN type instruction causes a pop from the stack; the contents of the location pointed to by the STKPTR are transferred to the PC and then the Stack Pointer is decremented. The Stack Pointer is initialized to ‘00000’ after all Resets. There is no RAM associated with the location corresponding to a Stack Pointer value of ‘00000’; this is only a Reset value. Status bits indicate if the stack is full or has overflowed or has underflowed. 3.1.2.1 Top-of-Stack Access Only the top of the return address stack (TOS) is readable and writable. A set of three registers, TOSU:TOSH:TOSL, hold the contents of the stack location pointed to by the STKPTR register (Figure 3-2). 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:TOSL registers. These values can be placed on a user defined software stack. At return time, the software can return these values to TOSU:TOSH:TOSL and do a return. The user must disable the global interrupt enable bits while accessing the stack to prevent inadvertent stack corruption. RETURN ADDRESS STACK AND ASSOCIATED REGISTERS Return Address Stack <20:0> 11111 11110 11101 Top-of-Stack Registers TOSU 00h TOSH 1Ah STKPTR<4:0> 00010 TOSL 34h Top-of-Stack DS41350D-page 30 Stack Pointer 001A34h 000D58h Preliminary 00011 00010 00001 00000 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.1.2.2 Return Stack Pointer (STKPTR) 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 zero. The STKUNF bit will remain set until cleared by software or until a POR occurs. The STKPTR register (Register 3-1) contains the Stack Pointer value, the STKFUL (stack full) bit and the STKUNF (stack underflow) bits. The value of the Stack Pointer can be 0 through 31. The Stack Pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. On Reset, the Stack Pointer value will be zero. The user may read and write the Stack Pointer value. This feature can be used by a Real-Time Operating System (RTOS) for return stack maintenance. Note: 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 is cleared by software or by a POR. 3.1.2.3 PUSH and POP Instructions Since the Top-of-Stack is readable and writable, the ability to push values onto the stack and pull values off the stack without disturbing normal program execution is a desirable feature. The PIC18 instruction set includes two instructions, PUSH and POP, that permit the TOS to be manipulated under software control. TOSU, TOSH and TOSL can be modified to place data or a return address on the stack. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) Configuration bit. (Refer to Section 24.1 “Configuration Bits” for a description of the device Configuration 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 zero. The PUSH instruction places the current PC value onto the stack. This increments the Stack Pointer and loads the current PC value onto the stack. 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. REGISTER 3-1: 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. This is not the same as a Reset, as the contents of the SFRs are not affected. The POP instruction discards the current TOS by decrementing the Stack Pointer. The previous value pushed onto the stack then becomes the TOS value. STKPTR: STACK POINTER REGISTER R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 STKFUL(1) STKUNF(1) — SP4 SP3 SP2 SP1 SP0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented C = Clearable only bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 STKFUL: Stack Full Flag bit(1) 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed bit 6 STKUNF: Stack Underflow Flag bit(1) 1 = Stack underflow occurred 0 = Stack underflow did not occur bit 5 Unimplemented: Read as ‘0’ bit 4-0 SP<4:0>: Stack Pointer Location bits Note 1: Bit 7 and bit 6 are cleared by user software or by a POR. 2010 Microchip Technology Inc. Preliminary DS41350D-page 31 PIC18F/LF1XK50 3.1.2.4 Stack Full and Underflow Resets 3.1.4 Device Resets on stack overflow and stack underflow conditions are enabled by setting the STVREN bit in Configuration Register 4L. When STVREN is set, a full or underflow will set the appropriate STKFUL or STKUNF bit and then cause a device Reset. When STVREN is cleared, a full or underflow condition will set the appropriate STKFUL or STKUNF bit but not cause a device Reset. The STKFUL or STKUNF bits are cleared by the user software or a Power-on Reset. 3.1.3 FAST REGISTER STACK A fast register stack is provided for the Status, WREG and BSR registers, to provide a “fast return” option for interrupts. The stack for each register is only one level deep and is neither readable nor writable. It is loaded with the current value of the corresponding register when the processor vectors for an interrupt. All interrupt sources will push values into the stack registers. The values in the registers are then loaded back into their associated registers if the RETFIE, FAST instruction is used to return from the interrupt. LOOK-UP TABLES IN PROGRAM MEMORY There may be programming situations that require the creation of data structures, or look-up tables, in program memory. For PIC18 devices, look-up tables can be implemented in two ways: • Computed GOTO • Table Reads 3.1.4.1 Computed GOTO A computed GOTO is accomplished by adding an offset to the program counter. An example is shown in Example 3-2. A look-up table can be formed with an ADDWF PCL instruction and a group of RETLW nn instructions. The W register 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 nn instructions that returns the value ‘nn’ to the calling function. If both low and high priority interrupts are enabled, the stack registers cannot be used reliably to return from low priority interrupts. If a high priority interrupt occurs while servicing a low priority interrupt, the stack register values stored by the low priority interrupt will be overwritten. In these cases, users must save the key registers by software during a low priority interrupt. The offset value (in WREG) specifies the number of bytes that the program counter should advance and should be multiples of 2 (LSb = 0). If interrupt priority is not used, all interrupts may use the fast register stack for returns from 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 CALL label, FAST instruction must be executed to save the Status, WREG and BSR registers to the fast register stack. A RETURN, FAST instruction is then executed to restore these registers from the fast register stack. EXAMPLE 3-2: Example 3-1 shows a source code example that uses the fast register stack during a subroutine call and return. EXAMPLE 3-1: CALL SUB1, FAST RETURN, FAST FAST REGISTER STACK CODE EXAMPLE ;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK SUB1 DS41350D-page 32 ;RESTORE VALUES SAVED ;IN FAST REGISTER STACK In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. ORG TABLE 3.1.4.2 MOVF CALL nn00h ADDWF RETLW RETLW RETLW . . . COMPUTED GOTO USING AN OFFSET VALUE OFFSET, W TABLE PCL nnh nnh nnh Table Reads and Table Writes A better method of storing data in program memory allows two bytes of data to be stored in each instruction location. Look-up table data may be stored two bytes per program word by using table reads and writes. The Table Pointer (TBLPTR) register specifies the byte address and the Table Latch (TABLAT) register contains the data that is read from or written to program memory. Data is transferred to or from program memory one byte at a time. Table read and table write operations are discussed further in Section 4.1 “Table Reads and Table Writes”. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.2 PIC18 Instruction Cycle 3.2.1 3.2.2 An “Instruction Cycle” consists of four Q cycles: Q1 through Q4. The instruction fetch and execute are pipelined in such a manner that a fetch takes one instruction cycle, while the decode and execute take 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 3-3). CLOCKING SCHEME The microcontroller clock input, whether from an internal or external source, is internally divided by four to generate four non-overlapping quadrature clocks (Q1, Q2, Q3 and Q4). Internally, the program counter is incremented on every Q1; the instruction is fetched from the program memory and latched into the instruction register during Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 3-3. FIGURE 3-3: INSTRUCTION FLOW/PIPELINING 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). CLOCK/INSTRUCTION CYCLE Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Internal Phase Clock Q3 Q4 PC PC PC + 2 PC + 4 OSC2/CLKOUT (RC mode) Execute INST (PC – 2) Fetch INST (PC) EXAMPLE 3-3: TCY0 TCY1 Fetch 1 Execute 1 2. MOVWF PORTB 4. BSF Execute INST (PC + 2) Fetch INST (PC + 4) INSTRUCTION PIPELINE FLOW 1. MOVLW 55h 3. BRA Execute INST (PC) Fetch INST (PC + 2) SUB_1 Fetch 2 TCY2 TCY3 TCY4 TCY5 Execute 2 Fetch 3 Execute 3 Fetch 4 PORTA, BIT3 (Forced NOP) Flush (NOP) Fetch SUB_1 Execute SUB_1 5. Instruction @ address SUB_1 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 33 PIC18F/LF1XK50 3.2.3 INSTRUCTIONS IN PROGRAM MEMORY The program memory is addressed in bytes. Instructions are stored as either two bytes or four bytes in program memory. The Least Significant Byte (LSB) of an instruction word is always stored in a program memory location with an even address (LSb = 0). To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSb will always read ‘0’ (see Section 3.1.1 “Program Counter”). Figure 3-4 shows an example of how instruction words are stored in the program memory. FIGURE 3-4: The CALL and GOTO instructions have the absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, 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 3-4 shows how the instruction GOTO 0006h 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 represents the number of single-word instructions that the PC will be offset by. Section 25.0 “Instruction Set Summary” provides further details of the instruction set. INSTRUCTIONS IN PROGRAM MEMORY LSB = 1 LSB = 0 0Fh EFh F0h C1h F4h 55h 03h 00h 23h 56h Program Memory Byte Locations 3.2.4 Instruction 1: Instruction 2: MOVLW GOTO 055h 0006h Instruction 3: MOVFF 123h, 456h TWO-WORD INSTRUCTIONS The standard PIC18 instruction set has four two-word instructions: CALL, MOVFF, GOTO and LSFR. In all cases, the second word of the instruction always has ‘1111’ as its four Most Significant bits (MSb); the other 12 bits are literal data, usually a data memory address. The use of ‘1111’ in the 4 MSbs of an instruction specifies a special form of NOP. If the instruction is executed in proper sequence – immediately after the first word – the data in the second word is accessed EXAMPLE 3-4: Word Address 000000h 000002h 000004h 000006h 000008h 00000Ah 00000Ch 00000Eh 000010h 000012h 000014h and used by the instruction sequence. If the first word is skipped for some reason and the second word is executed by itself, a NOP is executed instead. This is necessary for cases when the two-word instruction is preceded by a conditional instruction that changes the PC. Example 3-4 shows how this works. Note: See Section 3.6 “PIC18 Instruction Execution and the Extended Instruction Set” for information on two-word instructions in the extended instruction set. TWO-WORD INSTRUCTIONS CASE 1: Object Code 0110 0110 0000 1100 0001 0010 1111 0100 0101 0010 0100 0000 0000 0011 0110 0000 Source Code TSTFSZ REG1 ; is RAM location 0? MOVFF REG1, REG2 ; No, skip this word ; Execute this word as a NOP ADDWF REG3 ; continue code 0000 0011 0110 0000 Source Code TSTFSZ REG1 ; is RAM location 0? MOVFF REG1, REG2 ; Yes, execute this word ; 2nd word of instruction ADDWF REG3 ; continue code CASE 2: Object Code 0110 0110 0000 1100 0001 0010 1111 0100 0101 0010 0100 0000 DS41350D-page 34 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.3 Note: Data Memory Organization 3.3.2 The operation of some aspects of data memory are changed when the PIC18 extended instruction set is enabled. See Section 3.5 “Data Memory and the Extended Instruction Set” for more information. The data memory in PIC18 devices is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. The memory space is divided into as many as 16 banks that contain 256 bytes each. Figure 3-5 and Figure 3-6 show the data memory organization for the PIC18F/LF1XK50 devices. The data memory contains Special Function Registers (SFRs) and General Purpose Registers (GPRs). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratchpad operations in the user’s application. Any read of an unimplemented location will read as ‘0’s. The instruction set and architecture allow operations across all banks. The entire data memory may be accessed by Direct, Indirect or Indexed Addressing modes. Addressing modes are discussed later in this subsection. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, PIC18 devices implement an Access Bank. This is a 256-byte memory space that provides fast access to SFRs and the lower portion of GPR Bank 0 without using the Bank Select Register (BSR). Section 3.3.3 “Access Bank” provides a detailed description of the Access RAM. 3.3.1 USB RAM Part of the data memory is actually mapped to a special dual access RAM. When the USB module is disabled, the GPRs in these banks are used like any other GPR in the data memory space. When the USB module is enabled, the memory in these banks is allocated as buffer RAM for USB operation. This area is shared between the microcontroller core and the USB Serial Interface Engine (SIE) and is used to transfer data directly between the two. It is theoretically possible to use the areas of USB RAM that are not allocated as USB buffers for normal scratchpad memory or other variable storage. In practice, the dynamic nature of buffer allocation makes this risky at best. Additional information on USB RAM and buffer operation is provided in Section 22.0 “Universal Serial Bus (USB)” 2010 Microchip Technology Inc. BANK SELECT REGISTER (BSR) Large areas of data memory require an efficient addressing scheme to make rapid access to any address possible. Ideally, this means that an entire address does not need to be provided for each read or write operation. For PIC18 devices, this is accomplished with a RAM banking scheme. This divides the memory space into 16 contiguous banks of 256 bytes. Depending on the instruction, each location can be addressed directly by its full 12-bit address, or an 8-bit low-order address and a 4-bit Bank Pointer. Most instructions in the PIC18 instruction set make use of the Bank Pointer, known as the Bank Select Register (BSR). This SFR holds the 4 Most Significant bits of a location’s address; the instruction itself includes the 8 Least Significant bits. Only the four lower bits of the BSR are implemented (BSR<3:0>). The upper four bits are unused; they will always read ‘0’ and cannot be written to. The BSR can be loaded directly by using the MOVLB instruction. The value of the BSR indicates the bank in data memory; the 8 bits in the instruction show the location in the bank and can be thought of as an offset from the bank’s lower boundary. The relationship between the BSRs value and the bank division in data memory is shown in Figure 3-5 and Figure 3-6. Since up to 16 registers may share the same low-order address, the user must always be careful to ensure that the proper bank is selected before performing a data read or write. For example, writing what should be program data to an 8-bit address of F9h while the BSR is 0Fh will end up resetting the program counter. While any bank can be selected, only those banks that are actually implemented can be read or written to. Writes to unimplemented banks are ignored, while reads from unimplemented banks will return ‘0’s. Even so, the STATUS register will still be affected as if the operation was successful. The data memory maps in Figure 3-5 and Figure 3-6 indicate which banks are implemented. In the core PIC18 instruction set, only the MOVFF instruction fully specifies the 12-bit address of the source and target registers. This instruction ignores the BSR completely when it executes. All other instructions include only the low-order address as an operand and must use either the BSR or the Access Bank to locate their target registers. Preliminary DS41350D-page 35 PIC18F/LF1XK50 FIGURE 3-5: DATA MEMORY MAP FOR PIC18F13K50/PIC18LF13K50 DEVICES BSR<3:0> = 0000 = 0001 = 0010 = 0011 = 0100 = 0101 = 0110 = 0111 = 1000 = 1001 = 1010 = 1011 = 1100 = 1101 = 1110 00h Access RAM FFh 00h GPR Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8 Bank 9 FFh 00h FFh 00h Unused Read 00h GPR (DPRAM) 000h 05Fh 060h 0FFh 100h 1FFh 200h 2FFh 300h FFh 00h 3FFh 400h FFh 00h 4FFh 500h FFh 00h 5FFh 600h FFh 00h 6FFh 700h FFh 00h Unused Read 00h 9FFh A00h FFh 00h AFFh B00h FFh 00h BFFh C00h FFh Bank 13 00h CFFh D00h FFh 00h DFFh E00h Bank 11 Bank 12 Bank 14 Unused SFR(1) Bank 15 FFh The first 96 bytes are general purpose RAM (from Bank 0). The second 160 bytes are Special Function Registers (from Bank 15). When ‘a’ = 1: The BSR specifies the Bank used by the instruction. SFR Access Bank Access RAM Low 00h 5Fh Access RAM High 60h (SFRs) FFh 8FFh 900h FFh 00h Bank 10 The BSR is ignored and the Access Bank is used. 7FFh 800h FFh 00h FFh 00h = 1111 When ‘a’ = 0: Data Memory Map EFFh F00h F53h F5Fh F60h FFFh Note 1: SFRs occupying F53h to F5Fh address space are not in the virtual bank DS41350D-page 36 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 3-6: DATA MEMORY MAP FOR PIC18F14K50/PIC18LF14K50 DEVICES BSR<3:0> = 0000 = 0001 = 0010 = 0011 = 0100 = 0101 = 0110 = 0111 = 1000 = 1001 = 1010 = 1011 = 1100 = 1101 = 1110 00h Access RAM FFh 00h GPR Bank 0 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8 Bank 9 000h 05Fh 060h 0FFh 100h GPR Bank 1 FFh 00h FFh 00h GPR (DPRAM) 1FFh 200h 2FFh 300h FFh 00h 3FFh 400h FFh 00h 4FFh 500h FFh 00h 5FFh 600h FFh 00h 6FFh 700h FFh 00h Unused Read 00h 9FFh A00h FFh 00h AFFh B00h FFh 00h BFFh C00h FFh Bank 13 00h CFFh D00h FFh 00h DFFh E00h Bank 11 Bank 12 Bank 14 Unused SFR(1) Bank 15 FFh The first 96 bytes are general purpose RAM (from Bank 0). The second 160 bytes are Special Function Registers (from Bank 15). When ‘a’ = 1: The BSR specifies the Bank used by the instruction. SFR Access Bank Access RAM Low 00h 5Fh Access RAM High 60h (SFRs) FFh 8FFh 900h FFh 00h Bank 10 The BSR is ignored and the Access Bank is used. 7FFh 800h FFh 00h FFh 00h = 1111 When ‘a’ = 0: Data Memory Map EFFh F00h F53h F5Fh F60h FFFh Note 1: SFRs occupying F53h to F5Fh address space are not in the virtual bank 2010 Microchip Technology Inc. Preliminary DS41350D-page 37 PIC18F/LF1XK50 FIGURE 3-7: USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING) BSR(1) 7 0 0 0 0 Bank Select(2) 0 0 0 1 1 000h Data Memory 00h Bank 0 100h Bank 1 200h 300h Bank 2 FFh 00h From Opcode(2) 7 1 1 1 1 1 1 0 1 1 FFh 00h FFh 00h Bank 3 through Bank 13 E00h Bank 14 F00h FFFh Note 1: 2: Bank 15 FFh 00h FFh 00h FFh The Access RAM 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. The MOVFF instruction embeds the entire 12-bit address in the instruction. DS41350D-page 38 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.3.3 ACCESS BANK 3.3.4 While the use of the BSR with an embedded 8-bit address allows users to address the entire range of data memory, it also means that the user must always ensure that the correct bank is selected. Otherwise, data may be read from or written to the wrong location. This can be disastrous if a GPR is the intended target of an operation, but an SFR is written to instead. Verifying and/or changing the BSR for each read or write to data memory can become very inefficient. To streamline access for the most commonly used data memory locations, the data memory is configured with an Access Bank, which allows users to access a mapped block of memory without specifying a BSR. The Access Bank consists of the first 96 bytes of memory (00h-5Fh) in Bank 0 and the last 160 bytes of memory (60h-FFh) in Block 15. The lower half is known as the “Access RAM” and is composed of GPRs. This upper half is also where the device’s SFRs are mapped. These two areas are mapped contiguously in the Access Bank and can be addressed in a linear fashion by an 8-bit address (Figure 3-5 and Figure 36). The Access Bank is used by core PIC18 instructions that include the Access RAM bit (the ‘a’ parameter in the instruction). When ‘a’ is equal to ‘1’, the instruction uses the BSR and the 8-bit address included in the opcode for the data memory address. When ‘a’ is ‘0’, however, the instruction is forced to use the Access Bank address map; the current value of the BSR is ignored entirely. GENERAL PURPOSE REGISTER FILE PIC18 devices may have banked memory in the GPR area. This is data RAM, which is available for use by all instructions. GPRs start at the bottom of Bank 0 (address 000h) and grow upwards towards the bottom of the SFR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other Resets. 3.3.5 SPECIAL FUNCTION REGISTERS The Special Function Registers (SFRs) are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. SFRs start at the top of data memory (FFFh) and extend downward to occupy the top portion of Bank 15 (F60h to FFFh). A list of these registers is given in Table 3-1 and Table 3-2. The SFRs can be classified into two sets: those associated with the “core” device functionality (ALU, Resets and interrupts) and those related to the peripheral functions. The Reset and interrupt registers are described in their respective chapters, while the ALU’s STATUS register is described later in this section. Registers related to the operation of a peripheral feature are described in the chapter for that peripheral. The SFRs are typically distributed among the peripherals whose functions they control. Unused SFR locations are unimplemented and read as ‘0’s. Using this “forced” addressing allows the instruction to operate on a data address in a single cycle, without updating the BSR first. For 8-bit addresses of 60h and above, this means that users can evaluate and operate on SFRs more efficiently. The Access RAM below 60h is a good place for data values that the user might need to access rapidly, such as immediate computational results or common program variables. Access RAM also allows for faster and more code efficient context saving and switching of variables. The mapping of the Access Bank is slightly different when the extended instruction set is enabled (XINST Configuration bit = 1). This is discussed in more detail in Section 3.5.3 “Mapping the Access Bank in Indexed Literal Offset Mode”. 2010 Microchip Technology Inc. Preliminary DS41350D-page 39 PIC18F/LF1XK50 TABLE 3-1: Address SPECIAL FUNCTION REGISTER MAP FOR PIC18F/LF1XK50 DEVICES Name Address Name Address Name Address Name (2) Address Name FFFh TOSU FD7h TMR0H FAFh SPBRG F87h — F5Fh UEIR FFEh TOSH FD6h TMR0L FAEh RCREG F86h —(2) F5Eh UFRMH FFDh TOSL FD5h T0CON FADh TXREG F85h —(2) F5Dh UFRML (2) F5Ch UADDR (2) FFCh STKPTR FD4h FACh TXSTA F84h — FFBh PCLATU FD3h OSCCON — FABh RCSTA F83h —(2) F5Bh UEIE FFAh PCLATH FD2h OSCCON2 FAAh — F82h PORTC F5Ah UEP7 FF9h PCL FD1h WDTCON FA9h EEADR F81h PORTB F59h UEP6 FF8h TBLPTRU FD0h RCON FA8h EEDATA F80h PORTA F58h UEP5 FF7h TBLPTRH FCFh TMR1H FA7h EECON2(1) F7Fh ANSELH F57h UEP4 FF6h TBLPTRL FCEh TMR1L FA6h EECON1 F7Eh ANSEL F56h UEP3 FF5h TABLAT FCDh T1CON FA5h —(2) F7Dh —(2) F55h UEP2 (2) (2) F54h UEP1 F53h UEP0 FF4h PRODH FCCh TMR2 FA4h — F7Ch — FF3h PRODL FCBh PR2 FA3h —(2) F7Bh —(2) FF2h INTCON FCAh T2CON FA2h IPR2 F7Ah IOCB FF1h INTCON2 FC9h SSPBUF FA1h PIR2 F79h IOCA FF0h INTCON3 FC8h SSPADD FA0h PIE2 F78h WPUB FEFh INDF0(1) FC7h SSPSTAT F9Fh IPR1 F77h WPUA FEEh POSTINC0(1) FC6h SSPCON1 F9Eh PIR1 F76h SLRCON FEDh POSTDEC0(1) FC5h SSPCON2 F9Dh PIE1 F75h —(2) —(2) F74h —(2) FECh PREINC0(1) FC4h ADRESH F9Ch FEBh (1) FC3h ADRESL F9Bh OSCTUNE PLUSW0 F73h —(2) (2) F72h —(2) FEAh FSR0H FC2h ADCON0 F9Ah — FE9h FSR0L FC1h ADCON1 F99h —(2) F71h —(2) F98h — (2) F70h —(2) (2) FE8h FE7h FE6h WREG INDF1 FC0h (1) POSTINC1(1) FE5h POSTDEC1(1) ADCON2 FBFh CCPR1H F97h — FBEh CCPR1L F96h —(2) F6Eh F95h —(2) F6Dh CM1CON0 FBDh CCP1CON F6Fh SSPMASK —(2) FE4h PREINC1 (1) FBCh REFCON2 F94h TRISC F6Ch CM2CON1 FE3h PLUSW1(1) FBBh REFCON1 F93h TRISB F6Bh CM2CON0 FE2h FSR1H FBAh REFCON0 F92h TRISA F6Ah —(2) FE1h FSR1L FB9h PSTRCON F91h —(2) F69h SRCON1 FE0h BSR FB8h BAUDCON F90h —(2) F68h SRCON0 FDFh INDF2(1) FB7h PWM1CON F8Fh —(2) F67h —(2) (2) F66h —(2) F65h —(2) (1) FB6h ECCP1AS F8Eh — FDDh POSTDEC2(1) F8Dh —(2) (2) FDEh POSTINC2 FB5h —(2) FDCh PREINC2 (1) FB4h (2) FDBh PLUSW2(1) FB3h FDAh FSR2H FD9h FSR2L FD8h STATUS FB0h Note 1: 2: F8Ch — F64h UCON TMR3H — F8Bh LATC F63h USTAT FB2h TMR3L F8Ah LATB F62h UIR FB1h T3CON F89h LATA F61h UCFG SPBRGH F88h —(2) F60h UIE This is not a physical register. Unimplemented registers are read as ‘0’. DS41350D-page 40 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 3-2: File Name TOSU REGISTER FILE SUMMARY (PIC18F/LF1XK50) Bit 7 Bit 6 Bit 5 — — — TOSH Top-of-Stack, High Byte (TOS<15:8>) TOSL Top-of-Stack, Low Byte (TOS<7:0>) STKPTR STKFUL STKUNF — PCLATU — — — PCLATH Holding Register for PC<15:8> PCL PC, Low Byte (PC<7:0>) TBLPTRU TBLPTRH — Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Top-of-Stack Upper Byte (TOS<20:16>) Value on POR, BOR Details on page: ---0 0000 287, 30 0000 0000 287, 30 0000 0000 287, 30 SP4 SP3 SP2 SP1 SP0 Holding Register for PC<20:16> 00-0 0000 287, 31 ---0 0000 287, 30 0000 0000 287, 30 0000 0000 287, 30 — — Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) ---0 0000 287, 54 Program Memory Table Pointer, High Byte (TBLPTR<15:8>) 0000 0000 287, 54 0000 0000 287, 54 TBLPTRL Program Memory Table Pointer, Low Byte (TBLPTR<7:0>) TABLAT Program Memory Table Latch 0000 0000 287, 54 PRODH Product Register, High Byte xxxx xxxx 287, 65 PRODL Product Register, Low Byte xxxx xxxx 287, 65 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RABIE TMR0IF INTCON2 RABPU INTEDG0 INTEDG1 INTCON3 INT2IP INT1IP — INTEDG2 — TMR0IP INT2IE INT1IE — INT0IF RABIF 0000 000x 287, 69 — RABIP 1111 -1-1 287, 70 INT2IF INT1IF 11-0 0-00 287, 71 INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 287, 47 N/A 287, 47 POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register) 287, 47 PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 287, 47 PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) – value of FSR0 offset by W N/A 287, 47 FSR0H — — — — Indirect Data Memory Address Pointer 0, High Byte ---- 0000 287, 47 FSR0L Indirect Data Memory Address Pointer 0, Low Byte xxxx xxxx 287, 47 WREG Working Register xxxx xxxx 287 INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 287, 47 POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 287, 47 N/A 287, 47 PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 287, 47 PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) – value of FSR1 offset by W N/A 287, 47 FSR1H — FSR1L — — — Indirect Data Memory Address Pointer 1, High Byte ---- 0000 288, 47 Indirect Data Memory Address Pointer 1, Low Byte BSR — — — — xxxx xxxx 288, 47 Bank Select Register ---- 0000 288, 35 INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 288, 47 N/A 288, 47 POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) 288, 47 PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 288, 47 PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) – value of FSR2 offset by W N/A 288, 47 FSR2H — FSR2L — — — Indirect Data Memory Address Pointer 2, High Byte ---- 0000 288, 47 Indirect Data Memory Address Pointer 2, Low Byte STATUS Legend: Note 1: 2: 3: — — — N xxxx xxxx 288, 47 OV Z DC C ---x xxxx 288, 45 x = unknown, u = unchanged, — = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See Section 23.4 “Brown-out Reset (BOR)”. The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is read-only. Bits RA0 and RA1 are available only when USB is disabled. 2010 Microchip Technology Inc. Preliminary DS41350D-page 41 PIC18F/LF1XK50 TABLE 3-2: File Name REGISTER FILE SUMMARY (PIC18F/LF1XK50) (CONTINUED) Bit 7 Bit 6 TMR0H Timer0 Register, High Byte TMR0L Timer0 Register, Low Byte T0CON Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: 0000 0000 288, 103 xxxx xxxx 288, 103 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOSF SCS1 SCS0 0011 qq00 288, 20 OSCCON2 — — — — — PRI_SD HFIOFL LFIOFS ---- -10x 288, 21 — — — — — — — SWDTEN IPEN SBOREN(1) — RI TO PD POR BOR WDTCON RCON 1111 1111 288, 101 --- ---0 288, 305 0q-1 11q0 279, 286, 78 TMR1H Timer1 Register, High Byte xxxx xxxx 288, 110 TMR1L Timer1 Register, Low Bytes xxxx xxxx 288, 110 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 288, 105 TMR2 Timer2 Register 0000 0000 288, 112 PR2 Timer2 Period Register 1111 1111 288, 112 T2CON — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 SSPBUF SSP Receive Buffer/Transmit Register SSPADD SSP Address Register in I2C™ Slave Mode. SSP Baud Rate Reload Register in I 2C Master Mode. T2CKPS0 -000 0000 288, 111 xxxx xxxx 288, 143, 144 0000 0000 288, 144 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 288, 137, 146 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 288, 137, 146 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN SSPCON2 ADRESH A/D Result Register, High Byte ADRESL A/D Result Register, Low Byte 0000 0000 288, 147 xxxx xxxx 289, 223 xxxx xxxx 289, 223 ADCON0 — — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON --00 0000 289, 217 ADCON1 — — — — PVCFG1 PVCFG0 NVCFG1 NVCFG0 ---- 0000 289, 218 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 289, 219 ADCON2 CCPR1H Capture/Compare/PWM Register 1, High Byte CCPR1L Capture/Compare/PWM Register 1, Low Byte xxxx xxxx 289, 138 xxxx xxxx 289, 138 CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 289, 117 REFCON2 — — — DAC1R4 DAC1R3 DAC1R2 DAC1R1 DAC1R0 ---0 0000 289, 250 REFCON1 D1EN D1LPS DAC1OE --- D1PSS1 D1PSS0 — D1NSS 000- 00-0 289, 250 REFCON0 FVR1EN FVR1ST FVR1S1 FVR1S0 — — — — 0001 00-- 289, 249 PSTRCON — — — STRSYNC STRD STRC STRB STRA ---0 0001 289, 134 BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 0100 0-00 289, 194 PWM1CON PRSEN PDC6 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 0000 0000 289, 133 ECCP1AS ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 0000 0000 289, 129 TMR3H Timer3 Register, High Byte xxxx xxxx 289, 115 TMR3L Timer3 Register, Low Byte xxxx xxxx 289, 115 RD16 T3CON Legend: Note 1: 2: 3: — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0-00 0000 289, 113 x = unknown, u = unchanged, — = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See Section 23.4 “Brown-out Reset (BOR)”. The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is read-only. Bits RA0 and RA1 are available only when USB is disabled. DS41350D-page 42 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 3-2: File Name REGISTER FILE SUMMARY (PIC18F/LF1XK50) (CONTINUED) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page: SPBRGH EUSART Baud Rate Generator Register, High Byte 0000 0000 289, 183 SPBRG EUSART Baud Rate Generator Register, Low Byte 0000 0000 289, 183 RCREG EUSART Receive Register 0000 0000 289, 184 TXREG EUSART Transmit Register 0000 0000 289, 183 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 289, 192 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 289, 193 EEADR EEADR7 EEADR6 EEADR5 EEADR4 EEADR3 EEADR2 EEADR1 EEADR0 0000 0000 289, 52, 61 EEDATA EEPROM Data Register 0000 0000 289, 52, 61 EECON2 EEPROM Control Register 2 (not a physical register) 0000 0000 289, 52, 61 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 289, 53, 61 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP – 1111 111- 290, 77 PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF – 0000 000- 290, 73 0000 000- 290, 75 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE – IPR1 – ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP -111 1111 290, 76 PIR1 – ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF -000 0000 290, 72 PIE1 – ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE -000 0000 290, 74 OSCTUNE INTSRC SPLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 0000 0000 22, 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 1111 1111 290, 94 TRISB TRISB7 TRISB6 TRISB5 TRISB4 – – – – 1111 ---- 290, 89 TRISA – – TRISA5 TRISA4 – – – – --11 ---- 290, 83 LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 xxxx xxxx 290, 94 – – – – xxxx ---- 290, 89 LATB LATB7 LATB6 LATB5 LATB4 – – LATA5 LATA4 – – – – --xx ---- 290, 83 PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx 290, 94 PORTB RB7 RB6 RB5 RB4 – – – – xxxx ---- 290, 89 RA0(3) --xx x-xx 290, 83 LATA PORTA – – RA5 RA4 RA3(2) – RA1(3) ANSELH — — — — ANS11 ANS10 ANS9 ANS8 ---- 1111 290, 99 ANSEL ANS7 ANS6 ANS5 ANS4 ANS3 — — — 1111 1--- 290, 98 IOCB IOCB7 IOCB6 IOCB5 IOCB4 — — — — 0000 ---- 290, 89 IOCA — — IOCA5 IOCA4 IOCA3 — IOCA1 IOCA0 --00 0-00 290, 83 WPUB WPUB7 WPUB6 WPUB5 WPUB4 — — — — 1111 ---- 290, 89 WPUA — — WPUA3 — — — --11 1--- 287, 89 ---- -111 290, 100 WPUA5 WPUA4 SLRCON — — — — — SLRC SLRB SLRA SSPMSK MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 1111 1111 290, 154 CM1CON0 C1ON C1OUT C1OE C1POL C1SP C1R C1CH1 C1CH0 0000 1000 290, 231 CM2CON1 MC1OUT MC2OUT C1RSEL C2RSEL C1HYS C2HYS C1SYNC C2SYNC 0000 0000 290, 232 C2ON C2OUT C2OE C2POL C2SP C2R C2CH1 C2CH0 0000 1000 290, 232 SRCON1 SRSPE SRSCKE SRSC2E SRSC1E SRRPE SRRCKE SRRC2E SRRC1E 0000 0000 290, 245 SRCON0 SRLEN SRCLK2 SRCLK1 SRCLK0 SRQEN SRNQEN SRPS SRPR 0000 0000 290, 244 SUSPND — -0x0 000- 290, 254 CM2CON0 — UCON Legend: Note 1: 2: 3: PPBRST SE0 PKTDIS USBEN RESUME x = unknown, u = unchanged, — = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See Section 23.4 “Brown-out Reset (BOR)”. The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is read-only. Bits RA0 and RA1 are available only when USB is disabled. 2010 Microchip Technology Inc. Preliminary DS41350D-page 43 PIC18F/LF1XK50 TABLE 3-2: File Name REGISTER FILE SUMMARY (PIC18F/LF1XK50) (CONTINUED) Value on POR, BOR Details on page: Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 USTAT — ENDP3 ENDP2 ENDP1 ENDP0 DIR PPBI — UIR — SOFIF STALLIF IDLEIF TRNIF ACTVIF UERRIF URSTIF -000 0000 291, 268 UTEYE — — UPUEN — FSEN PPB1 PPB0 0--0 -000 291, 256 — SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE -000 0000 291, 270 — UCFG UIE -xxx xxx- 291, 258 BTSEF — BTOEF DFN8EF CRC16EF CRC5EF PIDEF 0--0 0000 291, 271 UFRMH — — — — — FRM10 FRM9 FRM8 ---- -xxx 291, 254 UFRML FRM7 FRM6 FRM5 FRM4 FRM3 FRM2 FRM1 FRM0 xxxx xxxx 291, 254 UADDR — ADDR6 ADDR5 ADDR4 ADDR3 ADDR2 ADDR1 ADDR0 -000 0000 291, 260 UEIE BTSEE — — BTOEE DFN8EE CRC16EE CRC5EE PIDEE 0--0 0000 291, 272 UEP7 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP6 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP5 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP4 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP3 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP2 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP1 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 291, 259 UEP0 – – – EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 287, 259 UEIR Legend: Note 1: 2: 3: x = unknown, u = unchanged, — = unimplemented, q = value depends on condition The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See Section 23.4 “Brown-out Reset (BOR)”. The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is read-only. Bits RA0 and RA1 are available only when USB is disabled. DS41350D-page 44 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.3.6 STATUS REGISTER The STATUS register, shown in Register 3-2, contains the arithmetic status of the ALU. As with any other SFR, it can be the operand for any instruction. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of the instruction are not written; instead, the STATUS register is updated according to the instruction performed. Therefore, the result of an instruction with the STATUS register as its destination may be different than intended. As an example, CLRF STATUS will set the Z bit and leave the remaining Status bits unchanged (‘000u u1uu’). REGISTER 3-2: U-0 For other instructions that do not affect Status bits, see the instruction set summaries in Table 25-2 and Table 25-3. Note: The C and DC bits operate as the borrow and digit borrow bits, respectively, in subtraction. STATUS: STATUS REGISTER U-0 — It is recommended 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 in the STATUS register. — U-0 — R/W-x N R/W-x OV R/W-x R/W-x R/W-x (1) Z C(1) DC bit 7 bit 0 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 bit 7-5 Unimplemented: Read as ‘0’ bit 4 N: Negative bit This bit is used for signed arithmetic (two’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 (two’s complement). It indicates an overflow of the 7-bit magnitude which causes the sign bit (bit 7 of the result) 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 (ADDWF, ADDLW,SUBLW,SUBWF instructions)(1) 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 bit 0 C: Carry/Borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)(1) 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 1: 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-order or low-order bit of the source register. 2010 Microchip Technology Inc. Preliminary DS41350D-page 45 PIC18F/LF1XK50 3.4 Data Addressing Modes Note: The execution of some instructions in the core PIC18 instruction set are changed when the PIC18 extended instruction set is enabled. See Section 3.5 “Data Memory and the Extended Instruction Set” for more information. While the program memory can be addressed in only one way – through the program counter – information in the data memory space can be addressed in several ways. For most instructions, the addressing mode is fixed. Other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled. The addressing modes are: • • • • Inherent Literal Direct Indirect A few instructions, such as MOVFF, include the entire 12-bit address (either source or destination) in their opcodes. In these cases, the BSR is ignored entirely. The destination of the operation’s results is determined by the destination bit ‘d’. When ‘d’ is ‘1’, the results are stored back in the source register, overwriting its original contents. When ‘d’ is ‘0’, the results are stored in the W register. Instructions without the ‘d’ argument have a destination that is implicit in the instruction; their destination is either the target register being operated on or the W register. 3.4.3 An additional addressing mode, Indexed Literal Offset, is available when the extended instruction set is enabled (XINST Configuration bit = 1). Its operation is discussed in greater detail in Section 3.5.1 “Indexed Addressing with Literal Offset”. 3.4.1 The Access RAM bit ‘a’ determines how the address is interpreted. When ‘a’ is ‘1’, the contents of the BSR (Section 3.3.2 “Bank Select Register (BSR)”) are used with the address to determine the complete 12-bit address of the register. When ‘a’ is ‘0’, the address is interpreted as being a register in the Access Bank. Addressing that uses the Access RAM is sometimes also known as Direct Forced Addressing mode. INHERENT AND LITERAL ADDRESSING Many PIC18 control instructions do not need any argument at all; they either perform an operation that globally affects the device or they operate implicitly on one register. This addressing mode is known as Inherent Addressing. Examples include SLEEP, RESET and DAW. Other instructions work in a similar way but require an additional explicit argument in the opcode. This is known as Literal Addressing mode because they require some literal value as an argument. Examples include ADDLW and MOVLW, which respectively, add or move a literal value to the W register. Other examples include CALL and GOTO, which include a 20-bit program memory address. Indirect addressing allows the user to access a location in data memory without giving a fixed address in the instruction. This is done by using File Select Registers (FSRs) as pointers to the locations which are to be read or written. Since the FSRs are themselves located in RAM as Special File Registers, they can also be directly manipulated under program control. This makes FSRs very useful in implementing data structures, such as tables and arrays in data memory. The registers for indirect addressing are also implemented with Indirect File Operands (INDFs) that permit automatic manipulation of the pointer value with auto-incrementing, auto-decrementing or offsetting with another value. This allows for efficient code, using loops, such as the example of clearing an entire RAM bank in Example 3-5. EXAMPLE 3-5: NEXT 3.4.2 INDIRECT ADDRESSING LFSR CLRF DIRECT ADDRESSING Direct addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. The options are specified by the arguments accompanying the instruction. BTFSS BRA CONTINUE HOW TO CLEAR RAM (BANK 1) USING INDIRECT ADDRESSING FSR0, 100h ; POSTINC0 ; Clear INDF ; register then ; inc pointer FSR0H, 1 ; All done with ; Bank1? NEXT ; NO, clear next ; YES, continue In the core PIC18 instruction set, bit-oriented and byteoriented instructions use some version of direct addressing by default. All of these instructions include some 8-bit literal address as their Least Significant Byte. This address specifies either a register address in one of the banks of data RAM (Section 3.3.4 “General Purpose Register File”) or a location in the Access Bank (Section 3.3.3 “Access Bank”) as the data source for the instruction. DS41350D-page 46 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 3.4.3.1 FSR Registers and the INDF Operand 3.4.3.2 At the core of indirect addressing are three sets of registers: FSR0, FSR1 and FSR2. Each represents a pair of 8-bit registers, FSRnH and FSRnL. Each FSR pair holds a 12-bit value, therefore the four upper bits of the FSRnH register are not used. The 12-bit FSR value can address the entire range of the data memory in a linear fashion. The FSR register pairs, then, serve as pointers to data memory locations. In addition to the INDF operand, each FSR register pair also has four additional indirect operands. Like INDF, these are “virtual” registers which cannot be directly read or written. Accessing these registers actually accesses the location to which the associated FSR register pair points, and also performs a specific action on the FSR value. They are: • POSTDEC: accesses the location to which the FSR points, then automatically decrements the FSR by 1 afterwards • POSTINC: accesses the location to which the FSR points, then automatically increments the FSR by 1 afterwards • PREINC: automatically increments the FSR by 1, then uses the location to which the FSR points in the operation • PLUSW: adds the signed value of the W register (range of -127 to 128) to that of the FSR and uses the location to which the result points in the operation. Indirect addressing is accomplished with a set of Indirect File Operands, INDF0 through INDF2. These can be thought of as “virtual” registers: they are mapped in the SFR space but are not physically implemented. Reading or writing to a particular INDF register actually accesses its corresponding FSR register pair. A read from INDF1, for example, reads the data at the address indicated by FSR1H:FSR1L. Instructions that use the INDF registers as operands actually use the contents of their corresponding FSR as a pointer to the instruction’s target. The INDF operand is just a convenient way of using the pointer. Because indirect addressing uses a full 12-bit address, data RAM banking is not necessary. Thus, the current contents of the BSR and the Access RAM bit have no effect on determining the target address. FIGURE 3-8: FSR Registers and POSTINC, POSTDEC, PREINC and PLUSW In this context, accessing an INDF register uses the value in the associated FSR register without changing it. Similarly, accessing a PLUSW register gives the FSR value an offset by that in the W register; however, neither W nor the FSR is actually changed in the operation. Accessing the other virtual registers changes the value of the FSR register. INDIRECT ADDRESSING 000h Using an instruction with one of the indirect addressing registers as the operand.... Bank 0 ADDWF, INDF1, 1 100h Bank 1 200h ...uses the 12-bit address stored in the FSR pair associated with that register.... 300h FSR1H:FSR1L 7 0 x x x x 1 1 1 0 7 0 Bank 2 Bank 3 through Bank 13 1 1 0 0 1 1 0 0 ...to determine the data memory location to be used in that operation. E00h In this case, the FSR1 pair contains ECCh. This means the contents of location ECCh will be added to that of the W register and stored back in ECCh. Bank 14 F00h FFFh Bank 15 Data Memory 2010 Microchip Technology Inc. Preliminary DS41350D-page 47 PIC18F/LF1XK50 Operations on the FSRs with POSTDEC, POSTINC and PREINC affect the entire register pair; that is, rollovers of the FSRnL register from FFh to 00h carry over to the FSRnH register. On the other hand, results of these operations do not change the value of any flags in the STATUS register (e.g., Z, N, OV, etc.). The PLUSW register can be used to implement a form of indexed addressing in the data memory space. By manipulating the value in the W register, users can reach addresses that are fixed offsets from pointer addresses. In some applications, this can be used to implement some powerful program control structure, such as software stacks, inside of data memory. 3.4.3.3 Operations by FSRs on FSRs Indirect addressing operations that target other FSRs or virtual registers represent special cases. For example, using an FSR to point to one of the virtual registers will not result in successful operations. As a specific case, assume that FSR0H:FSR0L contains FE7h, the address of INDF1. Attempts to read the value of the INDF1 using INDF0 as an operand will return 00h. Attempts to write to INDF1 using INDF0 as the operand will result in a NOP. On the other hand, using the virtual registers to write to an FSR pair may not occur as planned. In these cases, the value will be written to the FSR pair but without any incrementing or decrementing. Thus, writing to either the INDF2 or POSTDEC2 register will write the same value to the FSR2H:FSR2L. Since the FSRs are physical registers mapped in the SFR space, they can be manipulated through all direct operations. Users should proceed cautiously when working on these registers, particularly if their code uses indirect addressing. Similarly, operations by indirect addressing are generally permitted on all other SFRs. Users should exercise the appropriate caution that they do not inadvertently change settings that might affect the operation of the device. 3.5 Data Memory and the Extended Instruction Set Enabling the PIC18 extended instruction set (XINST Configuration bit = 1) significantly changes certain aspects of data memory and its addressing. Specifically, the use of the Access Bank for many of the core PIC18 instructions is different; this is due to the introduction of a new addressing mode for the data memory space. 3.5.1 INDEXED ADDRESSING WITH LITERAL OFFSET Enabling the PIC18 extended instruction set changes the behavior of indirect addressing using the FSR2 register pair within Access RAM. Under the proper conditions, instructions that use the Access Bank – that is, most bit-oriented and byte-oriented instructions – can invoke a form of indexed addressing using an offset specified in the instruction. This special addressing mode is known as Indexed Addressing with Literal Offset, or Indexed Literal Offset mode. When using the extended instruction set, this addressing mode requires the following: • The use of the Access Bank is forced (‘a’ = 0) and • The file address argument is less than or equal to 5Fh. Under these conditions, the file address of the instruction is not interpreted as the lower byte of an address (used with the BSR in direct addressing), or as an 8-bit address in the Access Bank. Instead, the value is interpreted as an offset value to an Address Pointer, specified by FSR2. The offset and the contents of FSR2 are added to obtain the target address of the operation. 3.5.2 INSTRUCTIONS AFFECTED BY INDEXED LITERAL OFFSET MODE Any of the core PIC18 instructions that can use direct addressing are potentially affected by the Indexed Literal Offset Addressing mode. This includes all byte-oriented and bit-oriented instructions, or almost one-half of the standard PIC18 instruction set. Instructions that only use Inherent or Literal Addressing modes are unaffected. Additionally, byte-oriented and bit-oriented instructions are not affected if they do not use the Access Bank (Access RAM bit is ‘1’), or include a file address of 60h or above. Instructions meeting these criteria will continue to execute as before. A comparison of the different possible addressing modes when the extended instruction set is enabled is shown in Figure 3-9. Those who desire to use byte-oriented or bit-oriented instructions in the Indexed Literal Offset mode should note the changes to assembler syntax for this mode. This is described in more detail in Section 25.2.1 “Extended Instruction Syntax”. What does not change is just as important. The size of the data memory space is unchanged, as well as its linear addressing. The SFR map remains the same. Core PIC18 instructions can still operate in both Direct and Indirect Addressing mode; inherent and literal instructions do not change at all. Indirect addressing with FSR0 and FSR1 also remain unchanged. DS41350D-page 48 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 3-9: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED) EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff) When ‘a’ = 0 and f 60h: The instruction executes in Direct Forced mode. ‘f’ is interpreted as a location in the Access RAM between 060h and 0FFh. This is the same as locations F60h to FFFh (Bank 15) of data memory. Locations below 60h are not available in this addressing mode. 000h 060h Bank 0 100h 00h Bank 1 through Bank 14 60h Valid range for ‘f’ Access RAM F00h FFh Bank 15 F60h SFRs FFFh When ‘a’ = 0 and f5Fh: The instruction executes in Indexed Literal Offset mode. ‘f’ is interpreted as an offset to the address value in FSR2. The two are added together to obtain the address of the target register for the instruction. The address can be anywhere in the data memory space. Note that in this mode, the correct syntax is now: ADDWF [k], d where ‘k’ is the same as ‘f’. When ‘a’ = 1 (all values of f): The instruction executes in Direct mode (also known as Direct Long mode). ‘f’ is interpreted as a location in one of the 16 banks of the data memory space. The bank is designated by the Bank Select Register (BSR). The address can be in any implemented bank in the data memory space. Data Memory 000h 060h Bank 0 100h 001001da ffffffff Bank 1 through Bank 14 FSR2H FSR2L F00h Bank 15 F60h SFRs FFFh Data Memory BSR 00000000 000h 060h Bank 0 100h Bank 1 through Bank 14 001001da ffffffff F00h Bank 15 F60h SFRs FFFh 2010 Microchip Technology Inc. Data Memory Preliminary DS41350D-page 49 PIC18F/LF1XK50 3.5.3 MAPPING THE ACCESS BANK IN INDEXED LITERAL OFFSET MODE The use of Indexed Literal Offset Addressing mode effectively changes how the first 96 locations of Access RAM (00h to 5Fh) are mapped. Rather than containing just the contents of the bottom section of Bank 0, this mode maps the contents from a user defined “window” that can be located anywhere in the data memory space. The value of FSR2 establishes the lower boundary of the addresses mapped into the window, while the upper boundary is defined by FSR2 plus 95 (5Fh). Addresses in the Access RAM above 5Fh are mapped as previously described (see Section 3.3.3 “Access Bank”). An example of Access Bank remapping in this addressing mode is shown in Figure 3-10. FIGURE 3-10: Remapping of the Access Bank applies only to operations using the Indexed Literal Offset mode. Operations that use the BSR (Access RAM bit is ‘1’) will continue to use direct addressing as before. 3.6 PIC18 Instruction Execution and the Extended Instruction Set Enabling the extended instruction set adds eight additional commands to the existing PIC18 instruction set. These instructions are executed as described in Section 25.2 “Extended Instruction Set”. REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET ADDRESSING Example Situation: ADDWF f, d, a FSR2H:FSR2L = 120h Locations in the region from the FSR2 pointer (120h) to the pointer plus 05Fh (17Fh) are mapped to the bottom of the Access RAM (000h-05Fh). 000h Bank 0 100h 120h 17Fh 200h Bank 1 Window 00h Bank 1 Bank 1 “Window” 5Fh 60h Special File Registers at F60h through FFFh are mapped to 60h through FFh, as usual. Bank 2 through Bank 14 Bank 0 addresses below 5Fh can still be addressed by using the BSR. SFRs FFh Access Bank F00h Bank 15 F60h FFFh SFRs Data Memory DS41350D-page 50 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 4.0 FLASH PROGRAM MEMORY 4.1 Table Reads and Table Writes The Flash program memory is readable, writable and erasable during normal operation over the entire VDD range. 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: A read from program memory is executed one byte at a time. A write to program memory is executed on blocks of 16 or 8 bytes at a time depending on the specific device (See Table 4-1). Program memory is erased in blocks of 64 bytes at a time. The difference between the write and erase block sizes requires from 1 to 8 block writes to restore the contents of a single block erase. A bulk erase operation can not be issued from user code. • Table Read (TBLRD) • Table Write (TBLWT) TABLE 4-1: WRITE/ERASE BLOCK SIZES Write Block Size (bytes) Erase Block Size (bytes) PIC18F13K50 8 64 PIC18F14K50 16 64 Device Writing or erasing program memory will cease instruction fetches until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming 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. FIGURE 4-1: 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). The table read operation retrieves one byte of data directly from program memory and places it into the TABLAT register. Figure 4-1 shows the operation of a table read. The table write operation stores one byte of data from the TABLAT register into a write block holding register. The procedure to write the contents of the holding registers into program memory is detailed in Section 4.5 “Writing to Flash Program Memory”. Figure 4-2 shows the operation of a table write with program memory and data RAM. Table operations work with byte entities. Tables containing data, rather than program instructions, are not required to be word aligned. Therefore, a table 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. TABLE READ OPERATION Instruction: TBLRD* Program Memory Table Pointer(1) TBLPTRU TBLPTRH Table Latch (8-bit) TBLPTRL TABLAT Program Memory (TBLPTR) Note 1: Table Pointer register points to a byte in program memory. 2010 Microchip Technology Inc. Preliminary DS41350D-page 51 PIC18F/LF1XK50 FIGURE 4-2: TABLE WRITE OPERATION Instruction: TBLWT* Program Memory Table Pointer(1) TBLPTRU TBLPTRH Holding Registers Table Latch (8-bit) TBLPTRL TABLAT Program Memory (TBLPTR<MSBs>) Note 1: During table writes the Table Pointer does not point directly to Program Memory. The LSBs of TBLPRTL actually point to an address within the write block holding registers. The MSBs of the Table Pointer determine where the write block will eventually be written. The process for writing the holding registers to the program memory array is discussed in Section 4.5 “Writing to Flash Program Memory”. 4.2 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 4.2.1 The FREE bit allows the program memory erase operation. When FREE is set, an 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. The WREN bit is clear on power-up. EECON1 AND EECON2 REGISTERS The EECON1 register (Register 4-1) is the control register for memory accesses. The EECON2 register is not a physical register; it is used exclusively in the memory write and erase sequences. Reading EECON2 will read all ‘0’s. The EEPGD control bit determines if the access will be a program or data EEPROM memory access. When EEPGD is clear, any subsequent operations will operate on the data EEPROM memory. When EEPGD is set, any subsequent operations will operate on the program memory. The WRERR bit is set by hardware when the WR bit is set and cleared when the internal programming timer expires and the write operation is complete. Note: The WR control bit initiates write operations. The WR bit cannot be cleared, only set, by firmware. Then WR bit is cleared by hardware at the completion of the write operation. Note: The CFGS control bit determines if the access will be to the Configuration/Calibration registers or to program memory/data EEPROM memory. When CFGS is set, subsequent operations will operate on Configuration registers regardless of EEPGD (see Section 24.0 “Special Features of the CPU”). When CFGS is clear, memory selection access is determined by EEPGD. DS41350D-page 52 During normal operation, the WRERR is read as ‘1’. This can indicate that a write operation was prematurely terminated by a Reset, or a write operation was attempted improperly. Preliminary The EEIF interrupt flag bit of the PIR2 register is set when the write is complete. The EEIF flag stays set until cleared by firmware. 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 4-1: EECON1: DATA EEPROM CONTROL 1 REGISTER 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 Legend: R = Readable bit W = Writable bit S = Bit can be set by software, but not cleared U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘0’ = Bit is cleared ‘1’ = Bit is set x = Bit is unknown 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 EEPROM 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 (Block) Erase Enable bit 1 = Erase the program memory block addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write-only bit 3 WRERR: Flash Program/Data EEPROM Error Flag bit(1) 1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal operation, or an improper write attempt) 0 = The write operation completed bit 2 WREN: Flash Program/Data EEPROM Write Enable bit 1 = Allows write cycles to Flash program/data EEPROM 0 = Inhibits write cycles to Flash program/data 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) by 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 by hardware. The RD bit can only be set (not cleared) by software. RD bit cannot be set when EEPGD = 1 or CFGS = 1.) 0 = Does not initiate an EEPROM read Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition. 2010 Microchip Technology Inc. Preliminary DS41350D-page 53 PIC18F/LF1XK50 4.2.2 TABLAT – TABLE LATCH REGISTER The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch register is used to hold 8-bit data during data transfers between program memory and data RAM. 4.2.3 TBLPTR – TABLE POINTER REGISTER The Table Pointer (TBLPTR) register 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 registers join to form a 22-bit wide pointer. The low-order 21 bits allow the device to address up to 2 Mbytes of program memory space. The 22nd bit allows access to the device ID, the user ID and the Configuration bits. The Table Pointer register, TBLPTR, is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 4-2. These operations on the TBLPTR affect only the low-order 21 bits. 4.2.4 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 TBLPTR determine which byte is read from program memory directly into the TABLAT register. When a TBLWT is executed the byte in the TABLAT register is written, not to Flash memory but, to a holding register in preparation for a program memory write. The holding registers constitute a write block which varies depending on the device (See Table 4-1).The 3, 4, or 5 LSbs of the TBLPTRL register determine which specific address within the holding register block is written to. The MSBs of the Table Pointer have no effect during TBLWT operations. When a program memory write is executed the entire holding register block is written to the Flash memory at the address determined by the MSbs of the TBLPTR. The 3, 4, or 5 LSBs are ignored during Flash memory writes. For more detail, see Section 4.5 “Writing to Flash Program Memory”. When an erase of program memory is executed, the 16 MSbs of the Table Pointer register (TBLPTR<21:6>) point to the 64-byte block that will be erased. The Least Significant bits (TBLPTR<5:0>) are ignored. Figure 4-3 describes the relevant boundaries of TBLPTR based on Flash program memory operations. TABLE 4-2: Example TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS 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 DS41350D-page 54 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 4-3: 21 TABLE POINTER BOUNDARIES BASED ON OPERATION TBLPTRU 16 15 8 TBLPTRH 7 TBLPTRL TABLE ERASE/WRITE TBLPTR<21:n+1>(1) 0 TABLE WRITE TBLPTR<n:0>(1) TABLE READ – TBLPTR<21:0> Note 1: n = 3, 4, 5, or 6 for block sizes of 8, 16, 32 or 64 bytes, respectively. 4.3 Reading the Flash Program Memory The TBLRD instruction retrieves data from program memory and places it into data RAM. Table reads from program memory are performed one byte at a time. 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 4-4 shows the interface between the internal program memory and the TABLAT. 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. FIGURE 4-4: READS FROM FLASH PROGRAM MEMORY Program Memory (Even Byte Address) (Odd Byte Address) TBLPTR = xxxxx1 Instruction Register (IR) 2010 Microchip Technology Inc. FETCH TBLRD Preliminary TBLPTR = xxxxx0 TABLAT Read Register DS41350D-page 55 PIC18F/LF1XK50 EXAMPLE 4-1: READING A FLASH PROGRAM MEMORY WORD MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; Load TBLPTR with the base ; address of the word READ_WORD TBLRD*+ MOVF MOVWF TBLRD*+ MOVFW MOVF DS41350D-page 56 TABLAT, W WORD_EVEN TABLAT, W WORD_ODD ; read into TABLAT and increment ; get data ; read into TABLAT and increment ; get data Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 4.4 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 Microcontroller 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. The TBLPTR<5:0> bits are ignored. The EECON1 register commands the erase operation. The EEPGD bit must be set to point to the Flash program memory. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. The write initiate sequence for EECON2, shown as steps 4 through 6 in Section 4.4.1 “Flash Program Memory Erase Sequence”, is used to guard against accidental writes. This is sometimes referred to as a long write. 4.4.1 FLASH PROGRAM MEMORY ERASE SEQUENCE The sequence of events for erasing a block of internal program memory is: 1. Load Table Pointer register with address of block being erased. Set the EECON1 register for the erase operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN bit to enable writes; • set FREE bit to enable the erase. Disable interrupts. Write 55h to EECON2. Write 0AAh to EECON2. Set the WR bit. This will begin the block erase cycle. The CPU will stall for duration of the erase (about 2 ms using internal timer). Re-enable interrupts. 2. 3. 4. 5. 6. 7. 8. A long write is necessary for erasing the internal Flash. Instruction execution is halted during the long write cycle. The long write is terminated by the internal programming timer. EXAMPLE 4-2: ERASING A FLASH PROGRAM MEMORY BLOCK MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; load TBLPTR with the base ; address of the memory block BSF BCF BSF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF EECON1, EECON1, EECON1, EECON1, INTCON, 55h EECON2 0AAh EECON2 EECON1, INTCON, ; ; ; ; ; ERASE_BLOCK Required Sequence 2010 Microchip Technology Inc. EEPGD CFGS WREN FREE GIE point to Flash program memory access Flash program memory enable write to memory enable block Erase operation disable interrupts ; write 55h WR GIE ; write 0AAh ; start erase (CPU stall) ; re-enable interrupts Preliminary DS41350D-page 57 PIC18F/LF1XK50 4.5 Writing to Flash Program Memory The programming block size is 8 or 16 bytes, depending on the device (See Table 4-1). Word or byte programming is not supported. Table writes are used internally to load the holding registers needed to program the Flash memory. There are only as many holding registers as there are bytes in a write block (See Table 4-1). Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction may need to be executed 8, or 16 times, depending on the device, for each programming operation. All of the table write operations will essentially be short writes because only the holding registers are written. After all the holding registers have been written, the programming operation of that block of memory is started by configuring the EECON1 register for a program memory write and performing the long write sequence. FIGURE 4-5: The long write is necessary for programming the internal Flash. Instruction execution is halted during 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. Note: The default value of the holding registers on device Resets and after write operations is FFh. A write of FFh to a holding register does not modify that byte. This means that individual bytes of program memory may be modified, provided that the change does not attempt to change any bit from a ‘0’ to a ‘1’. When modifying individual bytes, it is not necessary to load all holding registers before executing a long write operation. TABLE WRITES TO FLASH PROGRAM MEMORY TABLAT Write Register 8 8 TBLPTR = xxxx00 TBLPTR = xxxx01 Holding Register 8 TBLPTR = xxxxYY(1) TBLPTR = xxxx02 Holding Register 8 Holding Register Holding Register Program Memory Note 1: YY = x7, xF, or 1F for 8, 16 or 32 byte write blocks, respectively. 4.5.1 FLASH PROGRAM MEMORY WRITE SEQUENCE The sequence of events for programming an internal program memory location should be: 1. 2. 3. 4. 5. 6. 7. Read 64 bytes into RAM. Update data values in RAM as necessary. Load Table Pointer register with address being erased. Execute the block erase procedure. Load Table Pointer register with address of first byte being written. Write the 8 or 16-byte block into the holding registers with auto-increment. Set the EECON1 register for the write operation: • set EEPGD bit to point to program memory; • clear the CFGS bit to access program memory; • set WREN to enable byte writes. DS41350D-page 58 8. 9. 10. 11. 12. Disable interrupts. Write 55h to EECON2. Write 0AAh to EECON2. Set the WR bit. This will begin the write cycle. The CPU will stall for duration of the write (about 2 ms using internal timer). 13. Re-enable interrupts. 14. Repeat steps 6 to 13 for each block until all 64 bytes are written. 15. Verify the memory (table read). This procedure will require about 6 ms to update each write block of memory. An example of the required code is given in Example 4-3. Note: Preliminary Before setting the WR bit, the Table Pointer address needs to be within the intended address range of the bytes in the holding registers. 2010 Microchip Technology Inc. PIC18F/LF1XK50 EXAMPLE 4-3: WRITING TO FLASH PROGRAM MEMORY MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF D'64’ COUNTER BUFFER_ADDR_HIGH FSR0H BUFFER_ADDR_LOW FSR0L CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; number of bytes in erase block TBLRD*+ MOVF MOVWF DECFSZ BRA TABLAT, W POSTINC0 COUNTER READ_BLOCK MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF BUFFER_ADDR_HIGH FSR0H BUFFER_ADDR_LOW FSR0L NEW_DATA_LOW POSTINC0 NEW_DATA_HIGH INDF0 ; point to buffer MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF BSF BCF BSF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF TBLRD*MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL EECON1, EEPGD EECON1, CFGS EECON1, WREN EECON1, FREE INTCON, GIE 55h EECON2 0AAh EECON2 EECON1, WR INTCON, GIE ; load TBLPTR with the base ; address of the memory block MOVLW MOVWF MOVLW MOVWF BlockSize COUNTER D’64’/BlockSize COUNTER2 MOVF MOVWF TBLWT+* POSTINC0, W TABLAT ; point to buffer ; Load TBLPTR with the base ; address of the memory block READ_BLOCK ; ; ; ; ; read into TABLAT, and inc get data store data done? repeat MODIFY_WORD ; update buffer word ERASE_BLOCK Required Sequence BUFFER_ADDR_HIGH FSR0H BUFFER_ADDR_LOW FSR0L ; ; ; ; ; point to Flash program memory access Flash program memory enable write to memory enable Erase operation disable interrupts ; write 55h ; ; ; ; ; write 0AAh start erase (CPU stall) re-enable interrupts dummy read decrement point to buffer WRITE_BUFFER_BACK ; number of bytes in holding register ; number of write blocks in 64 bytes WRITE_BYTE_TO_HREGS 2010 Microchip Technology Inc. Preliminary ; ; ; ; get low byte of buffer data present data to table latch write data, perform a short write to internal TBLWT holding register. DS41350D-page 59 PIC18F/LF1XK50 EXAMPLE 4-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED) DECFSZ BRA COUNTER WRITE_WORD_TO_HREGS ; loop until holding registers are full BSF BCF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF DCFSZ BRA BSF BCF EECON1, EEPGD EECON1, CFGS EECON1, WREN INTCON, GIE 55h EECON2 0AAh EECON2 EECON1, WR COUNTER2 WRITE_BYTE_TO_HREGS INTCON, GIE EECON1, WREN ; ; ; ; PROGRAM_MEMORY Required Sequence 4.5.2 WRITE VERIFY 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 reprogrammed if needed. If the write operation is interrupted by a MCLR Reset or a WDT Time-out Reset during normal operation, the WRERR bit will be set which the user can check to decide whether a rewrite of the location(s) is needed. TABLE 4-3: ; write 55h ; ; ; ; ; ; write 0AAh start program (CPU stall) repeat for remaining write blocks re-enable interrupts disable write to memory 4.5.4 Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 4.5.3 point to Flash program memory access Flash program memory enable write to memory disable interrupts PROTECTION AGAINST SPURIOUS WRITES To protect against spurious writes to Flash program memory, the write initiate sequence must also be followed. See Section 24.0 “Special Features of the CPU” for more detail. 4.6 Flash Program Operation During Code Protection See Section 24.3 “Program Verification and Code Protection” for details on code protection of Flash program memory. REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY Name Bit 7 Bit 6 Bit 5 TBLPTRU — — bit 21 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) Reset Values on page 287 TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 287 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 287 TABLAT Program Memory Table Latch INTCON GIE/GIEH PEIE/GIEL TMR0IE 287 EECON2 EEPROM Control Register 2 (not a physical register) INT0IE RABIE TMR0IF INT0IF RABIF 287 289 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 289 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — 290 PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — 290 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access. DS41350D-page 60 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 5.0 DATA EEPROM MEMORY The data EEPROM is a nonvolatile memory array, separate from the data RAM and program memory, which is used for long-term storage of program data. It is not directly mapped in either the register file or program memory space but is indirectly addressed through the Special Function Registers (SFRs). The EEPROM is readable and writable during normal operation over the entire VDD range. Four SFRs are used to read and write to the data EEPROM as well as the program memory. They are: • • • • EECON1 EECON2 EEDATA EEADR The EEPROM data memory is rated for high erase/write cycle endurance. A byte write automatically erases the location and writes the new data (erase-before-write). The write time is controlled by an on-chip timer; it will vary with voltage and temperature as well as from chipto-chip. Please refer to parameter US122 (Table 27-13 in Section 27.0 “Electrical Specifications”) for exact limits. EEADR Register The EEADR register is used to address the data EEPROM for read and write operations. The 8-bit range of the register can address a memory range of 256 bytes (00h to FFh). 5.2 EECON1 and EECON2 Registers Access to the data EEPROM is controlled by two registers: EECON1 and EECON2. These are the same registers which control access to the program memory and are used in a similar manner for the data EEPROM. 2010 Microchip Technology Inc. Control bit, CFGS, determines if the access will be to the Configuration registers or to program memory/data EEPROM memory. When the CFGS bit is set, subsequent operations access Configuration registers. When the CFGS bit is clear, the EEPGD bit selects either program Flash or data EEPROM memory. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The data EEPROM allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and the EEADR register pair hold the address of the EEPROM location being accessed. 5.1 The EECON1 register (Register 5-1) is the control register for data and program memory access. Control bit EEPGD determines if the access will be to program or data EEPROM memory. When the EEPGD bit is clear, operations will access the data EEPROM memory. When the EEPGD bit is set, program memory is accessed. The WRERR bit is set by hardware when the WR bit is set and cleared when the internal programming timer expires and the write operation is complete. Note: During normal operation, the WRERR may read as ‘1’. This can indicate that a write operation was prematurely terminated by a Reset, or a write operation was attempted improperly. The WR control bit initiates write operations. The bit can be set but not cleared by software. It is cleared only by hardware at the completion of the write operation. Note: The EEIF interrupt flag bit of the PIR2 register is set when the write is complete. It must be cleared by software. Control bits, RD and WR, start read and erase/write operations, respectively. These bits are set by firmware and cleared by hardware at the completion of the operation. The RD bit cannot be set when accessing program memory (EEPGD = 1). Program memory is read using table read instructions. See Section 4.1 “Table Reads and Table Writes” regarding table reads. The EECON2 register is not a physical register. It is used exclusively in the memory write and erase sequences. Reading EECON2 will read all ‘0’s. Preliminary DS41350D-page 61 PIC18F/LF1XK50 REGISTER 5-1: EECON1: DATA EEPROM CONTROL 1 REGISTER 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 Legend: R = Readable bit W = Writable bit S = Bit can be set by software, but not cleared U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘0’ = Bit is cleared ‘1’ = Bit is set x = Bit is unknown 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 EEPROM 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 (Block) Erase Enable bit 1 = Erase the program memory block addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write-only bit 3 WRERR: Flash Program/Data EEPROM Error Flag bit(1) 1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal operation, or an improper write attempt) 0 = The write operation completed bit 2 WREN: Flash Program/Data EEPROM Write Enable bit 1 = Allows write cycles to Flash program/data EEPROM 0 = Inhibits write cycles to Flash program/data 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) by 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 by hardware. The RD bit can only be set (not cleared) by software. RD bit cannot be set when EEPGD = 1 or CFGS = 1.) 0 = Does not initiate an EEPROM read Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition. DS41350D-page 62 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 5.3 Reading the Data EEPROM Memory To read a data memory location, the user must write the address to the EEADR register, clear the EEPGD control bit of the EECON1 register and then set control bit, RD. The data is available on 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). The basic process is shown in Example 5-1. 5.4 Writing to the Data EEPROM Memory Additionally, the WREN bit in EECON1 must be set to enable writes. This mechanism prevents accidental writes to data EEPROM due to unexpected code execution (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 EEDATA cannot be modified. The WR bit will be inhibited from being set unless the WREN bit is set. Both WR and WREN cannot be set with the same instruction. At the completion of the write cycle, the WR bit is cleared by hardware and the EEPROM Interrupt Flag bit, EEIF, is set. The user may either enable this interrupt or poll this bit. EEIF must be cleared by software. To write an EEPROM data location, the address must first be written to the EEADR register and the data written to the EEDATA register. The sequence in Example 5-2 must be followed to initiate the write cycle. 5.5 The write will not begin if this sequence is not exactly followed (write 55h to EECON2, write 0AAh to EECON2, then set WR bit) for each byte. It is strongly recommended that interrupts be disabled during this code segment. Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. EXAMPLE 5-1: MOVLW MOVWF BCF BCF BSF MOVF DATA EEPROM READ DATA_EE_ADDR EEADR EECON1, EEPGD EECON1, CFGS EECON1, RD EEDATA, W EXAMPLE 5-2: Required Sequence Write Verify ; ; ; ; ; ; Data Memory Address to read Point to DATA memory Access EEPROM EEPROM Read W = EEDATA DATA EEPROM WRITE MOVLW MOVWF MOVLW MOVWF BCF BCF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF DATA_EE_ADDR_LOW EEADR DATA_EE_DATA EEDATA EECON1, EEPGD EECON1, CFGS EECON1, WREN INTCON, GIE 55h EECON2 0AAh EECON2 EECON1, WR INTCON, GIE ; ; ; ; ; ; ; ; ; ; ; ; ; ; BCF EECON1, WREN ; User code execution ; Disable writes on write complete (EEIF set) 2010 Microchip Technology Inc. Data Memory Address to write Data Memory Value to write Point to DATA memory Access EEPROM Enable writes Disable Interrupts Write 55h Write 0AAh Set WR bit to begin write Enable Interrupts Preliminary DS41350D-page 63 PIC18F/LF1XK50 5.6 Operation During Code-Protect Data EEPROM memory has its own code-protect bits in Configuration Words. External read and write operations are disabled if code protection is 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 Section 24.0 “Special Features of the CPU” for additional information. 5.7 Protection Against Spurious Write There are conditions when the user may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been implemented. On power-up, the WREN bit is cleared. In addition, writes to the EEPROM are blocked during the Power-up Timer period (TPWRT, parameter 33). EXAMPLE 5-3: EEADR EECON1, EECON1, INTCON, EECON1, BSF MOVLW MOVWF MOVLW MOVWF BSF BTFSC BRA INCFSZ BRA EECON1, RD 55h EECON2 0AAh EECON2 EECON1, WR EECON1, WR $-2 EEADR, F LOOP BCF BSF EECON1, WREN INTCON, GIE TABLE 5-1: INTCON EEADR 5.8 Using the Data EEPROM The data EEPROM is a high-endurance, byte addressable array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that are updated often). When variables in one section change frequently, while variables in another section do not change, it is possible to exceed the total number of write cycles to the EEPROM without exceeding the total number of write cycles to a single byte. If this is the case, then an array refresh must be performed. For this reason, variables that change infrequently (such as constants, IDs, calibration, etc.) should be stored in Flash program memory. DATA EEPROM REFRESH ROUTINE CLRF BCF BCF BCF BSF ; ; ; ; ; ; ; ; ; ; ; ; ; CFGS EEPGD GIE WREN Loop Name The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch or software malfunction. Start at address 0 Set for memory Set for Data EEPROM Disable interrupts Enable writes Loop to refresh array Read current address Write 55h Write 0AAh Set WR bit to begin write Wait for write to complete ; Increment address ; Not zero, do it again ; Disable writes ; Enable interrupts REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page GIE/GIEH PEIE/GIEL TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 EEADR7 EEADR6 EEADR5 EEADR4 EEADR3 EEADR2 EEADR1 EEADR0 EEDATA EEPROM Data Register EECON2 EEPROM Control Register 2 (not a physical register) 289 289 289 EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 289 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — 290 PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — 290 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access. DS41350D-page 64 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 6.0 8 x 8 HARDWARE MULTIPLIER 6.1 Introduction EXAMPLE 6-1: MOVF MULWF All PIC18 devices include an 8 x 8 hardware multiplier as part of the ALU. The multiplier performs an unsigned operation and yields a 16-bit result that is stored in the product register pair, PRODH:PRODL. The multiplier’s operation does not affect any flags in the STATUS register. ARG1, W ARG2 ; ; ARG1 * ARG2 -> ; PRODH:PRODL EXAMPLE 6-2: Making multiplication a hardware operation allows it to be completed in a single instruction cycle. This has the advantages of higher computational throughput and reduced code size for multiplication algorithms and allows the PIC18 devices to be used in many applications previously reserved for digital signal processors. A comparison of various hardware and software multiply operations, along with the savings in memory and execution time, is shown in Table 6-1. 6.2 8 x 8 UNSIGNED MULTIPLY ROUTINE 8 x 8 SIGNED MULTIPLY ROUTINE MOVF MULWF ARG1, W ARG2 BTFSC SUBWF ARG2, SB PRODH, F MOVF BTFSC SUBWF ARG2, W ARG1, SB PRODH, F ; ; ; ; ; ARG1 * ARG2 -> PRODH:PRODL Test Sign Bit PRODH = PRODH - ARG1 ; Test Sign Bit ; PRODH = PRODH ; - ARG2 Operation Example 6-1 shows the instruction sequence for an 8 x 8 unsigned multiplication. Only one instruction is required when one of the arguments is already loaded in the WREG register. Example 6-2 shows the sequence to do an 8 x 8 signed multiplication. To account for the sign bits of the arguments, each argument’s Most Significant bit (MSb) is tested and the appropriate subtractions are done. TABLE 6-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS Routine 8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed Multiply Method Program Memory (Words) Cycles (Max) Without hardware multiply 13 Hardware multiply 1 Without hardware multiply 33 Hardware multiply 6 Without hardware multiply Hardware multiply Time @ 40 MHz @ 10 MHz @ 4 MHz 69 6.9 s 27.6 s 69 s 1 100 ns 400 ns 1 s 91 9.1 s 36.4 s 91 s 6 600 ns 2.4 s 6 s 21 242 24.2 s 96.8 s 242 s 28 28 2.8 s 11.2 s 28 s Without hardware multiply 52 254 25.4 s 102.6 s 254 s Hardware multiply 35 40 4.0 s 16.0 s 40 s 2010 Microchip Technology Inc. Preliminary DS41350D-page 65 PIC18F/LF1XK50 Example 6-3 shows the sequence to do a 16 x 16 unsigned multiplication. Equation 6-1 shows the algorithm that is used. The 32-bit result is stored in four registers (RES<3:0>). EQUATION 6-1: RES3:RES0 = = EXAMPLE 6-3: 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM ARG1H:ARG1L ARG2H:ARG2L (ARG1H ARG2H 216) + (ARG1H ARG2L 28) + (ARG1L ARG2H 28) + (ARG1L ARG2L) EQUATION 6-2: RES3:RES0 = ARG1H:ARG1L ARG2H:ARG2L = (ARG1H ARG2H 216) + (ARG1H ARG2L 28) + (ARG1L ARG2H 28) + (ARG1L ARG2L) + (-1 ARG2H<7> ARG1H:ARG1L 216) + (-1 ARG1H<7> ARG2H:ARG2L 216) EXAMPLE 6-4: 16 x 16 UNSIGNED MULTIPLY ROUTINE MOVF MULWF ARG1L, W ARG2L MOVFF MOVFF PRODH, RES1 PRODL, RES0 MOVF MULWF ARG1H, W ARG2H MOVFF MOVFF PRODH, RES3 PRODL, RES2 MOVF MULWF ARG1L, W ARG2H MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F MOVF MULWF ARG1H, W ARG2L MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F ; ARG1L * ARG2L-> ; PRODH:PRODL ; ; ARG1L * ARG2H-> PRODH:PRODL Add cross products ARG1H * ARG2L-> PRODH:PRODL Add cross products MOVFF MOVFF PRODH, RES1 PRODL, RES0 MOVF MULWF ARG1H, W ARG2H MOVFF MOVFF PRODH, RES3 PRODL, RES2 MOVF MULWF ARG1L, W ARG2H MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F MOVF MULWF ARG1H, W ARG2L MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F BTFSS BRA MOVF SUBWF MOVF SUBWFB ARG2H, 7 SIGN_ARG1 ARG1L, W RES2 ARG1H, W RES3 ; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ; ARG1H, 7 CONT_CODE ARG2L, W RES2 ARG2H, W RES3 ; ARG1H:ARG1L neg? ; no, done ; ; ; ; ARG1L * ARG2L -> ; PRODH:PRODL ; ; ; ARG1H * ARG2H -> ; PRODH:PRODL ; ; ; ; ; ; ; ; ; ; ARG1L * ARG2H -> PRODH:PRODL Add cross products ; ; ; ; ; ; ; ; ; ARG1H * ARG2L -> PRODH:PRODL Add cross products ; Example 6-4 shows the sequence to do a 16 x 16 signed multiply. Equation 6-2 shows the algorithm used. The 32-bit result is stored in four registers (RES<3:0>). To account for the sign bits of the arguments, the MSb for each argument pair is tested and the appropriate subtractions are done. DS41350D-page 66 ARG1L, W ARG2L ; ; ; ; ; ; ; ; ; ; ; MOVF MULWF ; ; ; ; ; ; ; ; ; ; 16 x 16 SIGNED MULTIPLY ROUTINE ; ; ; ARG1H * ARG2H-> ; PRODH:PRODL ; ; 16 x 16 SIGNED MULTIPLICATION ALGORITHM ; SIGN_ARG1 BTFSS BRA MOVF SUBWF MOVF SUBWFB ; CONT_CODE : Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 7.0 INTERRUPTS 7.2 The PIC18F/LF1XK50 devices have multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned a high priority level or a low priority level. The high priority interrupt vector is at 0008h and the low priority interrupt vector is at 0018h. A high priority interrupt event will interrupt a low priority interrupt 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 supplied 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. In general, interrupt sources have three bits to control their operation. They 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 7.1 Mid-Range Compatibility When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PIC® microcontroller mid-range devices. In Compatibility mode, the interrupt priority bits of the IPRx registers have no effect. The PEIE bit of the INTCON register is the global interrupt enable for the peripherals. The PEIE bit disables only the peripheral interrupt sources and enables the peripheral interrupt sources when the GIE bit is also set. The GIE bit of the INTCON register is the global interrupt enable which enables all non-peripheral interrupt sources and disables all interrupt sources, including the peripherals. All interrupts branch to address 0008h in Compatibility mode. The interrupt priority feature is enabled by setting the IPEN bit of the RCON register. When interrupt priority is enabled the GIE and PEIE global interrupt enable bits of Compatibility mode are replaced by the GIEH high priority, and GIEL low priority, global interrupt enables. When set, the GIEH bit of the INTCON register enables all interrupts that have their associated IPRx register or INTCONx register priority bit set (high priority). When clear, the GIEL bit disables all interrupt sources including those selected as low priority. When clear, the GIEL bit of the INTCON register disables only the interrupts that have their associated priority bit cleared (low priority). When set, the GIEL bit enables the low priority sources when the GIEH bit is also set. When the interrupt flag, enable bit and appropriate global interrupt enable bit are all set, the interrupt will vector immediately to address 0008h for high priority, or 0018h for low priority, depending on level of the interrupting source’s priority bit. Individual interrupts can be disabled through their corresponding interrupt enable bits. 7.3 Interrupt Response When an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. The GIE bit is the global interrupt enable when the IPEN bit is cleared. When the IPEN bit is set, enabling interrupt priority levels, the GIEH bit is the high priority global interrupt enable and the GIEL bit is the low priority global interrupt enable. High priority interrupt sources can interrupt a low priority interrupt. Low priority interrupts are not processed while high priority interrupts are in progress. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (0008h or 0018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits in the INTCONx and PIRx registers. The interrupt flag bits must be cleared by software before re-enabling interrupts to avoid repeating the same interrupt. 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 interrupt-on-change, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one-cycle or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bits or the global interrupt enable bit. Note: 2010 Microchip Technology Inc. Interrupt Priority Preliminary 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. DS41350D-page 67 PIC18F/LF1XK50 FIGURE 7-1: PIC18 INTERRUPT LOGIC TMR0IF TMR0IE TMR0IP RABIF RABIE RABIP INT0IF INT0IE Wake-up if in Idle or Sleep modes (1) Interrupt to CPU Vector to Location 0008h INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP SSPIF SSPIE SSPIP GIEH/GIE ADIF ADIE ADIP IPEN IPEN GIEL/PEIE RCIF RCIE RCIP IPEN Additional Peripheral Interrupts High Priority Interrupt Generation Low Priority Interrupt Generation SSPIF SSPIE SSPIP ADIF ADIE ADIP RCIF RCIE RCIP Interrupt to CPU Vector to Location 0018h TMR0IF TMR0IE TMR0IP RABIF RABIE RABIP (1) GIEH/GIE GIEL/PEIE INT1IF INT1IE INT1IP Additional Peripheral Interrupts INT2IF INT2IE INT2IP Note 1: The RABIF interrupt also requires the individual pin IOCA and IOCB enable. DS41350D-page 68 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 7.4 INTCON Registers Note: The INTCON registers are readable and writable registers, which contain various enable, priority and flag bits. REGISTER 7-1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. INTCON: INTERRUPT CONTROL REGISTER 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 RABIE TMR0IF INT0IF RABIF bit 7 bit 0 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 bit 7 GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts including peripherals When IPEN = 1: 1 = Enables all high priority interrupts 0 = Disables all interrupts including low priority. 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 interrupts 0 = Disables all low priority 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 RABIE: RA and RB Port Change Interrupt Enable bit(2) 1 = Enables the RA and RB port change interrupt 0 = Disables the RA and RB port change interrupt bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared by software) 0 = TMR0 register did not overflow bit 1 INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared by software) 0 = The INT0 external interrupt did not occur bit 0 RABIF: RA and RB Port Change Interrupt Flag bit(1) 1 = At least one of the RA <5:3> or RB<7:4> pins changed state (must be cleared by software) 0 = None of the RA<5:3> or RB<7:4> pins have changed state Note 1: 2: A mismatch condition will continue to set the RABIF bit. Reading PORTA and PORTB will end the mismatch condition and allow the bit to be cleared. RA and RB port change interrupts also require the individual pin IOCA and IOCB enable. 2010 Microchip Technology Inc. Preliminary DS41350D-page 69 PIC18F/LF1XK50 REGISTER 7-2: INTCON2: INTERRUPT CONTROL 2 REGISTER R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 U-0 R/W-1 RABPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RABIP bit 7 bit 0 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 bit 7 RABPU: PORTA and PORTB Pull-up Enable bit 1 = All PORTA and PORTB pull-ups are disabled 0 = PORTA and PORTB pull-ups are enabled provided that the pin is an input and the corresponding WPUA and WPUB bits are set. bit 6 INTEDG0: External Interrupt 0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 5 INTEDG1: External Interrupt 1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 4 INTEDG2: External Interrupt 2 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 RABIP: RA and RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority 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. DS41350D-page 70 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 7-3: INTCON3: INTERRUPT CONTROL 3 REGISTER 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 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 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 by 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 by software) 0 = The INT1 external interrupt did not occur Note: x = Bit is unknown 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 71 PIC18F/LF1XK50 7.5 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 Request Flag registers (PIR1 and 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 Interrupt Enable bit, GIE of the INTCON register. 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt. REGISTER 7-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1 U-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared by software) 0 = The A/D conversion is not complete or has not been started bit 5 RCIF: EUSART Receive Interrupt Flag bit 1 = The EUSART receive buffer, RCREG, is full (cleared when RCREG is read) 0 = The EUSART receive buffer is empty bit 4 TXIF: EUSART Transmit Interrupt Flag bit 1 = The EUSART transmit buffer, TXREG, is empty (cleared when TXREG is written) 0 = The EUSART transmit buffer is full bit 3 SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared by software) 0 = Waiting to transmit/receive bit 2 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared by software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared by 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 by software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared by software) 0 = TMR1 register did not overflow DS41350D-page 72 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 7-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — bit 7 bit 0 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 bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit 1 = Device oscillator failed, clock input has changed to HFINTOSC (must be cleared by software) 0 = Device clock operating bit 6 C1IF: Comparator C1 Interrupt Flag bit 1 = Comparator C1 output has changed (must be cleared by software) 0 = Comparator C1 output has not changed bit 5 C2IF: Comparator C2 Interrupt Flag bit 1 = Comparator C2 output has changed (must be cleared by software) 0 = Comparator C2 output has not changed bit 4 EEIF: Data EEPROM/Flash Write Operation Interrupt Flag bit 1 = The write operation is complete (must be cleared by 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 by software) 0 = No bus collision occurred bit 2 USBIF: USB Interrupt Flag bit 1 = USB has requested an interrupt (must be cleared in software) 0 = No USB interrupt request bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared by software) 0 = TMR3 register did not overflow bit 0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary DS41350D-page 73 PIC18F/LF1XK50 7.6 PIE Registers The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable registers (PIE1 and PIE2). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts. REGISTER 7-6: PIE1: PERIPHERAL INTERRUPT ENABLE (FLAG) REGISTER 1 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt bit 5 RCIE: EUSART Receive Interrupt Enable bit 1 = Enables the EUSART receive interrupt 0 = Disables the EUSART receive interrupt bit 4 TXIE: EUSART Transmit Interrupt Enable bit 1 = Enables the EUSART transmit interrupt 0 = Disables the EUSART 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 DS41350D-page 74 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 7-7: PIE2: PERIPHERAL INTERRUPT ENABLE (FLAG) REGISTER 2 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — bit 7 bit 0 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 bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit 1 = Enabled 0 = Disabled bit 6 C1IE: Comparator C1 Interrupt Enable bit 1 = Enabled 0 = Disabled bit 5 C2IE: Comparator C2 Interrupt Enable bit 1 = Enabled 0 = Disabled 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 USBIE: USB Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enabled 0 = Disabled bit 0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 75 PIC18F/LF1XK50 7.7 IPR Registers The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority registers (IPR1 and IPR2). Using the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set. REGISTER 7-8: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6 ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 RCIP: EUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority bit 4 TXIP: EUSART Transmit Interrupt Priority bit x = Bit is unknown 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 DS41350D-page 76 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 7-9: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 U-0 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — bit 7 bit 0 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 bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 C1IP: Comparator C1 Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 C2IP: Comparator C2 Interrupt Priority bit 1 = High priority 0 = Low priority 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 USBIP: USB 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 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 77 PIC18F/LF1XK50 7.8 RCON Register The RCON register contains flag bits which are used to determine the cause of the last Reset or wake-up from Idle or Sleep modes. RCON also contains the IPEN bit which enables interrupt priorities. The operation of the SBOREN bit and the Reset flag bits is discussed in more detail in Section 23.1 “RCON Register”. REGISTER 7-10: R/W-0 IPEN RCON: RESET CONTROL REGISTER R/W-1 SBOREN U-0 (1) — R/W-1 RI R-1 TO R-1 R/W-0 PD (2) R/W-0 POR bit 7 BOR bit 0 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 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6 SBOREN: BOR Software Enable bit(1) If BOREN<1:0> = 01: 1 = BOR is enabled 0 = BOR is disabled If BOREN<1:0> = 00, 10 or 11: Bit is disabled and read as ‘0’. bit 5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware or Power-on Reset) 0 = The RESET instruction was executed causing a device Reset (must be set in firmware after a code-executed Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Set by execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit(2) 1 = No Power-on Reset 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(3) 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set by firmware after a POR or Brown-out Reset occurs) Note 1: 2: 3: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’. The actual Reset value of POR is determined by the type of device Reset. See the notes following this register and Section 23.6 “Reset State of Registers” for additional information. See Table 23-3. DS41350D-page 78 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 7.9 INTn Pin Interrupts 7.10 TMR0 Interrupt External interrupts on the RC0/INT0, RC1/INT1 and RC2/INT2 pins are edge-triggered. If the corresponding INTEDGx bit in the INTCON2 register is set (= 1), the interrupt is triggered by a rising edge; if the bit is clear, the trigger is on the falling edge. When a valid edge appears on the RCx/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 by software in the Interrupt Service Routine before re-enabling the interrupt. In 8-bit mode (which is the default), an overflow in the TMR0 register (FFh 00h) will set flag bit, TMR0IF. In 16-bit mode, an overflow in the TMR0H:TMR0L register pair (FFFFh 0000h) will set TMR0IF. The interrupt can be enabled/disabled by setting/clearing enable bit, TMR0IE of the INTCON register. Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit, TMR0IP of the INTCON2 register. See Section 10.0 “Timer0 Module” for further details on the Timer0 module. All external interrupts (INT0, INT1 and INT2) can wakeup the processor from Idle or Sleep modes if bit INTxE was set prior to going into those modes. If the Global Interrupt Enable bit, GIE, is set, the processor will branch to the interrupt vector following wake-up. 7.11 Interrupt priority for INT1 and INT2 is determined by the value contained in the interrupt priority bits, INT1IP and INT2IP of the INTCON3 register. There is no priority bit associated with INT0. It is always a high priority interrupt source. PORTA and PORTB Interrupt-onChange An input change on PORTA or PORTB sets flag bit, RABIF of the INTCON register. The interrupt can be enabled/disabled by setting/clearing enable bit, RABIE of the INTCON register. Pins must also be individually enabled with the IOCA and IOCB register. Interrupt priority for PORTA and PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RABIP of the INTCON2 register. 7.12 Context Saving During Interrupts During interrupts, the return PC address is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the fast return stack. If a fast return from interrupt is not used (see Section 3.3 “Data Memory Organization”), the user may need to save the WREG, STATUS and BSR registers on entry to the Interrupt Service Routine. Depending on the user’s application, other registers may also need to be saved. Example 7-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine. EXAMPLE 7-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM MOVWF W_TEMP MOVFF STATUS, STATUS_TEMP MOVFF BSR, BSR_TEMP ; ; USER ISR CODE ; MOVFF BSR_TEMP, BSR MOVF W_TEMP, W MOVFF STATUS_TEMP, STATUS 2010 Microchip Technology Inc. ; W_TEMP is in virtual bank ; STATUS_TEMP located anywhere ; BSR_TMEP located anywhere ; Restore BSR ; Restore WREG ; Restore STATUS Preliminary DS41350D-page 79 PIC18F/LF1XK50 NOTES: DS41350D-page 80 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 8.0 LOW DROPOUT (LDO) VOLTAGE REGULATOR The PIC18F1XK50 devices differ from the PIC18LF1XK50 devices due to an internal Low Dropout (LDO) voltage regulator. The PIC18F1XK50 contain an internal LDO, while the PIC18LF1XK50 do not. The lithography of the die allows a maximum operating voltage of the nominal 3.6V on the internal digital logic. In order to continue to support 5.0V designs, a LDO voltage regulator is integrated on the die. The LDO voltage regulator allows for the internal digital logic to operate at 3.3V, while I/O’s operate at 5.0V (VDD). The LDO voltage regulator requires an external bypass capacitor for stability. The VUSB pin is required to have an external bypass capacitor. It is recommended that the capacitor be a ceramic cap between 0.22 to 0.47 µF. On power-up, the external capacitor will look like a large load on the LDO voltage regulator. To prevent erroneous operation, the device is held in Reset while a constant current source charges the external capacitor. After the cap is fully charged, the device is released from Reset. For more information, refer to Section 27.0 “Electrical Specifications”. 2010 Microchip Technology Inc. Preliminary DS41350D-page 81 PIC18F/LF1XK50 NOTES: DS41350D-page 82 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 9.0 I/O PORTS 9.1 There are up to 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 PORTA Data Latch (LATA register) is useful for read-modify-write operations on the value that the I/O pins are driving. A simplified model of a generic I/O port, without the interfaces to other peripherals, is shown in Figure 9-1. FIGURE 9-1: GENERIC I/O PORT OPERATION WR LAT or Port D Q I/O pin(1) CK Data Latch D WR TRIS PORTA is 5 bits wide. PORTA<5:4> bits are bidirectional ports and PORTA<3,1:0> bits are inputonly ports. The corresponding data direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., disable the output driver). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., enable the output driver and 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 PORTA Data Latch (LATA) register is also memory mapped. Read-modify-write operations on the LATA register read and write the latched output value for PORTA. All of the PORTA pins are individually configurable as interrupt-on-change pins. Control bits in the IOCA register enable (when set) or disable (when clear) the interrupt function for each pin. When set, the RABIE bit of the INTCON register enables interrupts on all pins which also have their corresponding IOCA bit set. When clear, the RABIE bit disables all interrupt-on-changes. RD LAT Data Bus Q CK TRIS Latch Input Buffer RD TRIS Q D Only pins configured as inputs can cause this interrupt to occur (i.e., any pin configured as an output is excluded from the interrupt-on-change comparison). For enabled interrupt-on-change pins, the values are compared with the old value latched on the last read of PORTA. The ‘mismatch’ outputs of the last read are OR’d together to set the PORTA Change Interrupt flag bit (RABIF) in the INTCON register. This interrupt can wake the device from the Sleep mode, or any of the Idle modes. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) ENEN RD Port b) Note 1: I/O pins have diode protection to VDD and VSS. 2010 Microchip Technology Inc. PORTA, TRISA and LATA Registers Any read or write of PORTA to clear the mismatch condition (except when PORTA is the source or destination of a MOVFF instruction). Clear the flag bit, RABIF. A mismatch condition will continue to set the RABIF flag bit. Reading or writing PORTA will end the mismatch condition and allow the RABIF bit to be cleared. The latch holding the last read value is not affected by a MCLR nor Brown-out Reset. After either one of these Resets, the RABIF flag will continue to be set if a mismatch is present. Preliminary DS41350D-page 83 PIC18F/LF1XK50 Note 1: If a change on the I/O pin should occur when the read operation is being executed (start of the Q2 cycle), then the RABIF interrupt flag may not get set. Furthermore, since a read or write on a port affects all bits of that port, care must be taken when using multiple pins in Interrupt-on-change mode. Changes on one pin may not be seen while servicing changes on another pin. 2: When configured for USB operation, interrupt-on-change functionality on RA0 and RA1 is automatically disabled. 3: In order for the digital inputs to function on the RA<1:0> port pins, the interrupt-onchange pins must be enabled (IOCA <1:0> = 11) and the USB module must be disabled (USBEN = 0). The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTA is only used for the interrupt-on-change feature. Polling of PORTA is not recommended while using the interrupt-on-change feature. Pins RA4 and RA5 are multiplexed with the main oscillator pins; they are enabled as oscillator or I/O pins by the selection of the main oscillator in the Configuration register (see Section 24.1 “Configuration Bits” for details). When they are not used as port pins, RA4 and RA5 and their associated TRIS and LAT bits read as ‘0’. Pin RA4 is multiplexed with an analog input. The operation of pin RA4 as analog is selected by setting the ANS3 bit in the ANSEL register which is the default setting after a Power-on Reset. Note: On a Power-on Reset, RA4 is configured as analog inputs and read as ‘0’. EXAMPLE 9-1: CLRF PORTA CLRF LATA MOVLW 030h MOVWF TRISA INITIALIZING PORTA ; ; ; ; ; ; ; ; ; ; Initialize PORTA by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RA<5:4> as output Each of the PORTA pins has an individually controlled weak internal pull-up. When set, each bit of the WPUA register enables the corresponding pin pull-up. When cleared, the RABPU bit of the INTCON2 register enables pull-ups on all pins which also have their corresponding WPUA bit set. When set, the RABPU bit disables all weak pull-ups. 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. Note: On a Power-on Reset, RA4 is configured as analog inputs by default and read as ‘0’; RA<1:0> and RA<5:3> are configured as digital inputs. RA0 and RA1 are multiplexed with the USB module and can serve as the differential data lines for the onchip USB transceiver. RA0 and RA1 do not have TRISA bits associated with them. As digital port pins, they can only function as digital inputs. When configured for USB operation, the data direction is determined by the configuration and status of the USB module at a given time. RA3 is an input only pin. Its operation is controlled by the MCLRE bit of the CONFIG3H register. When selected as a port pin (MCLRE = 0), it functions as a digital input only pin; as such, it does not have TRIS or LAT bits associated with its operation. Note: On a Power-on Reset, RA3 is enabled as a digital input only if Master Clear functionality is disabled. DS41350D-page 84 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 9-1: PORTA: PORTA REGISTER U-0 U-0 R/W-x R/W-x R-x U-0 R/W-x R/W-x — — RA5 RA4 RA3 — RA1 RA0 bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-3 RA<5:3>: PORTA I/O Pin bit(1) 1 = Port pin is > VIH 0 = Port pin is < VIL bit 2 Unimplemented: Read as ‘0’ bit 1-0 RA<1:0>: PORTA I/O Pin bit 1 = Port pin is > VIH 0 = Port pin is < VIL Note 1: x = Bit is unknown The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is read-only. REGISTER 9-2: TRISA: PORTA TRI-STATE REGISTER U-0 U-0 R/W-1 R/W-1 U-0 U-0 U-0 U-0 — — TRISA5 TRISA4 — — — — bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-4 TRISA<5:4>: PORTA Tri-State Control bit 1 = PORTA pin configured as an input (tri-stated) 0 = PORTA pin configured as an output bit 3-0 Unimplemented: Read as ‘0’ Note 1: x = Bit is unknown TRISA<5:4> always reads ‘1’ in XT, HS and LP Oscillator modes. 2010 Microchip Technology Inc. Preliminary DS41350D-page 85 PIC18F/LF1XK50 REGISTER 9-3: WPUA: WEAK PULL-UP PORTA REGISTER U-0 U-0 R/W-1 R/W-1 RW-1 U-0 U-0 U-0 — — WPUA5 WPUA4 WPUA3 — — — bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-3 WPUA<5:3>: Weak Pull-up Enable bit 1 = Pull-up enabled 0 = Pull-up disabled bit 2 Unimplemented: Read as ‘0’ bit 1-0 WPUA<1:0>: Weak Pull-up Enable bit 1 = Pull-up enabled 0 = Pull-up disabled REGISTER 9-4: x = Bit is unknown IOCA: INTERRUPT-ON-CHANGE PORTA REGISTER U-0 U-0 R/W-0 R/W-0 R-0 U-0 R/W-0 R/W-0 — — IOCA5 IOCA4 IOCA3 — IOCA1 IOCA0 bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-3 IOCA<5:3>: PORTA I/O Pin bit 1 = Interrupt-on-change enabled 0 = Interrupt-on-change disabled bit 2 Unimplemented: Read as ‘0’ bit 1-0 IOCA<1:0>: PORTA I/O Pin bit 1 = Interrupt-on-change enabled 0 = Interrupt-on-change disabled REGISTER 9-5: x = Bit is unknown LATA: PORTA DATA LATCH REGISTER U-0 U-0 R/W-x R/W-x U-0 U-0 U-0 U-0 — — LATA5 LATA4 — — — — bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-4 LATA<5:4>: RA<5:4> Port I/O Output Latch Register bits bit 3-0 Unimplemented: Read as ‘0’ DS41350D-page 86 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 9-1: Pin RA0/IOCA0/D+/ PGD PORTA I/O SUMMARY Function TRIS Setting I/O I/O Type RA0 —(1) I TTL PORTA<0> data input; disabled when USB enabled. (1) I TTL Interrupt-on-pin change; disabled when USB enabled. —(1) I XCVR USB bus differential plus line input (internal transceiver). —(1) O XCVR USB bus differential plus line output (internal transceiver). (1) O IOCA0 D+ PGD RA1/IOCA1/D-/ PGC RA1 IOCA1 RA5/IOCA5/OSC1/ CLKIN Legend: —(1) (1) —(1) — (1) DIG Serial execution data output for ICSP™. I ST Serial execution data input for ICSP™. I TTL PORTA<1> data input; disabled when USB enabled. I TTL Interrupt-on-pin change; disabled when USB enabled. I XCVR USB bus differential minus line input (internal transceiver). O XCVR USB bus differential minus line output (internal transceiver). —(1) O DIG Serial execution clock output for ICSP™. —(1) I ST Serial execution clock input for ICSP™. (2) I ST PORTA<3> data input; enabled when MCLRE Configuration bit is clear; Programmable weak pull-up. IOCA3 —(1) I TTL Interrupt-on-pin change MCLR — I ST External Master Clear input; enabled when MCLRE Configuration bit is set. VPP — I ANA High-voltage detection; used for ICSP™ mode entry detection. Always available, regardless of pin mode. RA4 0 O DIG LATA<4> data output. Enabled in RCIO, INTIO2 and ECIO modes only. 1 I TTL PORTA<4> data input; Programmable weak pull-up. Enabled in RCIO, INTIO2 and ECIO modes only. IOCA4 1 I TTL Interrupt-on-pin change AN3 1 I ANA A/D input channel 3. Default configuration on POR. OSC2 x O ANA Main oscillator feedback output connection (XT, HS and LP modes). CLKOUT x O DIG System cycle clock output (FOSC/4) in RC, INTIO1 and EC Oscillator modes. RA5 0 O DIG LATA<5> data output. Disabled in external oscillator modes. 1 I TTL PORTA<5> data input. Disabled in external oscillator modes; Programmable weak pull-up. IOCA5 1 I TTL Interrupt-on-pin change OSC1 x I ANA Main oscillator input connection. CLKIN x I ANA Main clock input connection. PGC RA4/IOCA4/AN3/ OSC2/CLKOUT — —(1) D- RA3/IOCA3/MCLR/ VPP — Description RA3 — — DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). Note 1: 2: RA0 and RA1 do not have corresponding TRISA bits. In Port mode, these pins are input only. USB data direction is determined by the USB configuration. RA3 does not have a corresponding TRISA bit. This pin is always an input regardless of mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 87 PIC18F/LF1XK50 TABLE 9-2: Name SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Reset Values on page Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PORTA — — RA5(1) RA4(1) RA3(2) — RA1(3) RA0(3) 290 LATA — — LATA5(1) LATA4(1) — — — — 290 TRISA — — TRISA5(1) TRISA4(1) — — — — 290 ANSEL ANS7 ANS6 ANS5 ANS4 ANS3 — — — 290 — — — — — SLRC SLRB SLRA SLRCON (2) IOCA — — IOCA5 IOCA4 WPUA — — WPUA5 WPUA4 UCON — PPBRST SE0 PKTDIS USBEN TMR0IE INT0IE RABIE TMR0IF — TMR0IP INTCON INTCON2 GIE/GIEH PEIE/GIEL RABPU INTEDG0 INTEDG1 INTEDG2 IOCA3 (2) WPUA3 — — (3) IOCA1 — (3) IOCA0 290 290 — 290 — 290 INT0IF RABIF 287 — RABIP 287 RESUME SUSPND Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA. Note 1: RA<5:4> and their associated latch and data direction bits are enabled as I/O pins based on oscillator configuration; otherwise, they are read as ‘0’. 2: Implemented only when Master Clear functionality is disabled (MCLRE Configuration bit = 0). 3: RA1 and RA0 are only available as port pins when the USB module is disabled (UCON<3> = 0). DS41350D-page 88 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 9.2 PORTB, TRISB and LATB Registers holding the last read value is not affected by a MCLR nor Brown-out Reset. After either one of these Resets, the RABIF flag will continue to be set if a mismatch is present. PORTB is an 4-bit wide, bidirectional port. The corresponding data direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., disable the output driver). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). The PORTB Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register read and write the latched output value for PORTB. EXAMPLE 9-2: CLRF PORTB CLRF LATB MOVLW 0F0h MOVWF TRISB INITIALIZING PORTB ; ; ; ; ; ; ; ; ; ; Initialize PORTB by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RB<7:4> as outputs All PORTB pins are individually configurable as interrupt-on-change pins. Control bits in the IOCB register enable (when set) or disable (when clear) the interrupt function for each pin. Note: If a change on the I/O pin should occur when the read operation is being executed (start of the Q2 cycle), then the RABIF interrupt flag may not get set. Furthermore, since a read or write on a port affects all bits of that port, care must be taken when using multiple pins in Interrupt-on-change mode. Changes on one pin may not be seen while servicing changes on another pin. 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. All PORTB pins have individually controlled weak internal pull-up. When set, each bit of the WPUB register enables the corresponding pin pull-up. When cleared, the RABPU bit of the INTCON2 register enables pullups on all pins which also have their corresponding WPUB bit set. When set, the RABPU bit disables all weak pull-ups. 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. Note: On a Power-on Reset, RB<5:4> are configured as analog inputs by default and read as ‘0’. When set, the RABIE bit of the INTCON register enables interrupts on all pins which also have their corresponding IOCB bit set. When clear, the RABIE bit disables all interrupt-on-changes. Only pins configured as inputs can cause this interrupt to occur (i.e., any pin configured as an output is excluded from the interrupt-on-change comparison). For enabled interrupt-on-change pins, the values are compared with the old value latched on the last read of PORTB. The ‘mismatch’ outputs of the last read are OR’d together to set the PORTB Change Interrupt flag bit (RABIF) in the INTCON register. This interrupt can wake the device from the Sleep mode, or any of the Idle modes. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) b) Any read or write of PORTB to clear the mismatch condition (except when PORTB is the source or destination of a MOVFF instruction). Clear the flag bit, RABIF. A mismatch condition will continue to set the RABIF flag bit. Reading or writing PORTB will end the mismatch condition and allow the RABIF bit to be cleared. The latch 2010 Microchip Technology Inc. Preliminary DS41350D-page 89 PIC18F/LF1XK50 REGISTER 9-6: PORTB: PORTB REGISTER R/W-x R/W-x R/W-x R/W-x U-0 U-0 U-0 U-0 RB7 RB6 RB5 RB4 — — — — bit 7 bit 0 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 bit 7-4 RB<7:4>: PORTB I/O Pin bit 1 = Port pin is >VIH 0 = Port pin is <VIL bit 3-0 Unimplemented: Read as ‘0’ REGISTER 9-7: x = Bit is unknown TRISB: PORTB TRI-STATE REGISTER R/W-1 R/W-1 R/W-1 R/W-1 U-0 U-0 U-0 U-0 TRISB7 TRISB6 TRISB5 TRISB4 — — — — bit 7 bit 0 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 bit 7-4 TRISB<7:4>: PORTB Tri-State Control bit 1 = PORTB pin configured as an input (tri-stated) 0 = PORTB pin configured as an output bit 3-0 Unimplemented: Read as ‘0’ DS41350D-page 90 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 9-8: WPUB: WEAK PULL-UP PORTB REGISTER R/W-1 R/W-1 R/W-1 R/W-1 U-0 U-0 U-0 U-0 WPUB7 WPUB6 WPUB5 WPUB4 — — — — bit 7 bit 0 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 bit 7-4 WPUB<7:4>: Weak Pull-up Enable bit 1 = Pull-up enabled 0 = Pull-up disabled bit 3-0 Unimplemented: Read as ‘0’ REGISTER 9-9: x = Bit is unknown IOCB: INTERRUPT-ON-CHANGE PORTB REGISTER R/W-0 R/W-0 R/W-0 R/W-0 U-0 U-0 U-0 U-0 IOCB7 IOCB6 IOCB5 IOCB4 — — — — bit 7 bit 0 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 bit 7-4 IOCB<7:4>: Interrupt-on-change bits 1 = Interrupt-on-change enabled 0 = Interrupt-on-change disabled bit 3-0 Unimplemented: Read as ‘0’ REGISTER 9-10: x = Bit is unknown LATB: PORTB DATA LATCH REGISTER R/W-x R/W-x R/W-x R/W-x U-0 U-0 U-0 U-0 LATB7 LATB6 LATB5 LATB4 — — — — bit 7 bit 0 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 bit 7-4 LATB<7:4>: RB<7:4> Port I/O Output Latch Register bits bit 3-0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 91 PIC18F/LF1XK50 TABLE 9-3: PORTB I/O SUMMARY Pin Function TRIS Setting I/O I/O Type RB4/IOCB4/AN10/ SDI/SDA RB4 0 O DIG LATB<4> data output; not affected by analog input. PORTB<4> data input; Programmable weak pull-up. RB5/IOCB5/AN11/ RX/DT RB6/IOCB6/SCK/ SCL 1 I TTL IOCB4 1 I TTL Interrupt-on-pin change. AN10 1 I ANA ADC input channel 10. SDI 1 I ST SPI data input (MSSP module). SDA 1 I DIG I2C™ data output (MSSP module); takes priority over port data. 1 O I2C I2C™ data input (MSSP module); input type depends on module setting. 0 O DIG LATB<5> data output. 1 I TTL PORTB<5> data input; Programmable weak pull-up. IOCB5 1 I TTL Interrupt-on-pin change. AN11 1 I ANA ADC input channel 11. RX 1 I ST Asynchronous serial receive data input (USART module). DT 1 O DIG Synchronous serial data output (USART module); takes priority over port data. 1 I ST Synchronous serial data input (USART module). User must configure as an input. 0 O DIG LATB<6> data output. PORTB<6> data input; Programmable weak pull-up. RB5 RB6 1 I TTL IOCB6 1 I TTL Interrupt-on-pin change. SCK 0 O DIG SPI clock output (MSSP module); takes priority over port data. 1 I ST SPI clock input (MSSP module). 0 O DIG I2C™ clock output (MSSP module); takes priority over port data. 1 I I2C I2C™ clock input (MSSP module); input type depends on module setting. 0 O DIG LATB<7> data output. 1 I TTL PORTB<7> data input; Programmable weak pull-up. IOCB7 1 I TTL Interrupt-on-pin change. TX 1 O DIG Asynchronous serial transmit data output (USART module); takes priority over port data. User must configure as output. CK 1 O DIG Synchronous serial clock output (USART module); takes priority over port data. 1 I ST Synchronous serial clock input (USART module). SCL RB7/IOCB7/TX/CK Legend: Description RB7 DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). DS41350D-page 92 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 9-4: Name PORTB LATB SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RB7 RB6 RB5 RB4 — — — — 290 LATB7 LATB6 LATB5 LATB4 — — — — 290 TRISB TRISB7 TRISB6 TRISB5 TRISB4 — — — — 290 WPUB WPUB7 WPUB6 WPUB5 WPUB4 — — — — 290 IOCB IOCB7 IOCB6 IOCB5 IOCB4 — — — — — SLRC SLRB SLRA TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 — TMR0IP — RABIP 287 ANS11 ANS10 ANS9 ANS8 290 SLRCON INTCON GIE/GIEH PEIE/GIEL INTCON2 RABPU ANSELH — INTEDG0 INTEDG1 INTEDG2 — — — 290 290 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 288 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTB. 2010 Microchip Technology Inc. Preliminary DS41350D-page 93 PIC18F/LF1XK50 9.3 PORTC, TRISC and LATC Registers All the pins on PORTC are implemented with Schmitt Trigger input buffer. Each pin is individually configurable as an input or output. PORTC is an 8-bit wide, bidirectional port. The corresponding data direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., disable the output driver). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). The PORTC Data Latch register (LATC) is also memory mapped. Read-modify-write operations on the LATC register read and write the latched output value for PORTC. REGISTER 9-11: Note: On a Power-on Reset, RC<7:6> and RC<3:0> are configured as analog inputs and read as ‘0’. EXAMPLE 9-3: CLRF PORTC CLRF LATC MOVLW 0CFh MOVWF TRISC INITIALIZING PORTC ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTC by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RC<3:0> as inputs RC<5:4> as outputs RC<7:6> as inputs PORTC: PORTC REGISTER R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 bit 7 bit 0 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 bit 7-0 x = Bit is unknown RC<7:0>: PORTC I/O Pin bit 1 = Port pin is > VIH 0 = Port pin is < VIL REGISTER 9-12: TRISC: PORTC TRI-STATE REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 bit 7 bit 0 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 bit 7-0 x = Bit is unknown TRISC<7:0>: PORTC Tri-State Control bit 1 = PORTC pin configured as an input (tri-stated) 0 = PORTC pin configured as an output DS41350D-page 94 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 9-13: LATC: PORTC DATA LATCH REGISTER R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 bit 7 bit 0 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 bit 7-0 x = Bit is unknown LATC<7:0>: RB<7:0> Port I/O Output Latch Register bits 2010 Microchip Technology Inc. Preliminary DS41350D-page 95 PIC18F/LF1XK50 TABLE 9-14: Pin RC0/AN4/ C12IN+/VREF+/ INT0 RC1/AN5/ C12IN1-/VREF-/ INT1 RC2/AN6/ C12IN2-/CVREF/ P1D/INT2 RC3/AN7/ C12IN3-/P1C/ PGM RC4/C12OUT/ P1B Legend: PORTC I/O SUMMARY Function TRIS Setting I/O I/O Type RC0 0 O DIG 1 I ST AN4 1 I ANA A/D input channel 4. C12IN+ 1 I ANA Comparators C1 and C2 non-inverting input. Analog select is shared with ADC. VREF+ 1 I ANA ADC and comparator voltage reference high input. Description LATC<0> data output. PORTC<0> data input. INT0 1 I ST External Interrupt 0 input. RC1 0 O DIG LATC<1> data output. 1 I ST AN5 1 I ANA A/D input channel 5. C12IN1- 1 I ANA Comparators C1 and C2 inverting input. Analog select is shared with ADC. VREF- 1 I ANA ADC and comparator voltage reference low input. INT1 1 I ST External Interrupt 1 input. RC2 0 O DIG LATC<2> data output. 1 I ST PORTC<2> data input. AN6 1 I ANA A/D input channel 6. C12IN2- 1 I ANA Comparators C1 and C2 inverting input, channel 2. Analog select is shared with ADC. PORTC<1> data input. CVREF x O ANA Voltage reference output. Enabling this feature disables digital I/O. P1D 0 O DIG ECCP1 Enhanced PWM output, channel D. May be configured for tri-state during Enhanced PWM shutdown events. Takes priority over port data. INT2 1 I ST External Interrupt 2 input. RC3 0 O DIG LATC<3> data output. 1 I ST AN7 1 I ANA A/D input channel 7. C12IN3- 1 I ANA Comparators C1 and C2 inverting input, channel 3. Analog select is shared with ADC. P1C 0 O DIG ECCP1 Enhanced PWM output, channel C. May be configured for tri-state during Enhanced PWM shutdown events. Takes priority over port data. PGM x I ST Single-Supply Programming mode entry (ICSP™). Enabled by LVP Configuration bit; all other pin functions disabled. RC4 0 O DIG LATC<4> data output. PORTC<4> data input. PORTC<3> data input. 1 I ST C12OUT 0 O DIG Comparator 1 and 2 output; takes priority over port data. P1B 0 O DIG ECCP1 Enhanced PWM output, channel B. May be configured for tri-state during Enhanced PWM shutdown events. Takes priority over port data. DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; I2C/SMB = I2C/SMBus input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). DS41350D-page 96 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 9-14: PORTC I/O SUMMARY (CONTINUED) Pin RC5/CCP1/P1A/ T0CKI Function TRIS Setting I/O I/O Type RC5 0 O DIG CCP1 RC6/AN8/SS/ T13CKI/T1OSCI RC7/AN9/SDO/ T1OSCO LATC<5> data output. 1 I ST PORTC<5> data input. 0 O DIG ECCP1 compare or PWM output; takes priority over port data. 1 I ST ECCP1 capture input. P1A 0 0 DIG ECCP1 Enhanced PWM output, channel A. May be configured for tri-state during Enhanced PWM shutdown events. Takes priority over port data T0CKI 1 I ST Timer0 counter input. RC6 0 O DIG LATC<6> data output. 1 I ST AN8 1 I ANA PORTC<6> data input. A/D input channel 8. SS 1 I TTL Slave select input for SSP (MSSP module) T13CKI 1 I ST Timer1 and Timer3 counter input. T1OSCI x O ANA Timer1 oscillator input; enabled when Timer1 oscillator enabled. Disables digital I/O. RC7 0 O DIG LATC<7> data output. 1 I ST 1 I ANA AN9 Legend: Description PORTC<7> data input. A/D input channel 9. SDO 0 I DIG SPI data output (MSSP module); takes priority over port data. T1OSCO x O ANA Timer1 oscillator output; enabled when Timer1 oscillator enabled. Disables digital I/O. DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output; I2C/SMB = I2C/SMBus input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option). TABLE 9-5: Name PORTC SUMMARY OF REGISTERS ASSOCIATED WITH PORTC Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 290 LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 ANSEL ANS7 ANS6 ANS5 ANS4 ANS3 — — — 290 — — ANS11 ANS10 ANS9 ANS8 ANSELH T1CON — — RD16 T1RUN 288 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 289 SSPM3 288 T3CON RD16 — SSPCON1 WCOL SSPOV SSPEN CKP P1M1 P1M0 DC1B1 DC1B0 CCP1CON ECCP1AS 290 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON SSPM2 SSPM1 SSPM0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 289 289 PSTRCON — — — STRSYNC STRD STRC STRB STRA 289 SLRCON — — — — — SLRC SLRB SLRA 290 D1EN D1LPS DAC1OE --- --- D1NSS 289 TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 REFCON1 INTCON GIE/GIEH PEIE/GIEL D1PSS1 D1PSS0 INTCON2 RABPU INTEDG0 INTEDG1 INTEDG2 — TMR0IP — RABIP 287 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 287 2010 Microchip Technology Inc. Preliminary DS41350D-page 97 PIC18F/LF1XK50 9.4 Port Analog Control Some port pins are multiplexed with analog functions such as the Analog-to-Digital Converter and comparators. When these I/O pins are to be used as analog inputs it is necessary to disable the digital input buffer to avoid excessive current caused by improper biasing of the digital input. Individual control of the digital input buffers on pins which share analog functions is provided by the ANSEL and ANSELH registers. Setting an REGISTER 9-15: ANSx bit high will disable the associated digital input buffer and cause all reads of that pin to return ‘0’ while allowing analog functions of that pin to operate correctly. The state of the ANSx bits has no affect on digital output functions. A pin with the associated TRISx bit clear and ANSx bit set will still operate as a digital output but the Input mode will be analog. ANSEL: ANALOG SELECT REGISTER 1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 U-0 U-0 U-0 ANS7 ANS6 ANS5 ANS4 ANS3 — — — bit 7 bit 0 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 bit 7 ANS7: RC3 Analog Select Control bit 1 = Digital input buffer of RC3 is disabled 0 = Digital input buffer of RC3 is enabled bit 6 ANS6: RC2 Analog Select Control bit 1 = Digital input buffer of RC2 is disabled 0 = Digital input buffer of RC2 is enabled bit 5 ANS5: RC1 Analog Select Control bit 1 = Digital input buffer of RC1 is disabled 0 = Digital input buffer of RC1 is enabled bit 4 ANS4: RC0 Analog Select Control bit 1 = Digital input buffer of RC0 is disabled 0 = Digital input buffer of RC0 is enabled bit 3 ANS3: RA4 Analog Select Control bit 1 = Digital input buffer of RA4 is disabled 0 = Digital input buffer of RA4 is enabled bit 2-0 Unimplemented: Read as ‘0’ DS41350D-page 98 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 9-16: ANSELH: ANALOG SELECT REGISTER 2 U-0 U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 — — — — ANS11 ANS10 ANS9 ANS8 bit 7 bit 0 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 bit 7-4 Unimplemented: Read as ‘0’ bit 3 ANS11: RB5 Analog Select Control bit 1 = Digital input buffer of RB5 is disabled 0 = Digital input buffer of RB5 is enabled bit 2 ANS10: RB4 Analog Select Control bit 1 = Digital input buffer of RB4 is disabled 0 = Digital input buffer of RB4 is enabled bit 1 ANS9: RC7 Analog Select Control bit 1 = Digital input buffer of RC7 is disabled 0 = Digital input buffer of RC7 is enabled bit 0 ANS8: RC6 Analog Select Control bit 1 = Digital input buffer of RC6 is disabled 0 = Digital input buffer of RC6 is enabled 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 99 PIC18F/LF1XK50 9.5 Port Slew Rate Control The output slew rate of each port is programmable to select either the standard transition rate or a reduced transition rate of 0.1 times the standard to minimize EMI. The reduced transition time is the default slew rate for all ports. REGISTER 9-17: SLRCON: SLEW RATE CONTROL REGISTER U-0 U-0 U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 — — — — — SLRC SLRB SLRA bit 7 bit 0 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 bit 7-3 Unimplemented: Read as ‘0’ bit 2 SLRC: PORTC Slew Rate Control bit 1 = All outputs on PORTC slew at 0.1 times the standard rate 0 = All outputs on PORTC slew at the standard rate bit 1 SLRB: PORTB Slew Rate Control bit 1 = All outputs on PORTB slew at 0.1 times the standard rate 0 = All outputs on PORTB slew at the standard rate bit 0 SLRA: PORTA Slew Rate Control bit 1 = All outputs on PORTA slew at 0.1 times the standard rate(1) 0 = All outputs on PORTA slew at the standard rate x = Bit is unknown Note 1: The slew rate of RA4 defaults to standard rate when the pin is used as CLKOUT. DS41350D-page 100 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 10.0 TIMER0 MODULE The T0CON register (Register 10-1) controls all aspects of the module’s operation, including the prescale selection. It is both readable and writable. The Timer0 module incorporates the following features: A simplified block diagram of the Timer0 module in 8-bit mode is shown in Figure 10-1. Figure 10-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. • Software selectable operation as a timer or counter in both 8-bit or 16-bit modes • Readable and writable registers • Dedicated 8-bit, software programmable prescaler • Selectable clock source (internal or external) • Edge select for external clock • Interrupt-on-overflow REGISTER 10-1: T0CON: TIMER0 CONTROL REGISTER 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 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 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 (CLKOUT) 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 T0PS<2:0>: 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 2010 Microchip Technology Inc. Preliminary DS41350D-page 101 PIC18F/LF1XK50 10.1 Timer0 Operation 10.2 Timer0 can operate as either a timer or a counter; the mode is selected with the T0CS bit of the T0CON register. In Timer mode (T0CS = 0), the module increments on every clock by default unless a different prescaler value is selected (see Section 10.3 “Prescaler”). Timer0 incrementing is inhibited for two instruction cycles following a TMR0 register write. The user can work around this by adjusting the value written to the TMR0 register to compensate for the anticipated missing increments. The Counter mode is selected by setting the T0CS bit (= 1). In this mode, Timer0 increments either on every rising or falling edge of the T0CKI pin. The incrementing edge is determined by the Timer0 Source Edge Select bit, T0SE of the T0CON register; clearing this bit selects the rising edge. Restrictions on the external clock input are discussed below. Timer0 Reads and Writes in 16-Bit Mode TMR0H is not the actual high byte of Timer0 in 16-bit mode; it is actually a buffered version of the real high byte of Timer0 which is neither directly readable nor writable (refer to Figure 10-2). TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16 bits of Timer0 without the need to verify that the read of the high and low byte were valid. Invalid reads could otherwise occur due to a rollover between successive reads of the high and low byte. Similarly, a write to the high byte of Timer0 must also take place through the TMR0H Buffer register. Writing to TMR0H does not directly affect Timer0. Instead, the high byte of Timer0 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. An external clock source can be used to drive Timer0; however, it must meet certain requirements (see Table 27-6) to ensure that the external clock can be synchronized with the internal phase clock (TOSC). There is a delay between synchronization and the onset of incrementing the timer/counter. FIGURE 10-1: TIMER0 BLOCK DIAGRAM (8-BIT MODE) FOSC/4 0 0 1 T0CKI pin T0SE T0CS Programmable Prescaler 1 Sync with Internal Clocks Set TMR0IF on Overflow (2 TCY Delay) 8 3 T0PS<2:0> 8 PSA Note: TMR0L Internal Data Bus Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. DS41350D-page 102 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 10-2: TIMER0 BLOCK DIAGRAM (16-BIT MODE) FOSC/4 0 0 Sync with Internal Clocks 1 Programmable Prescaler T0CKI pin T0SE T0CS 1 TMR0 High Byte TMR0L 8 Set TMR0IF on Overflow (2 TCY Delay) 3 Read TMR0L T0PS<2:0> Write TMR0L PSA 8 8 TMR0H 8 8 Internal Data Bus Note: 10.3 Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. Prescaler 10.3.1 An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not directly readable or writable; its value is set by the PSA and T0PS<2:0> bits of the T0CON register which determine the prescaler assignment and prescale ratio. Clearing the PSA bit assigns the prescaler to the Timer0 module. When the prescaler is assigned, prescale values from 1:2 through 1:256 in integer power-of-2 increments are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, etc.) clear the prescaler count. Note: Writing to TMR0 when the prescaler is assigned to Timer0 will clear the prescaler count but will not change the prescaler assignment. TABLE 10-1: Name SWITCHING PRESCALER ASSIGNMENT The prescaler assignment is fully under software control and can be changed “on-the-fly” during program execution. 10.4 Timer0 Interrupt The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or from FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF flag bit. The interrupt can be masked by clearing the TMR0IE bit of the INTCON register. Before re-enabling the interrupt, the TMR0IF bit must be cleared by software in the Interrupt Service Routine. Since Timer0 is shut down in Sleep mode, the TMR0 interrupt cannot awaken the processor from Sleep. REGISTERS ASSOCIATED WITH TIMER0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 TMR0L Timer0 Register, Low Byte TMR0H Timer0 Register, High Byte INTCON GIE/GIEH PEIE/GIEL TMR0IE T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 Bit 1 Bit 0 Reset Values on page 288 288 INT0IE RABIE TMR0IF INT0IF RABIF 287 T0PS1 T0PS0 288 TRISC1 TRISC0 290 Legend: Shaded cells are not used by Timer0. Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary oscillator modes. When disabled, these bits read as ‘0’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 103 PIC18F/LF1XK50 NOTES: DS41350D-page 104 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 11.0 TIMER1 MODULE The Timer1 timer/counter module incorporates the following features: • Software selectable operation as a 16-bit timer or counter • Readable and writable 8-bit registers (TMR1H and TMR1L) • Selectable internal or external clock source and Timer1 oscillator options • Interrupt-on-overflow • Reset on CCP Special Event Trigger • Device clock status flag (T1RUN) REGISTER 11-1: A simplified block diagram of the Timer1 module is shown in Figure 11-1. A block diagram of the module’s operation in Read/Write mode is shown in Figure 11-2. The module incorporates its own low-power oscillator to provide an additional clocking option. The Timer1 oscillator can also be used as a low-power clock source for the microcontroller in power-managed operation. Timer1 can also be used to provide Real-Time Clock (RTC) functionality to applications with only a minimal addition of external components and code overhead. Timer1 is controlled through the T1CON Control register (Register 11-1). It also contains the Timer1 Oscillator Enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit, TMR1ON of the T1CON register. T1CON: TIMER1 CONTROL REGISTER R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON bit 7 bit 0 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 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 T1RUN: Timer1 System Clock Status bit 1 = Main system clock is derived from Timer1 oscillator 0 = Main system clock is derived from another source bit 5-4 T1CKPS<1:0>: 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 the T13CKI pin (on the rising edge) 0 = Internal clock (FOSC/4) bit 0 TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 2010 Microchip Technology Inc. Preliminary DS41350D-page 105 PIC18F/LF1XK50 11.1 Timer1 Operation instruction cycle (FOSC/4). When the bit is set, Timer1 increments on every rising edge of either the Timer1 external clock input or the Timer1 oscillator, if enabled. Timer1 can operate in one of the following modes: • Timer • Synchronous Counter • Asynchronous Counter When the Timer1 oscillator is enabled, the digital circuitry associated with the T1OSI and T1OSO pins is disabled. This means the values of TRISC<1:0> are ignored and the pins are read as ‘0’. The operating mode is determined by the clock select bit, TMR1CS of the T1CON register. When TMR1CS is cleared (= 0), Timer1 increments on every internal FIGURE 11-1: TIMER1 BLOCK DIAGRAM Timer1 Oscillator Timer1 Clock Input 1 On/Off T1OSI/T13CKI 1 FOSC/4 Internal Clock T1OSO Synchronize Prescaler 1, 2, 4, 8 0 Detect 0 2 T1OSCEN(1) Sleep Input TMR1CS Timer1 On/Off T1CKPS<1:0> T1SYNC TMR1ON Clear TMR1 (CCP Special Event Trigger) Set TMR1IF on Overflow TMR1 High Byte TMR1L Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. FIGURE 11-2: TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) Timer1 Oscillator Timer1 Clock Input 1 T1OSI/T13CKI 1 FOSC/4 Internal Clock T1OSO Synchronize Prescaler 1, 2, 4, 8 0 Detect 0 2 T1OSCEN(1) T1CKPS<1:0> T1SYNC TMR1ON Sleep Input TMR1CS Clear TMR1 (CCP Special Event Trigger) Timer1 On/Off TMR1 High Byte TMR1L 8 Set TMR1IF on Overflow Read TMR1L Write TMR1L 8 8 TMR1H 8 8 Internal Data Bus Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. DS41350D-page 106 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 11.2 Timer1 16-Bit Read/Write Mode TABLE 11-1: Timer1 can be configured for 16-bit reads and writes (see Figure 11-2). When the RD16 control bit of the T1CON register 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 the need to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover or carry between reads. Osc Type LP 11.3 Timer1 Oscillator An on-chip crystal oscillator circuit is incorporated between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting the Timer1 Oscillator Enable bit, T1OSCEN of the T1CON register. The oscillator is a low-power circuit rated for 32 kHz crystals. It will continue to run during all power-managed modes. The circuit for a typical LP oscillator is shown in Figure 11-3. 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. FIGURE 11-3: EXTERNAL COMPONENTS FOR THE TIMER1 LP OSCILLATOR C1 27 pF PIC® MCU Freq 32 kHz C1 27 pF C2 (1) 27 pF(1) Note 1: Microchip suggests these values only 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. Writing to TMR1H does not directly affect Timer1. Instead, the high byte of Timer1 is updated with the contents of TMR1H when a write occurs to TMR1L. This allows all 16 bits of Timer1 to be updated at once. The high byte of Timer1 is not directly readable or writable 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. CAPACITOR SELECTION FOR THE TIMER OSCILLATOR 4: Capacitor values are for design guidance only. 11.3.1 USING TIMER1 AS A CLOCK SOURCE The Timer1 oscillator is also available as a clock source in power-managed modes. By setting the clock select bits, SCS<1:0> of the OSCCON register, to ‘01’, the device switches to SEC_RUN mode; both the CPU and peripherals are clocked from the Timer1 oscillator. If the IDLEN bit of the OSCCON register is cleared and a SLEEP instruction is executed, the device enters SEC_IDLE mode. Additional details are available in Section 19.0 “Power-Managed Modes”. Whenever the Timer1 oscillator is providing the clock source, the Timer1 system clock status flag, T1RUN of the T1CON register, is set. This can be used to determine the controller’s current clocking mode. It can also indicate which clock source is currently being used by the Fail-Safe Clock Monitor. If the Clock Monitor is enabled and the Timer1 oscillator fails while providing the clock, polling the T1RUN bit will indicate whether the clock is being provided by the Timer1 oscillator or another source. T1OSI XTAL 32.768 kHz T1OSO C2 27 pF Note: See the Notes with Table 11-1 for additional information about capacitor selection. 2010 Microchip Technology Inc. Preliminary DS41350D-page 107 PIC18F/LF1XK50 11.3.2 11.5 TIMER1 OSCILLATOR LAYOUT CONSIDERATIONS The Timer1 oscillator circuit draws very little power during operation. Due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. The oscillator circuit, shown in Figure 11-3, should be located as close as possible to the microcontroller. There should be no circuits passing within the oscillator circuit boundaries other than VSS or VDD. If a high-speed circuit must be located near the oscillator (such as the CCP1 pin in Output Compare or PWM mode, or the primary oscillator using the OSC2 pin), a grounded guard ring around the oscillator circuit, as shown in Figure 11-4, may be helpful when used on a single-sided PCB or in addition to a ground plane. FIGURE 11-4: OSCILLATOR CIRCUIT WITH GROUNDED GUARD RING Resetting Timer1 Using the CCP Special Event Trigger If either of the CCP modules is configured to use Timer1 and generate a Special Event Trigger in Compare mode (CCP1M<3:0> or CCP2M<3:0> = 1011), this signal will reset Timer1. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 14.3.4 “Special Event Trigger” for more information). The module must be configured as either a timer or a synchronous counter to take advantage of this feature. When used this way, the CCPRH:CCPRL register pair effectively becomes a period register for Timer1. 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, the write operation will take precedence. Note: VDD The Special Event Triggers from the CCP2 module will not set the TMR1IF interrupt flag bit of the PIR1 register. VSS OSC1 OSC2 RC0 RC1 RC2 Note: Not drawn to scale. 11.4 Timer1 Interrupt The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The Timer1 interrupt, if enabled, is generated on overflow, which is latched in the TMR1IF interrupt flag bit of the PIR1 register. This interrupt can be enabled or disabled by setting or clearing the TMR1IE Interrupt Enable bit of the PIE1 register. DS41350D-page 108 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 11.6 Using Timer1 as a Real-Time Clock Adding an external LP oscillator to Timer1 (such as the one described in Section 11.3 “Timer1 Oscillator” above) gives users the option to include RTC functionality to their applications. This is accomplished with an inexpensive watch crystal to provide an accurate time base and several lines of application code to calculate the time. When operating in Sleep mode and using a battery or supercapacitor as a power source, it can completely eliminate the need for a separate RTC device and battery backup. The application code routine, RTCisr, shown in Example 11-1, demonstrates a simple method to increment a counter at one-second intervals using an Interrupt Service Routine. Incrementing the TMR1 register pair to overflow triggers the interrupt and calls the routine, which increments the seconds counter by one; additional counters for minutes and hours are incremented on overflows of the less significant counters. EXAMPLE 11-1: Since the register pair is 16 bits wide, a 32.768 kHz clock source will take 2 seconds to count up to overflow. To force the overflow at the required one-second intervals, it is necessary to preload it; the simplest method is to set the MSb of TMR1H with a BSF instruction. Note that the TMR1L register is never preloaded or altered; doing so may introduce cumulative error over many cycles. For this method to be accurate, Timer1 must operate in Asynchronous mode and the Timer1 overflow interrupt must be enabled (PIE1<0> = 1), as shown in the routine, RTCinit. The Timer1 oscillator must also be enabled and running at all times. IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE RTCinit MOVLW MOVWF CLRF MOVLW MOVWF CLRF CLRF MOVLW MOVWF BSF RETURN 80h TMR1H TMR1L b’00001111’ T1CON secs mins .12 hours PIE1, TMR1IE BSF BCF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN CLRF RETURN TMR1H, 7 PIR1, TMR1IF secs, F .59 secs ; Preload TMR1 register pair ; for 1 second overflow ; Configure for external clock, ; Asynchronous operation, external oscillator ; Initialize timekeeping registers ; ; Enable Timer1 interrupt RTCisr secs mins, F .59 mins mins hours, F .23 hours hours 2010 Microchip Technology Inc. ; ; ; ; Preload for 1 sec overflow Clear interrupt flag Increment seconds 60 seconds elapsed? ; ; ; ; No, done Clear seconds Increment minutes 60 minutes elapsed? ; ; ; ; No, done clear minutes Increment hours 24 hours elapsed? ; No, done ; Reset hours ; Done Preliminary DS41350D-page 109 PIC18F/LF1XK50 TABLE 11-2: Name INTCON REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 TMR1L Timer1 Register, Low Byte 288 TMR1H Timer1 Register, High Byte 288 T1CON TRISC ANSELH SSPCON1 RD16 T1RUN TMR1CS TMR1ON 288 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TRISC7 TRISC6 TRISC5 — — — — ANS11 ANS10 ANS9 ANS8 290 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 288 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module. DS41350D-page 110 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 12.0 TIMER2 MODULE 12.1 The Timer2 module timer incorporates the following features: • 8-bit timer and period registers (TMR2 and PR2, respectively) • Readable and writable (both registers) • Software programmable prescaler (1:1, 1:4 and 1:16) • Software programmable postscaler (1:1 through 1:16) • Interrupt on TMR2-to-PR2 match • Optional use as the shift clock for the MSSP module The module is controlled through the T2CON register (Register 12-1), which enables or disables the timer and configures the prescaler and postscaler. Timer2 can be shut off by clearing control bit, TMR2ON of the T2CON register, to minimize power consumption. A simplified block diagram of the module is shown in Figure 12-1. Timer2 Operation In normal operation, TMR2 is incremented from 00h on each clock (FOSC/4). A 4-bit counter/prescaler on the clock input gives direct input, divide-by-4 and divide-by-16 prescale options; these are selected by the prescaler control bits, T2CKPS<1:0> of the T2CON register. The value of TMR2 is compared to that of the period register, PR2, on each clock cycle. When the two values match, the comparator generates a match signal as the timer output. This signal also resets the value of TMR2 to 00h on the next cycle and drives the output counter/postscaler (see Section 12.2 “Timer2 Interrupt”). The TMR2 and PR2 registers are both directly readable and writable. The TMR2 register is cleared on any device Reset, whereas the PR2 register initializes to FFh. Both the prescaler and postscaler counters are cleared on the following events: • 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. REGISTER 12-1: T2CON: TIMER2 CONTROL REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6-3 T2OUTPS<3:0>: 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 T2CKPS<1:0>: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 111 PIC18F/LF1XK50 12.2 Timer2 Interrupt 12.3 Timer2 can also generate an optional device interrupt. The Timer2 output signal (TMR2-to-PR2 match) provides the input for the 4-bit output counter/postscaler. This counter generates the TMR2 match interrupt flag which is latched in TMR2IF of the PIR1 register. The interrupt is enabled by setting the TMR2 Match Interrupt Enable bit, TMR2IE of the PIE1 register. Timer2 Output The unscaled output of TMR2 is available primarily to the CCP modules, where it is used as a time base for operations in PWM mode. Timer2 can be optionally used as the shift clock source for the MSSP module operating in SPI mode. Additional information is provided in Section 14.0 “Master Synchronous Serial Port (MSSP) Module”. A range of 16 postscale options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, T2OUTPS<3:0> of the T2CON register. FIGURE 12-1: TIMER2 BLOCK DIAGRAM 4 T2OUTPS<3:0> 1:1 to 1:16 Postscaler Set TMR2IF 2 T2CKPS<1:0> TMR2/PR2 Match Reset 1:1, 1:4, 1:16 Prescaler FOSC/4 TMR2 TMR2 Output (to PWM or MSSP) Comparator 8 PR2 8 8 Internal Data Bus TABLE 12-1: Name REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Bit 7 Bit 6 INTCON GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP IPR1 TMR2 T2CON PR2 Timer2 Register — 290 288 T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 Timer2 Period Register 288 288 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module. DS41350D-page 112 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 13.0 TIMER3 MODULE The Timer3 module timer/counter incorporates these features: • Software selectable operation as a 16-bit timer or counter • Readable and writable 8-bit registers (TMR3H and TMR3L) • Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options • Interrupt-on-overflow • Module Reset on CCP Special Event Trigger REGISTER 13-1: A simplified block diagram of the Timer3 module is shown in Figure 13-1. A block diagram of the module’s operation in Read/Write mode is shown in Figure 13-2. The Timer3 module is controlled through the T3CON register (Register 13-1). It also selects the clock source options for the CCP modules (see Section 14.1.1 “CCP Module and Timer Resources” for more information). T3CON: TIMER3 CONTROL REGISTER R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 — T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON bit 7 bit 0 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 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 Unimplemented: Read as ‘0’ bit 5-4 T3CKPS<1:0>: 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 3 T3CCP1: Timer3 and Timer1 to CCP1 Enable bits 1 = Timer3 is the clock source for compare/capture of ECCP1 0 = Timer1 is the clock source for compare/capture of ECCP1 bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the device 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 T13CKI (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 2010 Microchip Technology Inc. Preliminary DS41350D-page 113 PIC18F/LF1XK50 13.1 Timer3 Operation The operating mode is determined by the clock select bit, TMR3CS of the T3CON register. When TMR3CS is cleared (= 0), Timer3 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. Timer3 can operate in one of three modes: • Timer • Synchronous Counter • Asynchronous Counter FIGURE 13-1: As with Timer1, the digital circuitry associated with the RC1/T1OSI and RC0/T1OSO/T13CKI pins is disabled when the Timer1 oscillator is enabled. This means the values of TRISC<1:0> are ignored and the pins are read as ‘0’. TIMER3 BLOCK DIAGRAM Timer1 Oscillator Timer1 Clock Input 1 T1OSO/T13CKI 1 FOSC/4 Internal Clock T1OSI Synchronize Prescaler 1, 2, 4, 8 Detect 0 0 2 T1OSCEN(1) Sleep Input TMR3CS T3CKPS<1:0> Timer3 On/Off T3SYNC TMR3ON CCP1 Special Event Trigger CCP1 Select from T3CON<3> Clear TMR3 TMR3L TMR3 High Byte Set TMR3IF on Overflow Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. DS41350D-page 114 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 13-2: TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) Timer1 Oscillator Timer1 Clock Input 1 T13CKI/T1OSI 1 FOSC/4 Internal Clock T1OSO Synchronize Prescaler 1, 2, 4, 8 0 Detect 0 2 T1OSCEN(1) Sleep Input TMR3CS Timer3 On/Off T3CKPS<1:0> T3SYNC TMR3ON CCP1 Special Event Trigger CCP1 Select from T3CON<3> Clear TMR3 Set TMR3IF on Overflow TMR3 High Byte TMR3L 8 Read TMR1L Write TMR1L 8 8 TMR3H 8 8 Internal Data Bus Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. 13.2 Timer3 16-Bit Read/Write Mode 13.3 Timer3 can be configured for 16-bit reads and writes (see Figure 13-2). When the RD16 control bit of the T3CON register is set, the address for TMR3H is mapped to a buffer register for the high byte of Timer3. A read from TMR3L will load the contents of the high byte of Timer3 into the Timer3 High Byte Buffer register. 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, has become invalid due to a rollover between reads. A write to the high byte of Timer3 must also take place through the TMR3H Buffer register. The Timer3 high byte is updated with the contents of TMR3H when a write occurs to TMR3L. This allows a user to write all 16 bits to both the high and low bytes of Timer3 at once. The high byte of Timer3 is not directly readable or writable in this mode. All reads and writes must take place through the Timer3 High Byte Buffer register. Writes to TMR3H do not clear the Timer3 prescaler. The prescaler is only cleared on writes to TMR3L. 2010 Microchip Technology Inc. Using the Timer1 Oscillator as the Timer3 Clock Source The Timer1 internal oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN bit of the T1CON register. To use it as the Timer3 clock source, the TMR3CS bit must also be set. As previously noted, this also configures Timer3 to increment on every rising edge of the oscillator source. The Timer1 oscillator is described in Section 11.0 “Timer1 Module”. 13.4 Timer3 Interrupt The TMR3 register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and overflows to 0000h. The Timer3 interrupt, if enabled, is generated on overflow and is latched in interrupt flag bit, TMR3IF of the PIR2 register. This interrupt can be enabled or disabled by setting or clearing the Timer3 Interrupt Enable bit, TMR3IE of the PIE2 register. Preliminary DS41350D-page 115 PIC18F/LF1XK50 13.5 Resetting Timer3 Using the CCP Special Event Trigger If CCP1 module is configured to use Timer3 and to generate a Special Event Trigger in Compare mode (CCP1M<3:0>), this signal will reset Timer3. It will also start an A/D conversion if the A/D module is enabled (see Section 17.2.8 “Special Event Trigger” for more information). The module must be configured as either a timer or synchronous counter to take advantage of this feature. When used this way, the CCPR1H:CCPR1L register pair effectively becomes a period register for Timer3. If Timer3 is running in Asynchronous Counter mode, the Reset operation may not work. In the event that a write to Timer3 coincides with a Special Event Trigger from a CCP module, the write will take precedence. TABLE 13-1: Name INTCON REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER Bit 7 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 Bit 6 GIE/GIEH PEIE/GIEL PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF CCP2IF 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE CCP2IE 290 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP CCP2IP IPR2 TMR3L Timer3 Register, Low Byte TMR3H Timer3 Register, High Byte 289 T1CON RD16 T1RUN T3CON RD16 — TRISC TRISC7 TRISC6 TRISC5 — — — ANSELH 290 289 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 288 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 289 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 — ANS11 ANS10 ANS9 ANS8 290 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module. DS41350D-page 116 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.0 ENHANCED CAPTURE/COMPARE/PWM (ECCP) MODULE CCP1 is implemented as a standard CCP module with enhanced PWM capabilities. These include: PIC18F/LF1XK50 devices have one ECCP (Capture/Compare/PWM) module. The module contains a 16-bit register which can operate as a 16-bit Capture register, a 16-bit Compare register or a PWM Master/Slave Duty Cycle register. REGISTER 14-1: • • • • • Provision for 2 or 4 output channels Output steering Programmable polarity Programmable dead-band control Automatic shutdown and restart. The enhanced features are discussed in detail in Section 14.4 “PWM (Enhanced Mode)”. CCP1CON: ENHANCED CAPTURE/COMPARE/PWM CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 bit 7 bit 0 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 bit 7-6 P1M<1:0>: Enhanced PWM Output Configuration bits If CCP1M<3:2> = 00, 01, 10: xx = P1A assigned as Capture/Compare input/output; P1B, P1C, P1D assigned as port pins If CCP1M<3:2> = 11: 00 = Single output: P1A, P1B, P1C and P1D controlled by steering (See Section 14.4.7 “Pulse Steering Mode”). 01 = Full-bridge output forward: P1D modulated; P1A active; P1B, P1C inactive 10 = Half-bridge output: P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins 11 = Full-bridge output reverse: P1B modulated; P1C active; P1A, P1D inactive bit 5-4 DC1B<1:0>: PWM Duty Cycle bit 1 and bit 0 Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found in CCPR1L. bit 3-0 CCP1M<3:0>: Enhanced CCP Mode Select bits 0000 = Capture/Compare/PWM off (resets ECCP module) 0001 = Reserved 0010 = Compare mode, toggle output on match 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 CCP1 pin low, set output on compare match (set CCP1IF) 1001 = Compare mode, initialize CCP1 pin high, clear output on compare match (set CCP1IF) 1010 = Compare mode, generate software interrupt only, CCP1 pin reverts to I/O state 1011 = Compare mode, trigger special event (ECCP resets TMR1 or TMR3, start A/D conversion, sets CC1IF bit) 1100 = PWM mode; P1A, P1C active-high; P1B, P1D active-high 1101 = PWM mode; P1A, P1C active-high; P1B, P1D active-low 1110 = PWM mode; P1A, P1C active-low; P1B, P1D active-high 1111 = PWM mode; P1A, P1C active-low; P1B, P1D active-low 2010 Microchip Technology Inc. Preliminary DS41350D-page 117 PIC18F/LF1XK50 In addition to the expanded range of modes available through the CCP1CON register and ECCP1AS register, the ECCP module has two additional registers associated with Enhanced PWM operation and auto-shutdown features. They are: • PWM1CON (Dead-band delay) • PSTRCON (output steering) 14.1 ECCP Outputs and Configuration The enhanced CCP module may have up to four PWM outputs, depending on the selected operating mode. These outputs, designated P1A through P1D, are multiplexed with I/O pins on PORTC. The outputs that are active depend on the CCP operating mode selected. The pin assignments are summarized in Table 14-2. To configure the I/O pins as PWM outputs, the proper PWM mode must be selected by setting the P1M<1:0> and CCP1M<3:0> bits. The appropriate TRISC direction bits for the port pins must also be set as outputs. 14.1.1 CCP MODULE AND TIMER RESOURCES The CCP modules utilize Timers 1, 2 or 3, depending on the mode selected. Timer1 and Timer3 are available to modules in Capture or Compare modes, while Timer2 is available for modules in PWM mode. TABLE 14-1: CCP MODE – TIMER RESOURCE CCP/ECCP Mode Timer Resource Capture Timer1 or Timer3 Compare Timer1 or Timer3 PWM Timer2 The assignment of a particular timer to a module is determined by the Timer-to-CCP enable bits in the T3CON register (Register 13-1). The interactions between the two modules are summarized in Figure 14-1. In Asynchronous Counter mode, the capture operation will not work reliably. DS41350D-page 118 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.2 Capture Mode to be used with each CCP module is selected in the T3CON register (see Section 14.1.1 “CCP Module and Timer Resources”). In Capture mode, the CCPR1H:CCPR1L register pair captures the 16-bit value of the TMR1 or TMR3 registers when an event occurs on the corresponding CCP1 pin. An event is defined as one of the following: • • • • 14.2.3 SOFTWARE INTERRUPT When the Capture mode is changed, a false capture interrupt may be generated. The user should keep the CCP1IE interrupt enable bit clear to avoid false interrupts. The interrupt flag bit, CCP1IF, should also be cleared following any such change in operating mode. every falling edge every rising edge every 4th rising edge every 16th rising edge The event is selected by the mode select bits, CCP1M<3:0> of the CCP1CON register. When a capture is made, the interrupt request flag bit, CCP1IF, is set; it must be cleared by software. If another capture occurs before the value in register CCPR1 is read, the old captured value is overwritten by the new captured value. 14.2.4 14.2.1 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 recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the “false” interrupt. There are four prescaler settings in Capture mode; they are specified as part of the operating mode selected by the mode select bits (CCP1M<3:0>). Whenever the CCP module is turned off or Capture mode is disabled, the prescaler counter is cleared. This means that any Reset will clear the prescaler counter. CCP PIN CONFIGURATION In Capture mode, the appropriate CCP1 pin should be configured as an input by setting the corresponding TRIS direction bit. Note: 14.2.2 If the CCP1 pin is configured as an output, a write to the port can cause a capture condition. EXAMPLE 14-1: TIMER1/TIMER3 MODE SELECTION The timers that are to be used with the capture feature (Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer CLRF MOVLW MOVWF FIGURE 14-1: CCP PRESCALER CHANGING BETWEEN CAPTURE PRESCALERS CCP1CON ; Turn CCP module off NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON CCP1CON ; Load CCP1CON with ; this value CAPTURE MODE OPERATION BLOCK DIAGRAM TMR3H Set CCP1IF T3CCP1 CCP1 pin Prescaler 1, 4, 16 and Edge Detect CCP1CON<3:0> Q1:Q4 2010 Microchip Technology Inc. TMR3 Enable CCPR1H T3CCP1 CCPR1L TMR1 Enable TMR1H 4 TMR3L TMR1L 4 Preliminary DS41350D-page 119 PIC18F/LF1XK50 14.3 Compare Mode 14.3.2 TIMER1/TIMER3 MODE SELECTION In Compare mode, the 16-bit CCPR1 register value is constantly compared against either the TMR1 or TMR3 register pair value. When a match occurs, the CCP1 pin can be: 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 will not work reliably. • • • • 14.3.3 driven high driven low toggled (high-to-low or low-to-high) remain unchanged (that is, reflects the state of the I/O latch) The action on the pin is based on the value of the mode select bits (CCP1M<3:0>). At the same time, the interrupt flag bit, CCP1IF, is set. 14.3.1 CCP PIN CONFIGURATION The user must configure the CCP1 pin as an output by clearing the appropriate TRIS bit. Note: Clearing the CCP1CON register will force the CCP1 compare output latch (depending on device configuration) to the default low level. This is not the PORTC I/O data latch. FIGURE 14-2: SOFTWARE INTERRUPT MODE When the Generate Software Interrupt mode is chosen (CCP1M<3:0> = 1010), the CCP1 pin is not affected. Only the CCP1IF interrupt flag is affected. 14.3.4 SPECIAL EVENT TRIGGER The CCP module is equipped with a Special Event Trigger. This is an internal hardware signal generated in Compare mode to trigger actions by other modules. The Special Event Trigger is enabled by selecting the Compare Special Event Trigger mode (CCP1M<3:0> = 1011). The Special Event Trigger resets the timer register pair for whichever timer resource is currently assigned as the module’s time base. This allows the CCPR1 registers to serve as a programmable period register for either timer. The Special Event Trigger can also start an A/D conversion. In order to do this, the A/D converter must already be enabled. COMPARE MODE OPERATION BLOCK DIAGRAM 0 TMR1H TMR1L 1 TMR3H TMR3L Special Event Trigger (Timer1/Timer3 Reset, A/D Trigger) T3CCP1 Set CCP1IF Comparator CCPR1H CCP1 pin Compare Match Output Logic 4 CCPR1L S Q R TRIS Output Enable CCP1CON<3:0> DS41350D-page 120 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4 PWM (Enhanced Mode) The PWM outputs are multiplexed with I/O pins and are designated P1A, P1B, P1C and P1D. The polarity of the PWM pins is configurable and is selected by setting the CCP1M bits in the CCP1CON register appropriately. The Enhanced PWM Mode can generate a PWM signal on up to four different output pins with up to 10-bits of resolution. It can do this through four different PWM output modes: • • • • Table 14-1 shows the pin assignments for each Enhanced PWM mode. Single PWM Half-Bridge PWM Full-Bridge PWM, Forward mode Full-Bridge PWM, Reverse mode Figure 14-3 shows an example of a simplified block diagram of the Enhanced PWM module. Note: To prevent the generation of an incomplete waveform when the PWM is first enabled, the ECCP module waits until the start of a new PWM period before generating a PWM signal. To select an Enhanced PWM mode, the P1M bits of the CCP1CON register must be set appropriately. FIGURE 14-3: EXAMPLE SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODE Duty Cycle Registers DC1B<1:0> CCP1M<3:0> 4 P1M<1:0> 2 CCPR1L CCP1/P1A CCP1/P1A TRIS CCPR1H (Slave) P1B R Comparator Output Controller Q P1B TRIS P1C TMR2 (1) Clear Timer2, toggle PWM pin and latch duty cycle PR2 1: S P1D Comparator Note P1C TRIS P1D TRIS PWM1CON The 8-bit timer TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler to create the 10-bit time base. Note 1: The TRIS register value for each PWM output must be configured appropriately. 2: Any pin not used by an Enhanced PWM mode is available for alternate pin functions. TABLE 14-2: EXAMPLE PIN ASSIGNMENTS FOR VARIOUS PWM ENHANCED MODES ECCP Mode P1M<1:0> CCP1/P1A P1B P1C P1D Yes(1) Yes(1) Yes(1) Single 00 Half-Bridge 10 Yes Yes No No Full-Bridge, Forward 01 Yes Yes Yes Yes Full-Bridge, Reverse 11 Yes Yes Yes Yes Note 1: Yes (1) Outputs are enabled by pulse steering in Single mode. See Register 14-4. 2010 Microchip Technology Inc. Preliminary DS41350D-page 121 PIC18F/LF1XK50 FIGURE 14-4: EXAMPLE PWM (ENHANCED MODE) OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE) P1M<1:0> Signal PR2+1 Pulse Width 0 Period 00 (Single Output) P1A Modulated Delay(1) Delay(1) P1A Modulated 10 (Half-Bridge) P1B Modulated P1A Active 01 (Full-Bridge, Forward) P1B Inactive P1C Inactive P1D Modulated P1A Inactive 11 (Full-Bridge, Reverse) P1B Modulated P1C Active P1D Inactive Relationships: • Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value) • Pulse Width = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value) • Delay = 4 * TOSC * (PWM1CON<6:0>) Note 1: Dead-band delay is programmed using the PWM1CON register (Section 14.4.6 “Programmable Dead-Band Delay mode”). DS41350D-page 122 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 14-5: EXAMPLE ENHANCED PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE) Signal P1M<1:0> PR2+1 Pulse Width 0 Period 00 (Single Output) P1A Modulated P1A Modulated 10 (Half-Bridge) Delay(1) Delay(1) P1B Modulated P1A Active 01 (Full-Bridge, Forward) P1B Inactive P1C Inactive P1D Modulated P1A Inactive 11 (Full-Bridge, Reverse) P1B Modulated P1C Active P1D Inactive Relationships: • Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value) • Pulse Width = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value) • Delay = 4 * TOSC * (PWM1CON<6:0>) Note 1: Dead-band delay is programmed using the PWM1CON register (Section 14.4.6 “Programmable Dead-Band Delay mode”). 2010 Microchip Technology Inc. Preliminary DS41350D-page 123 PIC18F/LF1XK50 14.4.1 HALF-BRIDGE MODE In Half-Bridge mode, two pins are used as outputs to drive push-pull loads. The PWM output signal is output on the CCP1/P1A pin, while the complementary PWM output signal is output on the P1B pin (see Figure 14-6). This mode can be used for Half-Bridge applications, as shown in Figure 14-7, or for Full-Bridge applications, where four power switches are being modulated with two PWM signals. In Half-Bridge mode, the programmable dead-band delay can be used to prevent shoot-through current in Half-Bridge power devices. The value of the PDC<6:0> bits of the PWM1CON register sets the number of instruction cycles before the output is driven active. If the value is greater than the duty cycle, the corresponding output remains inactive during the entire cycle. See Section 14.4.6 “Programmable Dead-Band Delay mode” for more details of the dead-band delay operations. Since the P1A and P1B outputs are multiplexed with the PORT data latches, the associated TRIS bits must be cleared to configure P1A and P1B as outputs. FIGURE 14-6: Period Period Pulse Width P1A(2) td td P1B(2) (1) (1) (1) td = Dead-Band Delay Note 1: 2: FIGURE 14-7: EXAMPLE OF HALF-BRIDGE PWM OUTPUT At this time, the TMR2 register is equal to the PR2 register. Output signals are shown as active-high. EXAMPLE OF HALF-BRIDGE APPLICATIONS Standard Half-Bridge Circuit (“Push-Pull”) FET Driver + P1A Load FET Driver + P1B - Half-Bridge Output Driving a Full-Bridge Circuit V+ FET Driver FET Driver P1A FET Driver Load FET Driver P1B DS41350D-page 124 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4.2 FULL-BRIDGE MODE In Full-Bridge mode, all four pins are used as outputs. An example of Full-Bridge application is shown in Figure 14-8. In the Forward mode, pin CCP1/P1A is driven to its active state, pin P1D is modulated, while P1B and P1C will be driven to their inactive state as shown in Figure 14-9. In the Reverse mode, P1C is driven to its active state, pin P1B is modulated, while P1A and P1D will be driven to their inactive state as shown Figure 14-9. P1A, P1B, P1C and P1D outputs are multiplexed with the PORT data latches. The associated TRIS bits must be cleared to configure the P1A, P1B, P1C and P1D pins as outputs. FIGURE 14-8: EXAMPLE OF FULL-BRIDGE APPLICATION V+ FET Driver QC QA FET Driver P1A Load P1B FET Driver P1C FET Driver QD QB VP1D 2010 Microchip Technology Inc. Preliminary DS41350D-page 125 PIC18F/LF1XK50 FIGURE 14-9: EXAMPLE OF FULL-BRIDGE PWM OUTPUT Forward Mode Period P1A (2) Pulse Width P1B(2) P1C(2) P1D(2) (1) (1) Reverse Mode Period Pulse Width P1A(2) P1B(2) P1C(2) P1D(2) (1) Note 1: 2: (1) At this time, the TMR2 register is equal to the PR2 register. Output signal is shown as active-high. DS41350D-page 126 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4.2.1 Direction Change in Full-Bridge Mode In the Full-Bridge mode, the P1M1 bit in the CCP1CON register allows users to control the forward/reverse direction. When the application firmware changes this direction control bit, the module will change to the new direction on the next PWM cycle. A direction change is initiated in software by changing the P1M1 bit of the CCP1CON register. The following sequence occurs prior to the end of the current PWM period: • The modulated outputs (P1B and P1D) are placed in their inactive state. • The associated unmodulated outputs (P1A and P1C) are switched to drive in the opposite direction. • PWM modulation resumes at the beginning of the next period. See Figure 14-10 for an illustration of this sequence. The Full-Bridge mode does not provide dead-band delay. As one output is modulated at a time, dead-band delay is generally not required. There is a situation where dead-band delay is required. This situation occurs when both of the following conditions are true: 1. 2. The direction of the PWM output changes when the duty cycle of the output is at or near 100%. The turn off time of the power switch, including the power device and driver circuit, is greater than the turn on time. Figure 14-11 shows an example of the PWM direction changing from forward to reverse, at a near 100% duty cycle. In this example, at time t1, the output P1A and P1D become inactive, while output P1C becomes active. Since the turn off time of the power devices is longer than the turn on time, a shoot-through current will flow through power devices QC and QD (see Figure 14-8) for the duration of ‘t’. The same phenomenon will occur to power devices QA and QB for PWM direction change from reverse to forward. If changing PWM direction at high duty cycle is required for an application, two possible solutions for eliminating the shoot-through current are: 1. 2. Reduce PWM duty cycle for one PWM period before changing directions. Use switch drivers that can drive the switches off faster than they can drive them on. Other options to prevent shoot-through current may exist. FIGURE 14-10: EXAMPLE OF PWM DIRECTION CHANGE Period(1) Signal Period P1A (Active-High) P1B (Active-High) Pulse Width P1C (Active-High) P1D (Active-High) Pulse Width Note 1: The direction bit P1M1 of the CCP1CON register is written any time during the PWM cycle. 2010 Microchip Technology Inc. Preliminary DS41350D-page 127 PIC18F/LF1XK50 FIGURE 14-11: EXAMPLE OF PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE Forward Period t1 Reverse Period P1A P1B PW P1C P1D PW TON External Switch C TOFF External Switch D Potential Shoot-Through Current Note 1: 14.4.3 T = TOFF – TON All signals are shown as active-high. 2: TON is the turn on delay of power switch QC and its driver. 3: TOFF is the turn off delay of power switch QD and its driver. START-UP CONSIDERATIONS When any PWM mode is used, the application hardware must use the proper external pull-up and/or pull-down resistors on the PWM output pins. Note: When the microcontroller is released from Reset, all of the I/O pins are in the high-impedance state. The external circuits must keep the power switch devices in the Off state until the microcontroller drives the I/O pins with the proper signal levels or activates the PWM output(s). The CCP1M<1:0> bits of the CCP1CON register allow the user to choose whether the PWM output signals are active-high or active-low for each pair of PWM output pins (P1A/P1C and P1B/P1D). The PWM output polarities must be selected before the PWM pin output drivers are enabled. Changing the polarity configuration while the PWM pin output drivers are enable is not recommended since it may result in damage to the application circuits. The P1A, P1B, P1C and P1D output latches may not be in the proper states when the PWM module is initialized. Enabling the PWM pin output drivers at the same time as the Enhanced PWM modes may cause damage to the application circuit. The Enhanced PWM modes must be enabled in the proper Output mode and complete a full PWM cycle before enabling the PWM pin output drivers. The completion of a full PWM cycle is indicated by the TMR2IF bit of the PIR1 register being set as the second PWM period begins. DS41350D-page 128 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4.4 ENHANCED PWM AUTO-SHUTDOWN MODE The PWM mode supports an Auto-Shutdown mode that will disable the PWM outputs when an external shutdown event occurs. Auto-Shutdown mode places the PWM output pins into a predetermined state. This mode is used to help prevent the PWM from damaging the application. The auto-shutdown sources are selected using the ECCPAS<2:0> bits of the ECCPAS register. A shutdown event may be generated by: • A logic ‘0’ on the INT0 pin • A logic ‘1’ on a comparator (Cx) output A shutdown condition is indicated by the ECCPASE (Auto-Shutdown Event Status) bit of the ECCPAS register. If the bit is a ‘0’, the PWM pins are operating normally. If the bit is a ‘1’, the PWM outputs are in the shutdown state. When a shutdown event occurs, two things happen: The ECCPASE bit is set to ‘1’. The ECCPASE will remain set until cleared in firmware or an auto-restart occurs (see Section 14.4.5 “Auto-Restart Mode”). The enabled PWM pins are asynchronously placed in their shutdown states. The PWM output pins are grouped into pairs [P1A/P1C] and [P1B/P1D]. The state of each pin pair is determined by the PSSAC and PSSBD bits of the ECCPAS register. Each pin pair may be placed into one of three states: • Drive logic ‘1’ • Drive logic ‘0’ • Tri-state (high-impedance) REGISTER 14-2: ECCP1AS: ENHANCED CAPTURE/COMPARE/PWM AUTO-SHUTDOWN CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 bit 7 bit 0 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 bit 7 ECCPASE: ECCP Auto-Shutdown Event Status bit 1 = A shutdown event has occurred; ECCP outputs are in shutdown state 0 = ECCP outputs are operating bit 6-4 ECCPAS<2:0>: ECCP Auto-shutdown Source Select bits 000 = Auto-Shutdown is disabled 001 = Comparator C1OUT output is high 010 = Comparator C2OUT output is high 011 = Either Comparator C1OUT or C2OUT is high 100 = VIL on INT0 pin 101 = VIL on INT0 pin or Comparator C1OUT output is high 110 = VIL on INT0 pin or Comparator C2OUT output is high 111 = VIL on INT0 pin or Comparator C1OUT or Comparator C2OUT is high bit 3-2 PSSACn: Pins P1A and P1C Shutdown State Control bits 00 = Drive pins P1A and P1C to ‘0’ 01 = Drive pins P1A and P1C to ‘1’ 1x = Pins P1A and P1C tri-state bit 1-0 PSSBDn: Pins P1B and P1D Shutdown State Control bits 00 = Drive pins P1B and P1D to ‘0’ 01 = Drive pins P1B and P1D to ‘1’ 1x = Pins P1B and P1D tri-state 2010 Microchip Technology Inc. Preliminary DS41350D-page 129 PIC18F/LF1XK50 Note 1: The auto-shutdown condition is a level-based signal, not an edge-based signal. As long as the level is present, the auto-shutdown will persist. 2: Writing to the ECCPASE bit is disabled while an auto-shutdown condition persists. 3: Once the auto-shutdown condition has been removed and the PWM restarted (either through firmware or auto-restart) the PWM signal will always restart at the beginning of the next PWM period. 4: Prior to an auto-shutdown event caused by a comparator output or INT pin event, a software shutdown can be triggered in firmware by setting the CCPxASE bit to a ‘1’. The auto-restart feature tracks the active status of a shutdown caused by a comparator output or INT pin event only so, if it is enabled at this time. It will immediately clear this bit and restart the ECCP module at the beginning of the next PWM period. FIGURE 14-12: PWM AUTO-SHUTDOWN WITH FIRMWARE RESTART (PRSEN = 0) PWM Period Shutdown Event ECCPASE bit PWM Activity Normal PWM Start of PWM Period DS41350D-page 130 ECCPASE Cleared by Shutdown Shutdown Firmware PWM Event Occurs Event Clears Resumes Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4.5 AUTO-RESTART MODE The Enhanced PWM can be configured to automatically restart the PWM signal once the auto-shutdown condition has been removed. Auto-restart is enabled by setting the PRSEN bit in the PWM1CON register. If auto-restart is enabled, the ECCPASE bit will remain set as long as the auto-shutdown condition is active. When the auto-shutdown condition is removed, the ECCPASE bit will be cleared via hardware and normal operation will resume. FIGURE 14-13: PWM AUTO-SHUTDOWN WITH AUTO-RESTART ENABLED (PRSEN = 1) PWM Period Shutdown Event ECCPASE bit PWM Activity Normal PWM Start of PWM Period 2010 Microchip Technology Inc. Shutdown Shutdown Event Occurs Event Clears Preliminary PWM Resumes DS41350D-page 131 PIC18F/LF1XK50 14.4.6 PROGRAMMABLE DEAD-BAND DELAY MODE FIGURE 14-14: In Half-Bridge applications where all power switches are modulated at the PWM frequency, the power switches normally require more time to turn off than to turn on. If both the upper and lower power switches are switched at the same time (one turned on, and the other turned off), both switches may be on for a short period of time until one switch completely turns off. During this brief interval, a very high current (shoot-through current) will flow through both power switches, shorting the bridge supply. To avoid this potentially destructive shoot-through current from flowing during switching, turning on either of the power switches is normally delayed to allow the other switch to completely turn off. Period Period Pulse Width P1A(2) td td P1B(2) (1) (1) (1) td = Dead-Band Delay Note 1: In Half-Bridge mode, a digitally programmable dead-band delay is available to avoid shoot-through current from destroying the bridge power switches. The delay occurs at the signal transition from the non-active state to the active state. See Figure 14-14 for illustration. The lower seven bits of the associated PWM1CON register (Register 14-3) sets the delay period in terms of microcontroller instruction cycles (TCY or 4 TOSC). FIGURE 14-15: EXAMPLE OF HALF-BRIDGE PWM OUTPUT 2: At this time, the TMR2 register is equal to the PR2 register. Output signals are shown as active-high. EXAMPLE OF HALF-BRIDGE APPLICATIONS V+ Standard Half-Bridge Circuit (“Push-Pull”) FET Driver + V - P1A Load FET Driver + V - P1B V- DS41350D-page 132 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 14-3: PWM1CON: ENHANCED PWM CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 PRSEN PDC6 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 bit 7 bit 0 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 bit 7 PRSEN: PWM Restart Enable bit 1 = Upon auto-shutdown, the ECCPASE bit clears automatically once the shutdown event goes away; the PWM restarts automatically 0 = Upon auto-shutdown, ECCPASE must be cleared by software to restart the PWM bit 6-0 PDC<6:0>: PWM Delay Count bits PDCn = Number of FOSC/4 (4 * TOSC) cycles between the scheduled time when a PWM signal should transition active and the actual time it transitions active 2010 Microchip Technology Inc. Preliminary DS41350D-page 133 PIC18F/LF1XK50 14.4.7 PULSE STEERING MODE In Single Output mode, pulse steering allows any of the PWM pins to be the modulated signal. Additionally, the same PWM signal can be simultaneously available on multiple pins. Once the Single Output mode is selected (CCP1M<3:2> = 11 and P1M<1:0> = 00 of the CCP1CON register), the user firmware can bring out the same PWM signal to one, two, three or four output pins by setting the appropriate STR<D:A> bits of the PSTRCON register, as shown in Table 14-2. REGISTER 14-4: Note: The associated TRIS bits must be set to output (‘0’) to enable the pin output driver in order to see the PWM signal on the pin. While the PWM Steering mode is active, CCP1M<1:0> bits of the CCP1CON register select the PWM output polarity for the P1<D:A> pins. The PWM auto-shutdown operation also applies to PWM Steering mode as described in Section 14.4.4 “Enhanced PWM Auto-shutdown mode”. An auto-shutdown event will only affect pins that have PWM outputs enabled. PSTRCON: PULSE STEERING CONTROL REGISTER(1) U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-1 — — — STRSYNC STRD STRC STRB STRA bit 7 bit 0 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 bit 7-5 Unimplemented: Read as ‘0’ bit 4 STRSYNC: Steering Sync bit 1 = Output steering update occurs on next PWM period 0 = Output steering update occurs at the beginning of the instruction cycle boundary bit 3 STRD: Steering Enable bit D 1 = P1D pin has the PWM waveform with polarity control from CCP1M<1:0> 0 = P1D pin is assigned to port pin bit 2 STRC: Steering Enable bit C 1 = P1C pin has the PWM waveform with polarity control from CCP1M<1:0> 0 = P1C pin is assigned to port pin bit 1 STRB: Steering Enable bit B 1 = P1B pin has the PWM waveform with polarity control from CCP1M<1:0> 0 = P1B pin is assigned to port pin bit 0 STRA: Steering Enable bit A 1 = P1A pin has the PWM waveform with polarity control from CCP1M<1:0> 0 = P1A pin is assigned to port pin Note 1: The PWM Steering mode is available only when the CCP1CON register bits CCP1M<3:2> = 11 and P1M<1:0> = 00. DS41350D-page 134 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 14-16: SIMPLIFIED STEERING BLOCK DIAGRAM STRA P1A Signal CCP1M1 PORT Data 0 STRB CCP1M0 PORT Data PORT Data 0 PORT Data P1B pin TRIS P1C pin 1 0 TRIS STRD CCP1M0 TRIS 1 STRC CCP1M1 P1A pin 1 P1D pin 1 0 TRIS Note 1: Port outputs are configured as shown when the CCP1CON register bits P1M<1:0> = 00 and CCP1M<3:2> = 11. 2: Single PWM output requires setting at least one of the STRx bits. 2010 Microchip Technology Inc. Preliminary DS41350D-page 135 PIC18F/LF1XK50 14.4.7.1 Steering Synchronization The STRSYNC bit of the PSTRCON register gives the user two selections of when the steering event will happen. When the STRSYNC bit is ‘0’, the steering event will happen at the end of the instruction that writes to the PSTRCON register. In this case, the output signal at the P1<D:A> pins may be an incomplete PWM waveform. This operation is useful when the user firmware needs to immediately remove a PWM signal from the pin. Figures 14-17 and 14-18 illustrate the timing diagrams of the PWM steering depending on the STRSYNC setting. When the STRSYNC bit is ‘1’, the effective steering update will happen at the beginning of the next PWM period. In this case, steering on/off the PWM output will always produce a complete PWM waveform. FIGURE 14-17: EXAMPLE OF STEERING EVENT AT END OF INSTRUCTION (STRSYNC = 0) PWM Period PWM STRn P1<D:A> PORT Data PORT Data P1n = PWM FIGURE 14-18: EXAMPLE OF STEERING EVENT AT BEGINNING OF INSTRUCTION (STRSYNC = 1) PWM STRn P1<D:A> PORT Data PORT Data P1n = PWM DS41350D-page 136 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 14.4.8 OPERATION IN POWER-MANAGED MODES In Sleep mode, all clock sources are disabled. Timer2 will not increment and the state of the module will not change. If the ECCP pin is driving a value, it will continue to drive that value. When the device wakes up, it will continue from this state. If Two-Speed Start-ups are enabled, the initial start-up frequency from HFINTOSC and the postscaler may not be stable immediately. In PRI_IDLE mode, the primary clock will continue to clock the ECCP module without change. In all other power-managed modes, the selected power-managed mode clock will clock Timer2. Other power-managed mode clocks will most likely be different than the primary clock frequency. 14.4.8.1 Operation with Fail-Safe Clock Monitor If the Fail-Safe Clock Monitor is enabled, a clock failure will force the device into the RC_RUN Power-Managed mode and the OSCFIF bit of the PIR2 register will be set. The ECCP will then be clocked from the internal oscillator clock source, which may have a different clock frequency than the primary clock. See the previous section for additional details. 14.4.9 EFFECTS OF A RESET Both Power-on Reset and subsequent Resets will force all ports to Input mode and the CCP registers to their Reset states. This forces the enhanced CCP module to reset to a state compatible with the standard CCP module. 2010 Microchip Technology Inc. Preliminary DS41350D-page 137 PIC18F/LF1XK50 TABLE 14-3: Name INTCON REGISTERS ASSOCIATED WITH ECCP1 MODULE AND TIMER1 TO TIMER3 Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 IPEN SBOREN — RI TO PD POR BOR 286 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — 290 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 RCON TMR1L Timer1 Register, Low Byte 288 TMR1H Timer1 Register, High Byte 288 T1CON TMR2 T2CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON Timer2 Register — 288 288 T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 288 PR2 Timer2 Period Register 288 TMR3L Timer3 Register, Low Byte 289 TMR3H Timer3 Register, High Byte T3CON RD16 — 289 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 289 CCPR1L Capture/Compare/PWM Register 1, Low Byte 289 CCPR1H Capture/Compare/PWM Register 1, High Byte 289 CCP1CON ECCP1AS PWM1CON Legend: P1M1 P1M0 ECCPASE ECCPAS2 PRSEN PDC6 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 289 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1 PSSBD0 289 PDC5 PDC4 PDC3 PDC2 PDC1 PDC0 289 — = unimplemented, read as ‘0’. Shaded cells are not used during ECCP operation. DS41350D-page 138 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.0 15.1 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE 15.2 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: 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, display 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) • Serial Data Out – SDO • Serial Data In – SDI • Serial Clock – SCK Additionally, a fourth pin may be used when in a Slave mode of operation: • Slave Select – SS Figure 15-1 shows the block diagram of the MSSP module when operating in SPI mode. FIGURE 15-1: MSSP BLOCK DIAGRAM (SPI MODE) The I2C interface supports the following modes in hardware: Internal Data Bus Read • Master mode • Multi-Master mode • Slave mode Write SSPBUF Reg SDI/SDA SSPSR Reg Shift Clock SDO bit 0 SS SS Control Enable Edge Select 2 Clock Select SSPM<3:0> 4 SCK/SCL Edge Select (TMR22Output) Prescaler TOSC 4, 16, 64 TRIS bit 2010 Microchip Technology Inc. Preliminary DS41350D-page 139 PIC18F/LF1XK50 15.2.1 REGISTERS SSPSR is the shift register used for shifting data in and out. SSPBUF provides indirect access to the SSPSR register. SSPBUF is the buffer register to which data bytes are written, and from which data bytes are read. The MSSP module has four registers for SPI mode operation. These are: • • • • SSPCON1 – Control Register SSPSTAT – STATUS register SSPBUF – Serial Receive/Transmit Buffer SSPSR – Shift Register (Not directly accessible) 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. SSPCON1 and SSPSTAT are the control and STATUS registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper two bits of the SSPSTAT are read/write. REGISTER 15-1: During transmission, the SSPBUF is not double-buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. SSPSTAT: MSSP STATUS REGISTER (SPI MODE) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE D/A P S R/W UA BF bit 7 bit 0 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 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 Select bit(1) 1 = Transmit occurs on transition from active to Idle clock state 0 = Transmit occurs on transition from Idle to active clock state 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 Information bit Used in I2C mode only. bit 1 UA: Update Address bit 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 Note 1: Polarity of clock state is set by the CKP bit of the SSPCON1 register. DS41350D-page 140 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 15-2: SSPCON1: MSSP CONTROL 1 REGISTER (SPI MODE) 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 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 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 by software) 0 = No collision bit 6 SSPOV: Receive Overflow Indicator bit(1) 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 by software). 0 = No overflow bit 5 SSPEN: Synchronous Serial Port Enable bit(2) 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 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 SSPM<3:0>: Synchronous Serial Port Mode Select bits(3) 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 1: 2: 3: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the SSPBUF register. When enabled, these pins must be properly configured as input or output. Bit combinations not specifically listed here are either reserved or implemented in I2C mode only. 2010 Microchip Technology Inc. Preliminary DS41350D-page 141 PIC18F/LF1XK50 15.2.2 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 register. Then, the Buffer Full detect bit, BF of the SSPSTAT register, 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 of the SSPCON1 register, will be set. User software must clear the WCOL bit to allow the following write(s) to the SSPBUF register to complete successfully. EXAMPLE 15-1: LOOP 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. The Buffer Full bit, BF of the SSPSTAT register, 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 completed. 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 register. Additionally, the MSSP STATUS register (SSPSTAT) indicates the various status conditions. LOADING THE SSPBUF (SSPSR) REGISTER BTFSS BRA MOVF SSPSTAT, BF LOOP SSPBUF, W ;Has data been received (transmit complete)? ;No ;WREG reg = contents of SSPBUF MOVWF RXDATA ;Save in user RAM, if data is meaningful MOVF MOVWF TXDATA, W SSPBUF ;W reg = contents of TXDATA ;New data to xmit DS41350D-page 142 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.2.3 ENABLING SPI I/O 15.2.4 To enable the serial port, SSP Enable bit, SSPEN of the SSPCON1 register, must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, reinitialize 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 function, some must have their data direction bits (in the TRIS register) appropriately programmed as follows: • SDI is automatically controlled by the SPI module • SDO must have corresponding TRIS bit cleared • SCK (Master mode) must have corresponding TRIS bit cleared • SCK (Slave mode) must have corresponding TRIS bit set • SS must have corresponding TRIS bit set 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 programmed clock edge and latched on the opposite edge of the clock. Both processors should be programmed 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 Any serial port function that is not desired may be overridden by programming the corresponding data direction (TRIS) register to the opposite value. FIGURE 15-2: TYPICAL SPI MASTER/SLAVE CONNECTION SPI Master SSPM<3:0> = 00xx SPI Slave SSPM<3:0> = 010x SDO SDI Serial Input Buffer (SSPBUF) SDI Shift Register (SSPSR) MSb Serial Input Buffer (SSPBUF) LSb SCK General I/O Processor 1 2010 Microchip Technology Inc. SDO Serial Clock Slave Select (optional) Preliminary Shift Register (SSPSR) MSb LSb SCK SS Processor 2 DS41350D-page 143 PIC18F/LF1XK50 15.2.5 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 disabled (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). FIGURE 15-3: The clock polarity is selected by appropriately programming the CKP bit of the SSPCON1 register. 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: • • • • FOSC/4 (or TCY) FOSC/16 (or 4 • TCY) FOSC/64 (or 16 • TCY) Timer2 output/2 This allows a maximum data rate (at 64 MHz) of 16.00 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. SPI MODE WAVEFORM (MASTER MODE) Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) 4 Clock Modes SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SDO (CKE = 1) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SDI (SMP = 0) bit 0 bit 7 Input Sample (SMP = 0) SDI (SMP = 1) bit 0 bit 7 Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF DS41350D-page 144 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.2.6 SLAVE MODE 15.2.7 In Slave mode, the data is transmitted and received as external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. Before enabling the module in SPI Slave mode, the clock line must match the proper Idle state. The clock line can be observed by reading the SCK pin. The Idle state is determined by the CKP bit of the SSPCON1 register. 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. 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> = 0100). When the SS pin is low, transmission 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. 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: When the SPI is used in Slave mode with CKE set the SS pin control must also be enabled. 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. FIGURE 15-4: SLAVE SYNCHRONIZATION WAVEFORM SS SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit 7 bit 6 bit 7 bit 0 bit 0 bit 7 bit 7 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF 2010 Microchip Technology Inc. Preliminary DS41350D-page 145 PIC18F/LF1XK50 FIGURE 15-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0) SS Optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 0 bit 7 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF FIGURE 15-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1) SS Not Optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO bit 7 SDI (SMP = 0) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 0 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF DS41350D-page 146 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.2.8 OPERATION IN POWER-MANAGED MODES 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. In SPI Master mode, module clocks may be operating at a different speed than when in full power mode; in the case of the Sleep mode, all clocks are halted. 15.2.9 In all Idle modes, a clock is provided to the peripherals. That clock could be from the primary clock source, the secondary clock (Timer1 oscillator at 32.768 kHz) or the INTOSC source. See Section 19.0 “Power-Managed Modes” for additional information. 15.2.10 In most cases, the speed that the master clocks SPI data is not important; however, this should be evaluated for each system. EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. BUS MODE COMPATIBILITY Table 15-1 shows the compatibility between the standard SPI modes and the states of the CKP and CKE control bits. TABLE 15-1: When MSSP interrupts are enabled, after the master completes sending data, an MSSP interrupt will wake the controller: SPI BUS MODES Control Bits State Standard SPI Mode Terminology CKP CKE • from Sleep, in slave mode • from Idle, in slave or master mode 0, 0 0 1 0, 1 0 0 If an exit from Sleep or Idle mode is not desired, MSSP interrupts should be disabled. 1, 0 1 1 1, 1 1 0 In SPI master mode, when the Sleep mode is selected, all module clocks are halted and the transmission/reception will remain in that state until the devices wakes. After the device returns to RUN mode, the module will resume transmitting and receiving data. There is also an SMP bit which controls when the data is sampled. In SPI Slave mode, the SPI Transmit/Receive Shift register operates asynchronously to the device. This allows the device to be placed in any power-managed mode and data to be shifted into the SPI TABLE 15-2: Name INTCON REGISTERS ASSOCIATED WITH SPI OPERATION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 TRISB7 TRISB6 TRISB5 TRISB4 — — — — 290 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 TRISB TRISC SSPBUF TRISC7 SSP Receive Buffer/Transmit Register 288 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 288 SSPSTAT SMP CKE D/A P S R/W UA BF 288 Legend: Shaded cells are not used by the MSSP in SPI mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 147 PIC18F/LF1XK50 15.3 I2C Mode 15.3.1 The MSSP module in I 2C mode fully implements all master and slave functions (including general call support) and provides interrupts on Start and Stop bits in hardware to determine a free bus (multi-master function). 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 • Serial data – SDA Note: The user must configure these pins as inputs with the corresponding TRIS bits. FIGURE 15-7: MSSP BLOCK DIAGRAM (I2C™ MODE) Internal Data Bus Read Write SSPSR Reg LSb MSb Addr Match SSPADD Reg Start and Stop bit Detect DS41350D-page 148 MSSP Control Register 1 (SSPCON1) MSSP Control Register 2 (SSPCON2) MSSP Status register (SSPSTAT) Serial Receive/Transmit Buffer Register (SSPBUF) • MSSP Shift Register (SSPSR) – Not directly accessible • MSSP Address Register (SSPADD) • MSSP Address Mask (SSPMSK) SSPCON1, SSPCON2 and SSPSTAT are the control and STATUS registers in I2C mode operation. The SSPCON1 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. 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. SSPMSK Reg Match Detect • • • • When the MSSP is configured in Master mode, the SSPADD register acts as the Baud Rate Generator reload value. When the MSSP is configured for I2C slave mode the SSPADD register holds the slave device address. The MSSP can be configured to respond to a range of addresses by qualifying selected bits of the address register with the SSPMSK register. Shift Clock SDI/SDA The MSSP module has seven registers for I2C operation. These are: 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. SSPBUF Reg SCK/SCL REGISTERS Set, Reset S, P bits (SSPSTAT Reg) During transmission, the SSPBUF is not double-buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 15-3: R/W-0 SSPSTAT: MSSP STATUS REGISTER (I2C MODE) R/W-0 SMP CKE R-0 R-0 R-0 D/A (1) (1) P S R-0 R/W (2, 3) R-0 R-0 UA BF bit 7 bit 0 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 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 was an address bit 4 P: Stop bit(1) 1 = Indicates that a Stop bit has been detected last 0 = Stop bit was not detected last bit 3 S: Start bit(1) 1 = Indicates that a Start bit has been detected last 0 = Start bit was not detected last bit 2 R/W: Read/Write Information bit (I2C mode only)(2, 3) In Slave mode: 1 = Read 0 = Write In Master mode: 1 = Transmit is in progress 0 = Transmit is not in progress bit 1 UA: Update Address bit (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 = SSPBUF is full 0 = SSPBUF is empty In Receive mode: 1 = SSPBUF is full (does not include the ACK and Stop bits) 0 = SSPBUF is empty (does not include the ACK and Stop bits) Note 1: 2: 3: This bit is cleared on Reset and when SSPEN is cleared. 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. ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the Master mode is active. 2010 Microchip Technology Inc. Preliminary DS41350D-page 149 PIC18F/LF1XK50 REGISTER 15-4: SSPCON1: MSSP CONTROL 1 REGISTER (I2C MODE) 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 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 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 by 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 by 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 by 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 When enabled, the SDA and SCL pins must be properly configured as inputs. 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 SSPM<3:0>: 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 Bit combinations not specifically listed here are either reserved or implemented in SPI mode only. DS41350D-page 150 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 15-5: R/W-0 SSPCON2: MSSP CONTROL REGISTER (I2C MODE) R/W-0 GCEN ACKSTAT R/W-0 (2) ACKDT R/W-0 (1) ACKEN R/W-0 (1) RCEN R/W-0 (1) PEN R/W-0 (1) RSEN R/W-0 SEN(1) bit 7 bit 0 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 bit 7 GCEN: General Call Enable bit (Slave mode only) 1 = Generate interrupt when a general call address 0x00 or 00h 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)(2) 1 = Not Acknowledge 0 = Acknowledge bit 4 ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(1) 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) 1 = Enables Receive mode for I2C 0 = Receive Idle bit 2 PEN: Stop Condition Enable bit (Master mode only)(1) 1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Stop condition Idle bit 1 RSEN: Repeated Start Condition Enable bit (Master mode only)(1) 1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated Start condition Idle bit 0 SEN: Start Condition Enable/Stretch Enable bit(1) 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 disabled Note 1: 2: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the Idle mode, these bits may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive. 2010 Microchip Technology Inc. Preliminary DS41350D-page 151 PIC18F/LF1XK50 15.3.2 OPERATION 15.3.3.1 The MSSP module functions are enabled by setting SSPEN bit of the SSPCON1 register. The SSPCON1 register allows control of the I 2C operation. Four mode selection bits of the SSPCON1 register allow one of the following I 2C modes to be selected: I2C Master mode, clock = (FOSC/(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 mode, slave is Idle • • • • Selection of any I 2C mode with the SSPEN bit set, forces the SCL and SDA pins to be open-drain, provided these pins are programmed to inputs by setting the appropriate TRIS bits Note: 15.3.3 To ensure proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins. SLAVE MODE In Slave mode, the SCL and SDA pins must be configured as inputs. The MSSP module will override the input state with the output data when required (slave-transmitter). The I 2C 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 automatically 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 bit of the SSPSTAT register, is set before the transfer is received. • The overflow bit, SSPOV bit of the SSPCON1 register, is set before the transfer is received. In this case, the SSPSR register value is not loaded into the SSPBUF, but bit SSPIF of the PIR1 register 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 Section 27.0 “Electrical Specifications”. DS41350D-page 152 Addressing Once the MSSP module has been enabled, it waits for a Start condition to occur. Following the Start condition, 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. 2. 3. 4. The SSPSR register value is loaded into the SSPBUF register. The Buffer Full bit, BF, is set. An ACK pulse is generated. MSSP Interrupt Flag bit, SSPIF of the PIR1 register, 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 of the SSPSTAT register 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 UA of the SSPSTAT register are set). 2. Read the SSPBUF register (clears bit BF) and clear flag bit, SSPIF. 3. Update the SSPADD register with second (low) byte of address (clears bit UA and releases the SCL line). 4. Receive second (low) byte of address (bits SSPIF, BF and UA are set). If the address matches then the SCL is held until the next step. Otherwise the SCL line is not held. 5. Read the SSPBUF register (clears bit BF) and clear flag bit, SSPIF. 6. Update the SSPADD register with the first (high) byte of address. (This will clear bit UA and release a held SCL line.) 7. Receive Repeated Start condition. 8. Receive first (high) byte of address with R/W bit set (bits SSPIF, BF, R/W are set). 9. Read the SSPBUF register (clears bit BF) and clear flag bit, SSPIF. 10. Load SSPBUF with byte the slave is to transmit, sets the BF bit. 11. Set the CKP bit to release SCL. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.3.2 Reception 15.3.3.3 When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into 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 bit of the SSPSTAT register is set, or bit SSPOV bit of the SSPCON1 register is set. An MSSP interrupt is generated for each data transfer byte. Flag bit, SSPIF of the PIR1 register, must be cleared by software. When the SEN bit of the SSPCON2 register is set, SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting the CKP bit of the SSPCON1 register. See Section 15.3.4 “Clock Stretching” for more detail. 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 SCK/SCL is held low regardless of SEN (see Section 15.3.4 “Clock Stretching” 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 SCK/SCL should be released by setting the CKP bit of the SSPCON1 register. 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 complete. In this case, when the ACK is latched by the slave, the slave logic is reset (resets SSPSTAT register) 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 SCK/SCL must be released by setting bit CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared by 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 153 DS41350D-page 154 Preliminary CKP 2 A6 3 A5 4 A4 5 A3 6 A2 (CKP does not reset to ‘0’ when SEN = 0) SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 SCL S A7 7 A1 8 9 ACK R/W = 0 1 D7 3 4 D4 5 D3 Receiving Data D5 Cleared by software SSPBUF is read 2 D6 6 D2 7 D1 8 D0 9 ACK 1 D7 2 D6 3 4 D4 5 D3 Receiving Data D5 6 D2 7 D1 8 D0 Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. 9 ACK FIGURE 15-8: SDA Receiving Address PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. Preliminary CKP 2 A6 Data in sampled 1 BF (SSPSTAT<0>) SSPIF (PIR1<3>) S A7 3 4 A4 5 A3 6 A2 Receiving Address A5 8 R/W = 0 9 ACK 1 D7 SCL held low while CPU responds to SSPIF SSPBUF is read by software 7 A1 3 D5 4 5 D3 CKP is set by software SSPBUF is written by software 6 D2 Transmitting Data D4 Cleared by software 2 D6 7 8 D0 9 ACK From SSPIF ISR D1 1 D7 4 D4 5 D3 6 D2 CKP is set by software 7 8 D0 9 ACK From SSPIF ISR D1 Transmitting Data Cleared by software 3 D5 SSPBUF is written by software 2 D6 Bus master terminates software P FIGURE 15-9: SCL SDA PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS) DS41350D-page 155 DS41350D-page 156 2 1 Preliminary 4 1 5 0 7 A8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 6 A9 8 9 (CKP does not reset to ‘0’ when SEN = 0) UA (SSPSTAT<1>) SSPOV (SSPCON1<6>) CKP 3 1 Cleared by software BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 SCL S 1 ACK R/W = 0 A7 2 4 A4 5 A3 6 A2 8 9 A0 ACK UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address 7 A1 Cleared by software 3 A5 Dummy read of SSPBUF to clear BF flag 1 A6 Receive Second Byte of Address 1 D7 4 5 6 7 Cleared by software 3 8 9 1 2 4 5 6 7 8 D1 D0 Cleared by software 3 D3 D2 Receive Data Byte D1 D0 ACK D7 D6 D5 D4 Cleared by hardware when SSPADD is updated with high byte of address 2 D3 D2 Receive Data Byte D6 D5 D4 Clock is held low until update of SSPADD has taken place 9 P Bus master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. ACK FIGURE 15-10: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. Preliminary CKP UA BF SSPIF 1 SCL S 1 2 1 4 1 5 0 6 7 A9 A8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 3 1 8 9 ACK R/W = 0 1 3 4 5 Cleared in software 2 7 UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address. 6 A6 A5 A4 A3 A2 A1 8 A0 Receive Second Byte of Address Dummy read of SSPBUF to clear BF flag A7 9 ACK Clock is held low until update of SSPADD has taken place 2 3 1 4 1 Cleared in software 1 1 5 0 6 7 A9 A8 Cleared by hardware when SSPADD is updated with high byte of address. Dummy read of SSPBUF to clear BF flag Sr 1 Receive First Byte of Address Bus Master sends Restarts condition 8 9 ACK R/W=1 4 5 6 Cleared in software 3 Write of SSPBUF 2 9 P Completion of data transmission clears BF flag 8 ACK CKP is automatically cleared in hardware holding SCL low CKP is set in software, initiates transmission 7 D4 D3 D2 D1 D0 Dummy read of SSPBUF to clear BF flag 1 D7 D6 D5 Transmitting Data Byte Clock is held low until CKP is set to ‘1’ Bus Master sends Stop condition FIGURE 15-11: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS) DS41350D-page 157 PIC18F/LF1XK50 15.3.3.4 SSP Mask Register This register must be initiated prior to setting SSPM<3:0> bits to select the I2C Slave mode (7-bit or 10-bit address). 2 An SSP Mask (SSPMSK) register is available in I C Slave mode as a mask for the value held in the SSPSR register during an address comparison operation. A zero (‘0’) bit in the SSPMSK register has the effect of making the corresponding bit in the SSPSR register a “don’t care”. The SSP Mask register is active during: • 7-bit Address mode: address compare of A<7:1>. • 10-bit Address mode: address compare of A<7:0> only. The SSP mask has no effect during the reception of the first (high) byte of the address. This register is reset to all ‘1’s upon any Reset condition and, therefore, has no effect on standard SSP operation until written with a mask value. REGISTER 15-6: SSPMSK: SSP MASK REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0(1) bit 7 bit 0 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 bit 7-1 MSK<7:1>: Mask bits 1 = The received address bit n is compared to SSPADD<n> to detect I2C address match 0 = The received address bit n is not used to detect I2C address match bit 0 MSK<0>: Mask bit for I2C Slave mode, 10-bit Address(1) I2C Slave mode, 10-bit Address (SSPM<3:0> = 0111): 1 = The received address bit 0 is compared to SSPADD<0> to detect I2C address match 0 = The received address bit 0 is not used to detect I2C address match Note 1: The MSK0 bit is used only in 10-bit slave mode. In all other modes, this bit has no effect. DS41350D-page 158 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 SSPADD: MSSP ADDRESS AND BAUD RATE REGISTER (I2C MODE) REGISTER 15-7: R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADD7 ADD6 ADD5 ADD4 ADD3 ADD2 ADD1 ADD0 bit 7 bit 0 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 Master mode: bit 7-0 ADD<7:0>: Baud Rate Clock Divider bits SCL pin clock period = ((ADD<7:0> + 1) *4)/FOSC 10-Bit Slave mode — Most significant address byte: bit 7-3 Not used: Unused for Most Significant Address Byte. Bit state of this register is a “don’t care.” Bit pattern sent by master is fixed by I2C specification and must be equal to ‘11110’. However, those bits are compared by hardware and are not affected by the value in this register. bit 2-1 ADD<9:8>: Two Most Significant bits of 10-bit address bit 0 Not used: Unused in this mode. Bit state is a “don’t care.” 10-Bit Slave mode — Least significant address byte: bit 7-0 ADD<7:0>: Eight Least Significant bits of 10-bit address 7-Bit Slave mode: bit 7-1 ADD<6:0>: 7-bit address bit 0 Not used: Unused in this mode. Bit state is a “don’t care.” 2010 Microchip Technology Inc. Preliminary DS41350D-page 159 PIC18F/LF1XK50 15.3.4 CLOCK STRETCHING 15.3.4.3 Both 7-bit and 10-bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit of the SSPCON2 register 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. 15.3.4.1 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 of the SSPCON1 register is automatically 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 data transfer sequence. This will prevent buffer overruns from occurring (see Figure 15-13). 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 by 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. 15.3.4.2 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. This occurs regardless of the state of the SEN bit. The user’s ISR must set the CKP bit before transmission 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 data transfer sequence (see Figure 15-9). 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 by software regardless of the state of the BF bit. 15.3.4.4 Clock Stretching for 10-bit Slave Transmit Mode In 10-bit Slave Transmit mode, clock stretching is controlled 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 automatic with the hardware clearing CKP, as in 7-bit Slave Transmit mode (see Figure 15-11). 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. DS41350D-page 160 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.4.5 Clock Synchronization and the CKP bit When the CKP bit is cleared, the SCL output is forced to ‘0’. However, clearing the CKP bit will not assert the SCL output low until the SCL output is already sampled low. Therefore, 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 deasserted 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 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 SDA DX DX – 1 SCL CKP Master device asserts clock Master device deasserts clock WR SSPCON1 2010 Microchip Technology Inc. Preliminary DS41350D-page 161 DS41350D-page 162 Preliminary CKP SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 SCL S A7 2 A6 3 4 A4 5 A3 6 A2 Receiving Address A5 7 A1 8 9 ACK R/W = 0 3 4 D4 5 D3 Receiving Data D5 Cleared by software 2 D6 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 SSPBUF is read 1 D7 6 D2 7 D1 9 ACK 1 D7 BF is set after falling edge of the 9th clock, CKP is reset to ‘0’ and clock stretching occurs 8 D0 3 4 D4 5 D3 Receiving Data D5 CKP written to ‘1’ in software 2 D6 Clock is held low until CKP is set to ‘1’ 6 D2 7 D1 8 D0 Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. 9 ACK Clock is not held low because ACK = 1 FIGURE 15-13: SDA Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. 2 1 Preliminary UA (SSPSTAT<1>) SSPOV (SSPCON1<6>) CKP 3 1 4 1 5 0 6 7 A9 A8 8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR Cleared by software BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 SCL S 1 9 ACK R/W = 0 A7 2 4 A4 5 A3 6 A2 Cleared by software 3 A5 7 A1 8 A0 Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address after falling edge of ninth clock Dummy read of SSPBUF to clear BF flag 1 A6 Receive Second Byte of Address 9 ACK 2 4 5 6 7 9 Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. Cleared by hardware when SSPADD is updated with high byte of address after falling edge of ninth clock 8 ACK 1 4 5 6 7 8 9 ACK Bus master terminates transfer P Clock is not held low because ACK = 1 SSPOV is set because SSPBUF is still full. ACK is not sent. D1 D0 Cleared by software 3 CKP written to ‘1’ by software 2 D3 D2 Receive Data Byte D7 D6 D5 D4 Clock is held low until CKP is set to ‘1’ D1 D0 Cleared by software 3 D3 D2 Dummy read of SSPBUF to clear BF flag 1 D7 D6 D5 D4 Receive Data Byte Clock is held low until update of SSPADD has taken place FIGURE 15-14: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F/LF1XK50 I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS) DS41350D-page 163 PIC18F/LF1XK50 15.3.5 GENERAL CALL ADDRESS SUPPORT 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. The addressing procedure for the I2C bus is such that the first byte after the Start condition usually determines 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. When the interrupt is serviced, the source for the interrupt 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 of the SSPSTAT register is set. 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). 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 GCEN bit of the SSPCON2 is 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. FIGURE 15-15: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESS MODE) Address is compared to General Call Address after ACK, set interrupt R/W = 0 ACK D7 General Call Address SDA SCL S 1 2 3 4 5 6 7 8 9 1 Receiving Data ACK D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 9 SSPIF BF (SSPSTAT<0>) Cleared by software SSPBUF is read SSPOV (SSPCON1<6>) ‘0’ GCEN (SSPCON2<7>) ‘1’ DS41350D-page 164 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 MASTER MODE Note: 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 I 2C bus may be taken when the P bit is set, or the bus is Idle, with both the S and P bits clear. The following events will cause the SSP Interrupt Flag bit, SSPIF, to be set (SSP interrupt, if enabled): In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on Start and Stop bit conditions. • • • • • Once Master mode is enabled, the user has six options. 1. 2. 3. 4. 5. 6. Assert a Start condition on SDA and SCL. Assert a Repeated Start condition on SDA and SCL. Write to the SSPBUF register initiating transmission of data/address. Configure the I2C port to receive data. Generate an Acknowledge condition at the end of a received byte of data. Generate a Stop condition on SDA and SCL. FIGURE 15-16: 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. Start condition Stop condition Data transfer byte transmitted/received Acknowledge transmit Repeated Start MSSP BLOCK DIAGRAM (I2C™ MASTER MODE) Internal Data Bus Read SSPM<3:0> SSPADD<6:0> Write SSPBUF SDA Baud Rate Generator Shift Clock SDA In SCL In Bus Collision 2010 Microchip Technology Inc. LSb Start bit, Stop bit, Acknowledge Generate Start bit Detect Stop bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV Preliminary Clock Cntl SCL Receive Enable SSPSR MSb Clock Arbitrate/WCOL Detect (hold off clock source) 15.3.6 Set/Reset, S, P, WCOL Set SSPIF, BCLIF Reset ACKSTAT, PEN DS41350D-page 165 PIC18F/LF1XK50 15.3.6.1 I2C Master Mode Operation A typical transmit sequence would go as follows: The master device generates all of the serial clock pulses and the Start and Stop conditions. A transfer is ended with a Stop condition or with a Repeated Start condition. Since the Repeated Start condition 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 transmitted, 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 contains 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 the 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. A Baud Rate Generator is used to set the clock frequency output on SCL. See Section 15.3.7 “Baud Rate” for more detail. DS41350D-page 166 1. The user generates a Start condition by setting the SEN bit of the SSPCON2 register. 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 ACKSTAT bit of the SSPCON2 register. 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 ACKSTAT bit of the SSPCON2 register. 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 PEN bit of the SSPCON2 register. 12. Interrupt is generated once the Stop condition is complete. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.7 BAUD RATE 2 In I C Master mode, the Baud Rate Generator (BRG) reload value is placed in the SSPADD register (Figure 15-17). When a write occurs to SSPBUF, the Baud Rate Generator will automatically begin counting. Table 15-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD. EQUATION 15-1: Once the given operation is complete (i.e., transmission 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. FIGURE 15-17: FOSC FSCL = --------------------------------------------- SSPADD + 1 4 BAUD RATE GENERATOR BLOCK DIAGRAM SSPM<3:0> SSPM<3:0> Reload SCL Control CLKOUT Reload BRG Down Counter FOSC/2 I2C™ CLOCK RATE W/BRG TABLE 15-3: Note 1: SSPADD<7:0> FOSC FCY BRG Value FSCL (2 Rollovers of BRG) 48 MHz 12 MHz 0Bh 1 MHz(1) 48 MHz 12 MHz 1Dh 400 kHz 48 MHz 12 MHz 77h 100 kHz 40 MHz 10 MHz 18h 400 kHz(1) 40 MHz 10 MHz 1Fh 312.5 kHz 40 MHz 10 MHz 63h 100 kHz 16 MHz 4 MHz 09h 400 kHz(1) 16 MHz 4 MHz 0Ch 308 kHz 16 MHz 4 MHz 27h 100 kHz 4 MHz 1 MHz 02h 333 kHz(1) 4 MHz 1 MHz 09h 100 kHz 4 MHz 1 MHz 00h 1 MHz(1) I2C I2C The interface does not conform to the 400 kHz 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 167 PIC18F/LF1XK50 15.3.7.1 Clock Arbitration Clock arbitration occurs when the master, during any receive, transmit or Repeated Start/Stop condition, deasserts 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 DX DX – 1 SCL deasserted but slave holds SCL low (clock arbitration) SCL allowed to transition high SCL BRG decrements on Q2 and Q4 cycles BRG Value 03h 02h 01h 00h (hold off) 03h 02h SCL is sampled high, reload takes place and BRG starts its count BRG Reload DS41350D-page 168 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.8 I2C MASTER MODE START CONDITION TIMING Note: To initiate a Start condition, the user sets the Start Enable bit, SEN bit of the SSPCON2 register. If the SDA and SCL pins are sampled high, the Baud Rate Generator 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 of the SSPSTAT1 register to be set. Following this, the Baud Rate Generator is reloaded with the contents of SSPADD<7:0> and resumes its count. When the Baud Rate Generator times out (TBRG), the SEN bit of the SSPCON2 register will be automatically cleared by hardware; the Baud Rate Generator is suspended, leaving the SDA line held low and the Start condition is complete. FIGURE 15-19: 15.3.8.1 If at the beginning of the Start condition, the SDA and SCL pins are already sampled 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. WCOL Status Flag If the user writes the SSPBUF when a Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the Start condition is complete. FIRST START BIT TIMING Write to SEN bit occurs here Set S bit (SSPSTAT<3>) SDA = 1, SCL = 1 TBRG At completion of Start bit, hardware clears SEN bit and sets SSPIF bit TBRG Write to SSPBUF occurs here 1st bit SDA 2nd bit TBRG SCL TBRG S 2010 Microchip Technology Inc. Preliminary DS41350D-page 169 PIC18F/LF1XK50 15.3.9 I2C MASTER MODE REPEATED START CONDITION TIMING Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. A Repeated Start condition occurs when the RSEN bit of the SSPCON2 register 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 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 deasserted (brought high). When SCL is sampled high, the Baud Rate Generator is reloaded 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 of the SSPCON2 register 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 of the SSPSTAT register will be set. The SSPIF bit will not be set until the Baud Rate Generator has timed out. 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’. 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). 15.3.9.1 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). Note: FIGURE 15-20: WCOL Status Flag Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start condition is complete. REPEAT START CONDITION WAVEFORM Write to SSPCON2 occurs here. SDA = 1, SCL (no change). S bit set by hardware SDA = 1, SCL = 1 TBRG At completion of Start bit, hardware clears RSEN bit and sets SSPIF TBRG TBRG 1st bit SDA RSEN bit set by hardware on falling edge of ninth clock, end of Xmit Write to SSPBUF occurs here TBRG SCL TBRG Sr = Repeated Start DS41350D-page 170 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.10 I2C MASTER MODE TRANSMISSION 15.3.10.3 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 transmission. 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 SP106). 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 SP107). 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 falling 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 suspended 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 the 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 falling edge of the eighth clock, the master will deassert 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 of the SSPCON2 register. Following the falling edge of the ninth clock transmission 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. 15.3.10.1 BF Status Flag In Transmit mode, the BF bit of the SSPSTAT register is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out. 15.3.10.2 ACKSTAT Status Flag In Transmit mode, the ACKSTAT bit of the SSPCON2 register 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. 15.3.11 I2C MASTER MODE RECEPTION Master mode reception is enabled by programming the Receive Enable bit, RCEN bit of the SSPCON2 register. Note: The MSSP module must be in an Idle state before the RCEN bit is set or the RCEN bit will be disregarded. 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 Generator is suspended from counting, holding SCL low. The MSSP is now in Idle state awaiting the next command. 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, ACKEN bit of the SSPCON2 register. 15.3.11.1 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. 15.3.11.2 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. 15.3.11.3 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). 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 by software before the next transmission. 2010 Microchip Technology Inc. Preliminary DS41350D-page 171 DS41350D-page 172 S Preliminary R/W PEN SEN BF (SSPSTAT<0>) SSPIF SCL SDA A6 A5 A4 A3 A2 A1 3 4 5 Cleared by software 2 6 7 8 9 After Start condition, SEN cleared by hardware SSPBUF written 1 D7 1 SCL held low while CPU responds to SSPIF ACK = 0 R/W = 0 SSPBUF written with 7-bit address and R/W start transmit A7 Transmit Address to Slave 3 D5 4 D4 5 D3 6 D2 7 D1 8 D0 SSPBUF is written by software Cleared by software service routine from SSP interrupt 2 D6 Transmitting Data or Second Half of 10-bit Address From slave, clear ACKSTAT bit SSPCON2<6> P Cleared by software 9 ACK ACKSTAT in SSPCON2 = 1 FIGURE 15-21: SEN = 0 Write SSPCON2<0> SEN = 1 Start condition begins PIC18F/LF1XK50 I 2C™ MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. Preliminary RCEN ACKEN SSPOV BF (SSPSTAT<0>) SDA = 0, SCL = 1 while CPU responds to SSPIF SSPIF S 1 A7 2 4 5 6 Cleared by software 3 A6 A5 A4 A3 A2 Transmit Address to Slave 7 A1 8 ACK 2 3 5 6 7 8 D0 9 ACK 2 3 4 RCEN cleared automatically 5 6 7 Cleared by software Set SSPIF interrupt at end of Acknowledge sequence Data shifted in on falling edge of CLK 1 ACK from Master SDA = ACKDT = 0 Cleared in software Set SSPIF at end of receive 9 ACK is not sent ACK P Set SSPIF interrupt at end of Acknowledge sequence Bus master terminates transfer Set P bit (SSPSTAT<4>) and SSPIF PEN bit = 1 written here SSPOV is set because SSPBUF is still full 8 D0 RCEN cleared automatically D7 D6 D5 D4 D3 D2 D1 RCEN cleared automatically Set ACKEN, start Acknowledge sequence SDA = ACKDT = 1 Receiving Data from Slave RCEN = 1, start next receive ACK from Master SDA = ACKDT = 0 Last bit is shifted into SSPSR and contents are unloaded into SSPBUF Cleared by software Set SSPIF interrupt at end of receive 4 Cleared by software 1 D7 D6 D5 D4 D3 D2 D1 Receiving Data from Slave RCEN cleared automatically Master configured as a receiver by programming SSPCON2<3> (RCEN = 1) 9 R/W = 0 ACK from Slave Master configured as a receiver by programming SSPCON2<3> (RCEN = 1) FIGURE 15-22: SCL SDA SEN = 0 Write to SSPBUF occurs here, start XMIT Write to SSPCON2<0> (SEN = 1), begin Start condition Write to SSPCON2<4> to start Acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 PIC18F/LF1XK50 I 2C™ MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS) DS41350D-page 173 PIC18F/LF1XK50 15.3.12 ACKNOWLEDGE SEQUENCE TIMING 15.3.13 A Stop bit is asserted on the SDA pin at the end of a receive/transmit by setting the Stop Sequence Enable bit, PEN bit of the SSPCON2 register. At the end of a receive/transmit, 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 deasserted. When the SDA pin is sampled high while SCL is high, the P bit of the SSPSTAT register is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 15-24). An Acknowledge sequence is enabled by setting the Acknowledge Sequence Enable bit, ACKEN bit of the SSPCON2 register. 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 generate 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 Generator then counts for one rollover period (TBRG) and the SCL pin is deasserted (pulled high). When the SCL pin is sampled high (clock arbitration), the Baud Rate Generator counts for TBRG. The SCL pin is then pulled low. Following 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). 15.3.12.1 15.3.13.1 WCOL Status Flag If the user writes the SSPBUF when a Stop sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t occur). WCOL Status Flag If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 15-23: STOP CONDITION TIMING ACKNOWLEDGE SEQUENCE WAVEFORM Acknowledge sequence starts here, write to SSPCON2 ACKEN = 1, ACKDT = 0 ACKEN automatically cleared TBRG TBRG SDA ACK D0 SCL 8 9 SSPIF SSPIF set at the end of receive Cleared in software SSPIF set at the end of Acknowledge sequence Cleared in software Note: TBRG = one Baud Rate Generator period. FIGURE 15-24: STOP CONDITION RECEIVE OR TRANSMIT MODE SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. Write to SSPCON2, set PEN PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set Falling edge of 9th clock TBRG SCL SDA ACK P TBRG TBRG TBRG SCL brought high after TBRG SDA asserted low before rising edge of clock to setup Stop condition Note: TBRG = one Baud Rate Generator period. DS41350D-page 174 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.14 SLEEP OPERATION 15.3.17 2 While in Sleep mode, the I C Slave 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). 15.3.15 EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. 15.3.16 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 I 2C bus may be taken when the P bit of the SSPSTAT register 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 monitored for arbitration to see if the signal level is the expected output level. This check is performed by 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 MULTI -MASTER COMMUNICATION, BUS COLLISION AND BUS ARBITRATION Multi-Master mode support is achieved by bus arbitration. 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 deasserted 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 deasserted and the respective control bits in the SSPCON2 register are cleared. 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. 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 register, or the bus is Idle and the S and P bits are cleared. FIGURE 15-25: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE Data changes while SCL = 0 SDA line pulled low by another source SDA released by master Sample SDA. While SCL is high, data doesn’t match what is driven by the master. Bus collision has occurred. SDA SCL Set bus collision interrupt (BCLIF) BCLIF 2010 Microchip Technology Inc. Preliminary DS41350D-page 175 PIC18F/LF1XK50 15.3.17.1 Bus Collision During a Start Condition During a Start condition, a bus collision occurs if: a) b) SDA or SCL are sampled low at the beginning of the Start condition (Figure 15-26). 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 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; if the SCL pin is sampled as ‘0’ during this time, a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. Note: 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 deasserted. When the SDA pin is sampled high, the Baud Rate Generator is loaded and counts down. 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. FIGURE 15-26: 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 following the Start condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated Start or Stop conditions. BUS COLLISION DURING START CONDITION (SDA ONLY) SDA goes low before the SEN bit is set. Set BCLIF, S bit and SSPIF set because SDA = 0, SCL = 1. SDA SCL Set SEN, enable Start condition if SDA = 1, SCL = 1 SEN cleared automatically because of bus collision. SSP module reset into Idle state. SEN BCLIF SDA sampled low before Start condition. Set BCLIF. S bit and SSPIF set because SDA = 0, SCL = 1. SSPIF and BCLIF are cleared by software S SSPIF SSPIF and BCLIF are cleared by software DS41350D-page 176 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 15-27: BUS COLLISION DURING START CONDITION (SCL = 0) SDA = 0, SCL = 1 TBRG TBRG SDA Set SEN, enable Start sequence if SDA = 1, SCL = 1 SCL SCL = 0 before SDA = 0, bus collision occurs. Set BCLIF. SEN SCL = 0 before BRG time-out, bus collision occurs. Set BCLIF. BCLIF Interrupt cleared by software S ‘0’ ‘0’ SSPIF ‘0’ ‘0’ FIGURE 15-28: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION SDA = 0, SCL = 1 Set S Less than TBRG SDA Set SSPIF TBRG SDA pulled low by other master. Reset BRG and assert SDA. SCL S SCL pulled low after BRG time-out SEN BCLIF Set SEN, enable START sequence if SDA = 1, SCL = 1 ‘0’ S SSPIF SDA = 0, SCL = 1, set SSPIF 2010 Microchip Technology Inc. Preliminary Interrupts cleared by software DS41350D-page 177 PIC18F/LF1XK50 15.3.17.2 Bus Collision During a Repeated Start Condition 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. During a Repeated Start condition, a bus collision occurs if: a) b) A low level is sampled on SDA when SCL goes from low level to high level. SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data ‘1’. 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, see Figure 15-30. When the user deasserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD and counts down to 0. The SCL pin is then deasserted and when sampled high, the SDA pin is sampled. FIGURE 15-29: 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. BUS COLLISION DURING A REPEATED START CONDITION (CASE 1) SDA SCL Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. RSEN BCLIF Cleared by software ‘0’ S ‘0’ SSPIF FIGURE 15-30: BUS COLLISION DURING REPEATED START CONDITION (CASE 2) TBRG TBRG SDA SCL BCLIF SCL goes low before SDA, set BCLIF. Release SDA and SCL. Interrupt cleared by software RSEN ‘0’ S SSPIF DS41350D-page 178 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 15.3.17.3 Bus Collision During a Stop Condition 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 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). Bus collision occurs during a Stop condition if: a) b) After the SDA pin has been deasserted and allowed to float high, SDA is sampled low after the BRG has timed out. After the SCL pin is deasserted, SCL is sampled low before SDA goes high. FIGURE 15-31: BUS COLLISION DURING A STOP CONDITION (CASE 1) TBRG TBRG TBRG SDA SDA sampled low after TBRG, set BCLIF SDA asserted low SCL PEN BCLIF P ‘0’ SSPIF ‘0’ FIGURE 15-32: BUS COLLISION DURING A STOP CONDITION (CASE 2) TBRG TBRG TBRG SDA SCL goes low before SDA goes high, set BCLIF Assert SDA SCL PEN BCLIF P ‘0’ SSPIF ‘0’ 2010 Microchip Technology Inc. Preliminary DS41350D-page 179 PIC18F/LF1XK50 TABLE 15-4: SUMMARY OF REGISTERS ASSOCIATED WITH I2C™ Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 Name PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — 290 290 290 PIR2 OSCFIF C1IF PIE2 OSCFIE C1IE I2 C2IF EEIF BCLIF USBIF TMR3IF — C2IE EEIE BCLIE USBIE TMR3IE — 2 SSPADD SSP Address Register in Mode. SSPBUF SSP Receive Buffer/Transmit Register C™ Slave Mode. SSP Baud Rate Reload Register in I C Master 288 288 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 288 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 288 SSPMSK MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 290 SSPSTAT SMP CKE D/A P S R/W UA BF 288 TRISB7 TRISB6 TRISB5 TRISB4 — — — — 290 TRISB Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by I2C™. DS41350D-page 180 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 NOTES: 2010 Microchip Technology Inc. Preliminary DS41350D-page 181 PIC18F/LF1XK50 DS41350D-page 182 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.0 ENHANCED UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (EUSART) The EUSART module includes the following capabilities: • • • • • • • • • • The Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module is a serial I/O communications peripheral. It contains all the clock generators, shift registers and data buffers necessary to perform an input or output serial data transfer independent of device program execution. The EUSART, also known as a Serial Communications Interface (SCI), can be configured as a full-duplex asynchronous system or half-duplex synchronous system. Full-Duplex mode is useful for communications with peripheral systems, such as CRT terminals and personal computers. Half-Duplex Synchronous mode is intended for communications with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs or other microcontrollers. These devices typically do not have internal clocks for baud rate generation and require the external clock signal provided by a master synchronous device. FIGURE 16-1: Full-duplex asynchronous transmit and receive Two-character input buffer One-character output buffer Programmable 8-bit or 9-bit character length Address detection in 9-bit mode Input buffer overrun error detection Received character framing error detection Half-duplex synchronous master Half-duplex synchronous slave Programmable clock and data polarity The EUSART module implements the following additional features, making it ideally suited for use in Local Interconnect Network (LIN) bus systems: • Automatic detection and calibration of the baud rate • Wake-up on Break reception • 13-bit Break character transmit Block diagrams of the EUSART transmitter and receiver are shown in Figure 16-1 and Figure 16-2. EUSART TRANSMIT BLOCK DIAGRAM Data Bus TXIE Interrupt TXIF TXREG Register 8 TX/CK pin MSb LSb (8) 0 Pin Buffer and Control TRMT SPEN • • • Transmit Shift Register (TSR) TXEN Baud Rate Generator FOSC TX9 n BRG16 +1 SPBRGH ÷n SPBRG Multiplier x4 x16 x64 SYNC 1 X 0 0 0 BRGH X 1 1 0 0 BRG16 X 1 0 1 0 2010 Microchip Technology Inc. TX9D Preliminary DS41350D-page 183 PIC18F/LF1XK50 FIGURE 16-2: EUSART RECEIVE BLOCK DIAGRAM SPEN CREN RX/DT pin Baud Rate Generator Data Recovery FOSC SPBRGH SPBRG x4 x16 x64 SYNC 1 X 0 0 0 BRGH X 1 1 0 0 BRG16 X 1 0 1 0 (8) ••• 7 1 LSb 0 START RX9 ÷n BRG16 Multiplier Stop RCIDL RSR Register MSb Pin Buffer and Control +1 OERR n FERR RX9D RCREG Register 8 FIFO Data Bus RCIF RCIE Interrupt The operation of the EUSART module is controlled through three registers: • Transmit Status and Control (TXSTA) • Receive Status and Control (RCSTA) • Baud Rate Control (BAUDCTL) These registers are detailed in Register 16-1, Register 16-2 and Register 16-3, respectively. For all modes of EUSART operation, the TRIS control bits corresponding to the RX/DT and TX/CK pins should be set to ‘1’. The EUSART control will automatically reconfigure the pin from input to output, as needed. DS41350D-page 184 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.1 EUSART Asynchronous Mode The EUSART transmits and receives data using the standard non-return-to-zero (NRZ) format. NRZ is implemented with two levels: a VOH mark state which represents a ‘1’ data bit, and a VOL space state which represents a ‘0’ data bit. NRZ refers to the fact that consecutively transmitted data bits of the same value stay at the output level of that bit without returning to a neutral level between each bit transmission. An NRZ transmission port idles in the mark state. Each character transmission consists of one Start bit followed by eight or nine data bits and is always terminated by one or more Stop bits. The Start bit is always a space and the Stop bits are always marks. The most common data format is 8 bits. Each transmitted bit persists for a period of 1/(Baud Rate). An on-chip dedicated 8-bit/16-bit Baud Rate Generator is used to derive standard baud rate frequencies from the system oscillator. See Table 16-5 for examples of baud rate configurations. The EUSART transmits and receives the LSb first. The EUSART’s transmitter and receiver are functionally independent, but share the same data format and baud rate. Parity is not supported by the hardware, but can be implemented in software and stored as the ninth data bit. 16.1.1 EUSART ASYNCHRONOUS TRANSMITTER 2: The TXIF transmitter interrupt flag is set when the TXEN enable bit is set. 16.1.1.2 Enabling the Transmitter The EUSART transmitter is enabled for asynchronous operations by configuring the following three control bits: Transmitting Data A transmission is initiated by writing a character to the TXREG register. If this is the first character, or the previous character has been completely flushed from the TSR, the data in the TXREG is immediately transferred to the TSR register. If the TSR still contains all or part of a previous character, the new character data is held in the TXREG until the Stop bit of the previous character has been transmitted. The pending character in the TXREG is then transferred to the TSR in one TCY immediately following the Stop bit transmission. The transmission of the Start bit, data bits and Stop bit sequence commences immediately following the transfer of the data to the TSR from the TXREG. 16.1.1.3 The EUSART transmitter block diagram is shown in Figure 16-1. The heart of the transmitter is the serial Transmit Shift Register (TSR), which is not directly accessible by software. The TSR obtains its data from the transmit buffer, which is the TXREG register. 16.1.1.1 Note 1: When the SPEN bit is set the RX/DT I/O pin is automatically configured as an input, regardless of the state of the corresponding TRIS bit and whether or not the EUSART receiver is enabled. The RX/DT pin data can be read via a normal PORT read but PORT latch data output is precluded. Transmit Data Polarity The polarity of the transmit data can be controlled with the CKTXP bit of the BAUDCON register. The default state of this bit is ‘0’ which selects high true transmit idle and data bits. Setting the CKTXP bit to ‘1’ will invert the transmit data resulting in low true idle and data bits. The CKTXP bit controls transmit data polarity only in Asynchronous mode. In Synchronous mode the CKTXP bit has a different function. • TXEN = 1 • SYNC = 0 • SPEN = 1 All other EUSART control bits are assumed to be in their default state. Setting the TXEN bit of the TXSTA register enables the transmitter circuitry of the EUSART. Clearing the SYNC bit of the TXSTA register configures the EUSART for asynchronous operation. Setting the SPEN bit of the RCSTA register enables the EUSART and automatically configures the TX/CK I/O pin as an output. If the TX/CK pin is shared with an analog peripheral the analog I/O function must be disabled by clearing the corresponding ANSEL bit. 2010 Microchip Technology Inc. Preliminary DS41350D-page 185 PIC18F/LF1XK50 16.1.1.4 Transmit Interrupt Flag 16.1.1.6 The TXIF interrupt flag bit of the PIR1 register is set whenever the EUSART transmitter is enabled and no character is being held for transmission in the TXREG. In other words, the TXIF bit is only clear when the TSR is busy with a character and a new character has been queued for transmission in the TXREG. The TXIF flag bit is not cleared immediately upon writing TXREG. TXIF becomes valid in the second instruction cycle following the write execution. Polling TXIF immediately following the TXREG write will return invalid results. The TXIF bit is read-only, it cannot be set or cleared by software. The TXIF interrupt can be enabled by setting the TXIE interrupt enable bit of the PIE1 register. However, the TXIF flag bit will be set whenever the TXREG is empty, regardless of the state of TXIE enable bit. To use interrupts when transmitting data, set the TXIE bit only when there is more data to send. Clear the TXIE interrupt enable bit upon writing the last character of the transmission to the TXREG. 16.1.1.5 The TRMT bit of the TXSTA register indicates the status of the TSR register. This is a read-only bit. The TRMT bit is set when the TSR register is empty and is cleared when a character is transferred to the TSR register from the TXREG. The TRMT bit remains clear until all bits have been shifted out of the TSR register. No interrupt logic is tied to this bit, so the user needs to poll this bit to determine the TSR status. Note: The EUSART supports 9-bit character transmissions. When the TX9 bit of the TXSTA register is set the EUSART will shift 9 bits out for each character transmitted. The TX9D bit of the TXSTA register is the ninth, and Most Significant, data bit. When transmitting 9-bit data, the TX9D data bit must be written before writing the 8 Least Significant bits into the TXREG. All nine bits of data will be transferred to the TSR shift register immediately after the TXREG is written. A special 9-bit Address mode is available for use with multiple receivers. See Section 16.1.2.8 “Address Detection” for more information on the Address mode. 16.1.1.7 1. 2. 3. TSR Status 4. 5. 6. The TSR register is not mapped in data memory, so it is not available to the user. 7. 8. DS41350D-page 186 Transmitting 9-Bit Characters Preliminary Asynchronous Transmission Set-up: Initialize the SPBRGH:SPBRG register pair and the BRGH and BRG16 bits to achieve the desired baud rate (see Section 16.3 “EUSART Baud Rate Generator (BRG)”). Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. If 9-bit transmission is desired, set the TX9 control bit. A set ninth data bit will indicate that the 8 Least Significant data bits are an address when the receiver is set for address detection. Set the CKTXP control bit if inverted transmit data polarity is desired. Enable the transmission by setting the TXEN control bit. This will cause the TXIF interrupt bit to be set. If interrupts are desired, set the TXIE interrupt enable bit. An interrupt will occur immediately provided that the GIE and PEIE bits of the INTCON register are also set. If 9-bit transmission is selected, the ninth bit should be loaded into the TX9D data bit. Load 8-bit data into the TXREG register. This will start the transmission. 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 16-3: ASYNCHRONOUS TRANSMISSION Write to TXREG Word 1 BRG Output (Shift Clock) RB7/TX/CK pin Start bit bit 0 bit 1 bit 7/8 Stop bit Word 1 TXIF bit (Transmit Buffer Reg. Empty Flag) 1 TCY Word 1 Transmit Shift Reg TRMT bit (Transmit Shift Reg. Empty Flag) FIGURE 16-4: ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK) Write to TXREG Word 1 BRG Output (Shift Clock) RB7/TX/CK pin Start bit bit 7/8 Stop bit Start bit Word 2 bit 0 Word 1 Transmit Shift Reg Word 2 Transmit Shift Reg This timing diagram shows two consecutive transmissions. TABLE 16-1: INTCON bit 1 Word 1 1 TCY TRMT bit (Transmit Shift Reg. Empty Flag) Name bit 0 1 TCY TXIF bit (Interrupt Reg. Flag) Note: Word 2 REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 IPR1 RCSTA TXREG TXSTA EUSART Transmit Register 289 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission. 2010 Microchip Technology Inc. Preliminary DS41350D-page 187 PIC18F/LF1XK50 16.1.2 EUSART ASYNCHRONOUS RECEIVER 16.1.2.2 The Asynchronous mode would typically be used in RS-232 systems. The receiver block diagram is shown in Figure 16-2. The data is received on the RX/DT pin and drives the data recovery block. The data recovery block is actually a high-speed shifter operating at 16 times the baud rate, whereas the serial Receive Shift Register (RSR) operates at the bit rate. When all 8 or 9 bits of the character have been shifted in, they are immediately transferred to a two character First-In-First-Out (FIFO) memory. The FIFO buffering allows reception of two complete characters and the start of a third character before software must start servicing the EUSART receiver. The FIFO and RSR registers are not directly accessible by software. Access to the received data is via the RCREG register. 16.1.2.1 Enabling the Receiver The EUSART receiver is enabled for asynchronous operation by configuring the following three control bits: • CREN = 1 • SYNC = 0 • SPEN = 1 All other EUSART control bits are assumed to be in their default state. Setting the CREN bit of the RCSTA register enables the receiver circuitry of the EUSART. Clearing the SYNC bit of the TXSTA register configures the EUSART for asynchronous operation. Setting the SPEN bit of the RCSTA register enables the EUSART. The RX/DT I/O pin must be configured as an input by setting the corresponding TRIS control bit. If the RX/DT pin is shared with an analog peripheral the analog I/O function must be disabled by clearing the corresponding ANSEL bit. Note: When the SPEN bit is set the TX/CK I/O pin is automatically configured as an output, regardless of the state of the corresponding TRIS bit and whether or not the EUSART transmitter is enabled. The PORT latch is disconnected from the output driver so it is not possible to use the TX/CK pin as a general purpose output. DS41350D-page 188 Receiving Data The receiver data recovery circuit initiates character reception on the falling edge of the first bit. The first bit, also known as the Start bit, is always a zero. The data recovery circuit counts one-half bit time to the center of the Start bit and verifies that the bit is still a zero. If it is not a zero then the data recovery circuit aborts character reception, without generating an error, and resumes looking for the falling edge of the Start bit. If the Start bit zero verification succeeds then the data recovery circuit counts a full bit time to the center of the next bit. The bit is then sampled by a majority detect circuit and the resulting ‘0’ or ‘1’ is shifted into the RSR. This repeats until all data bits have been sampled and shifted into the RSR. One final bit time is measured and the level sampled. This is the Stop bit, which is always a ‘1’. If the data recovery circuit samples a ‘0’ in the Stop bit position then a framing error is set for this character, otherwise the framing error is cleared for this character. See Section 16.1.2.5 “Receive Framing Error” for more information on framing errors. Immediately after all data bits and the Stop bit have been received, the character in the RSR is transferred to the EUSART receive FIFO and the RCIF interrupt flag bit of the PIR1 register is set. The top character in the FIFO is transferred out of the FIFO by reading the RCREG register. Note: 16.1.2.3 If the receive FIFO is overrun, no additional characters will be received until the overrun condition is cleared. See Section 16.1.2.6 “Receive Overrun Error” for more information on overrun errors. Receive Data Polarity The polarity of the receive data can be controlled with the DTRXP bit of the BAUDCON register. The default state of this bit is ‘0’ which selects high true receive idle and data bits. Setting the DTRXP bit to ‘1’ will invert the receive data resulting in low true idle and data bits. The DTRXP bit controls receive data polarity only in Asynchronous mode. In synchronous mode the DTRXP bit has a different function. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.1.2.4 Receive Interrupts 16.1.2.7 The RCIF interrupt flag bit of the PIR1 register is set whenever the EUSART receiver is enabled and there is an unread character in the receive FIFO. The RCIF interrupt flag bit is read-only, it cannot be set or cleared by software. RCIF interrupts are enabled by setting the following bits: • RCIE interrupt enable bit of the PIE1 register • PEIE peripheral interrupt enable bit of the INTCON register • GIE global interrupt enable bit of the INTCON register 16.1.2.5 The EUSART supports 9-bit character reception. When the RX9 bit of the RCSTA register is set, the EUSART will shift 9 bits into the RSR for each character received. The RX9D bit of the RCSTA register is the ninth and Most Significant data bit of the top unread character in the receive FIFO. When reading 9-bit data from the receive FIFO buffer, the RX9D data bit must be read before reading the 8 Least Significant bits from the RCREG. 16.1.2.8 The RCIF interrupt flag bit will be set when there is an unread character in the FIFO, regardless of the state of interrupt enable bits. Receive Framing Error Each character in the receive FIFO buffer has a corresponding framing error status bit. A framing error indicates that a Stop bit was not seen at the expected time. The framing error status is accessed via the FERR bit of the RCSTA register. The FERR bit represents the status of the top unread character in the receive FIFO. Therefore, the FERR bit must be read before reading the RCREG. The FERR bit is read-only and only applies to the top unread character in the receive FIFO. A framing error (FERR = 1) does not preclude reception of additional characters. It is not necessary to clear the FERR bit. Reading the next character from the FIFO buffer will advance the FIFO to the next character and the next corresponding framing error. Receiving 9-bit Characters Address Detection A special Address Detection mode is available for use when multiple receivers share the same transmission line, such as in RS-485 systems. Address detection is enabled by setting the ADDEN bit of the RCSTA register. Address detection requires 9-bit character reception. When address detection is enabled, only characters with the ninth data bit set will be transferred to the receive FIFO buffer, thereby setting the RCIF interrupt bit. All other characters will be ignored. Upon receiving an address character, user software determines if the address matches its own. Upon address match, user software must disable address detection by clearing the ADDEN bit before the next Stop bit occurs. When user software detects the end of the message, determined by the message protocol used, software places the receiver back into the Address Detection mode by setting the ADDEN bit. The FERR bit can be forced clear by clearing the SPEN bit of the RCSTA register which resets the EUSART. Clearing the CREN bit of the RCSTA register does not affect the FERR bit. A framing error by itself does not generate an interrupt. Note: 16.1.2.6 If all receive characters in the receive FIFO have framing errors, repeated reads of the RCREG will not clear the FERR bit. Receive Overrun Error The receive FIFO buffer can hold two characters. An overrun error will be generated If a third character, in its entirety, is received before the FIFO is accessed. When this happens the OERR bit of the RCSTA register is set. The characters already in the FIFO buffer can be read but no additional characters will be received until the error is cleared. The error must be cleared by either clearing the CREN bit of the RCSTA register or by resetting the EUSART by clearing the SPEN bit of the RCSTA register. 2010 Microchip Technology Inc. Preliminary DS41350D-page 189 PIC18F/LF1XK50 16.1.2.9 Asynchronous Reception Set-up: 16.1.2.10 1. Initialize the SPBRGH:SPBRG register pair and the BRGH and BRG16 bits to achieve the desired baud rate (see Section 16.3 “EUSART Baud Rate Generator (BRG)”). 2. Enable the serial port by setting the SPEN bit and the RX/DT pin TRIS bit. The SYNC bit must be clear for asynchronous operation. 3. If interrupts are desired, set the RCIE interrupt enable bit and set the GIE and PEIE bits of the INTCON register. 4. If 9-bit reception is desired, set the RX9 bit. 5. Set the DTRXP if inverted receive polarity is desired. 6. Enable reception by setting the CREN bit. 7. The RCIF interrupt flag bit will be set when a character is transferred from the RSR to the receive buffer. An interrupt will be generated if the RCIE interrupt enable bit was also set. 8. Read the RCSTA register to get the error flags and, if 9-bit data reception is enabled, the ninth data bit. 9. Get the received 8 Least Significant data bits from the receive buffer by reading the RCREG register. 10. If an overrun occurred, clear the OERR flag by clearing the CREN receiver enable bit. FIGURE 16-5: Rcv Shift Reg Rcv Buffer Reg RCIDL This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRGH, SPBRG register pair and the BRGH and BRG16 bits to achieve the desired baud rate (see Section 16.3 “EUSART Baud Rate Generator (BRG)”). 2. Enable the serial port by setting the SPEN bit. The SYNC bit must be clear for asynchronous operation. 3. If interrupts are desired, set the RCIE interrupt enable bit and set the GIE and PEIE bits of the INTCON register. 4. Enable 9-bit reception by setting the RX9 bit. 5. Enable address detection by setting the ADDEN bit. 6. Set the DTRXP if inverted receive polarity is desired. 7. Enable reception by setting the CREN bit. 8. The RCIF interrupt flag bit will be set when a character with the ninth bit set is transferred from the RSR to the receive buffer. An interrupt will be generated if the RCIE interrupt enable bit was also set. 9. Read the RCSTA register to get the error flags. The ninth data bit will always be set. 10. Get the received 8 Least Significant data bits from the receive buffer by reading the RCREG register. Software determines if this is the device’s address. 11. If an overrun occurred, clear the OERR flag by clearing the CREN receiver enable bit. 12. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and generate interrupts. ASYNCHRONOUS RECEPTION Start bit bit 0 RX/DT pin 9-bit Address Detection Mode Set-up bit 1 bit 7/8 Stop bit Start bit bit 0 Word 1 RCREG bit 7/8 Stop bit Start bit bit 7/8 Stop bit Word 2 RCREG Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN 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. DS41350D-page 190 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 16-2: Name INTCON REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Bit 7 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 Bit 6 GIE/GIEH PEIE/GIEL PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 IPR1 RCSTA RCREG TRISC TXSTA BAUDCON EUSART Receive Register TRISC7 TRISC6 TRISC5 289 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception. 2010 Microchip Technology Inc. Preliminary DS41350D-page 191 PIC18F/LF1XK50 16.2 Clock Accuracy with Asynchronous Operation The factory calibrates the internal oscillator block output (HFINTOSC). However, the HFINTOSC frequency may drift as VDD or temperature changes, and this directly affects the asynchronous baud rate. Two methods may be used to adjust the baud rate clock, but both require a reference clock source of some kind. REGISTER 16-1: The first (preferred) method uses the OSCTUNE register to adjust the HFINTOSC output. Adjusting the value in the OSCTUNE register allows for fine resolution changes to the system clock source. See Section 2.6.1 “OSCTUNE Register” for more information. The other method adjusts the value in the Baud Rate Generator. This can be done automatically with the Auto-Baud Detect feature (see Section 16.3.1 “Auto-Baud Detect”). There may not be fine enough resolution when adjusting the Baud Rate Generator to compensate for a gradual change in the peripheral clock frequency. TXSTA: TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D bit 7 bit 0 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 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) 1 = Transmit enabled 0 = Transmit disabled bit 4 SYNC: EUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 SENDB: Send Break Character bit Asynchronous mode: 1 = Send Sync Break on next transmission (cleared by hardware upon completion) 0 = Sync Break transmission completed Synchronous mode: Don’t care 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: Ninth bit of Transmit Data Can be address/data bit or a parity bit. Note 1: SREN/CREN overrides TXEN in Sync mode. DS41350D-page 192 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 16-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER(1) 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 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 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 (held in Reset) 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 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 Asynchronous mode 8-bit (RX9 = 0): Don’t care 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: Ninth bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware. 2010 Microchip Technology Inc. Preliminary DS41350D-page 193 PIC18F/LF1XK50 REGISTER 16-3: BAUDCON: BAUD RATE CONTROL REGISTER R-0 R-1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN bit 7 bit 0 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 bit 7 ABDOVF: Auto-Baud Detect Overflow bit Asynchronous mode: 1 = Auto-baud timer overflowed 0 = Auto-baud timer did not overflow Synchronous mode: Don’t care bit 6 RCIDL: Receive Idle Flag bit Asynchronous mode: 1 = Receiver is Idle 0 = Start bit has been detected and the receiver is active Synchronous mode: Don’t care bit 5 DTRXP: Data/Receive Polarity Select bit Asynchronous mode: 1 = Receive data (RX) is inverted (active-low) 0 = Receive data (RX) is not inverted (active-high) Synchronous mode: 1 = Data (DT) is inverted (active-low) 0 = Data (DT) is not inverted (active-high) bit 4 CKTXP: Clock/Transmit Polarity Select bit Asynchronous mode: 1 = Idle state for transmit (TX) is low 0 = Idle state for transmit (TX) is high Synchronous mode: 1 = Data changes on the falling edge of the clock and is sampled on the rising edge of the clock 0 = Data changes on the rising edge of the clock and is sampled on the falling edge of the clock bit 3 BRG16: 16-bit Baud Rate Generator bit 1 = 16-bit Baud Rate Generator is used (SPBRGH:SPBRG) 0 = 8-bit Baud Rate Generator is used (SPBRG) bit 2 Unimplemented: Read as ‘0’ bit 1 WUE: Wake-up Enable bit Asynchronous mode: 1 = Receiver is waiting for a falling edge. No character will be received but RCIF will be set on the falling edge. WUE will automatically clear on the rising edge. 0 = Receiver is operating normally Synchronous mode: Don’t care bit 0 ABDEN: Auto-Baud Detect Enable bit Asynchronous mode: 1 = Auto-Baud Detect mode is enabled (clears when auto-baud is complete) 0 = Auto-Baud Detect mode is disabled Synchronous mode: Don’t care DS41350D-page 194 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.3 EUSART Baud Rate Generator (BRG) The Baud Rate Generator (BRG) is an 8-bit or 16-bit timer that is dedicated to the support of both the asynchronous and synchronous EUSART operation. By default, the BRG operates in 8-bit mode. Setting the BRG16 bit of the BAUDCON register selects 16-bit mode. If the system clock is changed during an active receive operation, a receive error or data loss may result. To avoid this problem, check the status of the RCIDL bit to make sure that the receive operation is Idle before changing the system clock. EXAMPLE 16-1: For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG: The SPBRGH:SPBRG register pair determines the period of the free running baud rate timer. In Asynchronous mode the multiplier of the baud rate period is determined by both the BRGH bit of the TXSTA register and the BRG16 bit of the BAUDCON register. In Synchronous mode, the BRGH bit is ignored. F OS C Desired Baud Rate = --------------------------------------------------------------------64 [SPBRGH:SPBRG] + 1 Solving for SPBRGH:SPBRG: X= Table 16-3 contains the formulas for determining the baud rate. Example 16-1 provides a sample calculation for determining the baud rate and baud rate error. Typical baud rates and error values for various asynchronous modes have been computed for your convenience and are shown in Table 16-5. It may be advantageous to use the high baud rate (BRGH = 1), or the 16-bit BRG (BRG16 = 1) to reduce the baud rate error. The 16-bit BRG mode is used to achieve slow baud rates for fast oscillator frequencies. = F -1 (64 * (Desired Baud Rate) ) OSC ( 16,000,000 64 * 9600 )-1 = 25.042 = 25 16000000 Calculated Baud Rate = --------------------------64 25 + 1 = 9615 Writing a new value to the SPBRGH, SPBRG register pair causes the BRG timer to be reset (or cleared). This ensures that the BRG does not wait for a timer overflow before outputting the new baud rate. TABLE 16-3: CALCULATING BAUD RATE ERROR Calc. Baud Rate – Desired Baud Rate Error = -------------------------------------------------------------------------------------------Desired Baud Rate 9615 – 9600 = ---------------------------------- = 0.16% 9600 BAUD RATE FORMULAS Configuration Bits BRG/EUSART Mode Baud Rate Formula 0 8-bit/Asynchronous FOSC/[64 (n+1)] 0 1 8-bit/Asynchronous 0 1 0 16-bit/Asynchronous 0 1 1 16-bit/Asynchronous 1 0 x 8-bit/Synchronous 1 x 16-bit/Synchronous SYNC BRG16 BRGH 0 0 0 1 Legend: FOSC/[4 (n+1)] x = Don’t care, n = value of SPBRGH, SPBRG register pair TABLE 16-4: Name FOSC/[16 (n+1)] REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Reset Values on page Bit 0 TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 BAUDCON ABDOVF SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG. 2010 Microchip Technology Inc. Preliminary DS41350D-page 195 PIC18F/LF1XK50 TABLE 16-5: BAUD RATES FOR ASYNCHRONOUS MODES SYNC = 0, BRGH = 0, BRG16 = 0 BAUD RATE FOSC = 48.000 MHz FOSC = 18.432 MHz FOSC = 12.000 MHz FOSC = 11.0592 MHz Actual Rate % Error SPBRG value (decimal) 300 — — — — — — — — — — — — 1200 — — — 1200 0.00 239 1202 0.16 155 1200 0.00 143 Actual Rate % Error SPBRG value (decimal) Actual Rate % Error SPBRG value (decimal) Actual Rate % Error SPBRG value (decimal) 2400 — — — 2400 0.00 119 2404 0.16 77 2400 0.00 71 9600 9615 0.16 77 9600 0.00 29 9375 -2.34 19 9600 0.00 17 10417 10417 0.00 71 10286 -1.26 27 10417 0.00 17 10165 -2.42 16 19.2k 19.23k 0.16 38 19.20k 0.00 14 18.75k -2.34 9 19.20k 0.00 8 57.6k 57.69k 0.16 12 57.60k 0.00 7 — — — 57.60k 0.00 2 115.2k — — — — — — — — — — — — SYNC = 0, BRGH = 0, BRG16 = 0 BAUD RATE FOSC = 8.000 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 4.000 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 3.6864 MHz Actual Rate FOSC = 1.000 MHz % Error SPBRG value (decimal) Actual Rate % Error SPBRG value (decimal) 300 — — — 300 0.16 207 300 0.00 191 300 0.16 51 1200 1202 0.16 103 1202 0.16 51 1200 0.00 47 1202 0.16 12 2400 2404 0.16 51 2404 0.16 25 2400 0.00 23 — — — 9600 9615 0.16 12 — — — 9600 0.00 5 — — — 10417 10417 0.00 11 10417 0.00 5 — — — — — — 19.2k — — — — — — 19.20k 0.00 2 — — — 57.6k — — — — — — 57.60k 0.00 0 — — — 115.2k — — — — — — — — — — — — SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE FOSC = 48.000 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 18.432 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 12.000 MHz Actual Rate % Error FOSC = 11.0592 MHz SPBRG value (decimal) Actual Rate % Error SPBRG value (decimal) 300 — — — — — — — — — — — — 1200 — — — — — — — — — — — — 2400 — — — — — — — — — — — — 9600 — — — 9600 0.00 119 9615 0.16 77 9600 0.00 71 10417 — — — 10378 -0.37 110 10417 0.00 71 10473 0.53 65 19.2k 19.23k 0.16 155 19.20k 0.00 59 19.23k 0.16 38 19.20k 0.00 35 57.6k 57.69k 0.16 51 57.60k 0.00 19 57.69k 0.16 12 57.60k 0.00 11 115.2k 115.38k 0.16 25 115.2k 0.00 9 — — — 115.2k 0.00 5 DS41350D-page 196 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 16-5: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED) SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE FOSC = 8.000 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 4.000 MHz Actual Rate % Error SPBRG value (decimal) FOSC = 3.6864 MHz Actual Rate FOSC = 1.000 MHz % Error SPBRG value (decimal) Actual Rate % Error SPBRG value (decimal) 300 1200 — — — — — — — 1202 — 0.16 — 207 — 1200 — 0.00 — 191 300 1202 0.16 0.16 207 51 2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25 — 9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 — — 10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5 19.2k 19231 0.16 25 19.23k 0.16 12 19.2k 0.00 11 — — — 57.6k 55556 -3.55 8 — — — 57.60k 0.00 3 — — — 115.2k — — — — — — 115.2k 0.00 1 — — — SYNC = 0, BRGH = 0, BRG16 = 1 BAUD RATE FOSC = 48.000 MHz Actual Rate % Error FOSC = 18.432 MHz SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) FOSC = 12.000 MHz Actual Rate FOSC = 11.0592 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) 300 300.0 0.00 9999 300.0 0.00 3839 300 0.00 2499 300.0 0.00 2303 1200 1200.1 0.00 2499 1200 0.00 959 1200 0.00 624 1200 0.00 575 2400 2400 0.00 1249 2400 0.00 479 2404 0.16 311 2400 0.00 287 71 9600 9615 0.16 311 9600 0.00 119 9615 0.16 77 9600 0.00 10417 10417 0.00 287 10378 -0.37 110 10417 0.00 71 10473 0.53 65 19.2k 19.23k 0.16 155 19.20k 0.00 59 19.23k 0.16 38 19.20k 0.00 35 57.6k 57.69k 0.16 51 57.60k 0.00 19 57.69k 0.16 12 57.60k 0.00 11 115.2k 115.38k 0.16 25 115.2k 0.00 9 — — — 115.2k 0.00 5 SYNC = 0, BRGH = 0, BRG16 = 1 BAUD RATE FOSC = 8.000 MHz Actual Rate % Error SPBRGH :SPBRG (decimal) FOSC = 4.000 MHz Actual Rate FOSC = 3.6864 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate FOSC = 1.000 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) 300 299.9 -0.02 1666 300.1 0.04 832 300.0 0.00 767 300.5 0.16 207 1200 1199 -0.08 416 1202 0.16 207 1200 0.00 191 1202 0.16 51 2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25 9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 — — — 10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5 19.2k 19.23k 0.16 25 19.23k 0.16 12 19.20k 0.00 11 — — — 57.6k 55556 -3.55 8 — — — 57.60k 0.00 3 — — — 115.2k — — — — — — 115.2k 0.00 1 — — — 2010 Microchip Technology Inc. Preliminary DS41350D-page 197 PIC18F/LF1XK50 TABLE 16-5: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED) SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE FOSC = 48.000 MHz FOSC = 18.432 MHz FOSC = 12.000 MHz FOSC = 11.0592 MHz Actual Rate % Error SPBRGH :SPBRG (decimal) 300 1200 300 1200 0.00 0.00 39999 9999 300.0 1200 0.00 0.00 15359 3839 300 1200 0.00 0.00 9999 2499 300.0 1200 0.00 0.00 9215 2303 2400 2400 0.00 4999 2400 0.00 1919 2400 0.00 1249 2400 0.00 1151 Actual Rate % Error SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) 9600 9600 0.00 1249 9600 0.00 479 9615 0.16 311 9600 0.00 287 10417 10417 0.00 1151 10425 0.08 441 10417 0.00 287 10433 0.16 264 19.2k 19.20k 0.00 624 19.20k 0.00 239 19.23k 0.16 155 19.20k 0.00 143 57.6k 57.69k 0.16 207 57.60k 0.00 79 57.69k 0.16 51 57.60k 0.00 47 115.2k 115.38k 0.16 103 115.2k 0.00 39 115.38k 0.16 25 115.2k 0.00 23 SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE FOSC = 8.000 MHz Actual Rate FOSC = 4.000 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate FOSC = 3.6864 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate FOSC = 1.000 MHz % Error SPBRGH :SPBRG (decimal) Actual Rate % Error SPBRGH :SPBRG (decimal) 832 300 300.0 0.00 6666 300.0 0.01 3332 300.0 0.00 3071 300.1 0.04 1200 1200 -0.02 1666 1200 0.04 832 1200 0.00 767 1202 0.16 207 2400 2401 0.04 832 2398 0.08 416 2400 0.00 383 2404 0.16 103 9600 9615 0.16 207 9615 0.16 103 9600 0.00 95 9615 0.16 25 10417 10417 0.00 191 10417 0.00 95 10473 0.53 87 10417 0.00 23 19.2k 19.23k 0.16 103 19.23k 0.16 51 19.20k 0.00 47 19.23k 0.16 12 57.6k 57.14k -0.79 34 58.82k 2.12 16 57.60k 0.00 15 — — — 115.2k 117.6k 2.12 16 111.1k -3.55 8 115.2k 0.00 7 — — — DS41350D-page 198 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.3.1 AUTO-BAUD DETECT The EUSART module supports automatic detection and calibration of the baud rate. and SPBRG registers are clocked at 1/8th the BRG base clock rate. The resulting byte measurement is the average bit time when clocked at full speed. Note 1: If the WUE bit is set with the ABDEN bit, auto-baud detection will occur on the byte following the Break character (see Section 16.3.3 “Auto-Wake-up on Break”). In the Auto-Baud Detect (ABD) mode, the clock to the BRG is reversed. Rather than the BRG clocking the incoming RX signal, the RX signal is timing the BRG. The Baud Rate Generator is used to time the period of a received 55h (ASCII “U”) which is the Sync character for the LIN bus. The unique feature of this character is that it has five rising edges including the Stop bit edge. Setting the ABDEN bit of the BAUDCON register starts the auto-baud calibration sequence (Figure 16-6). While the ABD sequence takes place, the EUSART state machine is held in Idle. On the first rising edge of the receive line, after the Start bit, the SPBRG begins counting up using the BRG counter clock as shown in Table 16-6. The fifth rising edge will occur on the RX pin at the end of the eighth bit period. At that time, an accumulated value totaling the proper BRG period is left in the SPBRGH:SPBRG register pair, the ABDEN bit is automatically cleared, and the RCIF interrupt flag is set. A read operation on the RCREG needs to be performed to clear the RCIF interrupt. RCREG content should be discarded. When calibrating for modes that do not use the SPBRGH register the user can verify that the SPBRG register did not overflow by checking for 00h in the SPBRGH register. 2: It is up to the user to determine that the incoming character baud rate is within the range of the selected BRG clock source. Some combinations of oscillator frequency and EUSART baud rates are not possible. 3: During the auto-baud process, the auto-baud counter starts counting at 1. Upon completion of the auto-baud sequence, to achieve maximum accuracy, subtract 1 from the SPBRGH:SPBRG register pair. TABLE 16-6: The BRG auto-baud clock is determined by the BRG16 and BRGH bits as shown in Table 16-6. During ABD, both the SPBRGH and SPBRG registers are used as a 16-bit counter, independent of the BRG16 bit setting. While calibrating the baud rate period, the SPBRGH FIGURE 16-6: BRG16 BRGH BRG Base Clock BRG ABD Clock 0 0 FOSC/64 FOSC/512 0 1 FOSC/16 FOSC/128 1 0 FOSC/16 FOSC/128 1 FOSC/4 FOSC/32 1 Note: During the ABD sequence, SPBRG and SPBRGH registers are both used as a 16-bit counter, independent of BRG16 setting. AUTOMATIC BAUD RATE CALIBRATION XXXXh BRG Value BRG COUNTER CLOCK RATES RX pin 0000h 001Ch Start Edge #1 bit 1 bit 0 Edge #2 bit 3 bit 2 Edge #3 bit 5 bit 4 Edge #4 bit 7 bit 6 Edge #5 Stop bit BRG Clock Auto Cleared Set by User ABDEN bit RCIDL RCIF bit (Interrupt) Read RCREG SPBRG XXh 1Ch SPBRGH XXh 00h Note 1: The ABD sequence requires the EUSART module to be configured in Asynchronous mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 199 PIC18F/LF1XK50 16.3.2 AUTO-BAUD OVERFLOW 16.3.3.1 During the course of automatic baud detection, the ABDOVF bit of the BAUDCON register will be set if the baud rate counter overflows before the fifth rising edge is detected on the RX pin. The ABDOVF bit indicates that the counter has exceeded the maximum count that can fit in the 16 bits of the SPBRGH:SPBRG register pair. After the ABDOVF has been set, the counter continues to count until the fifth rising edge is detected on the RX pin. Upon detecting the fifth RX edge, the hardware will set the RCIF Interrupt Flag and clear the ABDEN bit of the BAUDCON register. The RCIF flag can be subsequently cleared by reading the RCREG register. The ABDOVF flag of the BAUDCON register can be cleared by software directly. To terminate the auto-baud process before the RCIF flag is set, clear the ABDEN bit then clear the ABDOVF bit of the BAUDCON register. The ABDOVF bit will remain set if the ABDEN bit is not cleared first. 16.3.3 AUTO-WAKE-UP ON BREAK During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper character reception cannot be performed. The Auto-Wake-up feature allows the controller to wake-up due to activity on the RX/DT line. This feature is available only in Asynchronous mode. The Auto-Wake-up feature is enabled by setting the WUE bit of the BAUDCON register. Once set, the normal receive sequence on RX/DT is disabled, and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX/DT line. (This coincides with the start of a Sync Break or a wake-up signal character for the LIN protocol.) The EUSART module generates an RCIF interrupt coincident with the wake-up event. The interrupt is generated synchronously to the Q clocks in normal CPU operating modes (Figure 16-7), and asynchronously if the device is in Sleep mode (Figure 16-8). The interrupt condition is cleared by reading the RCREG register. Special Considerations Break Character To avoid character errors or character fragments during a wake-up event, the wake-up character must be all zeros. When the wake-up is enabled the function works independent of the low time on the data stream. If the WUE bit is set and a valid non-zero character is received, the low time from the Start bit to the first rising edge will be interpreted as the wake-up event. The remaining bits in the character will be received as a fragmented character and subsequent characters can result in framing or overrun errors. Therefore, the initial character in the transmission must be all ‘0’s. This must be 10 or more bit times, 13-bit times recommended for LIN bus, or any number of bit times for standard RS-232 devices. Oscillator Startup Time Oscillator start-up time must be considered, especially in applications using oscillators with longer start-up intervals (i.e., LP, XT or HS/PLL mode). The Sync Break (or wake-up signal) character must be of sufficient length, and be followed by a sufficient interval, to allow enough time for the selected oscillator to start and provide proper initialization of the EUSART. WUE Bit The wake-up event causes a receive interrupt by setting the RCIF bit. The WUE bit is cleared by hardware by a rising edge on RX/DT. The interrupt condition is then cleared by software by reading the RCREG register and discarding its contents. To ensure that no actual data is lost, check the RCIDL bit to verify that a receive operation is not in process before setting the WUE bit. If a receive operation is not occurring, the WUE bit may then be set just prior to entering the Sleep mode. The WUE bit is automatically cleared by the low-to-high transition on the RX line at the end of the Break. This signals to the user that the Break event is over. At this point, the EUSART module is in Idle mode waiting to receive the next character. DS41350D-page 200 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 16-7: AUTO-WAKE-UP BIT (WUE) TIMING DURING NORMAL OPERATION Q1 Q2 Q3 Q4 Q1 Q2 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 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Auto Cleared Bit set by user WUE bit RX/DT Line RCIF Note 1: Cleared due to User Read of RCREG The EUSART remains in Idle while the WUE bit is set. FIGURE 16-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 OSC1 Auto Cleared Bit Set by User WUE bit RX/DT Line Note 1 RCIF Sleep Command Executed Note 1: 2: Sleep Ends Cleared due to User Read of RCREG If the wake-up event requires long oscillator warm-up time, the automatic clearing of the WUE bit can occur while the stposc signal is still active. This sequence should not depend on the presence of Q clocks. The EUSART remains in Idle while the WUE bit is set. 2010 Microchip Technology Inc. Preliminary DS41350D-page 201 PIC18F/LF1XK50 16.3.4 BREAK CHARACTER SEQUENCE The EUSART module has the capability of sending the special Break character sequences that are required by the LIN bus standard. A Break character consists of a Start bit, followed by 12 ‘0’ bits and a Stop bit. To send a Break character, set the SENDB and TXEN bits of the TXSTA register. The Break character transmission is then initiated by a write to the TXREG. The value of data written to TXREG will be ignored and all ‘0’s will be transmitted. The SENDB bit is automatically reset by hardware after the corresponding Stop bit is sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN specification). The TRMT bit of the TXSTA register indicates when the transmit operation is active or Idle, just as it does during normal transmission. See Figure 16-9 for the timing of the Break character sequence. 16.3.4.1 Break and Sync Transmit Sequence The following sequence will start a message frame header made up of a Break, followed by an auto-baud Sync byte. This sequence is typical of a LIN bus master. 1. 2. 3. 4. 5. 16.3.5 RECEIVING A BREAK CHARACTER The Enhanced EUSART module can receive a Break character in two ways. The first method to detect a Break character uses the FERR bit of the RCSTA register and the Received data as indicated by RCREG. The Baud Rate Generator is assumed to have been initialized to the expected baud rate. A Break character has been received when; • RCIF bit is set • FERR bit is set • RCREG = 00h The second method uses the Auto-Wake-up feature described in Section 16.3.3 “Auto-Wake-up on Break”. By enabling this feature, the EUSART will sample the next two transitions on RX/DT, cause an RCIF interrupt, and receive the next data byte followed by another interrupt. Note that following a Break character, the user will typically want to enable the Auto-Baud Detect feature. For both methods, the user can set the ABDEN bit of the BAUDCON register before placing the EUSART in Sleep mode. Configure the EUSART for the desired mode. Set the TXEN and SENDB bits to enable the Break sequence. Load the TXREG with a dummy character to initiate transmission (the value is ignored). Write ‘55h’ to TXREG to load the Sync character into the transmit FIFO buffer. After the Break has been sent, the SENDB bit is reset by hardware and the Sync character is then transmitted. When the TXREG becomes empty, as indicated by the TXIF, the next data byte can be written to TXREG. FIGURE 16-9: Write to TXREG SEND BREAK CHARACTER SEQUENCE Dummy Write BRG Output (Shift Clock) TX (pin) Start bit bit 0 bit 1 bit 11 Stop bit Break TXIF bit (Transmit interrupt Flag) TRMT bit (Transmit Shift Reg. Empty Flag) SENDB (send Break control bit) DS41350D-page 202 SENDB Sampled Here Preliminary Auto Cleared 2010 Microchip Technology Inc. PIC18F/LF1XK50 16.4 EUSART Synchronous Mode 16.4.1.2 Synchronous serial communications are typically used in systems with a single master and one or more slaves. The master device contains the necessary circuitry for baud rate generation and supplies the clock for all devices in the system. Slave devices can take advantage of the master clock by eliminating the internal clock generation circuitry. There are two signal lines in Synchronous mode: a bidirectional data line and a clock line. Slaves use the external clock supplied by the master to shift the serial data into and out of their respective receive and transmit shift registers. Since the data line is bidirectional, synchronous operation is half-duplex only. Half-duplex refers to the fact that master and slave devices can receive and transmit data but not both simultaneously. The EUSART can operate as either a master or slave device. Start and Stop bits are not used in synchronous transmissions. 16.4.1 SYNCHRONOUS MASTER MODE The following bits are used to configure the EUSART for Synchronous Master operation: • • • • • SYNC = 1 CSRC = 1 SREN = 0 (for transmit); SREN = 1 (for receive) CREN = 0 (for transmit); CREN = 1 (for receive) SPEN = 1 Clock Polarity A clock polarity option is provided for Microwire compatibility. Clock polarity is selected with the CKTXP bit of the BAUDCON register. Setting the CKTXP bit sets the clock Idle state as high. When the CKTXP bit is set, the data changes on the falling edge of each clock and is sampled on the rising edge of each clock. Clearing the CKTXP bit sets the Idle state as low. When the CKTXP bit is cleared, the data changes on the rising edge of each clock and is sampled on the falling edge of each clock. 16.4.1.3 Synchronous Master Transmission Data is transferred out of the device on the RX/DT pin. The RX/DT and TX/CK pin output drivers are automatically enabled when the EUSART is configured for synchronous master transmit operation. A transmission is initiated by writing a character to the TXREG register. If the TSR still contains all or part of a previous character the new character data is held in the TXREG until the last bit of the previous character has been transmitted. If this is the first character, or the previous character has been completely flushed from the TSR, the data in the TXREG is immediately transferred to the TSR. The transmission of the character commences immediately following the transfer of the data to the TSR from the TXREG. Each data bit changes on the leading edge of the master clock and remains valid until the subsequent leading clock edge. Setting the SYNC bit of the TXSTA register configures the device for synchronous operation. Setting the CSRC bit of the TXSTA register configures the device as a master. Clearing the SREN and CREN bits of the RCSTA register ensures that the device is in the Transmit mode, otherwise the device will be configured to receive. Setting the SPEN bit of the RCSTA register enables the EUSART. If the RX/DT or TX/CK pins are shared with an analog peripheral the analog I/O functions must be disabled by clearing the corresponding ANSEL bits. Note: 16.4.1.4 The TSR register is not mapped in data memory, so it is not available to the user. Data Polarity The polarity of the transmit and receive data can be controlled with the DTRXP bit of the BAUDCON register. The default state of this bit is ‘0’ which selects high true transmit and receive data. Setting the DTRXP bit to ‘1’ will invert the data resulting in low true transmit and receive data. The TRIS bits corresponding to the RX/DT and TX/CK pins should be set. 16.4.1.1 Master Clock Synchronous data transfers use a separate clock line, which is synchronous with the data. A device configured as a master transmits the clock on the TX/CK line. The TX/CK pin output driver is automatically enabled when the EUSART is configured for synchronous transmit or receive operation. Serial data bits change on the leading edge to ensure they are valid at the trailing edge of each clock. One clock cycle is generated for each data bit. Only as many clock cycles are generated as there are data bits. 2010 Microchip Technology Inc. Preliminary DS41350D-page 203 PIC18F/LF1XK50 16.4.1.5 1. 2. Synchronous Master Transmission Set-up: 3. Initialize the SPBRGH, SPBRG register pair and the BRGH and BRG16 bits to achieve the desired baud rate (see Section 16.3 “EUSART Baud Rate Generator (BRG)”). Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. Set the TRIS bits corresponding to the RX/DT and TX/CK I/O pins. 4. 5. 6. FIGURE 16-10: 7. 8. Disable Receive mode by clearing bits SREN and CREN. Enable Transmit mode by setting the TXEN bit. If 9-bit transmission is desired, set the TX9 bit. If interrupts are desired, set the TXIE, GIE and PEIE interrupt enable bits. If 9-bit transmission is selected, the ninth bit should be loaded in the TX9D bit. Start transmission by loading data to the TXREG register. SYNCHRONOUS TRANSMISSION RX/DT pin bit 0 bit 1 Word 1 bit 2 bit 7 bit 0 bit 1 Word 2 bit 7 TX/CK pin (SCKP = 0) TX/CK pin (SCKP = 1) Write to TXREG Reg Write Word 1 Write Word 2 TXIF bit (Interrupt Flag) TRMT bit TXEN bit Note: ‘1’ ‘1’ Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words. FIGURE 16-11: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) RX/DT pin bit 0 bit 1 bit 2 bit 6 bit 7 TX/CK pin Write to TXREG reg TXIF bit TRMT bit TXEN bit DS41350D-page 204 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 16-7: Name REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 INTCON GIE/GIEH PEIE/GIEL TMR0IE Bit 4 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 TXREG EUSART Transmit Register 289 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 TXSTA Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission. 16.4.1.6 Synchronous Master Reception 16.4.1.7 Data is received at the RX/DT pin. The RX/DT pin output driver must be disabled by setting the corresponding TRIS bits when the EUSART is configured for synchronous master receive operation. In Synchronous mode, reception is enabled by setting either the Single Receive Enable bit (SREN of the RCSTA register) or the Continuous Receive Enable bit (CREN of the RCSTA register). When SREN is set and CREN is clear, only as many clock cycles are generated as there are data bits in a single character. The SREN bit is automatically cleared at the completion of one character. When CREN is set, clocks are continuously generated until CREN is cleared. If CREN is cleared in the middle of a character the CK clock stops immediately and the partial character is discarded. If SREN and CREN are both set, then SREN is cleared at the completion of the first character and CREN takes precedence. To initiate reception, set either SREN or CREN. Data is sampled at the RX/DT pin on the trailing edge of the TX/CK clock pin and is shifted into the Receive Shift Register (RSR). When a complete character is received into the RSR, the RCIF bit is set and the character is automatically transferred to the two character receive FIFO. The Least Significant eight bits of the top character in the receive FIFO are available in RCREG. The RCIF bit remains set as long as there are un-read characters in the receive FIFO. 2010 Microchip Technology Inc. Slave Clock Synchronous data transfers use a separate clock line, which is synchronous with the data. A device configured as a slave receives the clock on the TX/CK line. The TX/CK pin output driver must be disabled by setting the associated TRIS bit when the device is configured for synchronous slave transmit or receive operation. Serial data bits change on the leading edge to ensure they are valid at the trailing edge of each clock. One data bit is transferred for each clock cycle. Only as many clock cycles should be received as there are data bits. 16.4.1.8 Receive Overrun Error The receive FIFO buffer can hold two characters. An overrun error will be generated if a third character, in its entirety, is received before RCREG is read to access the FIFO. When this happens the OERR bit of the RCSTA register is set. Previous data in the FIFO will not be overwritten. The two characters in the FIFO buffer can be read, however, no additional characters will be received until the error is cleared. The OERR bit can only be cleared by clearing the overrun condition. If the overrun error occurred when the SREN bit is set and CREN is clear then the error is cleared by reading RCREG. If the overrun occurred when the CREN bit is set then the error condition is cleared by either clearing the CREN bit of the RCSTA register or by clearing the SPEN bit which resets the EUSART. Preliminary DS41350D-page 205 PIC18F/LF1XK50 16.4.1.9 Receiving 9-bit Characters 16.4.1.10 The EUSART supports 9-bit character reception. When the RX9 bit of the RCSTA register is set the EUSART will shift 9-bits into the RSR for each character received. The RX9D bit of the RCSTA register is the ninth, and Most Significant, data bit of the top unread character in the receive FIFO. When reading 9-bit data from the receive FIFO buffer, the RX9D data bit must be read before reading the 8 Least Significant bits from the RCREG. FIGURE 16-12: RX/DT pin Synchronous Master Reception Set-up: 1. Initialize the SPBRGH, SPBRG register pair for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. Disable RX/DT and TX/CK output drivers by setting the corresponding TRIS bits. 3. Ensure bits CREN and SREN are clear. 4. If using interrupts, set the GIE and PEIE bits of the INTCON register and set RCIE. 5. If 9-bit reception is desired, set bit RX9. 6. Start reception by setting the SREN bit or for continuous reception, set the CREN bit. 7. Interrupt flag bit RCIF will be set when reception of a character is complete. 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 an overrun error occurs, clear the error by either clearing the CREN bit of the RCSTA register or by clearing the SPEN bit which resets the EUSART. SYNCHRONOUS RECEPTION (MASTER MODE, SREN) bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 TX/CK pin (SCKP = 0) TX/CK pin (SCKP = 1) Write to bit SREN SREN bit CREN bit ‘0’ ‘0’ RCIF bit (Interrupt) Read RXREG Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0. DS41350D-page 206 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 16-8: Name REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D INTCON RCSTA RCREG TXSTA GIE/GIEH PEIE/GIEL EUSART Receive Register CSRC BAUDCON ABDOVF 289 289 TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception. 16.4.2 SYNCHRONOUS SLAVE MODE 16.4.2.1 The following bits are used to configure the EUSART for Synchronous slave operation: • • • • • SYNC = 1 CSRC = 0 SREN = 0 (for transmit); SREN = 1 (for receive) CREN = 0 (for transmit); CREN = 1 (for receive) SPEN = 1 The operation of the Synchronous Master and Slave modes are identical (see Section 16.4.1.3 “Synchronous Master Transmission”), 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: Setting the SYNC bit of the TXSTA register configures the device for synchronous operation. Clearing the CSRC bit of the TXSTA register configures the device as a slave. Clearing the SREN and CREN bits of the RCSTA register ensures that the device is in the Transmit mode, otherwise the device will be configured to receive. Setting the SPEN bit of the RCSTA register enables the EUSART. If the RX/DT or TX/CK pins are shared with an analog peripheral the analog I/O functions must be disabled by clearing the corresponding ANSEL bits. 1. 2. 3. 4. 5. RX/DT and TX/CK pin output drivers must be disabled by setting the corresponding TRIS bits. The first character will immediately transfer to the TSR register and transmit. The second word will remain in TXREG register. The TXIF bit will not be set. After the first character has been shifted out of TSR, the TXREG register will transfer the second character to the TSR and the TXIF bit will now be set. If the PEIE and TXIE bits are set, the interrupt will wake the device from Sleep and execute the next instruction. If the GIE bit is also set, the program will call the Interrupt Service Routine. 16.4.2.2 1. 2. 3. 4. 5. 6. 7. 2010 Microchip Technology Inc. EUSART Synchronous Slave Transmit Preliminary Synchronous Slave Transmission Set-up: Set the SYNC and SPEN bits and clear the CSRC bit. Set the TRIS bits corresponding to the RX/DT and TX/CK I/O pins. Clear the CREN and SREN bits. If using interrupts, ensure that the GIE and PEIE bits of the INTCON register are set and set the TXIE bit. If 9-bit transmission is desired, set the TX9 bit. Enable transmission by setting the TXEN bit. If 9-bit transmission is selected, insert the Most Significant bit into the TX9D bit. Start transmission by writing the Least Significant 8 bits to the TXREG register. DS41350D-page 207 PIC18F/LF1XK50 TABLE 16-9: Name REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 INTCON GIE/GIEH PEIE/GIEL TMR0IE Bit 4 RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 TXREG EUSART Transmit Register 289 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 TXSTA Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission. 16.4.2.3 EUSART Synchronous Slave Reception 16.4.2.4 The operation of the Synchronous Master and Slave modes is identical (Section 16.4.1.6 “Synchronous Master Reception”), with the following exceptions: 1. • Sleep • CREN bit is always set, therefore the receiver is never Idle • SREN bit, which is a “don't care” in Slave mode 2. A character may be received while in Sleep mode by setting the CREN bit prior to entering Sleep. Once the word is received, the RSR register will transfer the data to the RCREG register. If the RCIE enable bit is set, the interrupt generated will wake the device from Sleep and execute the next instruction. If the GIE bit is also set, the program will branch to the interrupt vector. 3. 4. 5. 6. 7. 8. DS41350D-page 208 Preliminary Synchronous Slave Reception Set-up: Set the SYNC and SPEN bits and clear the CSRC bit. Set the TRIS bits corresponding to the RX/DT and TX/CK I/O pins. If using interrupts, ensure that the GIE and PEIE bits of the INTCON register are set and set the RCIE bit. If 9-bit reception is desired, set the RX9 bit. Set the CREN bit to enable reception. The RCIF bit will be set when reception is complete. An interrupt will be generated if the RCIE bit was set. If 9-bit mode is enabled, retrieve the Most Significant bit from the RX9D bit of the RCSTA register. Retrieve the 8 Least Significant bits from the receive FIFO by reading the RCREG register. If an overrun error occurs, clear the error by either clearing the CREN bit of the RCSTA register or by clearing the SPEN bit which resets the EUSART. 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name INTCON Bit 7 Bit 6 Bit 5 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 289 RCSTA RCREG GIE/GIEH PEIE/GIEL TMR0IE Bit 4 EUSART Receive Register 289 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 289 BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16 — WUE ABDEN 289 SPBRGH EUSART Baud Rate Generator Register, High Byte 289 SPBRG EUSART Baud Rate Generator Register, Low Byte 289 TXSTA Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception. 2010 Microchip Technology Inc. Preliminary DS41350D-page 209 PIC18F/LF1XK50 NOTES: DS41350D-page 210 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 17.0 ANALOG-TO-DIGITAL CONVERTER (ADC) MODULE The Analog-to-Digital Converter (ADC) allows conversion of an analog input signal to a 10-bit binary representation of that signal. This device uses analog inputs, which are multiplexed into a single sample and hold circuit. The output of the sample and hold is connected to the input of the converter. The converter generates a 10-bit binary result via successive approximation and stores the conversion result into the ADC result registers (ADRESL and ADRESH). The ADC voltage reference is software selectable to either VDD, or a voltage applied to the external reference pins. The ADC can generate an interrupt upon completion of a conversion. This interrupt can be used to wake-up the device from Sleep. Figure 17-1 shows the block diagram of the ADC. FIGURE 17-1: ADC BLOCK DIAGRAM NVCFG[1:0] = 00 AVSS NVCFG[1:0] = 01 VREF- AVDD PVCFG[1:0] = 00 VREF+ PVCFG[1:0] = 01 FVR Unused 0000 Unused 0001 Unused 0010 AN3 0011 AN4 0100 AN5 0101 AN6 0110 AN7 0111 AN8 1000 AN9 1001 AN10 1010 AN11 1011 Unused 1100 Unused 1101 DAC 1110 FVR 1111 PVCFG[1:0] = 10 ADC 10 GO/DONE ADFM 0 = Left Justify 1 = Right Justify ADON 10 VSS ADRESH ADRESL CHS<3:0> 2010 Microchip Technology Inc. Preliminary DS41350D-page 211 PIC18F/LF1XK50 17.1 ADC Configuration 17.1.4 When configuring and using the ADC the following functions must be considered: • • • • • • Port configuration Channel selection ADC voltage reference selection ADC conversion clock source Interrupt control Results formatting 17.1.1 PORT CONFIGURATION The ANSEL, ANSELH, TRISA, TRISB and TRISE registers all configure the A/D port pins. Any port pin needed as an analog input should have its corresponding ANSx bit set to disable the digital input buffer and TRISx bit set to disable the digital output driver. If the TRISx bit is cleared, the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the ANSx bits and the TRIS bits. Note 1: When reading the PORT register, all pins with their corresponding ANSx bit set read as cleared (a low level). However, analog conversion of pins configured as digital inputs (ANSx bit cleared and TRISx bit set) will be accurately converted. 2: Analog levels on any pin with the corresponding ANSx bit cleared may cause the digital input buffer to consume current out of the device’s specification limits. 17.1.2 CHANNEL SELECTION The CHS bits of the ADCON0 register determine which channel is connected to the sample and hold circuit. When changing channels, a delay is required before starting the next conversion. Refer to Section 17.2 “ADC Operation” for more information. 17.1.3 ADC VOLTAGE REFERENCE The PVCFG and NVCFG bits of the ADCON1 register provide independent control of the positive and negative voltage references, respectively. The positive voltage reference can be either VDD, FVR or an external voltage source. The negative voltage reference can be either VSS or an external voltage source. The ADCON2 register allows the user to select an acquisition time that occurs each time the GO/DONE bit is set. Acquisition time is set with the ACQT<2:0> bits of the ADCON2 register. Acquisition delays cover a range of 2 to 20 TAD. When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition time, then automatically begins a conversion. Since the acquisition time is programmed, there is no need to wait for an acquisition time between selecting a channel and setting the GO/DONE bit. Manual acquisition is selected when ACQT<2:0> = 000. When the GO/DONE bit is set, sampling is stopped and a conversion begins. The user is responsible for ensuring the required acquisition time has passed between selecting the desired input channel and setting the GO/DONE bit. This option is also the default Reset state of the ACQT<2:0> bits and is compatible with devices that do not offer programmable acquisition times. In either case, when the conversion is completed, the GO/DONE bit is cleared, the ADIF flag is set and the A/D begins sampling the currently selected channel again. When an acquisition time is programmed, there is no indication of when the acquisition time ends and the conversion begins. 17.1.5 CONVERSION CLOCK The source of the conversion clock is software selectable via the ADCS bits of the ADCON2 register. There are seven possible clock options: • • • • • • • FOSC/2 FOSC/4 FOSC/8 FOSC/16 FOSC/32 FOSC/64 FRC (dedicated internal oscillator) The time to complete one bit conversion is defined as TAD. One full 10-bit conversion requires 11 TAD periods as shown in Figure 17-3. For correct conversion, the appropriate TAD specification must be met. See A/D conversion requirements in Table 27-9 for more information. Table 17-1 gives examples of appropriate ADC clock selections. Note: DS41350D-page 212 SELECTING AND CONFIGURING ACQUISITION TIME Preliminary Unless using the FRC, any changes in the system clock frequency will change the ADC clock frequency, which may adversely affect the ADC result. 2010 Microchip Technology Inc. PIC18F/LF1XK50 17.1.6 INTERRUPTS This interrupt can be generated while the device is operating or while in Sleep. If the device is in Sleep, the interrupt will wake-up the device. Upon waking from Sleep, the next instruction following the SLEEP instruction is always executed. If the user is attempting to wake-up from Sleep and resume in-line code execution, the global interrupt must be disabled. If the global interrupt is enabled, execution will switch to the Interrupt Service Routine. Please see Section 17.1.6 “Interrupts” for more information. The ADC module allows for the ability to generate an interrupt upon completion of an Analog-to-Digital Conversion. The ADC interrupt flag is the ADIF bit in the PIR1 register. The ADC interrupt enable is the ADIE bit in the PIE1 register. The ADIF bit must be cleared by software. Note: The ADIF bit is set at the completion of every conversion, regardless of whether or not the ADC interrupt is enabled. TABLE 17-1: ADC CLOCK PERIOD (TAD) VS. DEVICE OPERATING FREQUENCIES ADC Clock Period (TAD) ADC Clock Source ADCS<2:0> FOSC/2 48 MHz 000 41.67 ns(2) 83.33 ns(2) 16 MHz 4 MHz 125 ns(2) 250 ns(2) 500 ns(2) 1 MHz 2.0 s FOSC/4 100 1.0 s 4.0 s FOSC/8 001 167 ns(2) 500 ns(2) 2.0 s 8.0 s(3) FOSC/16 101 333 ns(2) 1.0 s 4.0 s 16.0 s(3) FOSC/32 010 ns(2) FOSC/64 110 FRC Legend: Note 1: 2: 3: 4: 17.1.7 Device Frequency (FOSC) 667 1.33 s 1-4 x11 s(1,4) 2.0 s 8.0 s(3) 32.0 s(3) 4.0 s 16.0 s(3) 64.0 s(3) s(1,4) 1-4 s(1,4) 1-4 s(1,4) 1-4 Shaded cells are outside of recommended range. The FRC source has a typical TAD time of 1.7 s. These values violate the minimum required TAD time. For faster conversion times, the selection of another clock source is recommended. When the device frequency is greater than 1 MHz, the FRC clock source is only recommended if the conversion will be performed during Sleep. RESULT FORMATTING The 10-bit A/D conversion result can be supplied in two formats, left justified or right justified. The ADFM bit of the ADCON2 register controls the output format. Figure 17-2 shows the two output formats. FIGURE 17-2: 10-BIT A/D CONVERSION RESULT FORMAT ADRESH (ADFM = 0) ADRESL MSB LSB bit 7 bit 0 bit 7 10-bit A/D Result (ADFM = 1) bit 0 Unimplemented: Read as ‘0’ MSB bit 7 LSB bit 0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. bit 7 bit 0 10-bit A/D Result Preliminary DS41350D-page 213 PIC18F/LF1XK50 17.2 ADC Operation 17.2.1 Figure 17-3 shows the operation of the A/D converter after the GO bit has been set and the ACQT<2:0> bits are cleared. A conversion is started after the following instruction to allow entry into SLEEP mode before the conversion begins. STARTING A CONVERSION To enable the ADC module, the ADON bit of the ADCON0 register must be set to a ‘1’. Setting the GO/ DONE bit of the ADCON0 register to a ‘1’ will, depending on the ACQT bits of the ADCON2 register, either immediately start the Analog-to-Digital conversion or start an acquisition delay followed by the Analog-toDigital conversion. FIGURE 17-3: Figure 17-4 shows the operation of the A/D converter after the GO bit has been set and the ACQT<2:0> bits are set to ‘010’ which selects a 4 TAD acquisition time before the conversion starts. Note: The GO/DONE bit should not be set in the same instruction that turns on the ADC. Refer to Section 17.2.9 “A/D Conversion Procedure”. A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0) TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 2 TAD b4 b1 b0 b6 b7 b2 b9 b8 b3 b5 Conversion starts Discharge Holding capacitor is disconnected from analog input (typically 100 ns) Set GO bit On the following cycle: ADRESH:ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD) FIGURE 17-4: TAD Cycles TACQT Cycles 1 2 3 Automatic Acquisition Time 4 1 3 4 5 b9 b8 b7 b6 6 b5 7 8 9 10 11 b4 b3 b2 b1 b0 Conversion starts (Holding capacitor is disconnected from analog input) Set GO bit (Holding capacitor continues acquiring input) DS41350D-page 214 2 2 TAD Discharge On the following cycle: ADRESH:ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 17.2.2 COMPLETION OF A CONVERSION When the conversion is complete, the ADC module will: • Clear the GO/DONE bit • Set the ADIF flag bit • Update the ADRESH:ADRESL registers with new conversion result 17.2.3 DISCHARGE The discharge phase is used to initialize the value of the capacitor array. The array is discharged after every sample. This feature helps to optimize the unity-gain amplifier, as the circuit always needs to charge the capacitor array, rather than charge/discharge based on previous measure values. 17.2.4 TERMINATING A CONVERSION If a conversion must be terminated before completion, the GO/DONE bit can be cleared by software. The ADRESH:ADRESL registers will be updated with the partially complete Analog-to-Digital conversion sample. Unconverted bits will match the last bit converted. Note: 17.2.5 A device Reset forces all registers to their Reset state. Thus, the ADC module is turned off and any pending conversion is terminated. 17.2.7 ADC OPERATION DURING SLEEP The ADC module can operate during Sleep. This requires the ADC clock source to be set to the FRC option. When the FRC clock source is selected, the ADC waits one additional instruction before starting the conversion. This allows the SLEEP instruction to be executed, which can reduce system noise during the conversion. If the ADC interrupt is enabled, the device will wake-up from Sleep when the conversion completes. If the ADC interrupt is disabled, the ADC module is turned off after the conversion completes, although the ADON bit remains set. When the ADC clock source is something other than FRC, a SLEEP instruction causes the present conversion to be aborted and the ADC module is turned off, although the ADON bit remains set. 17.2.8 SPECIAL EVENT TRIGGER The CCP1 Special Event Trigger allows periodic ADC measurements without software intervention. When this trigger occurs, the GO/DONE bit is set by hardware and the Timer1 or Timer3 counter resets to zero. Using the Special Event Trigger does not assure proper ADC timing. It is the user’s responsibility to ensure that the ADC timing requirements are met. See Section 14.3.4 “Special Event Trigger” for more information. DELAY BETWEEN CONVERSIONS After the A/D conversion is completed or aborted, a 2 TAD wait is required before the next acquisition can be started. After this wait, the currently selected channel is reconnected to the charge holding capacitor commencing the next acquisition. 17.2.6 ADC OPERATION IN POWERMANAGED MODES The selection of the automatic acquisition time and A/D conversion clock is determined in part by the clock source and frequency while in a power-managed mode. If the A/D is expected to operate while the device is in a power-managed mode, the ACQT<2:0> and ADCS<2:0> bits in ADCON2 should be updated in accordance with the clock source to be used in that mode. After entering the mode, an A/D acquisition or conversion may be started. Once started, the device should continue to be clocked by the same clock source until the conversion has been completed. If desired, the device may be placed into the corresponding Idle mode during the conversion. If the device clock frequency is less than 1 MHz, the A/D FRC clock source should be selected. 2010 Microchip Technology Inc. Preliminary DS41350D-page 215 PIC18F/LF1XK50 17.2.9 A/D CONVERSION PROCEDURE EXAMPLE 17-1: This is an example procedure for using the ADC to perform an Analog-to-Digital conversion: 1. 2. 3. 4. 5. 6. 7. 8. Configure Port: • Disable pin output driver (See TRIS register) • Configure pin as analog Configure the ADC module: • Select ADC conversion clock • Configure voltage reference • Select ADC input channel • Select result format • Select acquisition delay • Turn on ADC module Configure ADC interrupt (optional): • Clear ADC interrupt flag • Enable ADC interrupt • Enable peripheral interrupt • Enable global interrupt(1) Wait the required acquisition time(2). Start conversion by setting the GO/DONE bit. Wait for ADC conversion to complete by one of the following: • Polling the GO/DONE bit • Waiting for the ADC interrupt (interrupts enabled) Read ADC Result Clear the ADC interrupt flag (required if interrupt is enabled). A/D CONVERSION ;This code block configures the ADC ;for polling, Vdd and Vss as reference, Frc clock and AN4 input. ; ;Conversion start & polling for completion ; are included. ; MOVLW B’10101111’ ;right justify, Frc, MOVWF ADCON2 ; & 12 TAD ACQ time MOVLW B’00000000’ ;ADC ref = Vdd,Vss MOVWF ADCON1 ; BSF TRISC,0 ;Set RC0 to input BSF ANSEL,4 ;Set RC0 to analog MOVLW B’00010001’ ;AN4, ADC on MOVWF ADCON0 ; BSF ADCON0,GO ;Start conversion ADCPoll: BTFSC ADCON0,GO ;Is conversion done? BRA ADCPoll ;No, test again ; Result is complete - store 2 MSbits in ; RESULTHI and 8 LSbits in RESULTLO MOVFF ADRESH,RESULTHI MOVFF ADRESL,RESULTLO Note 1: The global interrupt can be disabled if the user is attempting to wake-up from Sleep and resume in-line code execution. 2: Software delay required if ACQT bits are set to zero delay. See Section 17.3 “A/D Acquisition Requirements”. DS41350D-page 216 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 17.2.10 ADC REGISTER DEFINITIONS The following registers are used to control the operation of the ADC. Note: Analog pin control is performed by the ANSEL and ANSELH registers. For ANSEL and ANSELH registers, see Register 9-15 and Register 9-16, respectively. REGISTER 17-1: ADCON0: A/D CONTROL REGISTER 0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-2 CHS<3:0>: Analog Channel Select bits 0000 = Reserved 0001 = Reserved 0010 = Reserved 0011 = AN3 0100 = AN4 0101 = AN5 0110 = AN6 0111 = AN7 1000 = AN8 1001 = AN9 1010 = AN10 1011 = AN11 1100 = Reserved 1101 = Reserved 1110 = DAC 1111 = FVR bit 1 GO/DONE: A/D Conversion Status bit 1 = A/D conversion cycle in progress. Setting this bit starts an A/D conversion cycle. This bit is automatically cleared by hardware when the A/D conversion has completed. 0 = A/D conversion completed/not in progress bit 0 ADON: ADC Enable bit 1 = ADC is enabled 0 = ADC is disabled and consumes no operating current Note 1: Selecting reserved channels will yield unpredictable results as unimplemented input channels are left floating. 2010 Microchip Technology Inc. Preliminary DS41350D-page 217 PIC18F/LF1XK50 REGISTER 17-2: ADCON1: A/D CONTROL REGISTER 1 U-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 — — — — PVCFG1 PVCFG0 NVCFG1 NVCFG0 bit 7 bit 0 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 bit 7-4 Unimplemented: Read as ‘0’ bit 3-2 PVCFG<1:0>: Positive Voltage Reference select bit 00 = Positive voltage reference supplied internally by VDD. 01 = Positive voltage reference supplied externally through VREF+ pin. 10 = Positive voltage reference supplied internally through FVR. 11 = Reserved. bit 1-0 NVCFG<1:0>: Negative Voltage Reference select bit 00 = Negative voltage reference supplied internally by VSS. 01 = Negative voltage reference supplied externally through VREF- pin. 10 = Reserved. 11 = Reserved. DS41350D-page 218 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 17-3: ADCON2: A/D CONTROL REGISTER 2 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 bit 7 bit 0 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 bit 7 x = Bit is unknown ADFM: A/D Conversion Result Format Select bit 1 = Right justified 0 = Left justified bit 6 Unimplemented: Read as ‘0’ bit 5-3 ACQT<2:0>: A/D Acquisition time select bits. Acquisition time is the duration that the A/D charge holding capacitor remains connected to A/D channel from the instant the GO/DONE bit is set until conversions begins. 000 = 0(1) 001 = 2 TAD 010 = 4 TAD 011 = 6 TAD 100 = 8 TAD 101 = 12 TAD 110 = 16 TAD 111 = 20 TAD bit 2-0 ADCS<2:0>: A/D Conversion Clock Select bits 000 = FOSC/2 001 = FOSC/8 010 = FOSC/32 011 = FRC(1) (clock derived from a dedicated internal oscillator = 600 kHz nominal) 100 = FOSC/4 101 = FOSC/16 110 = FOSC/64 111 = FRC(1) (clock derived from a dedicated internal oscillator = 600 kHz nominal) Note 1: When the A/D clock source is selected as FRC then the start of conversion is delayed by one instruction cycle after the GO/DONE bit is set to allow the SLEEP instruction to be executed. 2010 Microchip Technology Inc. Preliminary DS41350D-page 219 PIC18F/LF1XK50 REGISTER 17-4: ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x ADRES9 ADRES8 ADRES7 ADRES6 ADRES5 ADRES4 ADRES3 ADRES2 bit 7 bit 0 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 bit 7-0 x = Bit is unknown ADRES<9:2>: ADC Result Register bits Upper 8 bits of 10-bit conversion result REGISTER 17-5: ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x ADRES1 ADRES0 — — — — — — bit 7 bit 0 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 bit 7-6 ADRES<1:0>: ADC Result Register bits Lower 2 bits of 10-bit conversion result bit 5-0 Reserved: Do not use. REGISTER 17-6: x = Bit is unknown ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 1 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x — — — — — — ADRES9 ADRES8 bit 7 bit 0 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 bit 7-2 Reserved: Do not use. bit 1-0 ADRES<9:8>: ADC Result Register bits Upper 2 bits of 10-bit conversion result REGISTER 17-7: x = Bit is unknown ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 1 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x ADRES7 ADRES6 ADRES5 ADRES4 ADRES3 ADRES2 ADRES1 ADRES0 bit 7 bit 0 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 bit 7-0 x = Bit is unknown ADRES<7:0>: ADC Result Register bits Lower 8 bits of 10-bit conversion result DS41350D-page 220 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 17.3 A/D Acquisition Requirements For the ADC 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 17-5. 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), see Figure 17-5. The maximum recommended impedance for analog sources is 10 k. As the source impedance is decreased, the acquisition time may be decreased. After the analog input channel is selected (or changed), EQUATION 17-1: an A/D acquisition must be done before the conversion can be started. 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 ADC). The 1/2 LSb error is the maximum error allowed for the ADC to meet its specified resolution. ACQUISITION TIME EXAMPLE Temperature = 50°C and external impedance of 10k 3.0V V DD Assumptions: T ACQ = Amplifier Settling Time + Hold Capacitor Charging Time + Temperature Coefficient = T AMP + T C + T COFF = 5µs + T C + Temperature - 25°C 0.05µs/°C The value for TC can be approximated with the following equations: 1 V AP PLIE D 1 – ------------ = V CHOLD 2047 ;[1] VCHOLD charged to within 1/2 lsb –TC ---------- RC V AP P LI ED 1 – e = V CHOLD ;[2] VCHOLD charge response to VAPPLIED – Tc --------- 1 RC V AP P LIED 1 – e = V A P PLIE D 1 – ------------ 2047 ;combining [1] and [2] Solving for TC: T C = – C HOLD R IC + R SS + R S ln(1/2047) = – 13.5pF 1k + 700 + 10k ln(0.0004885) = 1.20 µs Therefore: T ACQ = 5µs + 1.20µs + 50°C- 25°C 0.05µs/°C = 7.45µs Note 1: The reference voltage (VREF) has no effect on the equation, since it cancels itself out. 2: The charge holding capacitor (CHOLD) is discharged after each conversion. 3: The maximum recommended impedance for analog sources is 10 k. This is required to meet the pin leakage specification. 2010 Microchip Technology Inc. Preliminary DS41350D-page 221 PIC18F/LF1XK50 FIGURE 17-5: ANALOG INPUT MODEL VDD ANx Rs CPIN 5 pF VA VT = 0.6V VT = 0.6V RIC 1k Sampling Switch SS Rss CHOLD = 13.5 pF I LEAKAGE(1) Discharge Switch Note 1: VDD Legend: CPIN = Input Capacitance = Threshold Voltage VT I LEAKAGE = Leakage current at the pin due to various junctions RIC = Interconnect Resistance SS = Sampling Switch CHOLD = Sample/Hold Capacitance VSS/VREF- 3.5V 3.0V 2.5V 2.0V 1.5V .1 1 10 Rss (k) 100 See Section 27.0 “Electrical Specifications”. FIGURE 17-6: ADC TRANSFER FUNCTION Full-Scale Range 3FFh 3FEh ADC Output Code 3FDh 3FCh 1/2 LSB ideal 3FBh Full-Scale Transition 004h 003h 002h 001h 000h Analog Input Voltage 1/2 LSB ideal VSS/VREF- DS41350D-page 222 Zero-Scale Transition VDD/VREF+ Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 17-2: Name INTCON REGISTERS ASSOCIATED WITH A/D OPERATION Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 PIR1 — ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 290 PIE1 — ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 290 IPR1 — ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 290 ADRESH A/D Result Register, High Byte 289 ADRESL A/D Result Register, Low Byte 289 ADCON0 — — CHS3 CHS2 CHS1 CHS0 ADCON1 — — — — PVCFG1 PVCFG0 ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ANSEL GO/DONE ADON 289 NVCFG1 NVCFG0 289 ADCS1 ADCS0 289 ANS7 ANS6 ANS5 ANS4 ANS3 — — — 290 ANSELH — — — — ANS11 ANS10 ANS9 ANS8 290 TRISA – – TRISA5 TRISA4 – – – – 290 TRISB TRISB7 TRISB6 TRISB5 TRISB4 – – – – 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion. 2010 Microchip Technology Inc. Preliminary DS41350D-page 223 PIC18F/LF1XK50 NOTES: DS41350D-page 224 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 18.0 COMPARATOR MODULE FIGURE 18-1: Comparators are used to interface analog circuits to a digital circuit by comparing two analog voltages and providing a digital indication of their relative magnitudes. The comparators are very useful mixed signal building blocks because they provide analog functionality independent of the program execution. The Analog Comparator module includes the following features: • • • • • • • • • Independent comparator control Programmable input selection Comparator output is available internally/externally Programmable output polarity Interrupt-on-change Wake-up from Sleep Programmable Speed/Power optimization PWM shutdown Programmable and fixed voltage reference 18.1 SINGLE COMPARATOR VIN+ + VIN- – Output VINVIN+ Output Note: Comparator Overview The black areas of the output of the comparator represents the uncertainty due to input offsets and response time. A single comparator is shown in Figure 18-1 along with the relationship between the analog input levels and the digital output. When the analog voltage at VIN+ is less than the analog voltage at VIN-, the output of the comparator is a digital low level. When the analog voltage at VIN+ is greater than the analog voltage at VIN-, the output of the comparator is a digital high level. 2010 Microchip Technology Inc. Preliminary DS41350D-page 225 PIC18F/LF1XK50 FIGURE 18-2: COMPARATOR C1 SIMPLIFIED BLOCK DIAGRAM C1CH<1:0> 2 AGND C12IN1- D Q1 0 C12IN2- 1 MUX 2 C12IN3- 3 To Data Bus Q EN RD_CM1CON0 D Q3*RD_CM1CON0 Q Set C1IF EN CL NReset C1ON(1) C1R C1IN+ VREF FVR 0 MUX 1 C1VIN- C1 C1VIN+ + 0 MUX C1VREF 1 C1SP To PWM Logic C1OUT C1POL C1SYNC C2OE C1OE 0 C1RSEL D From TMR1L[0] Q 1 C12OUT (4) SYNCC1OUT Note 1: 2: 3: 4: DS41350D-page 226 When C1ON = 0, the C1 comparator will produce a ‘0’ output to the XOR Gate. Q1 and Q3 are phases of the four-phase system clock (FOSC). Q1 is held high during Sleep mode. Positive going pulse generated on both falling and rising edges of the bit. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 18-3: COMPARATOR C2 SIMPLIFIED BLOCK DIAGRAM D Q1 To Data Bus Q EN RD_CM2CON0 C2CH<1:0> 2 AGND C12IN1- D C2ON(1) 0 C12IN2- 1 MUX 2 C12IN3- 3 C2R Q3*RD_CM2CON0 EN CL NRESET C2VINC2VIN+ To PWM Logic C2OUT C2 C2SP C2SYNC C2POL 0 C2IN+ VREF FVR 0 MUX 1 0 MUX C2VREF 1 Set C2IF Q D From TMR1L[0] (4) Q C20E C12OUT pin 1 SYNCC2OUT C2RSEL Note 1: 2: 3: 4: 2010 Microchip Technology Inc. When C2ON = 0, the C2 comparator will produce a ‘0’ output to the XOR Gate. Q1 and Q3 are phases of the four-phase system clock (FOSC). Q1 is held high during Sleep mode. Positive going pulse generated on both falling and rising edges of the bit. Preliminary DS41350D-page 227 PIC18F/LF1XK50 18.2 Comparator Control TABLE 18-1: Each comparator has a separate control and Configuration register: CM1CON0 for Comparator C1 and CM2CON0 for Comparator C2. In addition, Comparator C2 has a second control register, CM2CON1, for controlling the interaction with Timer1 and simultaneous reading of both comparator outputs. The CM1CON0 and CM2CON0 registers (see Registers 18-1 and 18-2, respectively) contain the control and status bits for the following: • • • • • • Enable Input selection Reference selection Output selection Output polarity Speed selection 18.2.1 COMPARATOR ENABLE 18.2.3 COMPARATOR INPUT SELECTION To use CxIN+ and C12INx- pins as analog inputs, the appropriate bits must be set in the ANSEL register and the corresponding TRIS bits must also be set to disable the output drivers. COMPARATOR REFERENCE SELECTION Setting the CxR bit of the CMxCON0 register directs an internal voltage reference or an analog input pin to the non-inverting input of the comparator. See Section 21.0 “VOLTAGE REFERENCES” for more information on the Internal Voltage Reference module. 18.2.4 COMPARATOR OUTPUT SELECTION The output of the comparator can be monitored by reading either the CxOUT bit of the CMxCON0 register or the MCxOUT bit of the CM2CON1 register. In order to make the output available for an external connection, the following conditions must be true: • CxOE bit of the CMxCON0 register must be set • Corresponding TRIS bit must be cleared • CxON bit of the CMxCON0 register must be set Both comparators share the same output pin (C12OUT). Priority is determined by the states of the C1OE and C2OE bits. DS41350D-page 228 C2OE C12OUT 0 0 I/O 0 1 C2OUT 1 0 C1OUT 1 1 C2OUT Note 1: The CxOE bit overrides the PORT data latch. Setting the CxON has no impact on the port override. 18.2.5 The CxCH<1:0> bits of the CMxCON0 register direct one of four analog input pins to the comparator inverting input. Note: C10E 2: The internal output of the comparator is latched with each instruction cycle. Unless otherwise specified, external outputs are not latched. Setting the CxON bit of the CMxCON0 register enables the comparator for operation. Clearing the CxON bit disables the comparator resulting in minimum current consumption. 18.2.2 COMPARATOR OUTPUT PRIORITY COMPARATOR OUTPUT POLARITY Inverting the output of the comparator is functionally equivalent to swapping the comparator inputs. The polarity of the comparator output can be inverted by setting the CxPOL bit of the CMxCON0 register. Clearing the CxPOL bit results in a non-inverted output. Table 18-2 shows the output state versus input conditions, including polarity control. TABLE 18-2: COMPARATOR OUTPUT STATE VS. INPUT CONDITIONS Input Condition CxPOL CxOUT CxVIN- > CxVIN+ 0 0 CxVIN- < CxVIN+ 0 1 CxVIN- > CxVIN+ 1 1 CxVIN- < CxVIN+ 1 0 18.2.6 COMPARATOR SPEED SELECTION The trade-off between speed or power can be optimized during program execution with the CxSP control bit. The default state for this bit is ‘1’ which selects the normal speed mode. Device power consumption can be optimized at the cost of slower comparator propagation delay by clearing the CxSP bit to ‘0’. 18.3 Comparator Response Time The comparator output is indeterminate for a period of time after the change of an input source or the selection of a new reference voltage. This period is referred to as the response time. The response time of the comparator differs from the settling time of the voltage reference. Therefore, both of these times must be considered when determining the total response time to a comparator input change. See the Comparator and Voltage Reference Specifications in Section 27.0 “Electrical Specifications” for more details. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 18.4 Comparator Interrupt Operation 18.4.1 The comparator interrupt flag can be set whenever there is a change in the output value of the comparator. Changes are recognized by means of a mismatch circuit which consists of two latches and an exclusiveor gate (see Figure 18-2 and Figure 18-3). One latch is updated with the comparator output level when the CMxCON0 register is read. This latch retains the value until the next read of the CMxCON0 register or the occurrence of a Reset. The other latch of the mismatch circuit is updated on every Q1 system clock. A mismatch condition will occur when a comparator output change is clocked through the second latch on the Q1 clock cycle. At this point the two mismatch latches have opposite output levels which is detected by the exclusive-or gate and fed to the interrupt circuitry. The mismatch condition persists until either the CMxCON0 register is read or the comparator output returns to the previous state. Note 1: A write operation to the CMxCON0 register will also clear the mismatch condition because all writes include a read operation at the beginning of the write cycle. PRESETTING THE MISMATCH LATCHES The comparator mismatch latches can be preset to the desired state before the comparators are enabled. When the comparator is off the CxPOL bit controls the CxOUT level. Set the CxPOL bit to the desired CxOUT non-interrupt level while the CxON bit is cleared. Then, configure the desired CxPOL level in the same instruction that the CxON bit is set. Since all register writes are performed as a Read-Modify-Write, the mismatch latches will be cleared during the instruction Read phase and the actual configuration of the CxON and CxPOL bits will be occur in the final Write phase. FIGURE 18-4: COMPARATOR INTERRUPT TIMING W/O CMxCON0 READ Q1 Q3 CxIN+ TRT CxOUT Set CxIF (edge) CxIF Reset by Software 2: Comparator interrupts will operate correctly regardless of the state of CxOE. The comparator interrupt is set by the mismatch edge and not the mismatch level. This means that the interrupt flag can be reset without the additional step of reading or writing the CMxCON0 register to clear the mismatch registers. When the mismatch registers are cleared, an interrupt will occur upon the comparator’s return to the previous state, otherwise no interrupt will be generated. FIGURE 18-5: Software will need to maintain information about the status of the comparator output, as read from the CMxCON0 register, or CM2CON1 register, to determine the actual change that has occurred. See Figures 18-4 and 18-5. Set CxIF (edge) The CxIF bit of the PIR2 register is the comparator interrupt flag. This bit must be reset by software by clearing it to ‘0’. Since it is also possible to write a ‘1’ to this register, an interrupt can be generated. In mid-range Compatibility mode the CxIE bit of the PIE2 register and the PEIE and GIE bits of the INTCON register must all be set to enable comparator interrupts. If any of these bits are cleared, the interrupt is not enabled, although the CxIF bit of the PIR2 register will still be set if an interrupt condition occurs. 2010 Microchip Technology Inc. COMPARATOR INTERRUPT TIMING WITH CMxCON0 READ Q1 Q3 CxIN+ TRT CxOUT CxIF Cleared by CMxCON0 Read Reset by Software Note 1: If a change in the CMxCON0 register (CxOUT) should occur when a read operation is being executed (start of the Q2 cycle), then the CxIF interrupt flag of the PIR2 register may not get set. Preliminary 2: When either comparator is first enabled, bias circuitry in the Comparator module may cause an invalid output from the comparator until the bias circuitry is stable. Allow about 1 s for bias settling then clear the mismatch condition and interrupt flags before enabling comparator interrupts. DS41350D-page 229 PIC18F/LF1XK50 18.5 Operation During Sleep The comparator, if enabled before entering Sleep mode, remains active during Sleep. The additional current consumed by the comparator is shown separately in the Section 27.0 “Electrical Specifications”. If the comparator is not used to wake the device, power consumption can be minimized while in Sleep mode by turning off the comparator. Each comparator is turned off by clearing the CxON bit of the CMxCON0 register. A change to the comparator output can wake-up the device from Sleep. To enable the comparator to wake the device from Sleep, the CxIE bit of the PIE2 register and the PEIE bit of the INTCON register must be set. The instruction following the SLEEP instruction always executes following a wake from Sleep. If the GIE bit of the INTCON register is also set, the device will then execute the Interrupt Service Routine. 18.6 Effects of a Reset A device Reset forces the CMxCON0 and CM2CON1 registers to their Reset states. This forces both comparators and the voltage references to their Off states. DS41350D-page 230 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 18-1: CM1CON0: COMPARATOR 1 CONTROL REGISTER 0 R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 C1ON C1OUT C1OE C1POL C1SP C1R C1CH1 C1CH0 bit 7 bit 0 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 bit 7 C1ON: Comparator C1 Enable bit 1 = Comparator C1 is enabled 0 = Comparator C1 is disabled bit 6 C1OUT: Comparator C1 Output bit If C1POL = 1 (inverted polarity): C1OUT = 0 when C1VIN+ > C1VINC1OUT = 1 when C1VIN+ < C1VINIf C1POL = 0 (non-inverted polarity): C1OUT = 1 when C1VIN+ > C1VINC1OUT = 0 when C1VIN+ < C1VIN- bit 5 C1OE: Comparator C1 Output Enable bit If C2OE = 0 (C2 output disable) 0 = C1OUT is internal only 1 = C1OUT is present on the C12OUT pin(1) If C2OE = 1 (C2 output enable) 0 = C1OUT is internal only 1 = C2OUT is present on the C12OUT pin(1) bit 4 C1POL: Comparator C1 Output Polarity Select bit 1 = C1OUT logic is inverted 0 = C1OUT logic is not inverted bit 3 C1SP: Comparator C1 Speed/Power Select bit 1 = C1 operates in normal power, higher speed mode 0 = C1 operates in low-power, low-speed mode bit 2 C1R: Comparator C1 Reference Select bit (non-inverting input) 1 = C1VIN+ connects to C1VREF output 0 = C1VIN+ connects to C12IN+ pin bit 1-0 C1CH<1:0>: Comparator C1 Channel Select bit 00 = C1VIN- connects to AGND 01 = C12IN1- pin of C1 connects to C1VIN10 = C12IN2- pin of C1 connects to C1VIN11 = C12IN3- pin of C1 connects to C1VIN- Note 1: x = Bit is unknown Comparator output requires the following three conditions: C1OE = 1, C1ON = 1 and corresponding port TRIS bit = 0. 2010 Microchip Technology Inc. Preliminary DS41350D-page 231 PIC18F/LF1XK50 REGISTER 18-2: CM2CON0: COMPARATOR 2 CONTROL REGISTER 0 R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 C2ON C2OUT C2OE C2POL C2SP C2R C2CH1 C2CH0 bit 7 bit 0 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 bit 7 C2ON: Comparator C2 Enable bit 1 = Comparator C2 is enabled 0 = Comparator C2 is disabled bit 6 C2OUT: Comparator C2 Output bit If C2POL = 1 (inverted polarity): C2OUT = 0 when C2VIN+ > C2VINC2OUT = 1 when C2VIN+ < C2VINIf C2POL = 0 (non-inverted polarity): C2OUT = 1 when C2VIN+ > C2VINC2OUT = 0 when C2VIN+ < C2VIN- bit 5 C2OE: Comparator C2 Output Enable bit 1 = C2OUT is present on C12OUT pin(1) 0 = C2OUT is internal only bit 4 C2POL: Comparator C2 Output Polarity Select bit 1 = C2OUT logic is inverted 0 = C2OUT logic is not inverted bit 3 C2SP: Comparator C2 Speed/Power Select bit 1 = C2 operates in normal power, higher speed mode 0 = C2 operates in low-power, low-speed mode bit 2 C2R: Comparator C2 Reference Select bits (non-inverting input) 1 = C2VIN+ connects to C2VREF 0 = C2VIN+ connects to C2IN+ pin bit 1-0 C2CH<1:0>: Comparator C2 Channel Select bits 00 = C1VIN- connects to AGND 01 = C12IN1- pin of C2 connects to C2VIN10 = C12IN2- pin of C2 connects to C2VIN11 = C12IN3- pin of C2 connects to C2VIN- Note 1: x = Bit is unknown Comparator output requires the following three conditions: C2OE = 1, C2ON = 1 and corresponding port TRIS bit = 0. DS41350D-page 232 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 18.7 Analog Input Connection Considerations A simplified circuit for an analog input is shown in Figure 18-6. Since the analog input pins share their connection with a digital input, they have reverse biased ESD protection diodes to VDD and VSS. The analog input, therefore, must be between VSS and VDD. If the input voltage deviates from this range by more than 0.6V in either direction, one of the diodes is forward biased and a latch-up may occur. A maximum source impedance of 10 k is recommended for the analog sources. Also, any external component connected to an analog input pin, such as a capacitor or a Zener diode, should have very little leakage current to minimize inaccuracies introduced. Note 1: When reading a PORT register, all pins configured as analog inputs will read as a ‘0’. Pins configured as digital inputs will convert as an analog input, according to the input specification. 2: Analog levels on any pin defined as a digital input, may cause the input buffer to consume more current than is specified. FIGURE 18-6: ANALOG INPUT MODEL VDD VT 0.6V Rs < 10K AIN VA CPIN 5 pF VT 0.6V RIC ILEAKAGE(1) Vss Legend: CPIN = Input Capacitance ILEAKAGE = Leakage Current at the pin due to various junctions = Interconnect Resistance RIC RS = Source Impedance = Analog Voltage VA = Threshold Voltage VT Note 1: See Section 27.0 “Electrical Specifications”. 2010 Microchip Technology Inc. Preliminary DS41350D-page 233 PIC18F/LF1XK50 18.8 Additional Comparator Features There are four additional comparator features: • • • • Simultaneous read of comparator outputs Internal reference selection Hysteresis selection Output Synchronization 18.8.1 SIMULTANEOUS COMPARATOR OUTPUT READ The MC1OUT and MC2OUT bits of the CM2CON1 register are mirror copies of both comparator outputs. The ability to read both outputs simultaneously from a single register eliminates the timing skew of reading separate registers. Note 1: Obtaining the status of C1OUT or C2OUT by reading CM2CON1 does not affect the comparator interrupt mismatch registers. 18.8.2 INTERNAL REFERENCE SELECTION There are two internal voltage references available to the non-inverting input of each comparator. One of these is the Fixed Voltage Reference (FVR) and the other is the variable Comparator Voltage Reference (CVREF). The CxRSEL bit of the CM2CON register determines which of these references is routed to the Comparator Voltage reference output (CXVREF). Further routing to the comparator is accomplished by the CxR bit of the CMxCON0 register. See Section 21.1 “Voltage Reference” and Figure 18-2 and Figure 18-3 for more detail. 18.8.3 COMPARATOR HYSTERESIS The Comparator Cx have selectable hysteresis. The hysteresis can be enable by setting the CxHYS bit of the CM2CON1 register. See Section 27.0 “Electrical Specifications” for more details. 18.8.4 SYNCHRONIZING COMPARATOR OUTPUT TO TIMER 1 The Comparator Cx output can be synchronized with Timer1 by setting the CxSYNC bit of the CM2CON1 register. When enabled, the Cx output is latched on the rising edge of the Timer1 source clock. If a prescaler is used with Timer1, the comparator output is latched after the prescaling function. To prevent a race condition, the comparator output is latched on the rising edge of the Timer1 clock source and Timer1 increments on the rising edge of its clock source. See the Comparator Block Diagram (Figure 18-2 and Figure 18-3) and the Timer1 Block Diagram (Figure 18-2) for more information. DS41350D-page 234 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 18-3: CM2CON1: COMPARATOR 2 CONTROL REGISTER 1 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 MC1OUT MC2OUT C1RSEL C2RSEL C1HYS C2HYS C1SYNC C2SYNC bit 7 bit 0 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 bit 7 MC1OUT: Mirror Copy of C1OUT bit bit 6 MC2OUT: Mirror Copy of C2OUT bit bit 5 C1RSEL: Comparator C1 Reference Select bit 1 = FVR routed to C1VREF input 0 = CVREF routed to C1VREF input bit 4 C2RSEL: Comparator C2 Reference Select bit 1 = FVR routed to C2VREF input 0 = CVREF routed to C2VREF input bit 3 C1HYS: Comparator C1 Hysteresis Enable bit 1 = Comparator C1 hysteresis enabled 0 = Comparator C1 hysteresis disabled bit 2 C2HYS: Comparator C2 Hysteresis Enable bit 1 = Comparator C2 hysteresis enabled 0 = Comparator C2 hysteresis disabled bit 1 C1SYNC: C1 Output Synchronous Mode bit 1 = C1 output is synchronous to rising edge to TMR1 clock 0 = C1 output is asynchronous bit 0 C2SYNC: C2 Output Synchronous Mode bit 1 = C2 output is synchronous to rising edge to TMR1 clock 0 = C2 output is asynchronous 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 235 PIC18F/LF1XK50 TABLE 18-3: REGISTERS ASSOCIATED WITH COMPARATOR MODULE Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page CM1CON0 C1ON C1OUT C1OE C1POL C1SP C1R C1CH1 C1CH0 290 CM2CON0 C2ON C2OUT C2OE C2POL C2SP C2R C2CH1 C2CH0 290 CM2CON1 MC1OUT MC2OUT C1RSEL C2RSEL C1HYS C2HYS C1SYNC C2SYNC 290 REFCON0 FVR1EN FVR1ST FVR1S1 FVR1S0 — — — — 289 REFCON1 D1EN D1LPS DAC1OE --- D1PSS1 D1PSS0 — D1NSS 289 TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 287 INTCON GIE/GIEH PEIE/GIEL PIR2 OSCFIF C1IF C2IF EEIF BCLIF USBIF TMR3IF — 290 PIE2 OSCFIE C1IE C2IE EEIE BCLIE USBIE TMR3IE — 290 IPR2 OSCFIP C1IP C2IP EEIP BCLIP USBIP TMR3IP — 290 RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 290 LATC PORTC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 ANSEL ANS7 ANS6 ANS5 ANS4 ANS3 — — — 290 Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module. DS41350D-page 236 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 19.0 POWER-MANAGED MODES 19.1.1 The SCS<1:0> bits allow the selection of one of three clock sources for power-managed modes. They are: PIC18F/LF1XK50 devices offer a total of seven operating modes for more efficient power management. These modes provide a variety of options for selective power conservation in applications where resources may be limited (i.e., battery-powered devices). • the primary clock, as defined by the FOSC<3:0> Configuration bits • the secondary clock (the Timer1 oscillator) • the internal oscillator block There are three categories of power-managed modes: • Run modes • Idle modes • Sleep mode 19.1.2 ENTERING POWER-MANAGED MODES Switching from one power-managed mode to another begins by loading the OSCCON register. The SCS<1:0> bits select the clock source and determine which Run or Idle mode is to be used. Changing these bits causes an immediate switch to the new clock source, assuming that it is running. The switch may also be subject to clock transition delays. Refer to Section 2.8 “Clock Switching” for more information. These categories define which portions of the device are clocked and sometimes, what speed. The Run and Idle modes may use any of the three available clock sources (primary, secondary or internal oscillator block); the Sleep mode does not use a clock source. The power-managed modes include several powersaving features offered on previous PIC® microcontroller devices. One is the clock switching feature which allows the controller to use the Timer1 oscillator in place of the primary oscillator. Also included is the Sleep mode, offered by all PIC® microcontroller devices, where all device clocks are stopped. 19.1 CLOCK SOURCES Entry to the power-managed Idle or Sleep modes is triggered by the execution of a SLEEP instruction. The actual mode that results depends on the status of the IDLEN bit of the OSCCON register. Depending on the current mode and the mode being switched to, a change to a power-managed mode does not always require setting all of these bits. Many transitions may be done by changing the oscillator select bits, or changing the IDLEN bit, prior to issuing a SLEEP instruction. If the IDLEN bit is already configured correctly, it may only be necessary to perform a SLEEP instruction to switch to the desired mode. Selecting Power-Managed Modes Selecting a power-managed mode requires two decisions: • Whether or not the CPU is to be clocked • The selection of a clock source The IDLEN bit of the OSCCON register controls CPU clocking, while the SCS<1:0> bits of the OSCCON register select the clock source. The individual modes, bit settings, clock sources and affected modules are summarized in Table 19-1. TABLE 19-1: POWER-MANAGED MODES OSCCON Bits Mode Sleep IDLEN(1) SCS<1:0> Module Clocking CPU Peripherals Available Clock and Oscillator Source 0 N/A Off Off PRI_RUN N/A 00 Clocked Clocked Primary – LP, XT, HS, RC, EC and Internal Oscillator Block(2). This is the normal full power execution mode. SEC_RUN N/A 01 Clocked Clocked Secondary – Timer1 Oscillator RC_RUN N/A 1x Clocked Clocked Internal Oscillator Block(2) PRI_IDLE 1 00 Off Clocked Primary – LP, XT, HS, HSPLL, RC, EC SEC_IDLE 1 01 Off Clocked Secondary – Timer1 Oscillator RC_IDLE 1 1x Off Clocked Internal Oscillator Block(2) Note 1: 2: None – All clocks are disabled IDLEN reflects its value when the SLEEP instruction is executed. Includes HFINTOSC and HFINTOSC postscaler, as well as the LFINTOSC source. 2010 Microchip Technology Inc. Preliminary DS41350D-page 237 PIC18F/LF1XK50 19.1.3 MULTIPLE FUNCTIONS OF THE SLEEP COMMAND 19.2.3 The power-managed mode that is invoked with the SLEEP instruction is determined by the setting of the IDLEN bit of the OSCCON register at the time the instruction is executed. All clocks stop and minimum power is consumed when SLEEP is executed with the IDLEN bit cleared. The system clock continues to supply a clock to the peripherals but is disconnected from the CPU when SLEEP is executed with the IDLEN bit set. 19.2 Run Modes RC_RUN MODE In RC_RUN mode, the CPU and peripherals are clocked from the internal oscillator. In this mode, the primary external oscillator is shut down. RC_RUN mode provides the best power conservation of all the Run modes when the LFINTOSC is the system clock. RC_RUN mode is entered by setting the SCS1 bit. When the clock source is switched from the primary oscillator to the internal oscillator, the primary oscillator is shut down and the OSTS bit is cleared. The IRCF bits may be modified at any time to immediately change the clock speed. In the Run modes, clocks to both the core and peripherals are active. The difference between these modes is the clock source. 19.2.1 PRI_RUN MODE The PRI_RUN mode is the normal, full power execution mode of the microcontroller. This is also the default mode upon a device Reset, unless Two-Speed Startup is enabled (see Section 2.12 “Two-Speed Start-up Mode” for details). In this mode, the device operated off the oscillator defined by the FOSC bits of the CONFIGH Configuration register. 19.2.2 SEC_RUN MODE In SEC_RUN mode, the CPU and peripherals are clocked from the secondary external oscillator. This gives users the option of lower power consumption while still using a high accuracy clock source. SEC_RUN mode is entered by setting the SCS<1:0> bits of the OSCCON register to ‘01’. When SEC_RUN mode is active all of the following are true: • The main clock source is switched to the secondary external oscillator • Primary external oscillator is shut down • T1RUN bit of the T1CON register is set • OSTS bit is cleared. Note: The secondary external oscillator should already be running prior to entering SEC_RUN mode. If the T1OSCEN bit is not set when the SCS<1:0> bits are set to ‘01’, entry to SEC_RUN mode will not occur until T1OSCEN bit is set and secondary external oscillator is ready. DS41350D-page 238 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 19.3 Sleep Mode 19.4 The Power-Managed Sleep mode in the PIC18F/ LF1XK50 devices is identical to the legacy Sleep mode offered in all other PIC® microcontroller devices. It is entered by clearing the IDLEN bit of the OSCCON register and executing the SLEEP instruction. This shuts down the selected oscillator (Figure 19-1) and all clock source status bits are cleared. Idle Modes The Idle modes allow the controller’s CPU to be selectively shut down while the peripherals continue to operate. Selecting a particular Idle mode allows users to further manage power consumption. If the IDLEN bit is set to a ‘1’ when a SLEEP instruction is executed, the peripherals will be clocked from the clock source selected by the SCS<1:0> bits; however, the CPU will not be clocked. The clock source status bits are not affected. Setting IDLEN and executing a SLEEP instruction provides a quick method of switching from a given Run mode to its corresponding Idle mode. Entering the Sleep mode from either Run or Idle mode does not require a clock switch. This is because no clocks are needed once the controller has entered Sleep. If the WDT is selected, the LFINTOSC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. If the WDT is selected, the LFINTOSC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. When a wake event occurs in Sleep mode (by interrupt, Reset or WDT time-out), the device will not be clocked until the clock source selected by the SCS<1:0> bits becomes ready (see Figure 19-2), or it will be clocked from the internal oscillator block if either the Two-Speed Start-up or the Fail-Safe Clock Monitor are enabled (see Section 24.0 “Special Features of the CPU”). In either case, the OSTS bit is set when the primary clock is providing the device clocks. The IDLEN and SCS bits are not affected by the wake-up. Since the CPU is not executing instructions, the only exits from any of the Idle modes are by interrupt, WDT time-out, or a Reset. When a wake event occurs, CPU execution is delayed by an interval of TCSD while it becomes ready to execute code. When the CPU begins executing code, it resumes with the same clock source for the current Idle mode. For example, when waking from RC_IDLE mode, the internal oscillator block will clock the CPU and peripherals (in other words, RC_RUN mode). The IDLEN and SCS bits are not affected by the wake-up. While in any Idle mode or the Sleep mode, a WDT time-out will result in a WDT wake-up to the Run mode currently specified by the SCS<1:0> bits. FIGURE 19-1: TRANSITION TIMING FOR ENTRY TO SLEEP MODE Q1 Q2 Q3 Q4 Q1 OSC1 CPU Clock Peripheral Clock Sleep Program Counter PC FIGURE 19-2: PC + 2 TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 OSC1 TOST(1) PLL Clock Output TPLL(1) CPU Clock Peripheral Clock Program Counter PC Wake Event PC + 2 PC + 4 PC + 6 OSTS bit set Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2010 Microchip Technology Inc. Preliminary DS41350D-page 239 PIC18F/LF1XK50 19.4.1 PRI_IDLE MODE 19.4.2 This mode is unique among the three low-power Idle modes, in that it does not disable the primary device clock. For timing sensitive applications, this allows for the fastest resumption of device operation with its more accurate primary clock source, since the clock source does not have to “warm-up” or transition from another oscillator. PRI_IDLE mode is entered from PRI_RUN mode by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then clear the SCS bits and execute SLEEP. Although the CPU is disabled, the peripherals continue to be clocked from the primary clock source specified by the FOSC<3:0> Configuration bits. The OSTS bit remains set (see Figure 19-3). When a wake event occurs, the CPU is clocked from the primary clock source. A delay of interval TCSD is required between the wake event and when code execution starts. This is required to allow the CPU to become ready to execute instructions. After the wakeup, the OSTS bit remains set. The IDLEN and SCS bits are not affected by the wake-up (see Figure 19-4). FIGURE 19-3: SEC_IDLE MODE In SEC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the Timer1 oscillator. This mode is entered from SEC_RUN by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set the IDLEN bit first, then set the SCS<1:0> bits to ‘01’ and execute SLEEP. When the clock source is switched to the Timer1 oscillator, the primary oscillator is shut down, the OSTS bit is cleared and the T1RUN bit is set. When a wake event occurs, the peripherals continue to be clocked from the Timer1 oscillator. After an interval of TCSD following the wake event, the CPU begins executing code being clocked by the Timer1 oscillator. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run (see Figure 194). Note: The Timer1 oscillator should already be running prior to entering SEC_IDLE mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the main system clock will continue to operate in the previously selected mode and the corresponding IDLE mode will be entered (i.e., PRI_IDLE or RC_IDLE). TRANSITION TIMING FOR ENTRY TO IDLE MODE Q1 Q3 Q2 Q4 Q1 OSC1 CPU Clock Peripheral Clock Program Counter PC FIGURE 19-4: PC + 2 TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE Q1 Q2 Q3 Q4 OSC1 TCSD CPU Clock Peripheral Clock Program Counter PC Wake Event DS41350D-page 240 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 19.4.3 RC_IDLE MODE 19.5.1 In RC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the internal oscillator block from the HFINTOSC multiplexer output. This mode allows for controllable power conservation during Idle periods. From RC_RUN, this mode is entered by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, first set IDLEN, then set the SCS1 bit and execute SLEEP. It is recommended that SCS0 also be cleared, although its value is ignored, to maintain software compatibility with future devices. The HFINTOSC multiplexer may be used to select a higher clock frequency by modifying the IRCF bits before executing the SLEEP instruction. When the clock source is switched to the HFINTOSC multiplexer, the primary oscillator is shut down and the OSTS bit is cleared. If the IRCF bits are set to any non-zero value, or the INTSRC bit is set, the HFINTOSC output is enabled. The IOSF bit becomes set, after the HFINTOSC output becomes stable, after an interval of TIOBST. Clocks to the peripherals continue while the HFINTOSC source stabilizes. If the IRCF bits were previously at a nonzero value, or INTSRC was set before the SLEEP instruction was executed and the HFINTOSC source was already stable, the IOSF bit will remain set. If the IRCF bits and INTSRC are all clear, the HFINTOSC output will not be enabled, the IOSF bit will remain clear and there will be no indication of the current clock source. When a wake event occurs, the peripherals continue to be clocked from the HFINTOSC multiplexer output. After a delay of TCSD following the wake event, the CPU begins executing code being clocked by the HFINTOSC multiplexer. The IDLEN and SCS bits are not affected by the wake-up. The LFINTOSC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. 19.5 Exiting Idle and Sleep Modes An exit from Sleep mode or any of the Idle modes is triggered by any one of the following: EXIT BY INTERRUPT Any of the available interrupt sources can cause the device to exit from an Idle mode or the Sleep mode to a Run mode. To enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the INTCON or PIE registers. The PEIE bIt must also be set If the desired interrupt enable bit is in a PIE register. The exit sequence is initiated when the corresponding interrupt flag bit is set. The instruction immediately following the SLEEP instruction is executed on all exits by interrupt from Idle or Sleep modes. Code execution then branches to the interrupt vector if the GIE/GIEH bit of the INTCON register is set, otherwise code execution continues without branching (see Section 7.0 “Interrupts”). A fixed delay of interval TCSD following the wake event is required when leaving Sleep and Idle modes. This delay is required for the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. 19.5.2 EXIT BY WDT TIME-OUT A WDT time-out will cause different actions depending on which power-managed mode the device is in when the time-out occurs. If the device is not executing code (all Idle modes and Sleep mode), the time-out will result in an exit from the power-managed mode (see Section 19.2 “Run Modes” and Section 19.3 “Sleep Mode”). If the device is executing code (all Run modes), the time-out will result in a WDT Reset (see Section 24.2 “Watchdog Timer (WDT)”). The WDT timer and postscaler are cleared by any one of the following: • executing a SLEEP instruction • executing a CLRWDT instruction • the loss of the currently selected clock source when the Fail-Safe Clock Monitor is enabled • modifying the IRCF bits in the OSCCON register when the internal oscillator block is the device clock source • an interrupt • a Reset • a Watchdog Time-out This section discusses the triggers that cause exits from power-managed modes. The clocking subsystem actions are discussed in each of the power-managed modes (see Section 19.2 “Run Modes”, Section 19.3 “Sleep Mode” and Section 19.4 “Idle Modes”). 2010 Microchip Technology Inc. Preliminary DS41350D-page 241 PIC18F/LF1XK50 19.5.3 EXIT BY RESET 19.5.4 EXIT WITHOUT AN OSCILLATOR START-UP DELAY Exiting Sleep and Idle modes by Reset causes code execution to restart at address 0. See Section 23.0 “Reset” for more details. Certain exits from power-managed modes do not invoke the OST at all. There are two cases: The exit delay time from Reset to the start of code execution depends on both the clock sources before and after the wake-up and the type of oscillator. Exit delays are summarized in Table 19-2. • PRI_IDLE mode, where the primary clock source is not stopped and • the primary clock source is not any of the LP, XT, HS or HSPLL modes. In these instances, the primary clock source either does not require an oscillator start-up delay since it is already running (PRI_IDLE), or normally does not require an oscillator start-up delay (RC, EC, INTOSC, and INTOSCIO modes). However, a fixed delay of interval TCSD following the wake event is still required when leaving Sleep and Idle modes to allow the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. TABLE 19-2: EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE (BY CLOCK SOURCES) Clock Source before Wake-up Clock Source after Wake-up Exit Delay Clock Ready Status Bit (OSCCON) LP, XT, HS Primary Device Clock (PRI_IDLE mode) HSPLL EC, RC TCSD(1) HFINTOSC(2) T1OSC or LFINTOSC(1) HFINTOSC(2) None (Sleep mode) 2: 3: 4: IOSF LP, XT, HS TOST(3) HSPLL TOST + tPLL(3) EC, RC TCSD(1) HFINTOSC(1) TIOBST(4) LP, XT, HS TOST(4) HSPLL TOST + tPLL(3) EC, RC TCSD(1) OSTS IOSF OSTS HFINTOSC(1) None LP, XT, HS TOST(3) HSPLL TOST + tPLL(3) OSTS EC, RC TCSD(1) TIOBST(4) IOSF HFINTOSC(1) Note 1: OSTS IOSF TCSD is a required delay when waking from Sleep and all Idle modes and runs concurrently with any other required delays (see Section 19.4 “Idle Modes”). On Reset, HFINTOSC defaults to 1 MHz. Includes both the HFINTOSC 16 MHz source and postscaler derived frequencies. TOST is the Oscillator Start-up Timer. tPLL is the PLL Lock-out Timer (parameter F12). Execution continues during the HFINTOSC stabilization period, TIOBST. DS41350D-page 242 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 20.0 SR LATCH 20.2 The SRQEN and SRNQEN bits of the SRCON0 register control the latch output selection. Only one of the SR latch’s outputs may be directly output to an I/O pin at a time. Priority is determined by the state of bits SRQEN and SRNQEN in registers SRCON0. The module consists of a single SR Latch with multiple Set and Reset inputs as well as selectable latch output. The SR Latch module includes the following features: • • • • Programmable input selection SR Latch output is available internally/externally Selectable Q and Q output Firmware Set and Reset 20.1 Latch Output TABLE 20-1: Latch Operation The latch is a Set-Reset latch that does not depend on a clock source. Each of the Set and Reset inputs are active-high. The latch can be Set or Reset by CxOUT, INT1 pin, or variable clock. Additionally the SRPS and the SRPR bits of the SRCON0 register may be used to Set or Reset the SR Latch, respectively. The latch is reset-dominant, therefore, if both Set and Reset inputs are high the latch will go to the Reset state. Both the SRPS and SRPR bits are self resetting which means that a single write to either of the bits is all that is necessary to complete a latch Set or Reset operation. SR LATCH OUTPUT CONTROL SRLEN SRQEN SRNQEN SR Latch Output to Port I/O 0 X X I/O 1 0 0 I/O 1 0 1 Q 1 1 0 Q 1 1 1 Q The applicable TRIS bit of the corresponding port must be cleared to enable the port pin output driver. 20.3 Effects of a Reset Upon any device Reset, the SR latch is not initialized. The user’s firmware is responsible to initialize the latch output before enabling it to the output pins. FIGURE 20-1: SR LATCH SIMPLIFIED BLOCK DIAGRAM SRPS Pulse Gen(2) INT1 S SRSPE SRCLK SRSCKE SYNCC2OUT(4) SRSC2E SYNCC1OUT(4) SRSC1E SRPR Pulse Gen(2) SRRPE SRCLK SRRCKE SYNCC2OUT(4) SRRC2E SYNCC1OUT(4) SRRC1E SRLEN Q SR Latch(1) INT1 Note 1: 2: 3: 4: SRNQEN SRQEN SRQ pin(3) SRLEN SRNQEN R Q If R = 1 and S = 1 simultaneously, Q = 0, Q = 1 Pulse generator causes a 2 Q-state pulse width. Output shown for reference only. See I/O port pin block diagram for more detail. Name denotes the source of connection at the comparator output. 2010 Microchip Technology Inc. Preliminary DS41350D-page 243 PIC18F/LF1XK50 TABLE 20-2: SRCLK FREQUENCY TABLE SRCLK Divider FOSC = 20 MHz FOSC = 16 MHz 111 512 25.6 s 32 s 110 256 12.8 s 16 s 32 s 64 s 256 s 101 128 6.4 s 8 s 16 s 32 s 128 s FOSC = 8 MHz FOSC = 4 MHz 64 s 128 s FOSC = 1 MHz 512 s 100 64 3.2 s 4 s 8 s 16 s 64 s 011 32 1.6 s 2 s 4 s 8 s 32 s 010 16 0.8 s 1 s 2 s 4 s 16 s 001 8 0.4 s 0.5 s 1 s 2 s 8 s 000 4 0.2 s 0.25 s 0.5 s 1 s 4 s REGISTER 20-1: SRCON0: SR LATCH CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 SRLEN SRCLK2 SRCLK1 SRCLK0 SRQEN SRNQEN SRPS SRPR bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented C = Clearable only bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 SRLEN: SR Latch Enable bit(1) 1 = SR latch is enabled 0 = SR latch is disabled bit 6-4 SRCLK<2:0>(1): SR Latch Clock divider bits 000 = 1/4 Peripheral cycle clock 001 = 1/8 Peripheral cycle clock 010 = 1/16 Peripheral cycle clock 011 = 1/32 Peripheral cycle clock 100 = 1/64 Peripheral cycle clock 101 = 1/128 Peripheral cycle clock 110 = 1/256 Peripheral cycle clock 111 = 1/512 Peripheral cycle clock bit 3 SRQEN: SR Latch Q Output Enable bit If SRNQEN = 0 1 = Q is present on the RC4 pin 0 = Q is internal only bit 2 SRNQEN: SR Latch Q Output Enable bit 1 = Q is present on the RC4 pin 0 = Q is internal only bit 1 SRPS: Pulse Set Input of the SR Latch 1 = Pulse input 0 = Always reads back ‘0’ bit 0 SRPR: Pulse Reset Input of the SR Latch 1 = Pulse input 0 = Always reads back ‘0’ Note 1: Changing the SRCLK bits while the SR latch is enabled may cause false triggers to the set and Reset inputs of the latch. DS41350D-page 244 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 20-2: SRCON1: SR LATCH CONTROL REGISTER 1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 SRSPE SRSCKE SRSC2E SRSC1E SRRPE SRRCKE SRRC2E SRRC1E bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented C = Clearable only bit -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 SRSPE: SR Latch Peripheral Set Enable bit 1 = INT1 pin status sets SR Latch 0 = INT1pin status has no effect on SR Latch bit 6 SRSCKE: SR Latch Set Clock Enable bit 1 = Set input of SR latch is pulsed with SRCLK 0 = Set input of SR latch is not pulsed with SRCLK bit 5 SRSC2E: SR Latch C2 Set Enable bit 1 = C2 Comparator output sets SR Latch 0 = C2 Comparator output has no effect on SR Latch bit 4 SRSC1E: SR Latch C1 Set Enable bit 1 = C1 Comparator output sets SR Latch 0 = C1 Comparator output has no effect on SR Latch bit 3 SRRPE: SR Latch Peripheral Reset Enable bit 1 = INT1 pin resets SR Latch 0 = INT1 pin has no effect on SR Latch bit 2 SRRCKE: SR Latch Reset Clock Enable bit 1 = Reset input of SR latch is pulsed with SRCLK 0 = Reset input of SR latch is not pulsed with SRCLK bit 1 SRRC2E: SR Latch C2 Reset Enable bit 1 = C2 Comparator output resets SR Latch 0 = C2 Comparator output has no effect on SR Latch bit 0 SRRC1E: SR Latch C1 Reset Enable bit 1 = C1 Comparator output resets SR Latch 0 = C1 Comparator output has no effect on SR Latch TABLE 20-3: Name REGISTERS ASSOCIATED WITH THE SR LATCH Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page SRCON0 SRLEN SRCLK2 SRCLK1 SRCLK0 SRQEN SRNQEN SRPS SRPR 290 SRCON1 SRSPE SRSCKE SRSC2E SRSC1E SRRPE SRRCKE SRRC2E SRRC1E 290 C1RSEL C2RSEL C1HYS C2HYS C1SYNC C2SYNC 290 INTCON3 INT2IP INT1IP — INT2IE INT1IE — INT2IF INT1IF 287 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 290 CM2CON1 MC1OUT MC2OUT Legend: Shaded cells are not used with the comparator voltage reference. 2010 Microchip Technology Inc. Preliminary DS41350D-page 245 PIC18F/LF1XK50 NOTES: DS41350D-page 246 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 21.0 VOLTAGE REFERENCES 21.1.1 There are two independent voltage references available: • Programmable Voltage Reference • 1.024V Fixed Voltage Reference 21.1 Voltage Reference The Voltage Reference module provides an internally generated voltage reference for the comparators and the DAC module. The following features are available: • • • • • Independent from Comparator operation Single 32-level voltage ranges Output clamped to VSS Ratiometric with VDD 1.024V Fixed Reference Voltage (FVR) INDEPENDENT OPERATION The voltage reference is independent of the comparator configuration. Setting the D1EN bit of the REFCON1 register will enable the voltage reference by allowing current to flow in the VREF voltage divider. When the D1EN bit is cleared, current flow in the VREF voltage divider is disabled minimizing the power drain of the voltage reference peripheral. 21.1.2 OUTPUT VOLTAGE SELECTION The VREF voltage reference has 32 voltage level ranges. The 32 levels are set with the DAC1R<4:0> bits of the REFCON2 register. The VREF output voltage is determined by the following equations: The REFCON1 register (Register 21-2) controls the Voltage Reference module shown in Figure 21-1. EQUATION 21-1: VREF OUTPUT VOLTAGE IF D1EN = 1 DAC1R[4:0] V OUT = V SOURCE + – V SOURCE - x -------------------------------- + V SOURCE5 2 IF D1EN = 0 & D1LPS = 1 & DAC1R[4:0] = 11111: V OUT = V SOURCE + IF D1EN = 0 & D1LPS = 1 & DAC1R[4:0] = 00000: V OUT = V SOURCE - 21.1.3 21.1.5 OUTPUT RATIOMETRIC TO VDD OPERATION DURING SLEEP The comparator voltage reference is VDD derived and therefore, the VREF output changes with fluctuations in VDD. The tested absolute accuracy of the Comparator Voltage Reference can be found in Section 27.0 “Electrical Specifications”. When the device wakes up from Sleep through an interrupt or a Watchdog Timer time-out, the contents of the RECON1 register are not affected. To minimize current consumption in Sleep mode, the voltage reference should be disabled. 21.1.4 21.1.6 VOLTAGE REFERENCE OUTPUT The VREF voltage reference can be output to the device CVREF pin by setting the DAC1OE bit of the REFCON1 register to ‘1’. Selecting the reference voltage for output on the VREF pin automatically overrides the digital output buffer and digital input threshold detector functions of that pin. Reading the CVREF pin when it has been configured for reference voltage output will always return a ‘0’. EFFECTS OF A RESET A device Reset affects the following: • • • • Voltage reference is disabled Fixed voltage reference is disabled VREF is removed from the CVREF pin The DAC1R<4:0> range select bits are cleared Due to the limited current drive capability, a buffer must be used on the voltage reference output for external connections to CVREF. Figure 21-2 shows an example buffering technique. 2010 Microchip Technology Inc. Preliminary DS41350D-page 247 PIC18F/LF1XK50 21.2 FVR Reference Module 21.2.1 The FVR reference is a stable fixed voltage reference, independent of VDD, with a nominal output voltage of 1.024V. This reference can be enabled by setting the FVR1EN bit of the REFCON0 register to ‘1’. The FVR voltage reference can be routed to the comparators or an ADC input channel. FIGURE 21-1: FVR STABILIZATION PERIOD When the Fixed Voltage Reference module is enabled, it will require some time for the reference and its amplifier circuits to stabilize. The user program must include a small delay routine to allow the module to settle. The FVR1ST stable bit of the REFCON0 register also indicates that the FVR reference has been operating long enough to be stable. See Section 27.0 “Electrical Specifications” for the minimum delay requirement. VOLTAGE REFERENCE BLOCK DIAGRAM D1EN D1LPS VDD VREF+ FVR1 D1PSS<1:0> = 00 DAC1R<4:0> D1PSS<1:0> = 01 D1PSS<1:0> = 10 R R R 16-to-1 MUX R R 32 Steps VREF R DAC1OE R D1EN VREF- CVREF pin R D1LPS D1NSS = 1 D1NSS = 0 FVR1S<1:0> 2 X1 X2 X4 FVR1EN FVR1ST DS41350D-page 248 Preliminary + _ FVR 1.024V Fixed Reference 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 21-2: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE PIC18F1XK50/ PIC18LF1XK50 CVREF Module R(1) Voltage Reference Output Impedance Note 1: + – CVREF Buffered CVREF Output R is dependent upon the voltage reference Configuration bits, CVR<3:0> and CVRR. REGISTER 21-1: REFCON0: REFERENCE CONTROL REGISTER 0 R/W-0 R-0 R/W-0 R/W-1 U-0 U-0 U-0 U-0 FVR1EN FVR1ST FVR1S1 FVR1S0 — — — — bit 0 bit 7 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 bit 7 FVR1EN: Fixed Voltage Reference 1 Enable bit 0 = FVR is disabled 1 = FVR is enabled bit 6 FVR1ST: Fixed Voltage Reference 1 Stable bit 0 = FVR is not stable 1 = FVR is stable bit 5-4 FVR1S<1:0>: Fixed Voltage Reference 1 Voltage Select bits 00 = Reserved, do not use 01 = 1.024V (x1) 10 = 2.048V (x2) 11 = 4.096V (x4) bit 3-0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary x = Bit is unknown DS41350D-page 249 PIC18F/LF1XK50 REGISTER 21-2: REFCON1: REFERENCE CONTROL REGISTER 1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 U-0 R/W-0 D1EN D1LPS DAC1OE --- D1PSS1 D1PSS0 --- D1NSS bit 7 bit 0 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 bit 7 D1EN: DAC 1 Enable bit 0 = DAC 1 is disabled 1 = DAC 1 is enabled bit 6 D1LPS: DAC 1 Low-Power Voltage State Select bit 0 = VDAC = DAC1 Negative reference source selected 1 = VDAC = DAC1 Positive reference source selected bit 5 DAC1OE: DAC 1 Voltage Output Enable bit 1 = DAC 1 voltage level is also outputed on the RC2/AN6/P1D/C12IN2-/CVREF/INT2 pin 0 = DAC 1 voltage level is disconnected from RC2/AN6/P1D/C12IN2-/CVREF/INT2 pin bit 4 Unimplemented: Read as ‘0’ bit 3-2 D1PSS<1:0>: DAC 1 Positive Source Select bits 00 = VDD 01 = VREF+ 10 = FVR output 11 = Reserved, do not use bit 1 Unimplemented: Read as ‘0’ bit 0 D1NSS: DAC1 Negative Source Select bits 0 = VSS 1 = VREF- REGISTER 21-3: REFCON2: REFERENCE CONTROL REGISTER 2 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 --- --- --- DAC1R4 DAC1R3 DAC1R2 DAC1R1 DAC1R0 bit 7 bit 0 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 bit 7-5 Unimplemented: Read as ‘0’ bit 4-0 DAC1R<4:0>: DAC1 Voltage Output Select bits VOUT = ((VSOURCE+) - (VSOURCE-))*(DAC1R<4:0>/(2^5)) + VSOURCE- Note 1: x = Bit is unknown The output select bits are always right justified to ensure that any number of bits can be used without affecting the register layout. DS41350D-page 250 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 21-1: Name REGISTERS ASSOCIATED WITH VOLTAGE REFERENCE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page REFCON0 FVR1EN FVR1ST FVR1S1 FVR1S0 — — — — 289 REFCON1 D1EN D1LPS DAC1OE --- D1PSS1 D1PSS0 — D1NSS 289 REFCON2 — — — DAC1R4 DAC1R3 DAC1R2 DAC1R1 DAC1R0 289 TRISC0 290 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 Legend: Shaded cells are not used with the comparator voltage reference. 2010 Microchip Technology Inc. Preliminary DS41350D-page 251 PIC18F/LF1XK50 NOTES: DS41350D-page 252 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.0 UNIVERSAL SERIAL BUS (USB) 22.1 PIC18F1XK50/PIC18LF1XK50 devices contain a full-speed and low-speed, compatible USB Serial Interface Engine (SIE) that allows fast communication between any USB host and the PIC® microcontroller. The SIE can be interfaced directly to the USB by utilizing the internal transceiver. This section describes the details of the USB peripheral. Because of the very specific nature of the module, knowledge of USB is expected. Some high-level USB information is provided in Section 22.10 “Overview of USB” only for application design reference. Designers are encouraged to refer to the official specification published by the USB Implementers Forum (USB-IF) for the latest information. USB Specification Revision 2.0 is the most current specification at the time of publication of this document. FIGURE 22-1: Overview of the USB Peripheral Some special hardware features have been included to improve performance. Dual access port memory in the device’s data memory space (USB RAM) has been supplied to share direct memory access between the microcontroller core and the SIE. Buffer descriptors are also provided, allowing users to freely program endpoint memory usage within the USB RAM space. Figure 22-1 presents a general overview of the USB peripheral and its features. USB PERIPHERAL AND OPTIONS PIC18F1XK50/PIC18LF1XK50 Family External 3.3V Supply VUSB 3.3V LDO Regulator(2) Optional External Pull-ups(1) P FSEN UPUEN P Internal Pull-ups (Full Speed) Transceiver FS USB Clock from the Oscillator Module (Low Speed) USB Bus D+ D- USB Control and Configuration USB SIE 256 byte USB RAM Note 1: 2: The internal pull-up resistors should be disabled (UPUEN = 0) if external pull-up resistors are used. PIC18F13K50/PIC18F14K50 only. 2010 Microchip Technology Inc. Preliminary DS41350D-page 253 PIC18F/LF1XK50 22.2 USB Status and Control In addition, the USB Control register contains a status bit, SE0 (UCON<5>), which is used to indicate the occurrence of a single-ended zero on the bus. When the USB module is enabled, this bit should be monitored to determine whether the differential data lines have come out of a single-ended zero condition. This helps to differentiate the initial power-up state from the USB Reset signal. The operation of the USB module is configured and managed through three control registers. In addition, a total of 14 registers are used to manage the actual USB transactions. The registers are: • • • • • • USB Control register (UCON) USB Configuration register (UCFG) USB Transfer Status register (USTAT) USB Device Address register (UADDR) Frame Number registers (UFRMH:UFRML) Endpoint Enable registers 0 through 7 (UEPn) 22.2.1 The overall operation of the USB module is controlled by the USBEN bit (UCON<3>). Setting this bit activates the module and resets all of the PPBI bits in the Buffer Descriptor Table to ‘0’. This bit also activates the internal pull-up resistors, if they are enabled. Thus, this bit can be used as a soft attach/detach to the USB. Although all Status and control bits are ignored when this bit is clear, the module needs to be fully preconfigured prior to setting this bit. This bit cannot be set until the USB module is supplied with an active clock source. If the PLL is being used, it should be enabled at least two milliseconds (enough time for the PLL to lock) before attempting to set the USBEN bit. USB CONTROL REGISTER (UCON) The USB Control register (Register 22-1) contains bits needed to control the module behavior during transfers. The register contains bits that control the following: • Main USB Peripheral Enable • Ping-Pong Buffer Pointer Reset • Control of the Suspend mode • Packet Transfer Disable REGISTER 22-1: U-0 UCON: USB CONTROL REGISTER R/W-0 — PPBRST R-x SE0 R/C-0 R/W-0 R/W-0 R/W-0 U-0 PKTDIS USBEN(1) RESUME SUSPND — bit 7 bit 0 Legend: C = Clearable bit 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 bit 7 Unimplemented: Read as ‘0’ bit 6 PPBRST: Ping-Pong Buffers Reset bit 1 = Reset all Ping-Pong Buffer Pointers to the Even Buffer Descriptor (BD) banks 0 = Ping-Pong Buffer Pointers not being reset bit 5 SE0: Live Single-Ended Zero Flag bit 1 = Single-ended zero active on the USB bus 0 = No single-ended zero detected bit 4 PKTDIS: Packet Transfer Disable bit 1 = SIE token and packet processing disabled, automatically set when a SETUP token is received 0 = SIE token and packet processing enabled bit 3 USBEN: USB Module Enable bit(1) 1 = USB module and supporting circuitry enabled (device attached) 0 = USB module and supporting circuitry disabled (device detached) bit 2 RESUME: Resume Signaling Enable bit 1 = Resume signaling activated 0 = Resume signaling disabled bit 1 SUSPND: Suspend USB bit 1 = USB module and supporting circuitry in Power Conserve mode, SIE clock inactive 0 = USB module and supporting circuitry in normal operation, SIE clock clocked at the configured rate bit 0 Unimplemented: Read as ‘0’ Note 1: This bit cannot be set if the USB module does not have an appropriate clock source. DS41350D-page 254 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 The PPBRST bit (UCON<6>) controls the Reset status when Double-Buffering mode (ping-pong buffering) is used. When the PPBRST bit is set, all Ping-Pong Buffer Pointers are set to the Even buffers. PPBRST has to be cleared by firmware. This bit is ignored in buffering modes not using ping-pong buffering. The PKTDIS bit (UCON<4>) is a flag indicating that the SIE has disabled packet transmission and reception. This bit is set by the SIE when a SETUP token is received to allow setup processing. This bit cannot be set by the microcontroller, only cleared; clearing it allows the SIE to continue transmission and/or reception. Any pending events within the Buffer Descriptor Table will still be available, indicated within the USTAT register’s FIFO buffer. The RESUME bit (UCON<2>) allows the peripheral to perform a remote wake-up by executing Resume signaling. To generate a valid remote wake-up, firmware must set RESUME for 10 ms and then clear the bit. For more information on “resume signaling”, see the “Universal Serial Bus Specification Revision 2.0”. The SUSPND bit (UCON<1>) places the module and supporting circuitry in a Low-Power mode. The input clock to the SIE is also disabled. This bit should be set by the software in response to an IDLEIF interrupt. It should be reset by the microcontroller firmware after an ACTVIF interrupt is observed. When this bit is active, the device remains attached to the bus but the transceiver outputs remain Idle. The voltage on the VUSB pin may vary depending on the value of this bit. Setting this bit before a IDLEIF request will result in unpredictable bus behavior. Note: While in Suspend mode, a typical bus-powered USB device is limited to 500 A of current. This is the complete current which may be drawn by the PIC device and its supporting circuitry. Care should be taken to assure minimum current draw when the device enters Suspend mode. 22.2.2 USB CONFIGURATION REGISTER (UCFG) Prior to communicating over USB, the module’s associated internal and/or external hardware must be configured. Most of the configuration is performed with the UCFG register (Register 22-2).The UFCG register contains most of the bits that control the system level behavior of the USB module. These include: • Bus Speed (full speed versus low speed) • On-Chip Pull-up Resistor Enable • Ping-Pong Buffer Usage The UTEYE bit, UCFG<7>, enables eye pattern generation, which aids in module testing, debugging and USB certifications. Note: 22.2.2.1 The USB speed, transceiver and pull-up should only be configured during the module setup phase. It is not recommended to switch these settings while the module is enabled. Internal Transceiver The USB peripheral has a built-in, USB 2.0, full-speed and low-speed capable transceiver, internally connected to the SIE. This feature is useful for low-cost, single chip applications. Enabling the USB module (USBEN = 1) will also enable the internal transceiver. The FSEN bit (UCFG<2>) controls the transceiver speed; setting the bit enables full-speed operation. The on-chip USB pull-up resistors are controlled by the UPUEN bit (UCFG<4>). They can only be selected when the on-chip transceiver is enabled. The internal USB transceiver obtains power from the VUSB pin. In order to meet USB signalling level specifications, VUSB must be supplied with a voltage source between 3.0V and 3.6V. The best electrical signal quality is obtained when a 3.3V supply is used and locally bypassed with a high quality ceramic capacitor. The capacitor should be placed as close as possible to the VUSB and VSS pins found on the same edge of the package (i.e., route ground of the capacitor to VSS pin 20 on 20-lead PDIP, SOIC, SSOP and QFN packaged parts). The D+ and D- signal lines can be routed directly to their respective pins on the USB connector or cable (for hard-wired applications). No additional resistors, capacitors, or magnetic components are required as the D+ and D- drivers have controlled slew rate and output impedance intended to match with the characteristic impedance of the USB cable. In order to meet the USB specifications, the traces should be less than 30 cm long. Ideally, these traces should be designed to have a characteristic impedance matching that of the USB cable. 2010 Microchip Technology Inc. Preliminary DS41350D-page 255 PIC18F/LF1XK50 REGISTER 22-2: R/W-0 UCFG: USB CONFIGURATION REGISTER U-0 UTEYE — U-0 — R/W-0 UPUEN (1) U-0 — R/W-0 (1) FSEN R/W-0 R/W-0 PPB1 PPB0 bit 7 bit 0 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 bit 7 UTEYE: USB Eye Pattern Test Enable bit 1 = Eye pattern test enabled 0 = Eye pattern test disabled bit 6-5 Unimplemented: Read as ‘0’ bit 4 UPUEN: USB On-Chip Pull-up Enable bit(1) 1 = On-chip pull-up enabled (pull-up on D+ with FSEN = 1 or D- with FSEN = 0) 0 = On-chip pull-up disabled bit 3 Unimplemented: Read as ‘0’ bit 2 FSEN: Full-Speed Enable bit(1) 1 = Full-speed device: controls transceiver edge rates; requires input clock at 48 MHz 0 = Low-speed device: controls transceiver edge rates; requires input clock at 6 MHz bit 1-0 PPB<1:0>: Ping-Pong Buffers Configuration bits 11 = Even/Odd ping-pong buffers enabled for Endpoints 1 to 15 10 = Even/Odd ping-pong buffers enabled for all endpoints 01 = Even/Odd ping-pong buffer enabled for OUT Endpoint 0 00 = Even/Odd ping-pong buffers disabled Note 1: The UPUEN, and FSEN bits should never be changed while the USB module is enabled. These values must be preconfigured prior to enabling the module. DS41350D-page 256 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.2.2.2 Internal Pull-up Resistors 22.2.2.4 The PIC18F1XK50/PIC18LF1XK50 devices have built-in pull-up resistors designed to meet the requirements for low-speed and full-speed USB. The UPUEN bit (UCFG<4>) enables the internal pull-ups. Figure 22-1 shows the pull-ups and their control. Note: 22.2.2.3 The official USB specifications require that USB devices must never source any current onto the +5V VBUS line of the USB cable. Additionally, USB devices must never source any current on the D+ and Ddata lines whenever the +5V VBUS line is less than 1.17V. In order to meet this requirement, applications which are not purely bus powered should monitor the VBUS line and avoid turning on the USB module and the D+ or D- pull-up resistor until VBUS is greater than 1.17V. VBUS can be connected to and monitored by any 5V tolerant I/O pin for this purpose. External Pull-up Resistors External pull-up may also be used. The VUSB pin may be used to pull up D+ or D-. The pull-up resistor must be 1.5 k (±5%) as required by the USB specifications. Figure 22-2 shows an example. FIGURE 22-2: EXTERNAL CIRCUITRY PIC® Ping-Pong Buffer Configuration The usage of ping-pong buffers is configured using the PPB<1:0> bits. Refer to Section 22.4.4 “Ping-Pong Buffering” for a complete explanation of the ping-pong buffers. 22.2.2.5 Eye Pattern Test Enable An automatic eye pattern test can be generated by the module when the UCFG<7> bit is set. The eye pattern output will be observable based on module settings, meaning that the user is first responsible for configuring the SIE clock settings, pull-up resistor and Transceiver mode. In addition, the module has to be enabled. Once UTEYE is set, the module emulates a switch from a receive to transmit state and will start transmitting a J-K-J-K bit sequence (K-J-K-J for full speed). The sequence will be repeated indefinitely while the Eye Pattern Test mode is enabled. Note that this bit should never be set while the module is connected to an actual USB system. This Test mode is intended for board verification to aid with USB certification tests. It is intended to show a system developer the noise integrity of the USB signals which can be affected by board traces, impedance mismatches and proximity to other system components. It does not properly test the transition from a receive to a transmit state. Although the eye pattern is not meant to replace the more complex USB certification test, it should aid during first order system debugging. Host Controller/HUB Microcontroller VUSB 1.5 k D+ D- Note: The above setting shows a typical connection for a full-speed configuration using an on-chip regulator and an external pull-up resistor. 2010 Microchip Technology Inc. Preliminary DS41350D-page 257 PIC18F/LF1XK50 22.2.3 USB STATUS REGISTER (USTAT) Clearing the transfer complete flag bit, TRNIF, causes the SIE to advance the FIFO. If the next data in the FIFO holding register is valid, the SIE will reassert the interrupt within 6 TCY of clearing TRNIF. If no additional data is present, TRNIF will remain clear; USTAT data will no longer be reliable. The USB Status register reports the transaction status within the SIE. When the SIE issues a USB transfer complete interrupt, USTAT should be read to determine the status of the transfer. USTAT contains the transfer endpoint number, direction and Ping-Pong Buffer Pointer value (if used). Note: Note: The data in the USB Status register is valid two SIE clocks after the TRNIF interrupt flag is asserted. In low-speed operation with the system clock operating at 48 MHz, a delay may be required between receiving the TRNIF interrupt and processing the data in the USTAT register. FIGURE 22-3: U-0 Clearing TRNIF Advances FIFO 4-Byte FIFO for USTAT Data Bus USTAT: USB STATUS REGISTER U-0 — USTAT FIFO USTAT from SIE The USTAT register is actually a read window into a four-byte status FIFO, maintained by the SIE. It allows the microcontroller to process one transfer while the SIE processes additional endpoints (Figure 22-3). When the SIE completes using a buffer for reading or writing data, it updates the USTAT register. If another USB transfer is performed before a transaction complete interrupt is serviced, the SIE will store the status of the next transfer into the status FIFO. REGISTER 22-3: If an endpoint request is received while the USTAT FIFO is full, the SIE will automatically issue a NAK back to the host. — R-x ENDP2 R-x ENDP1 R-x ENDP0 R-x R-x U-0 DIR PPBI(1) — bit 7 bit 0 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 bit 7-6 Unimplemented: Read as ‘0’ bit 5-3 ENDP<2:0>: Encoded Number of Last Endpoint Activity bits (represents the number of the BDT updated by the last USB transfer) 111 = Endpoint 7 110 = Endpoint 6 .... 001 = Endpoint 1 000 = Endpoint 0 bit 2 DIR: Last BD Direction Indicator bit 1 = The last transaction was an IN token 0 = The last transaction was an OUT or SETUP token bit 1 PPBI: Ping-Pong BD Pointer Indicator bit(1) 1 = The last transaction was to the Odd BD bank 0 = The last transaction was to the Even BD bank bit 0 Unimplemented: Read as ‘0’ Note 1: x = Bit is unknown This bit is only valid for endpoints with available Even and Odd BD registers. DS41350D-page 258 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.2.4 USB ENDPOINT CONTROL Each of the 8 possible bidirectional endpoints has its own independent control register, UEPn (where ‘n’ represents the endpoint number). Each register has an identical complement of control bits. The prototype is shown in Register 22-4. The EPHSHK bit (UEPn<4>) controls handshaking for the endpoint; setting this bit enables USB handshaking. Typically, this bit is always set except when using isochronous endpoints. The EPCONDIS bit (UEPn<3>) is used to enable or disable USB control operations (SETUP) through the endpoint. Clearing this bit enables SETUP transactions. Note that the corresponding EPINEN and EPOUTEN bits must be set to enable IN and OUT REGISTER 22-4: transactions. For Endpoint 0, this bit should always be cleared since the USB specifications identify Endpoint 0 as the default control endpoint. The EPOUTEN bit (UEPn<2>) is used to enable or disable USB OUT transactions from the host. Setting this bit enables OUT transactions. Similarly, the EPINEN bit (UEPn<1>) enables or disables USB IN transactions from the host. The EPSTALL bit (UEPn<0>) is used to indicate a STALL condition for the endpoint. If a STALL is issued on a particular endpoint, the EPSTALL bit for that endpoint pair will be set by the SIE. This bit remains set until it is cleared through firmware, or until the SIE is reset. UEPn: USB ENDPOINT n CONTROL REGISTER (UEP0 THROUGH UEP7) U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL(1) bit 7 bit 0 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 bit 7-5 Unimplemented: Read as ‘0’ bit 4 EPHSHK: Endpoint Handshake Enable bit 1 = Endpoint handshake enabled 0 = Endpoint handshake disabled (typically used for isochronous endpoints) bit 3 EPCONDIS: Bidirectional Endpoint Control bit If EPOUTEN = 1 and EPINEN = 1: 1 = Disable Endpoint n from control transfers; only IN and OUT transfers allowed 0 = Enable Endpoint n for control (SETUP) transfers; IN and OUT transfers also allowed bit 2 EPOUTEN: Endpoint Output Enable bit 1 = Endpoint n output enabled 0 = Endpoint n output disabled bit 1 EPINEN: Endpoint Input Enable bit 1 = Endpoint n input enabled 0 = Endpoint n input disabled bit 0 EPSTALL: Endpoint STALL Enable bit(1) 1 = Endpoint n is stalled 0 = Endpoint n is not stalled Note 1: Valid only if Endpoint n is enabled; otherwise, the bit is ignored. 2010 Microchip Technology Inc. Preliminary DS41350D-page 259 PIC18F/LF1XK50 22.2.5 USB ADDRESS REGISTER (UADDR) FIGURE 22-4: The USB Address register contains the unique USB address that the peripheral will decode when active. UADDR is reset to 00h when a USB Reset is received, indicated by URSTIF, or when a Reset is received from the microcontroller. The USB address must be written by the microcontroller during the USB setup phase (enumeration) as part of the Microchip USB firmware support. 22.2.6 USB FRAME NUMBER REGISTERS (UFRMH:UFRML) The Frame Number registers contain the 11-bit frame number. The low-order byte is contained in UFRML, while the three high-order bits are contained in UFRMH. The register pair is updated with the current frame number whenever a SOF token is received. For the microcontroller, these registers are read-only. The Frame Number registers are primarily used for isochronous transfers. The contents of the UFRMH and UFRML registers are only valid when the 48 MHz SIE clock is active (i.e., contents are inaccurate when SUSPND (UCON<1>) bit = 1). 22.3 IMPLEMENTATION OF USB RAM IN DATA MEMORY SPACE 000h Banks 0 to 1 Banks 2 (USB RAM) Banks 3 to 14 User Data Buffer Descriptors, USB Data or User Data USB Data or User Data 1FFh 200h 27Fh 280h 2FFh 300h Unused USB RAM USB data moves between the microcontroller core and the SIE through a memory space known as the USB RAM. This is a special dual access memory that is mapped into the normal data memory space in Bank 2 (200h to 2FFh) for a total of 256 bytes (Figure 22-4). Bank 2 (200h through 27Fh) is used specifically for endpoint buffer control. Depending on the type of buffering being used, all but 8 bytes of Bank 2 may also be available for use as USB buffer space. Banks 15 SFRs F52h F53h F5Fh F60h FFFh Although USB RAM is available to the microcontroller as data memory, the sections that are being accessed by the SIE should not be accessed by the microcontroller. A semaphore mechanism is used to determine the access to a particular buffer at any given time. This is discussed in Section 22.4.1.1 “Buffer Ownership”. DS41350D-page 260 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.4 Buffer Descriptors and the Buffer Descriptor Table The registers in Bank 2 are used specifically for endpoint buffer control in a structure known as the Buffer Descriptor Table (BDT). This provides a flexible method for users to construct and control endpoint buffers of various lengths and configuration. FIGURE 22-5: Address The BDT is composed of Buffer Descriptors (BD) which are used to define and control the actual buffers in the USB RAM space. Each BD, in turn, consists of four registers, where n represents one of the 32 possible BDs (range of 0 to 31): • • • • BDnSTAT: BD Status register BDnCNT: BD Byte Count register BDnADRL: BD Address Low register BDnADRH: BD Address High register BD0STAT 201h BD0CNT 40h 202h BD0ADRL 00h 203h BD0ADRH 05h Size of Block Starting Address 280h USB Data Buffer Note: Depending on the buffering configuration used (Section 22.4.4 “Ping-Pong Buffering”), there are up to 16, 17 or 32 sets of buffer descriptors. At a minimum, the BDT must be at least 8 bytes long. This is because the USB specification mandates that every device must have Endpoint 0 with both input and output for initial setup. Depending on the endpoint and buffering configuration, the BDT can be as long as 128 bytes. Although they can be thought of as Special Function Registers, the Buffer Descriptor Status and Address registers are not hardware mapped, as conventional microcontroller SFRs in Bank 15 are. If the endpoint corresponding to a particular BD is not enabled, its registers are not used. Instead of appearing as unimplemented addresses, however, they appear as available RAM. Only when an endpoint is enabled by setting the UEPn<1> bit does the memory at those addresses become functional as BD registers. As with any address in the data memory space, the BD registers have an indeterminate value on any device Reset. An example of a BD for a 64-byte buffer, starting at 280h, is shown in Figure 22-5. A particular set of BD registers is only valid if the corresponding endpoint has been enabled using the UEPn register. All BD registers are available in USB RAM. The BD for each endpoint should be set up prior to enabling the endpoint. BD STATUS AND CONFIGURATION Buffer descriptors not only define the size of an endpoint buffer, but also determine its configuration and control. Most of the configuration is done with the BD Status register, BDnSTAT. Each BD has its own unique and correspondingly numbered BDnSTAT register. 2010 Microchip Technology Inc. Contents 2BFh BDs always occur as a four-byte block in the sequence, BDnSTAT:BDnCNT:BDnADRL:BDnADRH. The address of BDnSTAT is always an offset of (4n – 1) (in hexadecimal) from 200h, with n being the buffer descriptor number. 22.4.1 Registers (xxh) 200h Buffer Descriptor EXAMPLE OF A BUFFER DESCRIPTOR Memory regions not to scale. Unlike other control registers, the bit configuration for the BDnSTAT register is context sensitive. There are two distinct configurations, depending on whether the microcontroller or the USB module is modifying the BD and buffer at a particular time. Only three bit definitions are shared between the two. 22.4.1.1 Buffer Ownership Because the buffers and their BDs are shared between the CPU and the USB module, a simple semaphore mechanism is used to distinguish which is allowed to update the BD and associated buffers in memory. This is done by using the UOWN bit (BDnSTAT<7>) as a semaphore to distinguish which is allowed to update the BD and associated buffers in memory. UOWN is the only bit that is shared between the two configurations of BDnSTAT. When UOWN is clear, the BD entry is “owned” by the microcontroller core. When the UOWN bit is set, the BD entry and the buffer memory are “owned” by the USB peripheral. The core should not modify the BD or its corresponding data buffer during this time. Note that the microcontroller core can still read BDnSTAT while the SIE owns the buffer and vice versa. The buffer descriptors have a different meaning based on the source of the register update. Prior to placing ownership with the USB peripheral, the user can configure the basic operation of the peripheral through the BDnSTAT bits. During this time, the byte count and buffer location registers can also be set. When UOWN is set, the user can no longer depend on the values that were written to the BDs. From this point, the SIE updates the BDs as necessary, overwriting the original BD values. The BDnSTAT register is updated by the SIE with the token PID and the transfer count, BDnCNT, is updated. Preliminary DS41350D-page 261 PIC18F/LF1XK50 The BDnSTAT byte of the BDT should always be the last byte updated when preparing to arm an endpoint. The SIE will clear the UOWN bit when a transaction has completed. No hardware mechanism exists to block access when the UOWN bit is set. Thus, unexpected behavior can occur if the microcontroller attempts to modify memory when the SIE owns it. Similarly, reading such memory may produce inaccurate data until the USB peripheral returns ownership to the microcontroller. 22.4.1.2 BDnSTAT Register (CPU Mode) When UOWN = 0, the microcontroller core owns the BD. At this point, the other seven bits of the register take on control functions. The Data Toggle Sync Enable bit, DTSEN (BDnSTAT<3>), controls data toggle parity checking. Setting DTSEN enables data toggle synchronization by the SIE. When enabled, it checks the data packet’s parity against the value of DTS (BDnSTAT<6>). If a packet arrives with an incorrect synchronization, the data will essentially be ignored. It will not be written to the USB RAM and the USB transfer complete interrupt flag will not be set. The SIE will send an ACK token back to the host to Acknowledge receipt, however. The effects of the DTSEN bit on the SIE are summarized in Table 22-1. TABLE 22-1: The Buffer Stall bit, BSTALL (BDnSTAT<2>), provides support for control transfers, usually one-time stalls on Endpoint 0. It also provides support for the SET_FEATURE/CLEAR_FEATURE commands specified in Chapter 9 of the USB specification; typically, continuous STALLs to any endpoint other than the default control endpoint. The BSTALL bit enables buffer stalls. Setting BSTALL causes the SIE to return a STALL token to the host if a received token would use the BD in that location. The EPSTALL bit in the corresponding UEPn control register is set and a STALL interrupt is generated when a STALL is issued to the host. The UOWN bit remains set and the BDs are not changed unless a SETUP token is received. In this case, the STALL condition is cleared and the ownership of the BD is returned to the microcontroller core. The BD<9:8> bits (BDnSTAT<1:0>) store the two Most Significant digits of the SIE byte count; the lower 8 digits are stored in the corresponding BDnCNT register. See Section 22.4.2 “BD Byte Count” for more information. EFFECT OF DTSEN BIT ON ODD/EVEN (DATA0/DATA1) PACKET RECEPTION OUT Packet from Host BDnSTAT Settings Device Response after Receiving Packet DTSEN DTS Handshake UOWN TRNIF BDnSTAT and USTAT Status 1 0 ACK 0 1 Updated DATA0 DATA1 1 0 ACK 1 0 Not Updated DATA0 1 1 ACK 1 0 Not Updated DATA1 1 1 ACK 0 1 Updated Either 0 x ACK 0 1 Updated Either, with error x x NAK 1 0 Not Updated Legend: x = don’t care DS41350D-page 262 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 22-5: R/W-x UOWN(1) BDnSTAT: BUFFER DESCRIPTOR n STATUS REGISTER (BD0STAT THROUGH BD31STAT), CPU MODE (DATA IS WRITTEN TO THE SIDE) R/W-x U-0 U-0 (2) (3) (3) DTS — — R/W-x R/W-x R/W-x R/W-x DTSEN BSTALL BC9 BC8 bit 7 bit 0 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 bit 7 UOWN: USB Own bit(1) 0 = The microcontroller core owns the BD and its corresponding buffer bit 6 DTS: Data Toggle Synchronization bit(2) 1 = Data 1 packet 0 = Data 0 packet bit 5-4 Unimplemented: These bits should always be programmed to ‘0’(3). bit 3 DTSEN: Data Toggle Synchronization Enable bit 1 = Data toggle synchronization is enabled; data packets with incorrect Sync value will be ignored except for a SETUP transaction, which is accepted even if the data toggle bits do not match 0 = No data toggle synchronization is performed bit 2 BSTALL: Buffer Stall Enable bit 1 = Buffer stall enabled; STALL handshake issued if a token is received that would use the BD in the given location (UOWN bit remains set, BD value is unchanged) 0 = Buffer stall disabled bit 1-0 BC<9:8>: Byte Count 9 and 8 bits The byte count bits represent the number of bytes that will be transmitted for an IN token or received during an OUT token. Together with BC<7:0>, the valid byte counts are 0-1023. Note 1: 2: 3: This bit must be initialized by the user to the desired value prior to enabling the USB module. This bit is ignored unless DTSEN = 1. If these bits are set, USB communication may not work. Hence, these bits should always be maintained as ‘0’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 263 PIC18F/LF1XK50 22.4.1.3 BDnSTAT Register (SIE Mode) When the BD and its buffer are owned by the SIE, most of the bits in BDnSTAT take on a different meaning. The configuration is shown in Register 22-6. Once the UOWN bit is set, any data or control settings previously written there by the user will be overwritten with data from the SIE. The BDnSTAT register is updated by the SIE with the token Packet Identifier (PID) which is stored in BDnSTAT<5:3>. The transfer count in the corresponding BDnCNT register is updated. Values that overflow the 8-bit register carry over to the two Most Significant digits of the count, stored in BDnSTAT<1:0>. 22.4.2 BD BYTE COUNT The byte count represents the total number of bytes that will be transmitted during an IN transfer. After an IN transfer, the SIE will return the number of bytes sent to the host. The 10-bit byte count is distributed over two registers. The lower 8 bits of the count reside in the BDnCNT register. The upper two bits reside in BDnSTAT<1:0>. This represents a valid byte range of 0 to 1023. 22.4.3 BD ADDRESS VALIDATION The BD Address register pair contains the starting RAM address location for the corresponding endpoint buffer. No mechanism is available in hardware to validate the BD address. If the value of the BD address does not point to an address in the USB RAM, or if it points to an address within another endpoint’s buffer, data is likely to be lost or overwritten. Similarly, overlapping a receive buffer (OUT endpoint) with a BD location in use can yield unexpected results. When developing USB applications, the user may want to consider the inclusion of software-based address validation in their code. For an OUT transfer, the byte count represents the maximum number of bytes that can be received and stored in USB RAM. After an OUT transfer, the SIE will return the actual number of bytes received. If the number of bytes received exceeds the corresponding byte count, the data packet will be rejected and a NAK handshake will be generated. When this happens, the byte count will not be updated. REGISTER 22-6: BDnSTAT: BUFFER DESCRIPTOR n STATUS REGISTER (BD0STAT THROUGH BD31STAT), SIE MODE (DATA RETURNED BY THE SIDE TO THE MCU) R/W-x U-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x UOWN — PID3 PID2 PID1 PID0 BC9 BC8 bit 7 bit 0 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 bit 7 UOWN: USB Own bit 1 = The SIE owns the BD and its corresponding buffer bit 6 Reserved: Not written by the SIE bit 5-2 PID<3:0>: Packet Identifier bits The received token PID value of the last transfer (IN, OUT or SETUP transactions only). bit 1-0 BC<9:8>: Byte Count 9 and 8 bits These bits are updated by the SIE to reflect the actual number of bytes received on an OUT transfer and the actual number of bytes transmitted on an IN transfer. DS41350D-page 264 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.4.4 PING-PONG BUFFERING the completion of a transaction (UOWN cleared by the SIE), the pointer is toggled to the Odd BD. After the completion of the next transaction, the pointer is toggled back to the Even BD and so on. An endpoint is defined to have a ping-pong buffer when it has two sets of BD entries: one set for an Even transfer and one set for an Odd transfer. This allows the CPU to process one BD while the SIE is processing the other BD. Double-buffering BDs in this way allows for maximum throughput to/from the USB. The Even/Odd status of the last transaction is stored in the PPBI bit of the USTAT register. The user can reset all Ping-Pong Pointers to Even using the PPBRST bit. Figure 22-6 shows the four different modes of operation and how USB RAM is filled with the BDs. The USB module supports four modes of operation: • • • • No ping-pong support Ping-pong buffer support for OUT Endpoint 0 only Ping-pong buffer support for all endpoints Ping-pong buffer support for all other Endpoints except Endpoint 0 BDs have a fixed relationship to a particular endpoint, depending on the buffering configuration. The mapping of BDs to endpoints is detailed in Table 22-2. This relationship also means that gaps may occur in the BDT if endpoints are not enabled contiguously. This theoretically means that the BDs for disabled endpoints could be used as buffer space. In practice, users should avoid using such spaces in the BDT unless a method of validating BD addresses is implemented. The ping-pong buffer settings are configured using the PPB<1:0> bits in the UCFG register. The USB module keeps track of the Ping-Pong Pointer individually for each endpoint. All pointers are initially reset to the Even BD when the module is enabled. After FIGURE 22-6: BUFFER DESCRIPTOR TABLE MAPPING FOR BUFFERING MODES PPB<1:0> = 00 No Ping-Pong Buffers 200h PPB<1:0> = 10 Ping-Pong Buffers on all EPs PPB<1:0> = 01 Ping-Pong Buffer on EP0 OUT 200h EP0 OUT Descriptor 200h EP0 OUT Even Descriptor EP0 OUT Even Descriptor EP0 IN Descriptor EP0 OUT Odd Descriptor EP0 OUT Odd Descriptor EP0 IN Descriptor EP0 IN Even Descriptor EP1 OUT Even Descriptor EP0 IN Odd Descriptor EP1 OUT Odd Descriptor EP1 OUT Even Descriptor EP1 IN Even Descriptor EP1 OUT Odd Descriptor EP1 IN Odd Descriptor EP1 OUT Descriptor EP0 IN Descriptor EP1 IN Descriptor EP1 OUT Descriptor EP1 IN Descriptor EP7 IN Descriptor 23Fh PPB<1:0> = 11 Ping-Pong Buffers on all other EPs except EP0 Available as Data RAM EP0 OUT Descriptor EP1 IN Even Descriptor EP7 IN Descriptor 243h 200h EP1 IN Odd Descriptor Available as Data RAM 27Fh EP7 IN Odd Descriptor EP7 IN Odd Descriptor 277h Available as Data RAM 2FFh 2FFh Maximum Memory Used: 64 bytes Maximum BDs: 16 (BD0 to BD15) Note: Maximum Memory Used: 68 bytes Maximum BDs: 17 (BD0 to BD16) 2FFh 2FFh Maximum Memory Used: 128 bytes Maximum BDs: 32 (BD0 to BD31) Maximum Memory Used: 120 bytes Maximum BDs: 30 (BD0 to BD29) Memory area not shown to scale. 2010 Microchip Technology Inc. Preliminary DS41350D-page 265 PIC18F/LF1XK50 TABLE 22-2: ASSIGNMENT OF BUFFER DESCRIPTORS FOR THE DIFFERENT BUFFERING MODES BDs Assigned to Endpoint Mode 0 (No Ping-Pong) Endpoint Mode 1 (Ping-Pong on EP0 OUT) Mode 3 (Ping-Pong on all other EPs, except EP0) Mode 2 (Ping-Pong on all EPs) Out In Out In Out In Out 0 0 1 0 (E), 1 (O) 1 2 3 3 2 4 5 5 6 8 (E), 9 (O) 10 (E), 11 (O) 3 6 7 7 8 12 (E), 13 (O) 14 (E), 15 (O) In 2 0 (E), 1 (O) 2 (E), 3 (O) 0 1 4 4 (E), 5 (O) 6 (E), 7 (O) 2 (E), 3 (O) 4 (E), 5 (O) 6 (E), 7 (O) 8 (E), 9 (O) 10 (E), 11 (O) 12 (E), 13 (O) 4 8 9 9 10 16 (E), 17 (O) 18 (E), 19 (O) 14 (E), 15 (O) 16 (E), 17 (O) 5 10 11 11 12 20 (E), 21 (O) 22 (E), 23 (O) 18 (E), 19 (O) 20 (E), 21 (O) 6 12 13 13 14 24 (E), 25 (O) 26 (E), 27 (O) 22 (E), 23 (O) 24 (E), 25 (O) 7 14 15 15 16 28 (E), 29 (O) 30 (E), 31 (O) 26 (E), 27 (O) 28 (E), 29 (O) Legend: (E) = Even transaction buffer, (O) = Odd transaction buffer TABLE 22-3: SUMMARY OF USB BUFFER DESCRIPTOR TABLE REGISTERS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 BDnSTAT(1) UOWN DTS(4) PID3(2) PID2(2) PID1(2) PID0(2) BC9 BC8 BDnCNT(1) Byte Count BDnADRL(1) Buffer Address Low BDnADRH(1) Buffer Address High Note 1: 2: 3: 4: DTSEN(3) BSTALL(3) For buffer descriptor registers, n may have a value of 0 to 31. For the sake of brevity, all 32 registers are shown as one generic prototype. All registers have indeterminate Reset values (xxxx xxxx). Bits 5 through 2 of the BDnSTAT register are used by the SIE to return PID<3:0> values once the register is turned over to the SIE (UOWN bit is set). Once the registers have been under SIE control, the values written for DTSEN and BSTALL are no longer valid. Prior to turning the buffer descriptor over to the SIE (UOWN bit is cleared), bits 5 through 2 of the BDnSTAT register are used to configure the DTSEN and BSTALL settings. This bit is ignored unless DTSEN = 1. DS41350D-page 266 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.5 USB Interrupts Figure 22-7 shows the interrupt logic for the USB module. There are two layers of interrupt registers in the USB module. The top level consists of overall USB Status interrupts; these are enabled and flagged in the UIE and UIR registers, respectively. The second level consists of USB error conditions, which are enabled and flagged in the UEIR and UEIE registers. An interrupt condition in any of these triggers a USB Error Interrupt Flag (UERRIF) in the top level. The USB module can generate multiple interrupt conditions. To accommodate all of these interrupt sources, the module is provided with its own interrupt logic structure, similar to that of the microcontroller. USB interrupts are enabled with one set of control registers and trapped with a separate set of flag registers. All sources are funneled into a single USB interrupt request, USBIF (PIR2<2>), in the microcontroller’s interrupt logic. FIGURE 22-7: Interrupts may be used to trap routine events in a USB transaction. Figure 22-8 shows some common events within a USB frame and their corresponding interrupts. USB INTERRUPT LOGIC FUNNEL Second Level USB Interrupts (USB Error Conditions) Top Level USB Interrupts (USB Status Interrupts) UEIR (Flag) and UEIE (Enable) Registers UIR (Flag) and UIE (Enable) Registers SOFIF SOFIE BTSEF BTSEE TRNIF TRNIE BTOEF BTOEE USBIF IDLEIF IDLEIE DFN8EF DFN8EE UERRIF UERRIE CRC16EF CRC16EE STALLIF STALLIE CRC5EF CRC5EE PIDEF PIDEE ACTVIF ACTVIE URSTIF URSTIE FIGURE 22-8: EXAMPLE OF A USB TRANSACTION AND INTERRUPT EVENTS From Host From Host To Host SETUP Token Data ACK To Host From Host Data ACK From Host To Host Empty Data ACK From Host IN Token USB Reset URSTIF From Host Start-of-Frame (SOF) SOFIF OUT Token Set TRNIF Set TRNIF Set TRNIF Transaction Transaction Complete RESET SOF SETUP DATA SOF STATUS Differential Data Control Transfer(1) 1 ms Frame Note 1: The control transfer shown here is only an example showing events that can occur for every transaction. Typical control transfers will spread across multiple frames. 2010 Microchip Technology Inc. Preliminary DS41350D-page 267 PIC18F/LF1XK50 22.5.1 USB INTERRUPT STATUS REGISTER (UIR) Once an interrupt bit has been set by the SIE, it must be cleared by software by writing a ‘0’. The flag bits can also be set in software which can aid in firmware debugging. The USB Interrupt Status register (Register 22-7) contains the flag bits for each of the USB Status interrupt sources. Each of these sources has a corresponding interrupt enable bit in the UIE register. All of the USB status flags are ORed together to generate the USBIF interrupt flag for the microcontroller’s interrupt funnel. REGISTER 22-7: UIR: USB INTERRUPT STATUS REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R/W-0 — SOFIF STALLIF IDLEIF(1) TRNIF(2) ACTVIF(3) UERRIF(4) URSTIF bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6 SOFIF: Start-of-Frame Token Interrupt bit 1 = A Start-of-Frame token received by the SIE 0 = No Start-of-Frame token received by the SIE bit 5 STALLIF: A STALL Handshake Interrupt bit 1 = A STALL handshake was sent by the SIE 0 = A STALL handshake has not been sent bit 4 IDLEIF: Idle Detect Interrupt bit(1) 1 = Idle condition detected (constant Idle state of 3 ms or more) 0 = No Idle condition detected bit 3 TRNIF: Transaction Complete Interrupt bit(2) 1 = Processing of pending transaction is complete; read USTAT register for endpoint information 0 = Processing of pending transaction is not complete or no transaction is pending bit 2 ACTVIF: Bus Activity Detect Interrupt bit(3) 1 = Activity on the D+/D- lines was detected 0 = No activity detected on the D+/D- lines bit 1 UERRIF: USB Error Condition Interrupt bit(4) 1 = An unmasked error condition has occurred 0 = No unmasked error condition has occurred. bit 0 URSTIF: USB Reset Interrupt bit 1 = Valid USB Reset occurred; 00h is loaded into UADDR register 0 = No USB Reset has occurred Note 1: 2: 3: 4: Once an Idle state is detected, the user may want to place the USB module in Suspend mode. Clearing this bit will cause the USTAT FIFO to advance (valid only for IN, OUT and SETUP tokens). This bit is typically unmasked only following the detection of a UIDLE interrupt event. Only error conditions enabled through the UEIE register will set this bit. This bit is a status bit only and cannot be set or cleared by the user. DS41350D-page 268 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.5.1.1 Bus Activity Detect Interrupt Bit (ACTVIF) The ACTVIF bit cannot be cleared immediately after the USB module wakes up from Suspend or while the USB module is suspended. A few clock cycles are required to synchronize the internal hardware state machine before the ACTVIF bit can be cleared by firmware. Clearing the ACTVIF bit before the internal hardware is synchronized may not have an effect on the value of ACTVIF. Additionally, if the USB module uses the clock from the 48 MHz PLL source, then after EXAMPLE 22-1: clearing the SUSPND bit, the USB module may not be immediately operational while waiting for the 48 MHz PLL to lock. The application code should clear the ACTVIF flag as shown in Example 22-1. Only one ACTVIF interrupt is generated when resuming from the USB bus Idle condition. If user firmware clears the ACTVIF bit, the bit will not immediately become set again, even when there is continuous bus traffic. Bus traffic must cease long enough to generate another IDLEIF condition before another ACTVIF interrupt can be generated. CLEARING ACTVIF BIT (UIR<2>) Assembly: BCF LOOP: BTFSS BRA BCF BRA DONE: UCON, SUSPND UIR, ACTVIF DONE UIR, ACTVIF LOOP C: UCONbits.SUSPND = 0; while (UIRbits.ACTVIF) { UIRbits.ACTVIF = 0; } 2010 Microchip Technology Inc. Preliminary DS41350D-page 269 PIC18F/LF1XK50 22.5.2 USB INTERRUPT ENABLE REGISTER (UIE) The USB Interrupt Enable register (Register 22-8) contains the enable bits for the USB Status interrupt sources. Setting any of these bits will enable the respective interrupt source in the UIR register. REGISTER 22-8: The values in this register only affect the propagation of an interrupt condition to the microcontroller’s interrupt logic. The flag bits are still set by their interrupt conditions, allowing them to be polled and serviced without actually generating an interrupt. UIE: USB INTERRUPT ENABLE REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 — SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE bit 7 bit 0 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 bit 7 Unimplemented: Read as ‘0’ bit 6 SOFIE: Start-of-Frame Token Interrupt Enable bit 1 = Start-of-Frame token interrupt enabled 0 = Start-of-Frame token interrupt disabled bit 5 STALLIE: STALL Handshake Interrupt Enable bit 1 = STALL interrupt enabled 0 = STALL interrupt disabled bit 4 IDLEIE: Idle Detect Interrupt Enable bit 1 = Idle detect interrupt enabled 0 = Idle detect interrupt disabled bit 3 TRNIE: Transaction Complete Interrupt Enable bit 1 = Transaction interrupt enabled 0 = Transaction interrupt disabled bit 2 ACTVIE: Bus Activity Detect Interrupt Enable bit 1 = Bus activity detect interrupt enabled 0 = Bus activity detect interrupt disabled bit 1 UERRIE: USB Error Interrupt Enable bit 1 = USB error interrupt enabled 0 = USB error interrupt disabled bit 0 URSTIE: USB Reset Interrupt Enable bit 1 = USB Reset interrupt enabled 0 = USB Reset interrupt disabled DS41350D-page 270 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.5.3 USB ERROR INTERRUPT STATUS REGISTER (UEIR) The USB Error Interrupt Status register (Register 22-9) contains the flag bits for each of the error sources within the USB peripheral. Each of these sources is controlled by a corresponding interrupt enable bit in the UEIE register. All of the USB error flags are ORed together to generate the USB Error Interrupt Flag (UERRIF) at the top level of the interrupt logic. REGISTER 22-9: Each error bit is set as soon as the error condition is detected. Thus, the interrupt will typically not correspond with the end of a token being processed. Once an interrupt bit has been set by the SIE, it must be cleared by software by writing a ‘0’. UEIR: USB ERROR INTERRUPT STATUS REGISTER R/C-0 U-0 U-0 R/C-0 R/C-0 R/C-0 R/C-0 R/C-0 BTSEF — — BTOEF DFN8EF CRC16EF CRC5EF PIDEF bit 7 bit 0 Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 BTSEF: Bit Stuff Error Flag bit 1 = A bit stuff error has been detected 0 = No bit stuff error bit 6-5 Unimplemented: Read as ‘0’ bit 4 BTOEF: Bus Turnaround Time-out Error Flag bit 1 = Bus turnaround time-out has occurred (more than 16 bit times of Idle from previous EOP elapsed) 0 = No bus turnaround time-out bit 3 DFN8EF: Data Field Size Error Flag bit 1 = The data field was not an integral number of bytes 0 = The data field was an integral number of bytes bit 2 CRC16EF: CRC16 Failure Flag bit 1 = The CRC16 failed 0 = The CRC16 passed bit 1 CRC5EF: CRC5 Host Error Flag bit 1 = The token packet was rejected due to a CRC5 error 0 = The token packet was accepted bit 0 PIDEF: PID Check Failure Flag bit 1 = PID check failed 0 = PID check passed 2010 Microchip Technology Inc. Preliminary DS41350D-page 271 PIC18F/LF1XK50 22.5.4 USB ERROR INTERRUPT ENABLE REGISTER (UEIE) As with the UIE register, the enable bits only affect the propagation of an interrupt condition to the microcontroller’s interrupt logic. The flag bits are still set by their interrupt conditions, allowing them to be polled and serviced without actually generating an interrupt. The USB Error Interrupt Enable register (Register 22-10) contains the enable bits for each of the USB error interrupt sources. Setting any of these bits will enable the respective error interrupt source in the UEIR register to propagate into the UERR bit at the top level of the interrupt logic. REGISTER 22-10: UEIE: USB ERROR INTERRUPT ENABLE REGISTER R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 BTSEE — — BTOEE DFN8EE CRC16EE CRC5EE PIDEE bit 7 bit 0 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 bit 7 BTSEE: Bit Stuff Error Interrupt Enable bit 1 = Bit stuff error interrupt enabled 0 = Bit stuff error interrupt disabled bit 6-5 Unimplemented: Read as ‘0’ bit 4 BTOEE: Bus Turnaround Time-out Error Interrupt Enable bit 1 = Bus turnaround time-out error interrupt enabled 0 = Bus turnaround time-out error interrupt disabled bit 3 DFN8EE: Data Field Size Error Interrupt Enable bit 1 = Data field size error interrupt enabled 0 = Data field size error interrupt disabled bit 2 CRC16EE: CRC16 Failure Interrupt Enable bit 1 = CRC16 failure interrupt enabled 0 = CRC16 failure interrupt disabled bit 1 CRC5EE: CRC5 Host Error Interrupt Enable bit 1 = CRC5 host error interrupt enabled 0 = CRC5 host error interrupt disabled bit 0 PIDEE: PID Check Failure Interrupt Enable bit 1 = PID check failure interrupt enabled 0 = PID check failure interrupt disabled DS41350D-page 272 Preliminary x = Bit is unknown 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.6 USB Power Modes 22.6.2 Many USB applications will likely have several different sets of power requirements and configuration. The most common power modes encountered are Bus Power Only, Self-Power Only and Dual Power with Self-Power Dominance. The most common cases are presented here. Also provided is a means of estimating the current consumption of the USB transceiver. 22.6.1 BUS POWER ONLY In Bus Power Only mode, all power for the application is drawn from the USB (Figure 22-9). This is effectively the simplest power method for the device. SELF-POWER ONLY In Self-Power Only mode, the USB application provides its own power, with very little power being pulled from the USB. Figure 22-10 shows an example. In order to meet compliance specifications, the USB module (and the D+ or D- pull-up resistor) should not be enabled until the host actively drives VBUS high. The application should never source any current onto the 5V VBUS pin of the USB cable. FIGURE 22-10: In order to meet the inrush current requirements of the USB 2.0 specifications, the total effective capacitance appearing across VBUS and ground must be no more than 10 µF. If not, some kind of inrush liming is required. For more details, see section 7.2.4 of the USB 2.0 specification. VSELF SELF-POWER ONLY VDD VUSB VSS According to the USB 2.0 specification, all USB devices must also support a Low-Power Suspend mode. In the USB Suspend mode, devices must consume no more than 500 A (or 2.5 mA for high powered devices that are remote wake-up capable) from the 5V VBUS line of the USB cable. The host signals the USB device to enter the Suspend mode by stopping all USB traffic to that device for more than 3 ms. This condition will cause the IDLEIF bit in the UIR register to become set. During the USB Suspend mode, the D+ or D- pull-up resistor must remain active, which will consume some of the allowed suspend current: 500 A/2.5 mA budget. FIGURE 22-9: BUS POWER ONLY VBUS VDD VUSB VSS 2010 Microchip Technology Inc. Preliminary DS41350D-page 273 PIC18F/LF1XK50 22.6.3 DUAL POWER WITH SELF-POWER DOMINANCE 22.6.4 USB TRANSCEIVER CURRENT CONSUMPTION Some applications may require a dual power option. This allows the application to use internal power primarily, but switch to power from the USB when no internal power is available. Figure 22-11 shows a simple Dual Power with Self-Power Dominance mode example, which automatically switches between Self-Power Only and USB Bus Power Only modes. The USB transceiver consumes a variable amount of current depending on the characteristic impedance of the USB cable, the length of the cable, the VUSB supply voltage and the actual data patterns moving across the USB cable. Longer cables have larger capacitances and consume more total energy when switching output states. Dual power devices must also meet all of the special requirements for inrush current and Suspend mode current and must not enable the USB module until VBUS is driven high. See Section 22.6.1 “Bus Power Only” and Section 22.6.2 “Self-Power Only” for descriptions of those requirements. Additionally, dual power devices must never source current onto the 5V VBUS pin of the USB cable. Data patterns that consist of “IN” traffic consume far more current than “OUT” traffic. IN traffic requires the PIC® device to drive the USB cable, whereas OUT traffic requires that the host drive the USB cable. FIGURE 22-11: VBUS ~5V DUAL POWER EXAMPLE VDD 100 k VSELF ~5V Note: More details about NRZI encoding and bit-stuffing can be found in the USB 2.0 specification’s section 7.1, although knowledge of such details is not required to make USB applications using the PIC18F1XK50/PIC18LF1XK50 of microcontrollers. Among other things, the SIE handles bit-stuffing/unstuffing, NRZI encoding/decoding and CRC generation/checking in hardware. VUSB VSS Users should keep in mind the limits for devices drawing power from the USB. According to USB Specification 2.0, this cannot exceed 100 mA per low-power device or 500 mA per high-power device. DS41350D-page 274 The data that is sent across the USB cable is NRZI encoded. In the NRZI encoding scheme, ‘0’ bits cause a toggling of the output state of the transceiver (either from a “J” state to a “K” state, or vise versa). With the exception of the effects of bit-stuffing, NRZI encoded ‘1’ bits do not cause the output state of the transceiver to change. Therefore, IN traffic consisting of data bits of value, ‘0’, cause the most current consumption, as the transceiver must charge/discharge the USB cable in order to change states. The total transceiver current consumption will be application-specific. However, to help estimate how much current actually may be required in full-speed applications, Equation 22-1 can be used. Example 22-2 shows how this equation can be used for a theoretical application. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 EQUATION 22-1: ESTIMATING USB TRANSCEIVER CURRENT CONSUMPTION IXCVR = Legend: (60 mA • VUSB • PZERO • PIN • LCABLE) + IPULLUP (3.3V • 5m) VUSB: Voltage applied to the VUSB pin in volts. (Should be 3.0V to 3.6V.) PZERO: Percentage (in decimal) of the IN traffic bits sent by the PIC® device that are a value of ‘0’. PIN: Percentage (in decimal) of total bus bandwidth that is used for IN traffic. LCABLE: Length (in meters) of the USB cable. The USB 2.0 specification requires that full-speed applications use cables no longer than 5m. IPULLUP: Current which the nominal, 1.5 k pull-up resistor (when enabled) must supply to the USB cable. On the host or hub end of the USB cable, 15 k nominal resistors (14.25 k to 24.8 k) are present which pull both the D+ and D- lines to ground. During bus Idle conditions (such as between packets or during USB Suspend mode), this results in up to 218 A of quiescent current drawn at 3.3V. IPULLUP is also dependant on bus traffic conditions and can be as high as 2.2 mA when the USB bandwidth is fully utilized (either IN or OUT traffic) for data that drives the lines to the “K” state most of the time. EXAMPLE 22-2: CALCULATING USB TRANSCEIVER CURRENT† For this example, the following assumptions are made about the application: • 3.3V will be applied to VUSB and VDD, with the core voltage regulator enabled. • This is a full-speed application that uses one interrupt IN endpoint that can send one packet of 64 bytes every 1 ms, with no restrictions on the values of the bytes being sent. The application may or may not have additional traffic on OUT endpoints. • A regular USB “B” or “mini-B” connector will be used on the application circuit board. In this case, PZERO = 100% = 1, because there should be no restriction on the value of the data moving through the IN endpoint. All 64 kBps of data could potentially be bytes of value, 00h. Since ‘0’ bits cause toggling of the output state of the transceiver, they cause the USB transceiver to consume extra current charging/discharging the cable. In this case, 100% of the data bits sent can be of value ‘0’. This should be considered the “max” value, as normal data will consist of a fair mix of ones and zeros. This application uses 64 kBps for IN traffic out of the total bus bandwidth of 1.5 MBps (12 Mbps), therefore: 64 kBps Pin = = 4.3% = 0.043 1.5 MBps Since a regular “B” or “mini-B” connector is used in this application, the end user may plug in any type of cable up to the maximum allowed 5 m length. Therefore, we use the worst-case length: LCABLE = 5 meters Assume IPULLUP = 2.2 mA. The actual value of IPULLUP will likely be closer to 218 A, but allow for the worst-case. USB bandwidth is shared between all the devices which are plugged into the root port (via hubs). If the application is plugged into a USB 1.1 hub that has other devices plugged into it, your device may see host to device traffic on the bus, even if it is not addressed to your device. Since any traffic, regardless of source, can increase the IPULLUP current above the base 218 A, it is safest to allow for the worst-case of 2.2 mA. Therefore: IXCVR = (60 mA • 3.3V • 1 • 0.043 • 5m) + 2.2 mA = 4.8 mA (3.3V • 5m) The calculated value should be considered an approximation and additional guardband or application-specific product testing is recommended. The transceiver current is “in addition to” the rest of the current consumed by the PIC18F1XK50/PIC18LF1XK50 device that is needed to run the core, drive the other I/O lines, power the various modules, etc. 2010 Microchip Technology Inc. Preliminary DS41350D-page 275 PIC18F/LF1XK50 22.7 Oscillator The USB module has specific clock requirements. For full-speed operation, the clock source must be 48 MHz. Even so, the microcontroller core and other peripherals are not required to run at that clock speed. Available clocking options are described in detail in Section 2.11 “USB Operation”. 22.8 Interrupt-On-Change for D+/Dpins The PIC18F/LF1XK50 has interrupt-on-change functionality on both D+ and D- data pins. This feature allows the device to detect voltage level changes when first connected to a USB host/hub. The USB module must be disable (USBEN = 0) for the interrupt-on-change to function. Enabling the USB module (USBEN = 1) will automatically disable the interrupt-on-change for D+ and D- pins. Refer to Section 7.11 “PORTA and PORTB Interrupt-on-Change” for mode detail. 22.9 USB Firmware and Drivers Microchip provides a number of application-specific resources, such as USB firmware and driver support. Refer to www.microchip.com for the latest firmware and driver support. The USB host/hub has 15K pull-down resistors on the D+ and D- pins. When the PIC18F/LF1XK50 attaches to the bus the D+ and D- pins can detect voltage changes. External resistors are needed for each pin to maintain a high state on the pins when detached. TABLE 22-4: Name INTCON IPR2 REGISTERS ASSOCIATED WITH USB MODULE OPERATION(1) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 GIE/GIEH PEIE/GIEL TMR0IE OSCFIP C1IP C2IP INT0IE RABIE EEIP BCL1IP Details on Page: Bit 1 Bit 0 TMR0IF INT0IF RABIF 69 USBIP TMR3IP — 77 PIR2 OSCFIF C1IF C2IF EEIF BCL1IF USBIF TMR3IF — 73 PIE2 OSCFIE C1IE C2IE EEIE BCL1IE USBIE TMR3IE — 75 UCON — PPBRST SE0 PKTDIS USBEN RESUME SUSPND — 254 UCFG UTEYE — — UPUEN — FSEN PPB1 PPB0 256 USTAT — ENDP3 ENDP2 ENDP1 ENDP0 DIR PPBI — 258 UADDR — ADDR6 ADDR5 ADDR4 ADDR3 ADDR2 ADDR1 ADDR0 260 UFRML FRM7 FRM6 FRM5 FRM4 FRM3 FRM2 FRM1 FRM0 254 UFRMH — — — — — FRM10 FRM9 FRM8 254 UIR — SOFIF STALLIF IDLEIF TRNIF ACTVIF UERRIF URSTIF 268 UIE — SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE 270 UEIR BTSEF — — BTOEF DFN8EF CRC16EF CRC5EF PIDEF 271 UEIE BTSEE — — BTOEE DFN8EE CRC16EE CRC5EE PIDEE 272 UEP0 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP1 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP2 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP3 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP4 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP5 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP6 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 UEP7 — — — EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 259 Legend: Note 1: — = unimplemented, read as ‘0’. Shaded cells are not used by the USB module. This table includes only those hardware mapped SFRs located in Bank 15 of the data memory space. The Buffer Descriptor registers, which are mapped into Bank 4 and are not true SFRs, are listed separately in Table 22-3. DS41350D-page 276 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 22.10 Overview of USB 22.10.3 This section presents some of the basic USB concepts and useful information necessary to design a USB device. Although much information is provided in this section, there is a plethora of information provided within the USB specifications and class specifications. Thus, the reader is encouraged to refer to the USB specifications for more information (www.usb.org). If you are very familiar with the details of USB, then this section serves as a basic, high-level refresher of USB. There are four transfer types defined in the USB specification. 22.10.1 LAYERED FRAMEWORK USB device functionality is structured into a layered framework graphically shown in Figure 22-12. Each level is associated with a functional level within the device. The highest layer, other than the device, is the configuration. A device may have multiple configurations. For example, a particular device may have multiple power requirements based on Self-Power Only or Bus Power Only modes. For each configuration, there may be multiple interfaces. Each interface could support a particular mode of that configuration. Below the interface is the endpoint(s). Data is directly moved at this level. There can be as many as 16 bidirectional endpoints. Endpoint 0 is always a control endpoint and by default, when the device is on the bus, Endpoint 0 must be available to configure the device. 22.10.2 TRANSFERS • Isochronous: This type provides a transfer method for large amounts of data (up to 1023 bytes) with timely delivery ensured; however, the data integrity is not ensured. This is good for streaming applications where small data loss is not critical, such as audio. • Bulk: This type of transfer method allows for large amounts of data to be transferred with ensured data integrity; however, the delivery timeliness is not ensured. • Interrupt: This type of transfer provides for ensured timely delivery for small blocks of data, plus data integrity is ensured. • Control: This type provides for device setup control. While full-speed devices support all transfer types, low-speed devices are limited to interrupt and control transfers only. 22.10.4 POWER Power is available from the Universal Serial Bus. The USB specification defines the bus power requirements. Devices may either be self-powered or bus powered. Self-powered devices draw power from an external source, while bus powered devices use power supplied from the bus. FRAMES Information communicated on the bus is grouped into 1 ms time slots, referred to as frames. Each frame can contain many transactions to various devices and endpoints. Figure 22-8 shows an example of a transaction within a frame. FIGURE 22-12: USB LAYERS Device To other Configurations (if any) Configuration To other Interfaces (if any) Interface Interface Endpoint Endpoint 2010 Microchip Technology Inc. Endpoint Endpoint Preliminary Endpoint DS41350D-page 277 PIC18F/LF1XK50 The USB specification limits the power taken from the bus. Each device is ensured 100 mA at approximately 5V (one unit load). Additional power may be requested, up to a maximum of 500 mA. Note that power above one unit load is a request and the host or hub is not obligated to provide the extra current. Thus, a device capable of consuming more than one unit load must be able to maintain a low-power configuration of a one unit load or less, if necessary. The USB specification also defines a Suspend mode. In this situation, current must be limited to 500 A, averaged over 1 second. A device must enter a Suspend state after 3 ms of inactivity (i.e., no SOF tokens for 3 ms). A device entering Suspend mode must drop current consumption within 10 ms after Suspend. Likewise, when signaling a wake-up, the device must signal a wake-up within 10 ms of drawing current above the Suspend limit. 22.10.5 ENUMERATION When the device is initially attached to the bus, the host enters an enumeration process in an attempt to identify the device. Essentially, the host interrogates the device, gathering information such as power consumption, data rates and sizes, protocol and other descriptive information; descriptors contain this information. A typical enumeration process would be as follows: 1. 2. 3. 4. 5. 6. 7. 8. USB Reset: Reset the device. Thus, the device is not configured and does not have an address (address 0). Get Device Descriptor: The host requests a small portion of the device descriptor. USB Reset: Reset the device again. Set Address: The host assigns an address to the device. Get Device Descriptor: The host retrieves the device descriptor, gathering info such as manufacturer, type of device, maximum control packet size. Get configuration descriptors. Get any other descriptors. Set a configuration. The exact enumeration process depends on the host. 22.10.6 DESCRIPTORS There are eight different standard descriptor types of which five are most important for this device. 22.10.6.1 Device Descriptor The device descriptor provides general information, such as manufacturer, product number, serial number, the class of the device and the number of configurations. There is only one device descriptor. DS41350D-page 278 22.10.6.2 Configuration Descriptor The configuration descriptor provides information on the power requirements of the device and how many different interfaces are supported when in this configuration. There may be more than one configuration for a device (i.e., low-power and high-power configurations). 22.10.6.3 Interface Descriptor The interface descriptor details the number of endpoints used in this interface, as well as the class of the interface. There may be more than one interface for a configuration. 22.10.6.4 Endpoint Descriptor The endpoint descriptor identifies the transfer type (Section 22.10.3 “Transfers”) and direction, as well as some other specifics for the endpoint. There may be many endpoints in a device and endpoints may be shared in different configurations. 22.10.6.5 String Descriptor Many of the previous descriptors reference one or more string descriptors. String descriptors provide human readable information about the layer (Section 22.10.1 “Layered Framework”) they describe. Often these strings show up in the host to help the user identify the device. String descriptors are generally optional to save memory and are encoded in a unicode format. 22.10.7 BUS SPEED Each USB device must indicate its bus presence and speed to the host. This is accomplished through a 1.5 k resistor which is connected to the bus at the time of the attachment event. Depending on the speed of the device, the resistor either pulls up the D+ or D- line to 3.3V. For a low-speed device, the pull-up resistor is connected to the D- line. For a full-speed device, the pull-up resistor is connected to the D+ line. 22.10.8 CLASS SPECIFICATIONS AND DRIVERS USB specifications include class specifications which operating system vendors optionally support. Examples of classes include Audio, Mass Storage, Communications and Human Interface (HID). In most cases, a driver is required at the host side to ‘talk’ to the USB device. In custom applications, a driver may need to be developed. Fortunately, drivers are available for most common host systems for the most common classes of devices. Thus, these drivers can be reused. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 23.0 RESET The PIC18F/LF1XK50 devices differentiate between various kinds of Reset: a) b) c) d) e) f) g) h) Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during power-managed modes Watchdog Timer (WDT) Reset (during execution) Programmable Brown-out Reset (BOR) RESET Instruction Stack Full Reset Stack Underflow Reset 23.1 RCON Register Device Reset events are tracked through the RCON register (Register 23-1). The lower five bits of the register indicate that a specific Reset event has occurred. In most cases, these bits can only be cleared by the event and must be set by the application after the event. The state of these flag bits, taken together, can be read to indicate the type of Reset that just occurred. This is described in more detail in Section 23.6 “Reset State of Registers”. This section discusses Resets generated by MCLR, POR and BOR and covers the operation of the various start-up timers. Stack Reset events are covered in Section 3.1.2.4 “Stack Full and Underflow Resets”. WDT Resets are covered in Section 24.2 “Watchdog Timer (WDT)”. FIGURE 23-1: A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 23-1. The RCON register also has control bits for setting interrupt priority (IPEN) and software control of the BOR (SBOREN). Interrupt priority is discussed in Section 7.0 “Interrupts”. BOR is covered in Section 23.4 “Brown-out Reset (BOR)”. SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT RESET Instruction Stack Full/Underflow Reset Stack Pointer External Reset MCLRE MCLR ( )_IDLE Sleep WDT Time-out VDD Rise Detect POR Pulse VDD Brown-out Reset S BOREN OST/PWRT OST(2) 1024 Cycles Chip_Reset 10-bit Ripple Counter R OSC1 32 s LFINTOSC Q PWRT(2) 65.5 ms 11-bit Ripple Counter Enable PWRT Enable OST(1) Note 1: 2: See Table 23-2 for time-out situations. PWRT and OST counters are reset by POR and BOR. See Sections 23.3 and 23.4. 2010 Microchip Technology Inc. Preliminary DS41350D-page 279 PIC18F/LF1XK50 REGISTER 23-1: R/W-0 IPEN RCON: RESET CONTROL REGISTER R/W-1 SBOREN U-0 (1) — R/W-1 RI R-1 TO R-1 R/W-0 PD (2) R/W-0 POR bit 7 BOR bit 0 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 bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts bit 6 SBOREN: BOR Software Enable bit(1) If BOREN<1:0> = 01: 1 = BOR is enabled 0 = BOR is disabled If BOREN<1:0> = 00, 10 or 11: Bit is disabled and read as ‘0’. bit 5 Unimplemented: Read as ‘0’ bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware or Power-on Reset) 0 = The RESET instruction was executed causing a device Reset (must be set in firmware after a code-executed Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Set by execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit(2) 1 = No Power-on Reset 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(3) 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set by firmware after a POR or Brown-out Reset occurs) Note 1: 2: 3: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’. The actual Reset value of POR is determined by the type of device Reset. See the notes following this register and Section 23.6 “Reset State of Registers” for additional information. See Table 23-3. DS41350D-page 280 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 23.2 Master Clear (MCLR) FIGURE 23-2: The MCLR pin provides a method for triggering an external Reset of the device. A Reset is generated by holding the pin low. These devices have a noise filter in the MCLR Reset path which detects and ignores small pulses. In PIC18F/LF1XK50 devices, the MCLR input can be disabled with the MCLRE Configuration bit. When MCLR is disabled, the pin becomes a digital input. See Section 9.1 “PORTA, TRISA and LATA Registers” for more information. 23.3 VDD VDD The MCLR pin is not driven low by any internal Resets, including the WDT. EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) D PIC® MCU R R1 MCLR C 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 k is recommended to make sure that the voltage drop across R does not violate the device’s electrical specification. 3: R1 1 k will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). Power-on Reset (POR) A Power-on Reset pulse is generated on-chip whenever VDD rises above a certain threshold. This allows the device to start in the initialized state when VDD is adequate for operation. To take advantage of the POR circuitry, tie the MCLR pin through a resistor (1 k to 10 k) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. When the device starts normal operation (i.e., exits the Reset condition), device operating parameters (voltage, 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. POR events are captured by the POR bit of the RCON register. The state of the bit is set to ‘0’ whenever a POR occurs; it does not change for any other Reset event. POR is not reset to ‘1’ by any hardware event. To capture multiple events, the user must manually set the bit to ‘1’ by software following any POR. 2010 Microchip Technology Inc. Preliminary DS41350D-page 281 PIC18F/LF1XK50 23.4 Brown-out Reset (BOR) 23.4.1 PIC18F/LF1XK50 devices implement a BOR circuit that provides the user with a number of configuration and power-saving options. The BOR is controlled by the BORV<1:0> and BOREN<1:0> bits of the CONFIG2L Configuration register. There are a total of four BOR configurations which are summarized in Table 23-1. The BOR threshold is set by the BORV<1:0> bits. If BOR is enabled (any values of BOREN<1:0>, except ‘00’), any drop of VDD below VBOR for greater than TBOR will reset the device. A Reset may or may not occur if VDD falls below VBOR for less than TBOR. The chip will remain in Brown-out Reset until VDD rises above VBOR. If the Power-up Timer is enabled, it will be invoked after VDD rises above VBOR; it then will keep the chip in Reset for an additional time delay, TPWRT. If VDD drops below VBOR while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above VBOR, the Power-up Timer will execute the additional time delay. BOR and the Power-on Timer (PWRT) are independently configured. Enabling BOR Reset does not automatically enable the PWRT. SOFTWARE ENABLED BOR When BOREN<1:0> = 01, the BOR can be enabled or disabled by the user in software. This is done with the SBOREN control bit of the RCON register. Setting SBOREN enables the BOR to function as previously described. Clearing SBOREN disables the BOR entirely. The SBOREN bit operates only in this mode; otherwise it is read as ‘0’. Placing the BOR under software control gives the user the additional flexibility of tailoring the application to its environment without having to reprogram the device to change BOR configuration. It also allows the user to tailor device power consumption in software by eliminating the incremental current that the BOR consumes. While the BOR current is typically very small, it may have some impact in low-power applications. Note: 23.4.2 Even when BOR is under software control, the BOR Reset voltage level is still set by the BORV<1:0> Configuration bits. It cannot be changed by software. DETECTING BOR When BOR is enabled, the BOR bit always resets to ‘0’ on any BOR or POR event. This makes it difficult to determine if a BOR event has occurred just by reading the state of BOR alone. A more reliable method is to simultaneously check the state of both POR and BOR. This assumes that the POR and BOR bits are reset to ‘1’ by software immediately after any POR event. If BOR is ‘0’ while POR is ‘1’, it can be reliably assumed that a BOR event has occurred. 23.4.3 DISABLING BOR IN SLEEP MODE When BOREN<1:0> = 10, the BOR remains under hardware control and operates as previously described. Whenever the device enters Sleep mode, however, the BOR is automatically disabled. When the device returns to any other operating mode, BOR is automatically re-enabled. This mode allows for applications to recover from brown-out situations, while actively executing code, when the device requires BOR protection the most. At the same time, it saves additional power in Sleep mode by eliminating the small incremental BOR current. TABLE 23-1: BOR CONFIGURATIONS BOR Configuration BOREN1 BOREN0 Status of SBOREN (RCON<6>) 0 0 Unavailable 0 1 Available 1 0 Unavailable BOR enabled by hardware in Run and Idle modes, disabled during Sleep mode. 1 1 Unavailable BOR enabled by hardware; must be disabled by reprogramming the Configuration bits. DS41350D-page 282 BOR Operation BOR disabled; must be enabled by reprogramming the Configuration bits. BOR enabled by software; operation controlled by SBOREN. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 23.5 Device Reset Timers 23.5.2 OSCILLATOR START-UP TIMER (OST) PIC18F/LF1XK50 devices incorporate three separate on-chip timers that help regulate the Power-on Reset process. Their main function is to ensure that the device clock is stable before code is executed. These timers are: The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over. This ensures that the crystal oscillator or resonator has started and stabilized. • Power-up Timer (PWRT) • Oscillator Start-up Timer (OST) • PLL Lock Time-out The OST time-out is invoked only for XT, LP, HS and HSPLL modes and only on Power-on Reset, or on exit from all power-managed modes that stop the external oscillator. 23.5.1 POWER-UP TIMER (PWRT) 23.5.3 The Power-up Timer (PWRT) of PIC18F/LF1XK50 devices is an 11-bit counter which uses the LFINTOSC source as the clock input. This yields an approximate time interval of 2048 x 32 s = 65.6 ms. While the PWRT is counting, the device is held in Reset. The power-up time delay depends on the LFINTOSC clock and will vary from chip-to-chip due to temperature and process variation. See Section 27.0 “Electrical Specifications” for details. The PWRT is enabled by clearing the PWRTEN Configuration bit. PLL LOCK TIME-OUT With the PLL enabled in its PLL mode, the time-out sequence following a Power-on Reset is slightly different from other oscillator modes. A separate timer is used to provide 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. 23.5.4 TIME-OUT SEQUENCE On power-up, the time-out sequence is as follows: 1. 2. After the POR pulse has cleared, PWRT time-out is invoked (if enabled). Then, the OST is activated. The total time-out will vary based on oscillator configuration and the status of the PWRT. Figure 23-3, Figure 23-4, Figure 23-5, Figure 23-6 and Figure 23-7 all depict time-out sequences on power-up, with the Power-up Timer enabled and the device operating in HS Oscillator mode. Figures 23-3 through 23-6 also apply to devices operating in XT or LP modes. For devices in RC mode and with the PWRT disabled, on the other hand, there will be no time-out at all. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, all time-outs will expire, after which, bringing MCLR high will allow program execution to begin immediately (Figure 23-5). This is useful for testing purposes or to synchronize more than one PIC18F1XK50/PIC18LF1XK50 device operating in parallel. TABLE 23-2: TIME-OUT IN VARIOUS SITUATIONS Power-up(2) and Brown-out Oscillator Configuration HSPLL PWRTEN = 1 Exit from Power-Managed Mode 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) PWRTEN = 0 66 ms(1) + 1024 TOSC + 2 ms(2) HS, XT, LP 66 ms(1) + 1024 TOSC 1024 TOSC 1024 TOSC EC, ECIO 66 ms(1) — — RC, RCIO 66 ms(1) — — INTIO1, INTIO2 66 ms(1) — — Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay. 2: 2 ms is the nominal time required for the PLL to lock. 2010 Microchip Technology Inc. Preliminary DS41350D-page 283 PIC18F/LF1XK50 FIGURE 23-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT) VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET FIGURE 23-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET FIGURE 23-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET DS41350D-page 284 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 23-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT) 5V VDD 0V MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET TIME-OUT SEQUENCE ON POR W/PLL ENABLED (MCLR TIED TO VDD) FIGURE 23-7: VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT TPLL PLL TIME-OUT INTERNAL RESET Note: TOST = 1024 clock cycles. TPLL 2 ms max. First three stages of the PWRT timer. 2010 Microchip Technology Inc. Preliminary DS41350D-page 285 PIC18F/LF1XK50 23.6 Reset State of Registers Some registers are unaffected by a Reset. Their status is unknown on POR and unchanged by all other Resets. All other registers are forced to a “Reset state” depending on the type of Reset that occurred. Table 23-4 describes the Reset states for all of the Special Function Registers. These are categorized by Power-on and Brown-out Resets, Master Clear and WDT Resets and WDT wake-ups. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. 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 23-3. These bits are used by software to determine the nature of the Reset. TABLE 23-3: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER Condition Program Counter RCON Register SBOREN RI TO PD STKPTR Register POR BOR STKFUL STKUNF Power-on Reset 0000h 1 1 1 1 0 0 0 0 RESET Instruction 0000h u(2) 0 u u u u u u Brown-out Reset 0000h (2) u 1 1 1 u 0 u u MCLR during Power-Managed Run Modes 0000h u(2) u 1 u u u u u MCLR during Power-Managed Idle Modes and Sleep Mode 0000h u(2) u 1 0 u u u u WDT Time-out during Full Power or Power-Managed Run Mode 0000h u(2) u 0 u u u u u MCLR during Full Power Execution 0000h u(2) u u u u u u u Stack Full Reset (STVREN = 1) 0000h u(2) u u u u u 1 u Stack Underflow Reset (STVREN = 1) 0000h u(2) u u u u u u 1 Stack Underflow Error (not an actual Reset, STVREN = 0) 0000h u(2) u u u u u u 1 WDT Time-out during Power-Managed Idle or Sleep Modes PC + 2 u(2) u 0 0 u u u u PC + 2(1) u(2) u u 0 u u u u Interrupt Exit from Power-Managed Modes Legend: u = unchanged 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 (008h or 0018h). 2: Reset state is ‘1’ for POR and unchanged for all other Resets when software BOR is enabled (BOREN<1:0> Configuration bits = 01 and SBOREN = 1). Otherwise, the Reset state is ‘0’. DS41350D-page 286 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 23-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS Address Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets TOSU FFFh ---0 0000 ---0 0000 ---0 uuuu(3) TOSH FFEh 0000 0000 0000 0000 uuuu uuuu(3) TOSL FFDh 0000 0000 0000 0000 uuuu uuuu(3) STKPTR FFCh 00-0 0000 uu-0 0000 uu-u uuuu(3) PCLATU FFBh ---0 0000 ---0 0000 ---u uuuu PCLATH FFAh 0000 0000 0000 0000 uuuu uuuu PCL FF9h 0000 0000 0000 0000 TBLPTRU FF8h ---0 0000 ---0 0000 ---u uuuu TBLPTRH FF7h 0000 0000 0000 0000 uuuu uuuu TBLPTRL FF6h 0000 0000 0000 0000 uuuu uuuu TABLAT FF5h 0000 0000 0000 0000 uuuu uuuu PRODH FF4h xxxx xxxx uuuu uuuu uuuu uuuu PRODL FF3h xxxx xxxx uuuu uuuu uuuu uuuu INTCON FF2h 0000 000x 0000 000u uuuu uuuu(1) INTCON2 FF1h 1111 -1-1 1111 -1-1 uuuu -u-u(1) INTCON3 FF0h 11-0 0-00 11-0 0-00 uu-u u-uu(1) INDF0 FEFh N/A N/A N/A POSTINC0 FEEh N/A N/A N/A POSTDEC0 FEDh N/A N/A N/A PREINC0 Register Wake-up via WDT or Interrupt PC + 2(2) FECh N/A N/A N/A PLUSW0 FEBh N/A N/A N/A FSR0H FEAh ---- 0000 ---- 0000 ---- uuuu FSR0L FE9h xxxx xxxx uuuu uuuu uuuu uuuu WREG FE8h xxxx xxxx uuuu uuuu uuuu uuuu INDF1 FE7h N/A N/A N/A POSTINC1 FE6h N/A N/A N/A POSTDEC1 FE5h N/A N/A N/A PREINC1 FE4h N/A N/A N/A PLUSW1 FE3h N/A N/A N/A Legend: Note 1: 2: 3: 4: 5: 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. One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 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). 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. See Table 23-3 for Reset value for specific condition. All bits of the ANSELH register initialize to ‘0’ if the PBADEN bit of CONFIG3H is ‘0’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 287 PIC18F/LF1XK50 TABLE 23-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Address Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt FSR1H FE2h ---- 0000 ---- 0000 ---- uuuu FSR1L FE1h xxxx xxxx uuuu uuuu uuuu uuuu BSR FE0h ---- 0000 ---- 0000 ---- uuuu INDF2 FDFh N/A N/A N/A POSTINC2 FDEh N/A N/A N/A POSTDEC2 FDDh N/A N/A N/A PREINC2 FDCh N/A N/A N/A PLUSW2 Register FDBh N/A N/A N/A FSR2H FDAh ---- 0000 ---- 0000 ---- uuuu FSR2L FD9h xxxx xxxx uuuu uuuu uuuu uuuu STATUS FD8h ---x xxxx ---u uuuu ---u uuuu TMR0H FD7h 0000 0000 0000 0000 uuuu uuuu TMR0L FD6h xxxx xxxx uuuu uuuu uuuu uuuu T0CON FD5h 1111 1111 1111 1111 uuuu uuuu OSCCON FD3h 0011 qq00 0011 qq00 uuuu uuuu OSCCON2 FD2h ---- -10x ---- -10x ---- -uuu WDTCON FD1h ---- ---0 ---- ---0 ---- ---u RCON(4) FD0h 0q-1 11q0 0q-q qquu uq-u qquu TMR1H FCFh xxxx xxxx uuuu uuuu uuuu uuuu TMR1L FCEh xxxx xxxx uuuu uuuu uuuu uuuu T1CON FCDh 0000 0000 u0uu uuuu uuuu uuuu TMR2 FCCh 0000 0000 0000 0000 uuuu uuuu PR2 FCBh 1111 1111 1111 1111 1111 1111 T2CON FCAh -000 0000 -000 0000 -uuu uuuu SSPBUF FC9h xxxx xxxx uuuu uuuu uuuu uuuu SSPADD FC8h 0000 0000 0000 0000 uuuu uuuu SSPSTAT FC7h 0000 0000 0000 0000 uuuu uuuu SSPCON1 FC6h 0000 0000 0000 0000 uuuu uuuu SSPCON2 FC5h 0000 0000 0000 0000 uuuu uuuu Legend: Note 1: 2: 3: 4: 5: 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. One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 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). 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. See Table 23-3 for Reset value for specific condition. All bits of the ANSELH register initialize to ‘0’ if the PBADEN bit of CONFIG3H is ‘0’. DS41350D-page 288 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 23-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Address Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt ADRESH FC4h xxxx xxxx uuuu uuuu uuuu uuuu ADRESL FC3h xxxx xxxx uuuu uuuu uuuu uuuu ADCON0 FC2h --00 0000 --00 0000 --uu uuuu ADCON1 FC1h ---- 0000 ---- 0000 ---- uuuu ADCON2 FC0h 0-00 0000 0-00 0000 u-uu uuuu CCPR1H FBFh xxxx xxxx uuuu uuuu uuuu uuuu CCPR1L FBEh xxxx xxxx uuuu uuuu uuuu uuuu CCP1CON Register FBDh 0000 0000 0000 0000 uuuu uuuu REFCON2 FBCh ---0 0000 ---0 0000 ---u uuuu REFCON1 FBBh 000- 00-0 000- 00-0 uuu- uu-u REFCON0 FBAh 0001 00-- 0001 00-- uuuu uu-- PSTRCON FB9h ---0 0001 ---0 0001 ---u uuuu BAUDCON FB8h 0100 0-00 0100 0-00 uuuu u-uu PWM1CON FB7h 0000 0000 0000 0000 uuuu uuuu ECCP1AS FB6h 0000 0000 0000 0000 uuuu uuuu TMR3H FB3h xxxx xxxx uuuu uuuu uuuu uuuu TMR3L FB2h xxxx xxxx uuuu uuuu uuuu uuuu T3CON FB1h 0000 0000 uuuu uuuu uuuu uuuu SPBRGH FB0h 0000 0000 0000 0000 uuuu uuuu SPBRG FAFh 0000 0000 0000 0000 uuuu uuuu RCREG FAEh 0000 0000 0000 0000 uuuu uuuu TXREG FADh 0000 0000 0000 0000 uuuu uuuu TXSTA FACh 0000 0010 0000 0010 uuuu uuuu RCSTA FABh 0000 000x 0000 000x uuuu uuuu EEADR FAAh 0000 0000 0000 0000 uuuu uuuu EEDATA FA8h 0000 0000 0000 0000 uuuu uuuu EECON2 FA7h 0000 0000 0000 0000 0000 0000 EECON1 FA6h xx-0 x000 uu-0 u000 uu-0 u000 Legend: Note 1: 2: 3: 4: 5: 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. One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 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). 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. See Table 23-3 for Reset value for specific condition. All bits of the ANSELH register initialize to ‘0’ if the PBADEN bit of CONFIG3H is ‘0’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 289 PIC18F/LF1XK50 TABLE 23-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Address Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt IPR2 FA2h 1111 111- 1111 111- uuuu uuu- PIR2 FA1h 0000 000- 0000 000- uuuu uuu-(1) PIE2 FA0h 0000 000- 0000 000- uuuu uuu- IPR1 F9Fh -111 1111 -111 1111 -uuu uuuu PIR1 F9Eh -000 0000 -000 0000 -uuu uuuu(1) PIE1 F9Dh -000 0000 -000 0000 -uuu uuuu OSCTUNE F9Bh 0000 0000 0000 0000 uuuu uuuu TRISC Register F95h 1111 1111 1111 1111 uuuu uuuu TRISB F94h 1111 ---- 1111 ---- uuuu ---- TRISA F93h LATC F8Bh xxxx xxxx uuuu uuuu uuuu uuuu LATB F8Ah xxxx ---- uuuu ---- uuuu ---- LATA F89h PORTC F82h xxxx xxxx uuuu uuuu uuuu uuuu PORTB F81h xxxx ---- uuuu ---- uuuu ---- PORTA F80h ANSELH(5) F7Fh ---- 1111 ---- 1111 ---- uuuu ANSEL F7Eh 1111 1--- 1111 1--- uuuu u--- IOCB F7Ah 0000 ---- 0000 ---- uuuu ---- IOCA F79h --00 0-00 --00 0-00 --uu u-uu WPUB F78h 1111 ---- 1111 ---- uuuu ---- WPUA F77h --11 1--- --11 1--- --uu u--- SLRCON F76h ---- -111 ---- -111 ---- -uuu SSPMSK --11 ---- --xx ---- --xx x-xx --11 ---- --uu ---- --xx x-xx --uu ---- --uu ---- --uu u-uu F6Fh 1111 1111 1111 1111 uuuu uuuu CM1CON0 F6Dh 0000 0000 0000 0000 uuuu uuuu CM2CON1 F6Ch 0000 0000 0000 0000 uuuu uuuu CM2CON0 F6Bh 0000 0000 0000 0000 uuuu uuuu SRCON1 F69h 0000 0000 0000 0000 uuuu uuuu SRCON0 F68h 0000 0000 0000 0000 uuuu uuuu UCON F64h -0x0 000- -0x0 000- -uuu uuu- Legend: Note 1: 2: 3: 4: 5: 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. One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 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). 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. See Table 23-3 for Reset value for specific condition. All bits of the ANSELH register initialize to ‘0’ if the PBADEN bit of CONFIG3H is ‘0’. DS41350D-page 290 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 23-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Address Power-on Reset, Brown-out Reset MCLR Resets, WDT Reset, RESET Instruction, Stack Resets Wake-up via WDT or Interrupt USTAT F63h -xxx xxx- -xxx xxx- -uuu uuu- UIR F62h -000 0000 -000 0000 -uuu uuuu UCFG F61h 0--0 -000 0--0 -000 u--u -uuu UIE F60h -000 0000 -000 0000 -uuu uuuu UEIR F5Fh 0--0 0000 0--0 0000 u--u uuuu UFRMH F5Eh ---- -xxx ---- -xxx ---- -uuu UFRML F5Dh xxxx xxxx xxxx xxxx uuuu uuuu UADDR Register F5Ch -000 0000 -000 0000 -uuu uuuu UEIE F5Bh 0--0 0000 0--0 0000 u--u uuuu UEP7 F5Ah ----0 0000 ----0 0000 ----u uuuu UEP6 F59h ----0 0000 ----0 0000 ----u uuuu UEP5 F58h ----0 0000 ----0 0000 ----u uuuu UEP4 F57h ----0 0000 ----0 0000 ----u uuuu UEP3 F56h ----0 0000 ----0 0000 ----u uuuu UEP2 F55h ----0 0000 ----0 0000 ----u uuuu UEP1 F54h ----0 0000 ----0 0000 ----u uuuu UEP0 F53h ----0 0000 ----0 0000 ----u uuuu Legend: Note 1: 2: 3: 4: 5: 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. One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 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). 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. See Table 23-3 for Reset value for specific condition. All bits of the ANSELH register initialize to ‘0’ if the PBADEN bit of CONFIG3H is ‘0’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 291 PIC18F/LF1XK50 NOTES: DS41350D-page 292 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 24.0 SPECIAL FEATURES OF THE CPU PIC18F/LF1XK50 devices include several features intended to maximize reliability and minimize cost through elimination of external components. These are: • Oscillator Selection • Resets: - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) • Interrupts • Watchdog Timer (WDT) • Code Protection • ID Locations • In-Circuit Serial Programming™ The oscillator can be configured for the application depending on frequency, power, accuracy and cost. All of the options are discussed in detail in Section 2.0 “Oscillator Module”. A complete discussion of device Resets and interrupts is available in previous sections of this data sheet. In addition to their Power-up and Oscillator Start-up Timers provided for Resets, PIC18F/LF1XK50 devices have a Watchdog Timer, which is either permanently enabled via the Configuration bits or software controlled (if configured as disabled). The inclusion of an internal RC oscillator also provides the additional benefits of a Fail-Safe Clock Monitor (FSCM) and Two-Speed Start-up. FSCM provides for background monitoring of the peripheral clock and automatic switchover in the event of its failure. TwoSpeed Start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. All of these features are enabled and configured by setting the appropriate Configuration register bits. 2010 Microchip Technology Inc. Preliminary DS41350D-page 293 PIC18F/LF1XK50 24.1 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. The WR bit in the EECON1 register starts a self-timed write to the Configuration register. In normal operation mode, a TBLWT instruction with the TBLPTR pointing to the Configuration register sets up the address and the data for the Configuration register write. Setting the WR bit starts a long write to the Configuration register. The Configuration registers are written a byte at a time. To write or erase a configuration cell, a TBLWT instruction can write a ‘1’ or a ‘0’ into the cell. For additional details on Flash programming, refer to Section 4.5 “Writing to Flash Program Memory”. TABLE 24-1: CONFIGURATION BITS AND DEVICE IDs File Name Bit 7 Bit 6 Bit 5 300000h CONFIG1L — — 300001h CONFIG1H IESO FCMEN PCLKEN Bit 4 Bit 3 USBDIV CPUDIV1 CPUDIV0 PLLEN FOSC3 Bit 2 Bit 1 Bit 0 Default/ Unprogrammed Value — — — --00 0--- FOSC2 FOSC1 FOSC0 0010 0111 300002h CONFIG2L — — — BORV1 BORV0 300003h CONFIG2H — — — WDTPS3 WDTPS2 BOREN1 300005h CONFIG3H MCLRE — — — HFOFST — 300006h CONFIG4L BKBUG(2) ENHCPU — — BBSIZ 300008h CONFIG5L — — — — — 300009h CONFIG5H CPD CPB — — BOREN0 PWRTEN WDTPS1 WDTPS0 ---1 1111 WDTEN ---1 1111 — — 1--- 1--- LVP — STVREN -0-- 01-1 — CP1 CP0 ---- --11 — — — — 11-- ------- --11 30000Ah CONFIG6L — — — — — — WRT1 WRT0 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 111- ---- 30000Ch CONFIG7L — — — — — — EBTR1 EBTR0 ---- --11 30000Dh CONFIG7H — EBTRB — — — — — — -1-- ---- DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 qqqq qqqq(1) DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0000 1100 3FFFFEh DEVID1 3FFFFFh Legend: Note 1: 2: (1) DEVID2(1) x = unknown, u = unchanged, – = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as ‘0’ See Register 24-13 for DEVID1 values. DEVID registers are read-only and cannot be programmed by the user. BKBUG is only used for the ICD device. Otherwise, this bit is unimplemented and reads as ‘1’. DS41350D-page 294 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 24-1: CONFIG1L: CONFIGURATION REGISTER 1 LOW U-0 U-0 R/P-0 R/P-0 R/P-0 U-0 U-0 U-0 — — USBDIV CPUDIV1 CPUDIV0 — — — bit 7 bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7-6 Unimplemented: Read as ‘0’ bit 5 USBDIV: USB Clock Selection bit Selects the clock source for Low-speed USB operation 1 = USB clock comes from the OSC1/OSC2 divided by 2 0 = USB clock comes directly from the OSC1/OSC2 Oscillator block; no divide bit 4-3 CPUDIV<1:0>: CPU System Clock Selection bits 11 = CPU system clock divided by 4 10 = CPU system clock divided by 3 01 = CPU system clock divided by 2 00 = No CPU system clock divide bit 2-0 Unimplemented: Read as ‘0’ 2010 Microchip Technology Inc. Preliminary DS41350D-page 295 PIC18F/LF1XK50 REGISTER 24-2: CONFIG1H: CONFIGURATION REGISTER 1 HIGH R/P-0 R/P-0 R/P-1 R/P-0 R/P-0 R/P-1 R/P-1 R/P-1 IESO FCMEN PCLKEN PLLEN FOSC3 FOSC2 FOSC1 FOSC0 bit 7 bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7 IESO: Internal/External Oscillator Switchover bit 1 = Oscillator Switchover mode enabled 0 = Oscillator Switchover mode disabled bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor enabled 0 = Fail-Safe Clock Monitor disabled bit 5 PCLKEN: Primary Clock Enable bit 1 = Primary Clock enabled 0 = Primary Clock is under software control bit 4 PLLEN: 4 X PLL Enable bit 1 = Oscillator multiplied by 4 0 = PLL is under software control bit 3-0 FOSC<3:0>: Oscillator Selection bits 1111 = External RC oscillator, CLKOUT function on OSC2 1110 = External RC oscillator, CLKOUT function on OSC2 1101 = EC (low) 1100 = EC, CLKOUT function on OSC2 (low) 1011 = EC (medium) 1010 = EC, CLKOUT function on OSC2 (medium) 1001 = Internal RC oscillator, CLKOUT function on OSC2 1000 = Internal RC oscillator 0111 = External RC oscillator 0110 = External RC oscillator, CLKOUT function on OSC2 0101 = EC (high) 0100 = EC, CLKOUT function on OSC2 (high) 0011 = External RC oscillator, CLKOUT function on OSC2 0010 = HS oscillator 0001 = XT oscillator 0000 = LP oscillator DS41350D-page 296 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 24-3: U-0 CONFIG2L: CONFIGURATION REGISTER 2 LOW U-0 — — U-0 — R/P-1 BORV1 R/P-1 (1) BORV0 (1) R/P-1 BOREN1 R/P-1 (2) R/P-1 BOREN0 bit 7 (2) PWRTEN(2) bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7-5 Unimplemented: Read as ‘0’ bit 4-3 BORV<1:0>: Brown-out Reset Voltage bits(1) 11 = VBOR set to 1.9V nominal 10 = VBOR set to 2.2V nominal 01 = VBOR set to 2.7V nominal 00 = VBOR set to 3.0V nominal bit 2-1 BOREN<1:0>: Brown-out Reset Enable bits(2) 11 = Brown-out Reset enabled in hardware only (SBOREN is disabled) 10 = Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled) 01 = Brown-out Reset enabled and controlled by software (SBOREN is enabled) 00 = Brown-out Reset disabled in hardware and software bit 0 PWRTEN: Power-up Timer Enable bit(2) 1 = PWRT disabled 0 = PWRT enabled Note 1: 2: See Table 27-5 for specifications. The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently controlled. 2010 Microchip Technology Inc. Preliminary DS41350D-page 297 PIC18F/LF1XK50 REGISTER 24-4: CONFIG2H: CONFIGURATION REGISTER 2 HIGH U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN bit 7 bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7-5 Unimplemented: Read as ‘0’ bit 4-1 WDTPS<3:0>: Watchdog Timer Postscale Select bits 1111 = 1:32,768 1110 = 1:16,384 1101 = 1:8,192 1100 = 1:4,096 1011 = 1:2,048 1010 = 1:1,024 1001 = 1:512 1000 = 1:256 0111 = 1:128 0110 = 1:64 0101 = 1:32 0100 = 1:16 0011 = 1:8 0010 = 1:4 0001 = 1:2 0000 = 1:1 bit 0 WDTEN: Watchdog Timer Enable bit 1 = WDT is always enabled. SWDTEN bit has no effect 0 = WDT is controlled by SWDTEN bit of the WDTCON register DS41350D-page 298 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 24-5: CONFIG3H: CONFIGURATION REGISTER 3 HIGH R/P-1 U-0 U-0 U-0 R/P-1 U-0 U-0 U-0 MCLRE — — — HFOFST — — — bit 7 bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7 MCLRE: MCLR Pin Enable bit 1 = MCLR pin enabled; RA3 input pin disabled 0 = RA3 input pin enabled; MCLR disabled bit 6-4 Unimplemented: Read as ‘0’ bit 3 HFOFST: HFINTOSC Fast Start-up bit 1 = HFINTOSC starts clocking the CPU without waiting for the oscillator to stabilize. 0 = The system clock is held off until the HFINTOSC is stable. bit 2-0 Unimplemented: Read as ‘0’ REGISTER 24-6: CONFIG4L: CONFIGURATION REGISTER 4 LOW R/W-1(1) R/W-0 U-0 U-0 R/P-0 R/P-1 U-0 R/P-1 BKBUG ENHCPU — — BBSIZ LVP — STVREN bit 7 bit 0 Legend: R = Readable bit P = Programmable bit -n = Value when device is unprogrammed U = Unimplemented bit, read as ‘0’ x = Bit is unknown bit 7 BKBUG: Background Debugger Enable bit(1) 1 = Background debugger disabled 0 = Background debugger functions enabled bit 6 ENHCPU: Enhanced CPU Enable bit 1 = Enhanced CPU enabled 0 = Enhanced CPU disabled bit 5-4 Unimplemented: Read as ‘0’ bit 3 BBSIZ: Boot BLock Size Select bit 1 = 2 kW boot block size for PIC18F14K50/PIC18LF14K50 (1 kW boot block size for PIC18F13K50/PIC18LF13K50) 0 = 1 kW boot block size for PIC18F14K50/PIC18LF14K50 (512 W boot block size for PIC18F13K50/PIC18LF13K50) bit 2 LVP: Single-Supply ICSP™ Enable bit 1 = Single-Supply ICSP enabled 0 = Single-Supply 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 Note 1: BKBUG is only used for the ICD device. Otherwise, this bit is unimplemented and reads as ‘1’. 2010 Microchip Technology Inc. Preliminary DS41350D-page 299 PIC18F/LF1XK50 REGISTER 24-7: CONFIG5L: CONFIGURATION REGISTER 5 LOW U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1 — — — — — — CP1 CP0 bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7-2 Unimplemented: Read as ‘0’ bit 1 CP1: Code Protection bit 1 = Block 1 not code-protected 0 = Block 1 code-protected bit 0 CP0: Code Protection bit 1 = Block 0 not code-protected 0 = Block 0 code-protected REGISTER 24-8: R/C-1 CPD CONFIG5H: CONFIGURATION REGISTER 5 HIGH R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 CPB — — — — — — bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit 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 not code-protected 0 = Boot block code-protected bit 5-0 Unimplemented: Read as ‘0’ DS41350D-page 300 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 24-9: CONFIG6L: CONFIGURATION REGISTER 6 LOW U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1 — — — — — — WRT1 WRT0 bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7-2 Unimplemented: Read as ‘0’ bit 1 WRT1: Write Protection bit 1 = Block 1 not write-protected 0 = Block 1 write-protected bit 0 WRT0: Write Protection bit 1 = Block 0 not write-protected 0 = Block 0 write-protected REGISTER 24-10: CONFIG6H: CONFIGURATION REGISTER 6 HIGH R/C-1 R/C-1 R-1 U-0 U-0 U-0 U-0 U-0 WRTD WRTB WRTC(1) — — — — — bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit 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 not write-protected 0 = Boot block write-protected bit 5 WRTC: Configuration Register Write Protection bit(1) 1 = Configuration registers not write-protected 0 = Configuration registers write-protected bit 4-0 Unimplemented: Read as ‘0’ Note 1: This bit is read-only in normal execution mode; it can be written only in Program mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 301 PIC18F/LF1XK50 REGISTER 24-11: CONFIG7L: CONFIGURATION REGISTER 7 LOW U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1 — — — — — — EBTR1 EBTR0 bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7-2 Unimplemented: Read as ‘0’ bit 1 EBTR1: Table Read Protection bit 1 = Block 1 not protected from table reads executed in other blocks 0 = Block 1 protected from table reads executed in other blocks bit 0 EBTR0: Table Read Protection bit 1 = Block 0 not protected from table reads executed in other blocks 0 = Block 0 protected from table reads executed in other blocks REGISTER 24-12: CONFIG7H: CONFIGURATION REGISTER 7 HIGH U-0 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0 — EBTRB — — — — — — bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7 Unimplemented: Read as ‘0’ bit 6 EBTRB: Boot Block Table Read Protection bit 1 = Boot block not protected from table reads executed in other blocks 0 = Boot block protected from table reads executed in other blocks bit 5-0 Unimplemented: Read as ‘0’ DS41350D-page 302 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REGISTER 24-13: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F1XK50/PIC18LF1XK50 R R R R R R R R DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7-5 DEV<2:0>: Device ID bits 010 = PIC18F13K50 011 = PIC18F14K50 bit 4-0 REV<4:0>: Revision ID bits These bits are used to indicate the device revision. REGISTER 24-14: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F1XK50/PIC18LF1XK50 R R R R R R R R DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 bit 7 bit 0 Legend: R = Readable bit U = Unimplemented bit, read as ‘0’ -n = Value when device is unprogrammed C = Clearable only bit bit 7-0 Note 1: DEV<10:3>: Device ID bits These bits are used with the DEV<2:0> bits in the Device ID Register 1 to identify the part number. 0010 0000 = PIC18F1XK50/PIC18LF1XK50 devices These values for DEV<10:3> may be shared with other devices. The specific device is always identified by using the entire DEV<10:0> bit sequence. 2010 Microchip Technology Inc. Preliminary DS41350D-page 303 PIC18F/LF1XK50 24.2 Watchdog Timer (WDT) For PIC18F/LF1XK50 devices, the WDT is driven by the LFINTOSC source. When the WDT is enabled, the clock source is also enabled. The nominal WDT period is 4 ms and has the same stability as the LFINTOSC oscillator. The 4 ms period of the WDT is multiplied by a 16-bit postscaler. Any output of the WDT postscaler is selected by a multiplexer, controlled by bits in Configuration Register 2H. Available periods range from 4 ms to 131.072 seconds (2.18 minutes). The WDT and postscaler are cleared when any of the following events occur: a SLEEP or CLRWDT instruction is executed, the IRCF bits of the OSCCON register are changed or a clock failure has occurred. Note 1: The CLRWDT and SLEEP instructions clear the WDT and postscaler counts when executed. 2: Changing the setting of the IRCF bits of the OSCCON register clears the WDT and postscaler counts. 3: When a CLRWDT instruction is executed, the postscaler count will be cleared. FIGURE 24-1: WDT BLOCK DIAGRAM SWDTEN WDTEN Enable WDT WDT Counter LFINTOSC Source Wake-up from Power Managed Modes 128 Change on IRCF bits Programmable Postscaler 1:1 to 1:32,768 CLRWDT Reset WDT Reset All Device Resets WDTPS<3:0> 4 Sleep DS41350D-page 304 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 24.2.1 CONTROL REGISTER Register 24-15 shows the WDTCON register. This is a readable and writable register which contains a control bit that allows software to override the WDT enable Configuration bit, but only if the Configuration bit has disabled the WDT. REGISTER 24-15: WDTCON: WATCHDOG TIMER CONTROL REGISTER U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 — — — — — — — SWDTEN(1) bit 7 bit 0 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 bit 7-1 Unimplemented: Read as ‘0’ bit 0 SWDTEN: Software Enable or Disable the Watchdog Timer bit(1) 1 = WDT is turned on 0 = WDT is turned off (Reset value) x = Bit is unknown Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled. TABLE 24-2: Name RCON WDTCON SUMMARY OF WATCHDOG TIMER REGISTERS Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 IPEN SBOREN — RI TO PD POR BOR 280 — — — — — — — SWDTEN 288 WDTEN 298 CONFIG2H WDTPS3 WDTPS2 WDTPS1 WDTPS0 Bit 0 Reset Values on page Bit 7 Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer. 24.3 Program Verification and Code Protection The overall structure of the code protection on the PIC18 Flash devices differs significantly from other PIC® microcontroller devices. Figure 24-2 shows the program memory organization for 8, 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 24-3. The user program memory is divided into five blocks. One of these is a boot block of 0.5K or 2K bytes, depending on the device. The remainder of the memory is divided into individual 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) 2010 Microchip Technology Inc. Preliminary DS41350D-page 305 PIC18F/LF1XK50 FIGURE 24-2: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F/LF1XK50 Device Address (from/to) 14K50 BBSIZ = 1 0000h 01FFh 13K50 BBSIZ = 0 BBSIZ = 1 BBSIZ = 0 Boot Block, 2 KW Boot Block, 1 KW Boot Block, 1 KW CPB, WRTB, EBTRB CPB, WRTB, EBTRB CPB, WRTB, EBTRB 0200h 03FFh Block 0 3 KW CP0, WRT0, EBTR0 0400h 05FFh 0600h Block 0 1 KW CP0, WRT0, EBTR0 Boot Block, 0.512 KW CPB, WRTB, EBTRB Block 0 1.512 KW CP0, WRT0, EBTR0 07FFh 0800h 0FFFh Block 0 2 KW CP0, WRT0, EBTR0 1000h 1FFFh Block 1 4 KW CP1, WRT1, EBTR1 Block 1 4 KW CP1, WRT1, EBTR1 2000h 27FFh Reads all ‘0’s Reads all ‘0’s Block 1 2 KW CP1, WRT1, EBTR1 Block 1 2 KW CP1, WRT1, EBTR1 Reads all ‘0’s Reads all ‘0’s 2800h 2FFFh 3000h 37FFh 3800h 3FFFh 4000h 47FFh 4800h 4FFFh 5000h 57FFh 5800h 5FFFh 6000h 67FFh 6800h 6FFFh 7000h 77FFh 7800h 7FFFh 8000h FFFFh Note: Refer to the test section for requirements on test memory mapping. DS41350D-page 306 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 24-3: SUMMARY OF CODE PROTECTION REGISTERS File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 300008h CONFIG5L — — — — — — CP1 CP0 300009h CONFIG5H CPD CPB — — — — — — 30000Ah CONFIG6L — — — — — — WRT1 WRT0 30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 30000Ch CONFIG7L — — — — — — EBTR1 EBTR0 30000Dh CONFIG7H — EBTRB — — — — — — Legend: Shaded cells are unimplemented. 24.3.1 PROGRAM MEMORY CODE PROTECTION The program memory may be read to or written from any location using the table read and table write instructions. 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. instruction that executes from a location outside of that block is not allowed to read and will result in reading ‘0’s. Figures 24-3 through 24-5 illustrate table write and table read protection. Note: In normal execution 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 cleared to ‘0’, a table READ instruction that executes from within that block is allowed to read. A table read FIGURE 24-3: 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 protection 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. TABLE WRITE (WRTn) DISALLOWED Register Values Program Memory Configuration Bit Settings 000000h 0007FFh 000800h TBLPTR = 0008FFh PC = 001FFEh WRTB, EBTRB = 11 WRT0, EBTR0 = 01 TBLWT* 001FFFh 002000h WRT1, EBTR1 = 11 003FFFh 004000h PC = 005FFEh WRT2, EBTR2 = 11 TBLWT* 005FFFh 006000h WRT3, EBTR3 = 11 007FFFh Results: All table writes disabled to Blockn whenever WRTn = 0. 2010 Microchip Technology Inc. Preliminary DS41350D-page 307 PIC18F/LF1XK50 FIGURE 24-4: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED Register Values Program Memory Configuration Bit Settings 000000h 0007FFh 000800h TBLPTR = 0008FFh WRTB, EBTRB = 11 WRT0, EBTR0 = 10 001FFFh 002000h PC = 003FFEh TBLRD* WRT1, EBTR1 = 11 003FFFh 004000h WRT2, EBTR2 = 11 005FFFh 006000h WRT3, EBTR3 = 11 007FFFh Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0. TABLAT register returns a value of ‘0’. FIGURE 24-5: EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED Register Values Program Memory Configuration Bit Settings 000000h 0007FFh 000800h TBLPTR = 0008FFh PC = 001FFEh WRTB, EBTRB = 11 WRT0, EBTR0 = 10 TBLRD* 001FFFh 002000h WRT1, EBTR1 = 11 003FFFh 004000h WRT2, EBTR2 = 11 005FFFh 006000h WRT3, EBTR3 = 11 007FFFh Results: Table reads permitted within Blockn, even when EBTRBn = 0. TABLAT register returns the value of the data at the location TBLPTR. DS41350D-page 308 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 24.3.2 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 internal and external writes to data EEPROM. The CPU can always read data EEPROM under normal operation, regardless of the protection bit settings. 24.3.3 ID Locations Eight memory locations (200000h-200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are both readable and writable 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. 24.5 In-Circuit Serial Programming PIC18F/LF1XK50 devices can be serially programmed 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. 24.6 • • • • • MCLR/VPP/RA3 VDD VSS RA0 RA1 This will interface to the In-Circuit Debugger module available from Microchip or one of the third party development tool companies. CONFIGURATION REGISTER PROTECTION The Configuration registers can be write-protected. The WRTC bit controls protection of the Configuration registers. In normal execution mode, the WRTC bit is readable only. WRTC can only be written via ICSP or an external programmer. 24.4 To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to the following pins: 24.7 The LVP Configuration bit enables Single-Supply ICSP Programming (formerly known as Low-Voltage ICSP Programming or LVP). When Single-Supply Programming is enabled, the microcontroller can be programmed without requiring high voltage being applied to the MCLR/VPP/RA3 pin, but the RC3/PGM pin is then dedicated to controlling Program mode entry and is not available as a general purpose I/O pin. While programming, using Single-Supply Programming mode, VDD is applied to the MCLR/VPP/RA3 pin as in normal execution mode. To enter Programming mode, VDD is applied to the PGM pin. Note 1: High-voltage programming is always available, regardless of the state of the LVP bit or the PGM pin, by applying VIHH to the MCLR pin. 2: By default, Single-Supply ICSP is enabled in unprogrammed devices (as supplied from Microchip) and erased devices. 3: When Single-Supply Programming is enabled, the RC3 pin can no longer be used as a general purpose I/O pin. 4: When LVP is enabled, externally pull the PGM pin to VSS to allow normal program execution. In-Circuit Debugger When the DEBUG Configuration bit 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 resources are not available for general use. Table 24-4 shows which resources are required by the background debugger. TABLE 24-4: DEBUGGER RESOURCES I/O pins: RA0, RA1 Stack: 2 levels Program Memory: 512 bytes Data Memory: 10 bytes 2010 Microchip Technology Inc. Single-Supply ICSP Programming If Single-Supply ICSP Programming mode will not be used, the LVP bit can be cleared. RC3/PGM then becomes available as the digital I/O pin, RC3. The LVP bit may be set or cleared only when using standard high-voltage programming (VIHH applied to the MCLR/ VPP/RA3 pin). Once LVP has been disabled, only the standard high-voltage programming is available and must be used to program the device. Memory that is not code-protected can be erased using either a block erase, or erased row by row, then written at any specified VDD. If code-protected memory is to be erased, a block erase is required. Preliminary DS41350D-page 309 PIC18F/LF1XK50 NOTES: DS41350D-page 310 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 25.0 INSTRUCTION SET SUMMARY PIC18F/LF1XK50 devices incorporate the standard set of 75 PIC18 core instructions, as well as an extended set of 8 new instructions, for the optimization of code that is recursive or that utilizes a software stack. The extended set is discussed later in this section. 25.1 Standard Instruction Set The standard PIC18 instruction set adds many enhancements to the previous PIC® MCU instruction sets, while maintaining an easy migration from these PIC® MCU instruction sets. Most instructions are a single program memory word (16 bits), but there are four 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 PIC18 instruction set summary in Table 25-2 lists byte-oriented, bit-oriented, literal and control operations. Table 25-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. 2. 3. The file register (specified by ‘f’) The destination of the result (specified by ‘d’) The accessed memory (specified by ‘a’) The file register designator ‘f’ specifies which file register is to be used by the instruction. 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. • 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 four double-word instructions. These instructions were made double-word to contain the required information in 32 bits. In the second word, the 4 MSbs are ‘1’s. If this second word is executed 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 instruction. 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 s. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Two-word branch instructions (if true) would take 3 s. Figure 25-1 shows the general formats that the instructions can have. All examples use the convention ‘nnh’ to represent a hexadecimal number. The Instruction Set Summary, shown in Table 25-2, lists the standard instructions recognized by the Microchip Assembler (MPASMTM). All bit-oriented instructions have three operands: 1. 2. 3. The literal instructions may use some of the following operands: The file register (specified by ‘f’) The bit in the file register (specified by ‘b’) The accessed memory (specified by ‘a’) Section 25.1.1 “Standard Instruction Set” provides a description of each instruction. The bit field designator ‘b’ selects the number of the bit affected by the operation, while the file register designator ‘f’ represents the number of the file in which the bit is located. 2010 Microchip Technology Inc. Preliminary DS41350D-page 311 PIC18F/LF1XK50 TABLE 25-1: OPCODE FIELD DESCRIPTIONS Field Description a RAM 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. C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative. d Destination 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. f 8-bit Register file address (00h to FFh) or 2-bit FSR designator (0h to 3h). fs 12-bit Register file address (000h to FFFh). This is the source address. fd 12-bit Register file address (000h to FFFh). This is the destination address. GIE Global Interrupt Enable bit. k Literal 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) +* n The relative address (2’s complement number) for relative branch instructions or the direct address for CALL/BRANCH and RETURN instructions. 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. PD Power-down bit. PRODH Product of Multiply High Byte. PRODL Product of Multiply Low Byte. s Fast 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) TBLPTR 21-bit Table Pointer (points to a Program Memory location). TABLAT 8-bit Table Latch. TO Time-out bit. TOS Top-of-Stack. u Unused or unchanged. WDT Watchdog Timer. WREG Working register (accumulator). x Don’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. zs 7-bit offset value for indirect addressing of register files (source). 7-bit offset value for indirect addressing of register files (destination). zd { } Optional argument. [text] Indicates an indexed address. (text) The contents of text. [expr]<n> Specifies bit n of the register indicated by the pointer expr. Assigned to. < > Register bit field. In the set of. italics User defined term (font is Courier). DS41350D-page 312 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 25-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 15 10 9 8 7 OPCODE d a Example Instruction 0 f (FILE #) ADDWF MYREG, W, B d = 0 for result destination to be WREG register d = 1 for result destination to be file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Byte to Byte move operations (2-word) 15 12 11 OPCODE 15 0 f (Source FILE #) 12 11 MOVFF MYREG1, MYREG2 0 f (Destination FILE #) 1111 f = 12-bit file register address Bit-oriented file register operations 15 12 11 9 8 7 OPCODE b (BIT #) a 0 BSF MYREG, bit, B f (FILE #) b = 3-bit position of bit in file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Literal operations 15 8 7 OPCODE 0 k (literal) MOVLW 7Fh k = 8-bit immediate value Control operations CALL, GOTO and Branch operations 15 8 7 OPCODE 15 0 n<7:0> (literal) 12 11 GOTO Label 0 n<19:8> (literal) 1111 n = 20-bit immediate value 15 8 7 OPCODE 15 S 0 CALL MYFUNC n<7:0> (literal) 12 11 0 n<19:8> (literal) 1111 S = Fast bit 15 OPCODE 15 OPCODE 2010 Microchip Technology Inc. 11 10 0 BRA MYFUNC n<10:0> (literal) 8 7 0 n<7:0> (literal) Preliminary BC MYFUNC DS41350D-page 313 PIC18F/LF1XK50 TABLE 25-2: PIC18FXXXX INSTRUCTION SET Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes BYTE-ORIENTED OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a SUBWF SUBWFB f, d, a f, d, a SWAPF TSTFSZ XORWF f, d, a f, a f, d, a 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’. If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 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. Some instructions are two-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. 2: 3: 4: DS41350D-page 314 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 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1 1 1 1 1 1 1 1 1 1 0010 01da0 0010 0da 0001 01da 0110 101a 0001 11da 0110 001a 0110 010a 0110 000a 0000 01da 0010 11da 0100 11da 0010 10da 0011 11da 0100 10da 0001 00da 0101 00da 1100 ffff 1111 ffff 0110 111a 0000 001a 0110 110a 0011 01da 0100 01da 0011 00da 0100 00da 0110 100a 0101 01da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff 1 1 0101 0101 11da 10da ffff ffff ffff C, DC, Z, OV, N ffff C, DC, Z, OV, N 1, 2 1 1 (2 or 3) 1 0011 0110 0001 10da 011a 10da ffff ffff ffff ffff None ffff None ffff Z, N 4 1, 2 Preliminary None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N 1, 2 1, 2 1, 2 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 25-2: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes BIT-ORIENTED OPERATIONS BCF BSF BTFSC BTFSS BTG f, b, a f, b, a f, b, a 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 1 1 (2 or 3) 1 (2 or 3) 1 1001 1000 1011 1010 0111 bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff None None None None None 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s None None None None None None None None None None 1 1 1 1 2 1 2 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 2 2 1 0000 0000 0000 1100 0000 0000 kkkk 0001 0000 1, 2 1, 2 3, 4 3, 4 1, 2 CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL n n n n n n n n n n, s CLRWDT DAW GOTO — — n NOP NOP POP PUSH RCALL RESET RETFIE — — — — 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 subroutine 1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to address 1st word 2nd word No Operation No Operation Pop top of return stack (TOS) Push top of return stack (TOS) Relative Call Software device Reset Return from interrupt enable RETLW RETURN SLEEP k s — Return with literal in WREG Return from Subroutine Go into Standby mode 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’. If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 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. Some instructions are two-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. 2: 3: 4: 2010 Microchip Technology Inc. 1 1 2 Preliminary TO, PD C None None None None None None All GIE/GIEH, PEIE/GIEL kkkk None 001s None 0011 TO, PD 4 DS41350D-page 315 PIC18F/LF1XK50 TABLE 25-2: PIC18FXXXX INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR k k k f, k MOVLB MOVLW MULLW RETLW SUBLW XORLW k k k k k k Add literal and WREG AND literal with WREG Inclusive OR literal with WREG Move literal (12-bit) 2nd word to FSR(f) 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 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk C, DC, Z, OV, N Z, N Z, N None 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111 None None None None None None None None None None None None C, DC, Z, OV, N Z, N DATA MEMORY PROGRAM MEMORY OPERATIONS TBLRD* TBLRD*+ TBLRD*TBLRD+* TBLWT* TBLWT*+ TBLWT*TBLWT+* Note 1: 2: 3: 4: 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 2 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’. If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if assigned. 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. Some instructions are two-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. DS41350D-page 316 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 25.1.1 STANDARD INSTRUCTION SET ADDLW ADD literal to W ADDWF ADD W to f Syntax: ADDLW Syntax: ADDWF Operands: 0 f 255 d [0,1] a [0,1] Operation: (W) + (f) dest Status Affected: N, OV, C, DC, Z 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 Encoding: 0010 Q1 Q2 Q3 Q4 Read literal ‘k’ Process Data Write to W Example: ADDLW = 25h ffff Words: 1 Cycles: 1 Before Instruction W ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 15h W = 10h After Instruction 01da Description: Q Cycle Activity: Decode f {,d {,a}} Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWF REG, 0, 0 Before Instruction W = REG = After Instruction W REG Note: = = 17h 0C2h 0D9h 0C2h All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s). 2010 Microchip Technology Inc. Preliminary DS41350D-page 317 PIC18F/LF1XK50 ADDWFC ADD W and CARRY bit to f ANDLW Syntax: ADDWFC Syntax: ANDLW Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 k 255 Operation: (W) .AND. k W Status Affected: N, Z f {,d {,a}} Operation: (W) + (f) + (C) dest Status Affected: N,OV, C, DC, Z Encoding: 0010 Description: 00da Encoding: ffff ffff 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 location ‘f’. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 AND literal with W 0000 k 1011 kkkk kkkk Description: The contents of W are AND’ed 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 05Fh Before Instruction W = After Instruction W = A3h 03h Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: ADDWFC Before Instruction CARRY bit = REG = W = After Instruction CARRY bit = REG = W = DS41350D-page 318 REG, 0, 1 1 02h 4Dh 0 02h 50h Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 ANDWF AND W with f BC Branch if Carry Syntax: ANDWF Syntax: BC Operands: 0 f 255 d [0,1] a [0,1] Operands: -128 n 127 Operation: if CARRY bit is ‘1’ (PC) + 2 + 2n PC Status Affected: None f {,d {,a}} Operation: (W) .AND. (f) dest Status Affected: N, Z Encoding: 0001 Description: Encoding: 01da ffff ffff The contents of W are AND’ed with 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination ANDWF REG, 0, 0 Before Instruction W = REG = After Instruction W REG = = Description: 0010 nnnn nnnn 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 No operation No operation No operation No operation Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE Before Instruction PC After Instruction If CARRY PC If CARRY PC 17h C2h 02h C2h 2010 Microchip Technology Inc. 1110 If No Jump: Q1 Example: n Preliminary BC 5 = address (HERE) = = = = 1; address (HERE + 12) 0; address (HERE + 2) DS41350D-page 319 PIC18F/LF1XK50 BCF Bit Clear f BN Branch if Negative Syntax: BCF Syntax: BN Operands: 0 f 255 0b7 a [0,1] Operands: -128 n 127 Operation: if NEGATIVE bit is ‘1’ (PC) + 2 + 2n PC Status Affected: None f, b {,a} Operation: 0 f<b> Status Affected: None Encoding: Encoding: 1001 Description: bbba ffff ffff Bit ‘b’ in register ‘f’ is cleared. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 Read register ‘f’ Process Data Write register ‘f’ Example: BCF Before Instruction FLAG_REG = After Instruction FLAG_REG = DS41350D-page 320 FLAG_REG, 1110 Description: 0110 nnnn nnnn 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: Q Cycle Activity: Decode n Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation If No Jump: 7, 0 Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation C7h 47h Example: HERE Before Instruction PC After Instruction If NEGATIVE PC If NEGATIVE PC Preliminary BN Jump = address (HERE) = = = = 1; address (Jump) 0; address (HERE + 2) 2010 Microchip Technology Inc. PIC18F/LF1XK50 BNC Branch if Not Carry BNN Branch if Not Negative Syntax: BNC Syntax: BNN Operands: -128 n 127 Operands: -128 n 127 Operation: if CARRY bit is ‘0’ (PC) + 2 + 2n PC Operation: if NEGATIVE bit is ‘0’ (PC) + 2 + 2n PC Status Affected: None Status Affected: None Encoding: n 1110 Description: 0011 nnnn nnnn Encoding: 1110 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. Description: Words: 1 Words: 1 Cycles: 1(2) Cycles: 1(2) Q Cycle Activity: If Jump: n 0111 nnnn nnnn 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. Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation No operation No operation No operation No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Decode Read literal ‘n’ Process Data No operation If No Jump: Example: If No Jump: HERE Before Instruction PC After Instruction If CARRY PC If CARRY PC BNC Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) 2010 Microchip Technology Inc. Example: HERE Before Instruction PC After Instruction If NEGATIVE PC If NEGATIVE PC Preliminary BNN Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) DS41350D-page 321 PIC18F/LF1XK50 BNOV Branch if Not Overflow BNZ Branch if Not Zero Syntax: BNOV Syntax: BNZ Operands: -128 n 127 Operands: -128 n 127 Operation: if OVERFLOW bit is ‘0’ (PC) + 2 + 2n PC Operation: if ZERO bit is ‘0’ (PC) + 2 + 2n PC Status Affected: None Status Affected: None Encoding: n 1110 Description: 0101 nnnn nnnn Encoding: 1110 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. Description: Words: 1 Words: 1 Cycles: 1(2) Cycles: 1(2) Q Cycle Activity: If Jump: n 0001 nnnn nnnn If the ZERO 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. Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data Write to PC Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation No operation No operation No operation No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Decode Read literal ‘n’ Process Data No operation If No Jump: If No Jump: Example: HERE Before Instruction PC = After Instruction If OVERFLOW = PC = If OVERFLOW = PC = DS41350D-page 322 BNOV Jump Example: HERE Before Instruction PC After Instruction If ZERO PC If ZERO PC address (HERE) 0; address (Jump) 1; address (HERE + 2) Preliminary BNZ Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) 2010 Microchip Technology Inc. PIC18F/LF1XK50 BRA Unconditional Branch BSF Syntax: BRA Syntax: BSF Operands: -1024 n 1023 Operands: 0 f 255 0b7 a [0,1] n Operation: (PC) + 2 + 2n PC Status Affected: None Encoding: 1101 Description: 0nnn nnnn nnnn 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 Bit Set f Operation: 1 f<b> Status Affected: None Encoding: 1000 Q1 Q2 Q3 Q4 Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation Example: HERE Before Instruction PC After Instruction PC BRA Jump = address (HERE) = address (Jump) ffff ffff Bit ‘b’ in register ‘f’ is set. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: BSF Before Instruction FLAG_REG After Instruction FLAG_REG 2010 Microchip Technology Inc. bbba Description: Q Cycle Activity: Decode f, b {,a} Preliminary FLAG_REG, 7, 1 = 0Ah = 8Ah DS41350D-page 323 PIC18F/LF1XK50 BTFSC Bit Test File, Skip if Clear BTFSS Syntax: BTFSC f, b {,a} Syntax: BTFSS f, b {,a} Operands: 0 f 255 0b7 a [0,1] Operands: 0 f 255 0b<7 a [0,1] Operation: skip if (f<b>) = 0 Operation: skip if (f<b>) = 1 Status Affected: None Status Affected: None Encoding: 1011 bbba ffff ffff Bit Test File, Skip if Set Encoding: 1010 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 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 instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Cycles: 1(2) Note: Q Cycle Activity: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation Decode Read register ‘f’ Process Data No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation If skip: If skip: If skip and followed by 2-word instruction: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC DS41350D-page 324 BTFSC : : FLAG, 1, 0 = address (HERE) = = = = 0; address (TRUE) 1; address (FALSE) Example: HERE FALSE TRUE Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC Preliminary BTFSS : : FLAG, 1, 0 = address (HERE) = = = = 0; address (FALSE) 1; address (TRUE) 2010 Microchip Technology Inc. PIC18F/LF1XK50 BTG Bit Toggle f BOV Branch if Overflow Syntax: BTG f, b {,a} Syntax: BOV Operands: 0 f 255 0b<7 a [0,1] Operands: -128 n 127 Operation: if OVERFLOW bit is ‘1’ (PC) + 2 + 2n PC Status Affected: None Operation: (f<b>) f<b> Status Affected: None Encoding: 0111 Description: Words: Cycles: Encoding: bbba ffff ffff Bit ‘b’ in data memory location ‘f’ is inverted. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 1110 Description: 0100 nnnn nnnn 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: 1 Q1 Q2 Q3 Q4 1 Decode Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: n BTG PORTC, 4, 0 Before Instruction: PORTC = 0111 0101 [75h] After Instruction: PORTC = 0110 0101 [65h] 2010 Microchip Technology Inc. If No Jump: Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation Example: HERE Before Instruction PC = After Instruction If OVERFLOW = PC = If OVERFLOW = PC = Preliminary BOV Jump address (HERE) 1; address (Jump) 0; address (HERE + 2) DS41350D-page 325 PIC18F/LF1XK50 BZ Branch if Zero CALL Subroutine Call Syntax: BZ Syntax: CALL k {,s} Operands: -128 n 127 Operands: Operation: if ZERO bit is ‘1’ (PC) + 2 + 2n PC 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 Status Affected: n None Encoding: 1110 Description: 0000 nnnn nnnn If the ZERO 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) Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Q1 Q2 Q3 Q4 Read literal ‘n’ Process Data Write to PC No operation No operation No operation No operation Q1 Q2 Q3 Q4 Decode Read literal ‘n’ Process Data No operation If No Jump: Example: HERE Before Instruction PC After Instruction If ZERO PC If ZERO PC DS41350D-page 326 BZ k7kkk kkkk 110s k19kkk 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 Decode Q2 Q3 Q4 Read literal PUSH PC to ‘k’<7:0>, stack Jump = address (HERE) = = = = 1; address (Jump) 0; address (HERE + 2) kkkk0 kkkk8 Description: Q Cycle Activity: If Jump: Decode 1110 1111 No operation Example: No operation HERE Before Instruction PC = After Instruction PC = TOS = WS = BSRS = STATUSS = Preliminary No operation CALL Read literal ‘k’<19:8>, Write to PC No operation THERE, 1 address (HERE) address (THERE) address (HERE + 4) W BSR Status 2010 Microchip Technology Inc. PIC18F/LF1XK50 CLRF Clear f Syntax: CLRF Operands: 0 f 255 a [0,1] Operation: 000h f 1Z Status Affected: Z Encoding: f {,a} 0110 Description: 101a ffff ffff Clears the contents of the specified register. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 CLRWDT Clear Watchdog Timer Syntax: CLRWDT Operands: None Operation: 000h WDT, 000h WDT postscaler, 1 TO, 1 PD Status Affected: TO, PD Encoding: Q2 Q3 Q4 Read register ‘f’ Process Data Write register ‘f’ Example: CLRF Before Instruction FLAG_REG After Instruction FLAG_REG 5Ah = 00h 2010 Microchip Technology Inc. 0100 Words: 1 Cycles: 1 Q Cycle Activity: FLAG_REG, 1 = 0000 CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits, TO and PD, are set. Q1 Q2 Q3 Q4 Decode No operation Process Data No operation Example: Q1 0000 Description: Q Cycle Activity: Decode 0000 Preliminary CLRWDT Before Instruction WDT Counter After Instruction WDT Counter WDT Postscaler TO PD = ? = = = = 00h 0 1 1 DS41350D-page 327 PIC18F/LF1XK50 COMF Complement f CPFSEQ Compare f with W, skip if f = W Syntax: COMF Syntax: CPFSEQ Operands: 0 f 255 a [0,1] Operation: (f) – (W), skip if (f) = (W) (unsigned comparison) Status Affected: None f {,d {,a}} 0 f 255 d [0,1] a [0,1] Operands: Operation: (f) dest Status Affected: N, Z Encoding: 0001 11da ffff ffff Description: The contents of register ‘f’ are complemented. 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Encoding: 0110 Description: f {,a} 001a ffff ffff Compares the contents of data memory location ‘f’ to the contents of W by performing an unsigned subtraction. If ‘f’ = 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Example: COMF Before Instruction REG = After Instruction REG = W = REG, 0, 0 Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation 13h If skip: 13h ECh Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation Example: DS41350D-page 328 Preliminary HERE NEQUAL EQUAL Q4 No operation Q4 No operation No operation CPFSEQ REG, 0 : : Before Instruction PC Address W REG After Instruction = = = HERE ? ? If REG PC If REG PC = = = W; Address (EQUAL) W; Address (NEQUAL) 2010 Microchip Technology Inc. PIC18F/LF1XK50 CPFSGT Compare f with W, skip if f > W CPFSLT Compare f with W, skip if f < W Syntax: CPFSGT Syntax: CPFSLT Operands: 0 f 255 a [0,1] Operands: 0 f 255 a [0,1] Operation: (f) –W), skip if (f) > (W) (unsigned comparison) Operation: (f) –W), skip if (f) < (W) (unsigned comparison) Status Affected: None Status Affected: None Encoding: 0110 Description: Words: f {,a} 010a ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Encoding: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2 Read register ‘f’ Q3 Process Data Q4 No operation Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation Q4 No operation Example: HERE NGREATER GREATER = = Address (HERE) ? If REG PC If REG PC = = W; Address (GREATER) W; Address (NGREATER) 2010 Microchip Technology Inc. ffff 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 register ‘f’ Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: CPFSGT REG, 0 : : Before Instruction PC W After Instruction ffff Words: If skip: Q4 No operation No operation 000a 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). Q Cycle Activity: Q1 Decode 0110 Description: 1 Cycles: f {,a} Preliminary HERE NLESS LESS CPFSLT REG, 1 : : Before Instruction PC W After Instruction = = Address (HERE) ? If REG PC If REG PC < = = W; Address (LESS) W; Address (NLESS) DS41350D-page 329 PIC18F/LF1XK50 DAW Decimal Adjust W Register DECF Syntax: DAW Syntax: DECF f {,d {,a}} Operands: None Operands: Operation: If [W<3:0> > 9] or [DC = 1] then (W<3:0>) + 6 W<3:0>; else (W<3:0>) W<3:0>; 0 f 255 d [0,1] a [0,1] Operation: (f) – 1 dest Status Affected: C, DC, N, OV, Z If [W<7:4> + DC > 9] or [C = 1] then (W<7:4>) + 6 + DC W<7:4>; else (W<7:4>) + DC W<7:4> Status Affected: Decrement f Encoding: 0000 0000 0000 DAW adjusts the eight-bit value in W, resulting from the earlier addition 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 register W Process Data Write W Cycles: 1 Q Cycle Activity: DAW Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Before Instruction = = = A5h 0 0 ffff 1 Example1: W = C = DC = After Instruction ffff Words: 0111 Description: 01da 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. C Encoding: W C DC Example 2: 0000 Description: Example: DECF Before Instruction CNT = Z = After Instruction CNT = Z = 05h 1 0 CNT, 1, 0 01h 0 00h 1 Before Instruction W = C = DC = After Instruction W C DC = = = DS41350D-page 330 CEh 0 0 34h 1 0 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 Decrement f, skip if 0 DCFSNZ Syntax: DECFSZ f {,d {,a}} Syntax: DCFSNZ Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f) – 1 dest, skip if result = 0 Operation: (f) – 1 dest, skip if result 0 Status Affected: None Status Affected: None DECFSZ Encoding: 0010 Description: 11da ffff ffff The contents of register ‘f’ are decremented. 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 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Decrement f, skip if not 0 Encoding: 0100 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination ffff The contents of register ‘f’ are decremented. 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q1 Q2 Q3 Q4 No operation No operation No operation No operation Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: If skip: If skip and followed by 2-word instruction: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation HERE DECFSZ GOTO CNT, 1, 1 LOOP Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: CONTINUE HERE ZERO NZERO Before Instruction TEMP After Instruction TEMP If TEMP PC If TEMP PC Address (HERE) CNT - 1 0; Address (CONTINUE) 0; Address (HERE + 2) 2010 Microchip Technology Inc. ffff Q Cycle Activity: Q1 Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC = 11da Description: Q Cycle Activity: Example: f {,d {,a}} Preliminary DCFSNZ : : TEMP, 1, 0 = ? = = = = TEMP – 1, 0; Address (ZERO) 0; Address (NZERO) DS41350D-page 331 PIC18F/LF1XK50 GOTO Unconditional Branch INCF Syntax: GOTO k Syntax: INCF Operands: 0 k 1048575 Operands: Operation: k PC<20:1> Status Affected: None 0 f 255 d [0,1] a [0,1] Operation: (f) + 1 dest Status Affected: C, DC, N, OV, Z Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8 GOTO allows an unconditional branch Description: Increment f Encoding: 0010 2 Cycles: 2 Q1 Q2 Q3 Q4 Read literal ‘k’<7:0>, No operation Read literal ‘k’<19:8>, Write to PC No operation No operation No operation No operation ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Decode 10da Description: 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: f {,d {,a}} Q Cycle Activity: Example: GOTO THERE After Instruction PC = Address (THERE) Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: INCF Before Instruction CNT = Z = C = DC = After Instruction CNT = Z = C = DC = DS41350D-page 332 Preliminary CNT, 1, 0 FFh 0 ? ? 00h 1 1 1 2010 Microchip Technology Inc. PIC18F/LF1XK50 INCFSZ Increment f, skip if 0 INFSNZ Syntax: INCFSZ Syntax: INFSNZ 0 f 255 d [0,1] a [0,1] f {,d {,a}} Increment f, skip if not 0 f {,d {,a}} Operands: 0 f 255 d [0,1] a [0,1] Operands: Operation: (f) + 1 dest, skip if result = 0 Operation: (f) + 1 dest, skip if result 0 Status Affected: None Status Affected: None Encoding: 0011 Description: 11da ffff ffff 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 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Encoding: 0100 Description: Words: 1 Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Cycles: 1(2) Note: Q Cycle Activity: 10da ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Decode Read register ‘f’ Process Data Write to destination Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation If skip: If skip: If skip and followed by 2-word instruction: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE NZERO ZERO Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC = INCFSZ : : CNT, 1, 0 Example: Before Instruction PC = After Instruction REG = If REG PC = If REG = PC = Address (HERE) CNT + 1 0; Address (ZERO) 0; Address (NZERO) 2010 Microchip Technology Inc. HERE ZERO NZERO Preliminary INFSNZ REG, 1, 0 Address (HERE) REG + 1 0; Address (NZERO) 0; Address (ZERO) DS41350D-page 333 PIC18F/LF1XK50 IORLW Inclusive OR literal with W IORWF Syntax: IORLW k Syntax: IORWF Operands: 0 k 255 Operands: Operation: (W) .OR. k W Status Affected: N, Z 0 f 255 d [0,1] a [0,1] Operation: (W) .OR. (f) dest Status Affected: N, Z Encoding: 0000 Description: 1001 kkkk kkkk The contents of W are ORed with the eight-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Inclusive OR W with f Encoding: 0001 Q1 Q2 Q3 Q4 Read literal ‘k’ Process Data Write to W Example: IORLW W = ffff Words: 1 Cycles: 1 35h 9Ah BFh ffff 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 register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Before Instruction W = After Instruction 00da Description: Q Cycle Activity: Decode f {,d {,a}} Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: IORWF Before Instruction RESULT = W = After Instruction RESULT = W = DS41350D-page 334 Preliminary RESULT, 0, 1 13h 91h 13h 93h 2010 Microchip Technology Inc. PIC18F/LF1XK50 LFSR Load FSR MOVF Syntax: LFSR f, k Syntax: MOVF Operands: 0f2 0 k 4095 Operands: Operation: k FSRf 0 f 255 d [0,1] a [0,1] Status Affected: None Operation: f dest Status Affected: N, Z 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 Move f Encoding: 0101 Q1 Q2 Q3 Q4 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: After Instruction FSR2H FSR2L 03h ABh ffff ffff 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 anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 LFSR 2, 3ABh = = 00da Description: Q Cycle Activity: Decode f {,d {,a}} Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write W Example: MOVF Before Instruction REG W After Instruction REG W 2010 Microchip Technology Inc. Preliminary REG, 0, 0 = = 22h FFh = = 22h 22h DS41350D-page 335 PIC18F/LF1XK50 MOVFF Move f to f MOVLB Syntax: MOVFF fs,fd Syntax: MOVLW k Operands: 0 fs 4095 0 fd 4095 Operands: 0 k 255 Operation: k BSR Operation: (fs) fd Status Affected: None Status Affected: None Encoding: Encoding: 1st word (source) 2nd word (destin.) 1100 1111 Description: ffff ffff ffff ffff ffffs ffffd 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 anywhere 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. Words: 2 Cycles: 2 (3) Move literal to low nibble in BSR 0000 0001 kkkk kkkk Description: The eight-bit literal ‘k’ is loaded into the Bank Select Register (BSR). The value of BSR<7:4> always remains ‘0’, regardless of the value of k7:k4. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write literal ‘k’ to BSR MOVLB 5 Example: Before Instruction BSR Register = After Instruction BSR Register = 02h 05h Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ (src) Process Data No operation Decode No operation No operation Write register ‘f’ (dest) No dummy read Example: MOVFF Before Instruction REG1 REG2 After Instruction REG1 REG2 DS41350D-page 336 REG1, REG2 = = 33h 11h = = 33h 33h Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 MOVLW Move literal to W MOVWF Syntax: MOVLW k Syntax: MOVWF Operands: 0 k 255 Operands: Operation: kW 0 f 255 a [0,1] Status Affected: None Operation: (W) f Status Affected: None Encoding: 0000 1110 kkkk kkkk Description: The eight-bit literal ‘k’ is loaded into W. Words: 1 Cycles: 1 Move W to f Encoding: 0110 Q1 Q2 Q3 Q4 Read literal ‘k’ Process Data Write to W Example: MOVLW = ffff ffff Move data from W to register ‘f’. Location ‘f’ can be anywhere in the 256-byte bank. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 5Ah After Instruction W 111a Description: Q Cycle Activity: Decode f {,a} 5Ah Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: MOVWF REG, 0 Before Instruction W = REG = After Instruction W REG 2010 Microchip Technology Inc. Preliminary = = 4Fh FFh 4Fh 4Fh DS41350D-page 337 PIC18F/LF1XK50 MULLW Multiply literal with W MULWF Multiply W with f Syntax: MULLW Syntax: MULWF Operands: 0 k 255 Operands: Operation: (W) x k PRODH:PRODL 0 f 255 a [0,1] Status Affected: None Operation: (W) x (f) PRODH:PRODL Status Affected: None Encoding: 0000 Description: k 1101 kkkk kkkk An unsigned multiplication is carried out between the contents of W and the 8-bit literal ‘k’. The 16-bit result is placed in the 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 operation. A zero result is possible but not detected. Words: 1 Cycles: 1 Encoding: 0000 Q1 Q2 Q3 Q4 Read literal ‘k’ Process Data Write registers PRODH: PRODL Example: MULLW W PRODH PRODL After Instruction W PRODH PRODL = = = E2h ? ? = = = E2h ADh 08h ffff ffff An unsigned multiplication is carried 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 operation. A zero result is possible but not detected. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 0C4h Before Instruction 001a Description: Q Cycle Activity: Decode f {,a} Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write registers PRODH: PRODL Example: MULWF REG, 1 Before Instruction W REG PRODH PRODL After Instruction W REG PRODH PRODL DS41350D-page 338 Preliminary = = = = C4h B5h ? ? = = = = C4h B5h 8Ah 94h 2010 Microchip Technology Inc. PIC18F/LF1XK50 NEGF Negate f NOP No Operation Syntax: NEGF Syntax: NOP Operands: 0 f 255 a [0,1] Operands: None Operation: (f)+1f Status Affected: N, OV, C, DC, Z Encoding: f {,a} 0110 Description: 1 Cycles: 1 No operation Status Affected: None Encoding: 110a ffff 0000 1111 ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: Operation: 0000 xxxx Description: No operation. Words: 1 Cycles: 1 0000 xxxx 0000 xxxx Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation Example: None. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: NEGF Before Instruction REG = After Instruction REG = REG, 1 0011 1010 [3Ah] 1100 0110 [C6h] 2010 Microchip Technology Inc. Preliminary DS41350D-page 339 PIC18F/LF1XK50 POP Pop Top of Return Stack PUSH Push Top of Return Stack Syntax: POP Syntax: PUSH Operands: None Operands: None Operation: (TOS) bit bucket Operation: (PC + 2) TOS Status Affected: None 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 previous 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 Encoding: 0000 0101 Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation POP TOS value No operation POP GOTO NEW Before Instruction TOS Stack (1 level down) After Instruction TOS PC DS41350D-page 340 0000 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 implementing a software stack by modifying TOS and then pushing it onto the return stack. Q Cycle Activity: Example: 0000 Description: Q1 Q2 Q3 Q4 Decode PUSH PC + 2 onto return stack No operation No operation Example: = = 0031A2h 014332h = = 014332h NEW Preliminary PUSH Before Instruction TOS PC = = 345Ah 0124h After Instruction PC TOS Stack (1 level down) = = = 0126h 0126h 345Ah 2010 Microchip Technology Inc. PIC18F/LF1XK50 RCALL Relative Call RESET Reset Syntax: RCALL Syntax: RESET Operands: -1024 n 1023 Operands: None Operation: (PC) + 2 TOS, (PC) + 2 + 2n PC Operation: Reset all registers and flags that are affected by a MCLR Reset. Status Affected: None Status Affected: All Encoding: n 1101 Description: 1nnn nnnn nnnn 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 Encoding: 0000 Q2 Q3 Q4 Read literal ‘n’ Process Data Write to PC No operation No operation 1111 This instruction provides a way to execute a MCLR Reset by software. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Start Reset No operation No operation Example: Q1 1111 Description: Q Cycle Activity: Decode 0000 After Instruction Registers = Flags* = RESET Reset Value Reset Value PUSH PC to stack No operation Example: No operation HERE RCALL Jump Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE + 2) 2010 Microchip Technology Inc. Preliminary DS41350D-page 341 PIC18F/LF1XK50 RETFIE Return from Interrupt RETLW Return literal to W Syntax: RETFIE {s} Syntax: RETLW k Operands: s [0,1] Operands: 0 k 255 Operation: (TOS) PC, 1 GIE/GIEH or PEIE/GIEL, if s = 1 (WS) W, (STATUSS) Status, (BSRS) BSR, PCLATU, PCLATH are unchanged. Operation: k W, (TOS) PC, PCLATU, PCLATH are unchanged Status Affected: None Status Affected: 0000 0000 0001 1 Cycles: 2 Q Cycle Activity: Q2 Q3 Q4 Decode No operation No operation POP PC from stack Set GIEH or GIEL No operation RETFIE After Interrupt PC W BSR Status GIE/GIEH, PEIE/GIEL DS41350D-page 342 kkkk kkkk Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data POP PC from stack, Write to W No operation No operation No operation No operation Example: Q1 Example: 1100 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. 000s 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: No operation 0000 Description: GIE/GIEH, PEIE/GIEL. Encoding: Description: Encoding: No operation No operation 1 = = = = = TOS WS BSRS STATUSS 1 CALL TABLE ; ; ; ; : TABLE ADDWF PCL ; RETLW k0 ; RETLW k1 ; : : RETLW kn ; Before Instruction W = After Instruction W = Preliminary W contains table offset value W now has table value W = offset Begin table End of table 07h value of kn 2010 Microchip Technology Inc. PIC18F/LF1XK50 RETURN Return from Subroutine RLCF Syntax: RETURN {s} Syntax: RLCF Operands: s [0,1] Operands: Operation: (TOS) PC, if s = 1 (WS) W, (STATUSS) Status, (BSRS) BSR, PCLATU, PCLATH are unchanged 0 f 255 d [0,1] a [0,1] Operation: (f<n>) dest<n + 1>, (f<7>) C, (C) dest<0> Status Affected: C, N, Z Status Affected: None Encoding: 0000 Rotate Left f through Carry Encoding: 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 corresponding registers, W, Status and BSR. If ‘s’ = 0, no update of these registers occurs (default). Words: 1 Cycles: 2 0011 Description: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data POP PC from stack No operation No operation No operation No operation f {,d {,a}} 01da ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. register f C Words: 1 Cycles: 1 Q Cycle Activity: Example: RETURN After Instruction: PC = TOS Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: Before Instruction REG = C = After Instruction REG = W = C = 2010 Microchip Technology Inc. Preliminary RLCF REG, 0, 0 1110 0110 0 1110 0110 1100 1100 1 DS41350D-page 343 PIC18F/LF1XK50 RLNCF Rotate Left f (No Carry) RRCF Syntax: RLNCF Syntax: RRCF Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f<n>) dest<n + 1>, (f<7>) dest<0> Operation: Status Affected: N, Z (f<n>) dest<n – 1>, (f<0>) C, (C) dest<7> Status Affected: C, N, Z Encoding: 0100 Description: f {,d {,a}} 01da ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Rotate Right f through Carry Encoding: 0011 Description: register f Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Before Instruction REG = After Instruction REG = DS41350D-page 344 00da RLNCF Words: 1 Cycles: 1 ffff register f Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination RRCF REG, 0, 0 REG, 1, 0 1010 1011 ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. C Q Cycle Activity: Example: f {,d {,a}} Example: Before Instruction REG = C = After Instruction REG = W = C = 0101 0111 Preliminary 1110 0110 0 1110 0110 0111 0011 0 2010 Microchip Technology Inc. PIC18F/LF1XK50 RRNCF Rotate Right f (No Carry) SETF Syntax: RRNCF Syntax: SETF Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 a [0,1] Operation: FFh f Operation: (f<n>) dest<n – 1>, (f<0>) dest<7> Status Affected: None Status Affected: f {,d {,a}} Encoding: N, Z Encoding: 0100 Description: 00da ffff ffff 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). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 1 Cycles: 1 Q2 Q3 Q4 Read register ‘f’ Process Data Write to destination Example 1: RRNCF Before Instruction REG = After Instruction REG = Example 2: 100a ffff ffff Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write register ‘f’ Example: Q1 0110 The contents of the specified register are set to FFh. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Q Cycle Activity: Decode f {,a} Description: register f Words: Set f SETF Before Instruction REG After Instruction REG REG, 1 = 5Ah = FFh REG, 1, 0 1101 0111 1110 1011 RRNCF REG, 0, 0 Before Instruction W = REG = After Instruction ? 1101 0111 = = 1110 1011 1101 0111 W REG 2010 Microchip Technology Inc. Preliminary DS41350D-page 345 PIC18F/LF1XK50 SLEEP Enter Sleep mode SUBFWB Syntax: SLEEP Syntax: SUBFWB Operands: None Operands: Operation: 00h WDT, 0 WDT postscaler, 1 TO, 0 PD 0 f 255 d [0,1] a [0,1] Operation: (W) – (f) – (C) dest Status Affected: N, OV, C, DC, Z Status Affected: TO, PD Encoding: 0000 Encoding: 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 0101 Q1 Q2 Q3 Q4 Decode No operation Process Data Go to Sleep SLEEP Before Instruction TO = ? PD = ? DS41350D-page 346 01da ffff ffff 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: After Instruction 1† TO = 0 PD = † If WDT causes wake-up, this bit is cleared. f {,d {,a}} Description: Q Cycle Activity: Example: Subtract f from W with borrow Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination SUBFWB REG, 1, 0 Example 1: Before Instruction REG = 3 W = 2 C = 1 After Instruction REG = FF W = 2 C = 0 Z = 0 N = 1 ; result is negative SUBFWB REG, 0, 0 Example 2: Before Instruction REG = 2 W = 5 C = 1 After Instruction REG = 2 W = 3 C = 1 Z = 0 N = 0 ; result is positive SUBFWB REG, 1, 0 Example 3: Before Instruction REG = 1 W = 2 C = 0 After Instruction REG = 0 W = 2 C = 1 Z = 1 ; result is zero N = 0 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 SUBLW Subtract W from literal SUBWF Syntax: SUBLW k Syntax: SUBWF Operands: 0 k 255 Operands: Operation: k – (W) W Status Affected: N, OV, C, DC, Z 0 f 255 d [0,1] a [0,1] Operation: (f) – (W) dest Status Affected: N, OV, C, DC, Z Encoding: 0000 Description 1000 kkkk kkkk W is subtracted from the eight-bit literal ‘k’. The result is placed in W. Words: 1 Cycles: 1 Subtract W from f Encoding: 0101 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to W Example 1: Before Instruction W = C = After Instruction W = C = Z = N = Example 2: Before Instruction W = C = After Instruction W = C = Z = N = Example 3: Before Instruction W = C = After Instruction W = C = Z = N = SUBLW 02h 1 Cycles: 1 Q Cycle Activity: 02h ? 00h 1 ; result is zero 1 0 SUBLW ffff Words: 01h ? SUBLW ffff 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 register ‘f’ (default). If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. 02h 01h 1 ; result is positive 0 0 11da Description: Q Cycle Activity: Q1 f {,d {,a}} Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination SUBWF REG, 1, 0 Example 1: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = 02h 03h ? FFh ; (2’s complement) 0 ; result is negative 0 1 Example 2: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = 2010 Microchip Technology Inc. Preliminary 3 2 ? 1 2 1 0 0 ; result is positive SUBWF REG, 0, 0 2 2 ? 2 0 1 1 0 SUBWF ; result is zero REG, 1, 0 1 2 ? FFh ;(2’s complement) 2 0 ; result is negative 0 1 DS41350D-page 347 PIC18F/LF1XK50 SUBWFB Subtract W from f with Borrow SWAPF Swap f Syntax: SUBWFB Syntax: SWAPF f {,d {,a}} Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f) – (W) – (C) dest Operation: Status Affected: N, OV, C, DC, Z (f<3:0>) dest<7:4>, (f<7:4>) dest<3:0> Status Affected: None Encoding: 0101 Description: f {,d {,a}} 10da ffff ffff Subtract W and the CARRY flag (borrow) 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Read register ‘f’ Example 1: SUBWFB Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 2: Q4 Write to destination (0001 1001) (0000 1101) 0Ch 0Dh 1 0 0 (0000 1011) (0000 1101) 10da ffff ffff Description: The upper and lower nibbles of register ‘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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination REG, 1, 0 19h 0Dh 1 0011 Example: SWAPF Before Instruction REG = After Instruction REG = REG, 1, 0 53h 35h ; result is positive SUBWFB REG, 0, 0 Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: 1Bh 1Ah 0 (0001 1011) (0001 1010) 1Bh 00h 1 1 0 (0001 1011) SUBWFB Before Instruction REG = W = C = After Instruction REG = W C Z N Q3 Process Data Encoding: = = = = DS41350D-page 348 ; result is zero REG, 1, 0 03h 0Eh 1 (0000 0011) (0000 1101) F5h (1111 0100) ; [2’s comp] (0000 1101) 0Eh 0 0 1 ; result is negative Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TBLRD Table Read TBLRD Table Read (Continued) Syntax: TBLRD ( *; *+; *-; +*) Example1: 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; Example2: Status Affected: None Encoding: 0000 0000 0000 *+ ; Before Instruction TABLAT TBLPTR MEMORY (00A356h) After Instruction TABLAT TBLPTR 10nn nn=0 * =1 *+ =2 *=3 +* Description: This instruction is used to read the contents 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 TBLRD = = = 55h 00A356h 34h = = 34h 00A357h +* ; Before Instruction TABLAT TBLPTR MEMORY (01A357h) MEMORY (01A358h) After Instruction TABLAT TBLPTR = = = = AAh 01A357h 12h 34h = = 34h 01A358h Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read Program Memory) No operation No operation (Write TABLAT) 2010 Microchip Technology Inc. Preliminary DS41350D-page 349 PIC18F/LF1XK50 TBLWT Table Write TBLWT Table Write (Continued) Syntax: TBLWT ( *; *+; *-; +*) Example1: 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: Before Instruction TABLAT = 55h TBLPTR = 00A356h HOLDING REGISTER (00A356h) = FFh After Instructions (table write completion) TABLAT = 55h TBLPTR = 00A357h HOLDING REGISTER (00A356h) = 55h Example 2: None Encoding: 0000 0000 0000 11nn nn=0 * =1 *+ =2 *=3 +* Description: This instruction uses the 3 LSBs of TBLPTR to determine which of the 8 holding registers the TABLAT is written to. The holding registers are used to program the contents of Program Memory (P.M.). (Refer to Section 4.0 “Flash Program Memory” for additional details on programming Flash memory.) The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-MByte 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 TBLWT +*; Before Instruction TABLAT = 34h TBLPTR = 01389Ah HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = FFh After Instruction (table write completion) TABLAT = 34h TBLPTR = 01389Bh HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = 34h Q Cycle Activity: Q1 Decode Q2 Q3 Q4 No No No operation operation operation No No No No operation operation operation operation (Read (Write to TABLAT) Holding Register ) DS41350D-page 350 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TSTFSZ Test f, skip if 0 XORLW Syntax: TSTFSZ f {,a} Syntax: XORLW k Operands: 0 f 255 a [0,1] Operands: 0 k 255 Operation: (W) .XOR. k W Operation: skip if f = 0 Status Affected: N, Z Status Affected: None Encoding: Encoding: 0110 Description: Exclusive OR literal with W 011a ffff ffff If ‘f’ = 0, the next instruction fetched during the current instruction execution is discarded and a NOP is executed, making this a two-cycle instruction. If ‘a’ is ‘0’, the Access Bank is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. 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 0AFh Before Instruction W = After Instruction W = B5h 1Ah Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE NZERO ZERO Before Instruction PC After Instruction If CNT PC If CNT PC TSTFSZ : : CNT, 1 = Address (HERE) = = = 00h, Address (ZERO) 00h, Address (NZERO) 2010 Microchip Technology Inc. Preliminary DS41350D-page 351 PIC18F/LF1XK50 XORWF Exclusive OR W with f Syntax: XORWF Operands: 0 f 255 d [0,1] a [0,1] Operation: (W) .XOR. (f) dest Status Affected: N, Z Encoding: 0001 f {,d {,a}} 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 is selected. If ‘a’ is ‘1’, the BSR is used to select the GPR bank (default). If ‘a’ is ‘0’ and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 25.2.3 “Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode” for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination Example: XORWF Before Instruction REG = W = After Instruction REG = W = DS41350D-page 352 REG, 1, 0 AFh B5h 1Ah B5h Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 25.2 Extended Instruction Set A summary of the instructions in the extended instruction set is provided in Table 25-3. Detailed descriptions are provided in Section 25.2.2 “Extended Instruction Set”. The opcode field descriptions in Table 25-1 (page 312) apply to both the standard and extended PIC18 instruction sets. In addition to the standard 75 instructions of the PIC18 instruction set, PIC18F/LF1XK50 devices also provide an optional extension to the core CPU functionality. The added features include eight additional instructions that augment indirect and indexed addressing operations and the implementation of Indexed Literal Offset Addressing mode for many of the standard PIC18 instructions. Note: The additional features of the extended instruction set are disabled by default. To enable them, users must set the XINST Configuration bit. The instructions in the extended set can all be classified as literal operations, which either manipulate the File Select Registers, or use them for indexed addressing. Two of the instructions, ADDFSR and SUBFSR, each have an additional special instantiation for using FSR2. These versions (ADDULNK and SUBULNK) allow for automatic return after execution. 25.2.1 EXTENDED INSTRUCTION SYNTAX Most of the extended instructions use indexed arguments, using one of the File Select Registers and some offset to specify a source or destination register. When an argument for an instruction serves as part of indexed addressing, it is enclosed in square brackets (“[ ]”). This is done to indicate that the argument is used as an index or offset. MPASM™ Assembler will flag an error if it determines that an index or offset value is not bracketed. The extended instructions are specifically implemented to optimize re-entrant program code (that is, code that is recursive or that uses a software stack) written in high-level languages, particularly C. Among other things, they allow users working in high-level languages to perform certain operations on data structures more efficiently. These include: When the extended instruction set is enabled, brackets are also used to indicate index arguments in byteoriented and bit-oriented instructions. This is in addition to other changes in their syntax. For more details, see Section 25.2.3.1 “Extended Instruction Syntax with Standard PIC18 Commands”. • dynamic allocation and deallocation of software stack space when entering and leaving subroutines • function pointer invocation • software Stack Pointer manipulation • manipulation of variables located in a software stack TABLE 25-3: The instruction set extension and the Indexed Literal Offset Addressing mode were designed for optimizing applications written in C; the user may likely never use these instructions directly in assembler. The syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler. Note: In the past, square brackets have been used to denote optional arguments in the PIC18 and earlier instruction sets. In this text and going forward, optional arguments are denoted by braces (“{ }”). EXTENSIONS TO THE PIC18 INSTRUCTION SET Mnemonic, Operands ADDFSR ADDULNK CALLW MOVSF f, k k MOVSS zs, zd PUSHL k SUBFSR SUBULNK f, k k zs, fd Description Cycles Add literal to FSR Add literal to FSR2 and return Call subroutine using WREG Move zs (source) to 1st word fd (destination) 2nd word Move zs (source) to 1st word 2nd word zd (destination) Store literal at FSR2, decrement FSR2 Subtract literal from FSR Subtract literal from FSR2 and return 2010 Microchip Technology Inc. 1 2 2 2 16-Bit Instruction Word MSb LSb Status Affected 1000 1000 0000 1011 ffff 1011 xxxx 1010 ffkk 11kk 0001 0zzz ffff 1zzz xzzz kkkk kkkk kkkk 0100 zzzz ffff zzzz zzzz kkkk None None None None 1 1110 1110 0000 1110 1111 1110 1111 1110 1 2 1110 1110 1001 1001 ffkk 11kk kkkk kkkk None None 2 Preliminary None None DS41350D-page 353 PIC18F/LF1XK50 25.2.2 EXTENDED INSTRUCTION SET ADDFSR Add Literal to FSR ADDULNK Syntax: ADDFSR f, k Syntax: ADDULNK k Operands: 0 k 63 f [ 0, 1, 2 ] Operands: 0 k 63 Operation: FSR(f) + k FSR(f) Status Affected: None Encoding: 1110 Add Literal to FSR2 and Return FSR2 + k FSR2, Operation: (TOS) PC Status Affected: 1000 ffkk kkkk Description: The 6-bit literal ‘k’ is added to the contents of the FSR specified by ‘f’. Words: 1 Cycles: 1 None Encoding: 1110 Q1 Q2 Q3 Q4 Read literal ‘k’ Process Data Write to FSR Example: ADDFSR 2, 23h Before Instruction FSR2 = 03FFh After Instruction FSR2 = 0422h kkkk Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal ‘k’ Process Data Write to FSR No Operation No Operation No Operation No Operation Example: Note: 11kk The 6-bit literal ‘k’ is added to the contents of FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the ADDFSR instruction, where f = 3 (binary ‘11’); it operates only on FSR2. Q Cycle Activity: Decode 1000 Description: ADDULNK 23h Before Instruction FSR2 = PC = 03FFh 0100h After Instruction FSR2 = PC = 0422h (TOS) All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction syntax then becomes: {label} instruction argument(s). DS41350D-page 354 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 CALLW Subroutine Call Using WREG MOVSF Syntax: CALLW Syntax: MOVSF [zs], fd Operands: None Operands: Operation: (PC + 2) TOS, (W) PCL, (PCLATH) PCH, (PCLATU) PCU 0 zs 127 0 fd 4095 Operation: ((FSR2) + zs) fd Status Affected: None Status Affected: None Encoding: 0000 0000 0001 0100 Description First, the return address (PC + 2) is pushed onto the return stack. Next, the contents of W are written to PCL; the existing value is discarded. Then, the contents of PCLATH and PCLATU are latched into PCH and PCU, respectively. The second cycle is executed as a NOP instruction while the new next instruction is fetched. Unlike CALL, there is no option to update W, Status or BSR. Words: 1 Cycles: 2 Move Indexed to f Encoding: 1st word (source) 2nd word (destin.) Q1 Q2 Q3 Q4 Read WREG PUSH PC to stack No operation No operation No operation No operation No operation HERE Before Instruction PC = PCLATH = PCLATU = W = After Instruction PC = TOS = PCLATH = PCLATU = W = 2 Cycles: 2 Q Cycle Activity: Q1 Decode address (HERE) 10h 00h 06h 2010 Microchip Technology Inc. zzzzs ffffd Words: CALLW 001006h address (HERE + 2) 10h 00h 06h 0zzz ffff The contents of the source register are moved to destination register ‘fd’. The actual address of the source register is determined by adding the 7-bit literal offset ‘zs’ in the first word to the value of FSR2. The address of the destination register is specified by the 12-bit literal ‘fd’ in the second word. Both addresses can be anywhere in the 4096-byte data space (000h to FFFh). The MOVSF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an indirect addressing register, the value returned will be 00h. Decode Example: 1011 ffff Description: Q Cycle Activity: Decode 1110 1111 Q2 Q3 Determine Determine source addr source addr No operation No operation No dummy read Example: MOVSF Before Instruction FSR2 Contents of 85h REG2 After Instruction FSR2 Contents of 85h REG2 Preliminary Q4 Read source reg Write register ‘f’ (dest) [05h], REG2 = 80h = = 33h 11h = 80h = = 33h 33h DS41350D-page 355 PIC18F/LF1XK50 MOVSS Move Indexed to Indexed PUSHL Syntax: Syntax: PUSHL k Operands: MOVSS [zs], [zd] 0 zs 127 0 zd 127 Operands: 0k 255 Operation: ((FSR2) + zs) ((FSR2) + zd) Operation: k (FSR2), FSR2 – 1 FSR2 Status Affected: None Status Affected: None Encoding: 1st word (source) 2nd word (dest.) 1110 1111 Description 1011 xxxx 1zzz xzzz zzzzs zzzzd The contents of the source register are moved to the destination register. The addresses of the source and destination registers are determined by adding the 7-bit literal offsets ‘zs’ or ‘zd’, respectively, to the value of FSR2. Both registers can be located anywhere in the 4096-byte data memory space (000h to FFFh). The MOVSS instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an indirect addressing register, the value returned will be 00h. If the resultant destination address points to an indirect addressing register, the instruction will execute as a NOP. Words: 2 Cycles: 2 Encoding: Q1 Decode Q2 Q3 Determine Determine source addr source addr Determine dest addr Example: 1010 kkkk kkkk The 8-bit literal ‘k’ is written to the data memory address specified by FSR2. FSR2 is decremented by 1 after the operation. This instruction allows users to push values onto a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process data Write to destination Example: PUSHL 08h Before Instruction FSR2H:FSR2L Memory (01ECh) = = 01ECh 00h After Instruction FSR2H:FSR2L Memory (01ECh) = = 01EBh 08h Q4 Read source reg Write to dest reg MOVSS [05h], [06h] Before Instruction FSR2 Contents of 85h Contents of 86h After Instruction FSR2 Contents of 85h Contents of 86h DS41350D-page 356 Determine dest addr 1111 Description: Q Cycle Activity: Decode Store Literal at FSR2, Decrement FSR2 = 80h = 33h = 11h = 80h = 33h = 33h Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 SUBFSR Subtract Literal from FSR SUBULNK Syntax: SUBFSR f, k Syntax: SUBULNK k Operands: 0 k 63 Operands: 0 k 63 f [ 0, 1, 2 ] Operation: Operation: FSR(f) – k FSRf Status Affected: None Encoding: 1110 FSR2 – k FSR2 (TOS) PC Status Affected: None 1001 ffkk kkkk Description: The 6-bit literal ‘k’ is subtracted from the contents of the FSR specified by ‘f’. Words: 1 Cycles: 1 Encoding: 1110 Q1 Q2 Q3 Q4 Decode Read register ‘f’ Process Data Write to destination SUBFSR 2, 23h 1001 11kk kkkk Description: The 6-bit literal ‘k’ is subtracted from the contents of the FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. This may be thought of as a special case of the SUBFSR instruction, where f = 3 (binary ‘11’); it operates only on FSR2. Words: 1 Cycles: 2 Q Cycle Activity: Example: Subtract Literal from FSR2 and Return Q Cycle Activity: Before Instruction FSR2 = Q1 Q2 Q3 Q4 03FFh Decode After Instruction FSR2 = Read register ‘f’ Process Data Write to destination 03DCh No Operation No Operation No Operation No Operation Example: 2010 Microchip Technology Inc. Preliminary SUBULNK 23h Before Instruction FSR2 = PC = 03FFh 0100h After Instruction FSR2 = PC = 03DCh (TOS) DS41350D-page 357 PIC18F/LF1XK50 25.2.3 Note: BYTE-ORIENTED AND BIT-ORIENTED INSTRUCTIONS IN INDEXED LITERAL OFFSET MODE Enabling the PIC18 instruction set extension may cause legacy applications to behave erratically or fail entirely. In addition to eight new commands in the extended set, enabling the extended instruction set also enables Indexed Literal Offset Addressing mode (Section 3.5.1 “Indexed Addressing with Literal Offset”). This has a significant impact on the way that many commands of the standard PIC18 instruction set are interpreted. When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations: either as a location in the Access Bank (‘a’ = 0), or in a GPR bank designated by the BSR (‘a’ = 1). When the extended instruction set is enabled and ‘a’ = 0, however, a file register argument of 5Fh or less is interpreted as an offset from the pointer value in FSR2 and not as a literal address. For practical purposes, this means that all instructions that use the Access RAM bit as an argument – that is, all byte-oriented and bitoriented instructions, or almost half of the core PIC18 instructions – may behave differently when the extended instruction set is enabled. When the content of FSR2 is 00h, the boundaries of the Access RAM are essentially remapped to their original values. This may be useful in creating backward compatible code. If this technique is used, it may be necessary to save the value of FSR2 and restore it when moving back and forth between C and assembly routines in order to preserve the Stack Pointer. Users must also keep in mind the syntax requirements of the extended instruction set (see Section 25.2.3.1 “Extended Instruction Syntax with Standard PIC18 Commands”). 25.2.3.1 Extended Instruction Syntax with Standard PIC18 Commands When the extended instruction set is enabled, the file register argument, ‘f’, in the standard byte-oriented and bit-oriented commands is replaced with the literal offset value, ‘k’. As already noted, this occurs only when ‘f’ is less than or equal to 5Fh. When an offset value is used, it must be indicated by square brackets (“[ ]”). As with the extended instructions, the use of brackets indicates to the compiler that the value is to be interpreted as an index or an offset. Omitting the brackets, or using a value greater than 5Fh within brackets, will generate an error in the MPASM™ assembler. If the index argument is properly bracketed for Indexed Literal Offset Addressing, the Access RAM argument is never specified; it will automatically be assumed to be ‘0’. This is in contrast to standard operation (extended instruction set disabled) when ‘a’ is set on the basis of the target address. Declaring the Access RAM bit in this mode will also generate an error in the MPASM assembler. The destination argument, ‘d’, functions as before. In the latest versions of the MPASM assembler, language support for the extended instruction set must be explicitly invoked. This is done with either the command line option, /y, or the PE directive in the source listing. 25.2.4 CONSIDERATIONS WHEN ENABLING THE EXTENDED INSTRUCTION SET It is important to note that the extensions to the instruction set may not be beneficial to all users. In particular, users who are not writing code that uses a software stack may not benefit from using the extensions to the instruction set. Although the Indexed Literal Offset Addressing mode can be very useful for dynamic stack and pointer manipulation, it can also be very annoying if a simple arithmetic operation is carried out on the wrong register. Users who are accustomed to the PIC18 programming must keep in mind that, when the extended instruction set is enabled, register addresses of 5Fh or less are used for Indexed Literal Offset Addressing. Additionally, the Indexed Literal Offset Addressing mode may create issues with legacy applications written to the PIC18 assembler. This is because instructions in the legacy code may attempt to address registers in the Access Bank below 5Fh. Since these addresses are interpreted as literal offsets to FSR2 when the instruction set extension is enabled, the application may read or write to the wrong data addresses. Representative examples of typical byte-oriented and bit-oriented instructions in the Indexed Literal Offset Addressing mode are provided on the following page to show how execution is affected. The operand conditions shown in the examples are applicable to all instructions of these types. When porting an application to the PIC18F/LF1XK50, it is very important to consider the type of code. A large, re-entrant application that is written in ‘C’ and would benefit from efficient compilation will do well when using the instruction set extensions. Legacy applications that heavily use the Access Bank will most likely not benefit from using the extended instruction set. DS41350D-page 358 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 ADDWF ADD W to Indexed (Indexed Literal Offset mode) BSF Bit Set Indexed (Indexed Literal Offset mode) Syntax: ADDWF Syntax: BSF [k], b Operands: 0 k 95 d [0,1] Operands: 0 f 95 0b7 Operation: (W) + ((FSR2) + k) dest Operation: 1 ((FSR2) + k)<b> Status Affected: N, OV, C, DC, Z Status Affected: None Encoding: [k] {,d} 0010 Description: 01d0 kkkk kkkk The contents of W are added to the contents of the register indicated by FSR2, offset by the value ‘k’. If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’, the result is stored back in register ‘f’ (default). Encoding: 1000 bbb0 kkkk kkkk Description: Bit ‘b’ of the register indicated by FSR2, offset by the value ‘k’, is set. Words: 1 Cycles: 1 Q Cycle Activity: Words: 1 Q1 Q2 Q3 Q4 Cycles: 1 Decode Read register ‘f’ Process Data Write to destination Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process Data Write to destination Example: ADDWF Example: Before Instruction FLAG_OFST FSR2 Contents of 0A0Ah After Instruction Contents of 0A0Ah [OFST] , 0 Before Instruction W OFST FSR2 Contents of 0A2Ch After Instruction W Contents of 0A2Ch = = = 17h 2Ch 0A00h = 20h = 37h = 20h BSF [FLAG_OFST], 7 = = 0Ah 0A00h = 55h = D5h SETF Set Indexed (Indexed Literal Offset mode) Syntax: SETF [k] Operands: 0 k 95 Operation: FFh ((FSR2) + k) Status Affected: None Encoding: 0110 1000 kkkk kkkk Description: The contents of the register indicated by FSR2, offset by ‘k’, are set to FFh. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read ‘k’ Process Data Write register Example: SETF Before Instruction OFST FSR2 Contents of 0A2Ch After Instruction Contents of 0A2Ch 2010 Microchip Technology Inc. Preliminary [OFST] = = 2Ch 0A00h = 00h = FFh DS41350D-page 359 PIC18F/LF1XK50 25.2.5 SPECIAL CONSIDERATIONS WITH MICROCHIP MPLAB® IDE TOOLS The latest versions of Microchip’s software tools have been designed to fully support the extended instruction set of the PIC18F/LF1XK50 family of devices. This includes the MPLAB® C18 C compiler, MPASM assembly language and MPLAB Integrated Development Environment (IDE). When selecting a target device for software development, MPLAB IDE will automatically set default Configuration bits for that device. The default setting for the XINST Configuration bit is ‘0’, disabling the extended instruction set and Indexed Literal Offset Addressing mode. For proper execution of applications developed to take advantage of the extended instruction set, XINST must be set during programming. To develop software for the extended instruction set, the user must enable support for the instructions and the Indexed Addressing mode in their language tool(s). Depending on the environment being used, this may be done in several ways: • A menu option, or dialog box within the environment, that allows the user to configure the language tool and its settings for the project • A command line option • A directive in the source code These options vary between different compilers, assemblers and development environments. Users are encouraged to review the documentation accompanying their development systems for the appropriate information. DS41350D-page 360 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 26.0 DEVELOPMENT SUPPORT 26.1 The PIC® microcontrollers and dsPIC® digital signal controllers are supported with a full range of software and hardware development tools: • Integrated Development Environment - MPLAB® IDE Software • Compilers/Assemblers/Linkers - MPLAB C Compiler for Various Device Families - HI-TECH C for Various Device Families - MPASMTM Assembler - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB Assembler/Linker/Librarian for Various Device Families • Simulators - MPLAB SIM Software Simulator • Emulators - MPLAB REAL ICE™ In-Circuit Emulator • In-Circuit Debuggers - MPLAB ICD 3 - PICkit™ 3 Debug Express • Device Programmers - PICkit™ 2 Programmer - MPLAB PM3 Device Programmer • Low-Cost Demonstration/Development Boards, Evaluation Kits, and Starter Kits MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8/16/32-bit microcontroller market. The MPLAB IDE is a Windows® operating system-based application that contains: • A single graphical interface to all debugging tools - Simulator - Programmer (sold separately) - In-Circuit Emulator (sold separately) - In-Circuit Debugger (sold separately) • A full-featured editor with color-coded context • A multiple project manager • Customizable data windows with direct edit of contents • High-level source code debugging • Mouse over variable inspection • Drag and drop variables from source to watch windows • Extensive on-line help • Integration of select third party tools, such as IAR C Compilers The MPLAB IDE allows you to: • Edit your source files (either C or assembly) • One-touch compile or assemble, and download to emulator and simulator tools (automatically updates all project information) • Debug using: - Source files (C or assembly) - Mixed C and assembly - Machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power. 2010 Microchip Technology Inc. Preliminary DS41350D-page 361 PIC18F/LF1XK50 26.2 MPLAB C Compilers for Various Device Families The MPLAB C Compiler code development systems are complete ANSI C compilers for Microchip’s PIC18, PIC24 and PIC32 families of microcontrollers and the dsPIC30 and dsPIC33 families of digital signal controllers. These compilers provide powerful integration capabilities, superior code optimization and ease of use. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. 26.3 HI-TECH C for Various Device Families For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. The compilers include a macro assembler, linker, preprocessor, and one-step driver, and can run on multiple platforms. MPASM Assembler The MPASM Assembler is a full-featured, universal macro assembler for PIC10/12/16/18 MCUs. The MPASM Assembler generates relocatable object files for the MPLINK Object Linker, Intel® standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM Assembler features include: MPLINK Object Linker/ MPLIB Object Librarian The MPLINK Object Linker combines relocatable objects created by the MPASM Assembler and the MPLAB C18 C Compiler. It can link relocatable objects from precompiled libraries, using directives from a linker script. The MPLIB Object Librarian manages the creation and modification of library files of precompiled code. When a routine from a library is called from a 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 object linker/library features include: The HI-TECH C Compiler code development systems are complete ANSI C compilers for Microchip’s PIC family of microcontrollers and the dsPIC family of digital signal controllers. These compilers provide powerful integration capabilities, omniscient code generation and ease of use. 26.4 26.5 • Efficient linking of single libraries instead of many smaller files • Enhanced code maintainability by grouping related modules together • Flexible creation of libraries with easy module listing, replacement, deletion and extraction 26.6 MPLAB Assembler, Linker and Librarian for Various Device Families MPLAB Assembler produces relocatable machine code from symbolic assembly language for PIC24, PIC32 and dsPIC devices. MPLAB C Compiler uses the assembler to produce its object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: • • • • • • Support for the entire device instruction set Support for fixed-point and floating-point data Command line interface Rich directive set Flexible macro language MPLAB IDE compatibility • 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 DS41350D-page 362 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 26.7 MPLAB SIM Software Simulator 26.9 The MPLAB SIM Software Simulator allows code development in a PC-hosted environment by simulating the PIC MCUs and dsPIC® DSCs on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. Registers can be logged to files for further run-time analysis. The trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on I/O, most peripherals and internal registers. The MPLAB SIM Software Simulator fully supports symbolic debugging using the MPLAB C Compilers, and the MPASM and MPLAB Assemblers. The software simulator offers the flexibility to develop and debug code outside of the hardware laboratory environment, making it an excellent, economical software development tool. 26.8 MPLAB REAL ICE In-Circuit Emulator System MPLAB REAL ICE In-Circuit Emulator System is Microchip’s next generation high-speed emulator for Microchip Flash DSC and MCU devices. It debugs and programs PIC® Flash MCUs and dsPIC® Flash DSCs with the easy-to-use, powerful graphical user interface of the MPLAB Integrated Development Environment (IDE), included with each kit. The emulator is connected to the design engineer’s PC using a high-speed USB 2.0 interface and is connected to the target with either a connector compatible with incircuit debugger systems (RJ11) or with the new highspeed, noise tolerant, Low-Voltage Differential Signal (LVDS) interconnection (CAT5). The emulator is field upgradable through future firmware downloads in MPLAB IDE. In upcoming releases of MPLAB IDE, new devices will be supported, and new features will be added. MPLAB REAL ICE offers significant advantages over competitive emulators including low-cost, full-speed emulation, run-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables. 2010 Microchip Technology Inc. MPLAB ICD 3 In-Circuit Debugger System MPLAB ICD 3 In-Circuit Debugger System is Microchip's most cost effective high-speed hardware debugger/programmer for Microchip Flash Digital Signal Controller (DSC) and microcontroller (MCU) devices. It debugs and programs PIC® Flash microcontrollers and dsPIC® DSCs with the powerful, yet easyto-use graphical user interface of MPLAB Integrated Development Environment (IDE). The MPLAB ICD 3 In-Circuit Debugger probe is connected to the design engineer's PC using a high-speed USB 2.0 interface and is connected to the target with a connector compatible with the MPLAB ICD 2 or MPLAB REAL ICE systems (RJ-11). MPLAB ICD 3 supports all MPLAB ICD 2 headers. 26.10 PICkit 3 In-Circuit Debugger/ Programmer and PICkit 3 Debug Express The MPLAB PICkit 3 allows debugging and programming of PIC® and dsPIC® Flash microcontrollers at a most affordable price point using the powerful graphical user interface of the MPLAB Integrated Development Environment (IDE). The MPLAB PICkit 3 is connected to the design engineer's PC using a full speed USB interface and can be connected to the target via an Microchip debug (RJ-11) connector (compatible with MPLAB ICD 3 and MPLAB REAL ICE). The connector uses two device I/O pins and the reset line to implement in-circuit debugging and In-Circuit Serial Programming™. The PICkit 3 Debug Express include the PICkit 3, demo board and microcontroller, hookup cables and CDROM with user’s guide, lessons, tutorial, compiler and MPLAB IDE software. Preliminary DS41350D-page 363 PIC18F/LF1XK50 26.11 PICkit 2 Development Programmer/Debugger and PICkit 2 Debug Express 26.13 Demonstration/Development Boards, Evaluation Kits, and Starter Kits The PICkit™ 2 Development Programmer/Debugger is a low-cost development tool with an easy to use interface for programming and debugging Microchip’s Flash families of microcontrollers. The full featured Windows® programming interface supports baseline (PIC10F, PIC12F5xx, PIC16F5xx), midrange (PIC12F6xx, PIC16F), PIC18F, PIC24, dsPIC30, dsPIC33, and PIC32 families of 8-bit, 16-bit, and 32-bit microcontrollers, and many Microchip Serial EEPROM products. With Microchip’s powerful MPLAB Integrated Development Environment (IDE) the PICkit™ 2 enables in-circuit debugging on most PIC® microcontrollers. In-Circuit-Debugging runs, halts and single steps the program while the PIC microcontroller is embedded in the application. When halted at a breakpoint, the file registers can be examined and modified. A wide variety of demonstration, development and evaluation boards for various PIC MCUs and dsPIC DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. The PICkit 2 Debug Express include the PICkit 2, demo board and microcontroller, hookup cables and CDROM with user’s guide, lessons, tutorial, compiler and MPLAB IDE software. 26.12 MPLAB PM3 Device Programmer The MPLAB PM3 Device Programmer is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features a large LCD display (128 x 64) for menus and error messages and a modular, detachable socket assembly to support various package types. The ICSP™ cable assembly is included as a standard item. In Stand-Alone mode, the MPLAB PM3 Device Programmer can read, verify and program PIC devices without a PC connection. It can also set code protection in this mode. The MPLAB PM3 connects to the host PC via an RS-232 or USB cable. The MPLAB PM3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an MMC card for file storage and data applications. DS41350D-page 364 The boards support a variety of features, including LEDs, temperature sensors, switches, speakers, RS-232 interfaces, LCD displays, potentiometers and additional EEPROM memory. The demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. In addition to the PICDEM™ and dsPICDEM™ demonstration/development board series of circuits, Microchip has a line of evaluation kits and demonstration software for analog filter design, KEELOQ® security ICs, CAN, IrDA®, PowerSmart battery management, SEEVAL® evaluation system, Sigma-Delta ADC, flow rate sensing, plus many more. Also available are starter kits that contain everything needed to experience the specified device. This usually includes a single application and debug capability, all on one board. Check the Microchip web page (www.microchip.com) for the complete list of demonstration, development and evaluation kits. Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.0 ELECTRICAL SPECIFICATIONS Absolute Maximum Ratings(†) Ambient temperature under bias....................................................................................................... -40°C to +125°C Storage temperature ........................................................................................................................ -65°C to +150°C Voltage on VDD with respect to VSS, PIC18F1XK50 .......................................................................... -0.3V to +6.0V Voltage on VDD with respect to VSS, PIC18LF1XK50 ........................................................................ -0.3V to +4.0V Voltage on MCLR with respect to Vss ................................................................................................. -0.3V to +9.0V Voltage on VUSB pin with respect to VSS ............................................................................................ -0.3V to +4.0V Voltage on D+ and D- pins with respect to VSS ...................................................................... -0.3V to (VUSB + 0.3V) Voltage on all other pins with respect to VSS ........................................................................... -0.3V to (VDD + 0.3V) Total power dissipation(1) ............................................................................................................................... 800 mW Maximum current out of VSS pin ...................................................................................................................... 95 mA Maximum current into VDD pin ......................................................................................................................... 95 mA Clamp current, IK (VPIN < 0 or VPIN > 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 all ports ................................................................................................................... 90 mA Maximum current sourced by all ports ............................................................................................................. 90 mA Note 1: 2: Power dissipation is calculated as follows: PDIS = VDD x {IDD – IOH} + {(VDD – VOH) x IOH} + (VOl x IOL). Vusb must always be VDD + 0.3V † 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 above maximum rating conditions for extended periods may affect device reliability. 2010 Microchip Technology Inc. Preliminary DS41350D-page 365 PIC18F/LF1XK50 27.1 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param. No. D001 Sym VDD Characteristic VDR D004* Max Units Conditions PIC18LF1XK50 1.8 2.7 — — 3.6 3.6 V V FOSC < = 20 MHz FOSC < = 48 MHz PIC18F1XK50 1.8 2.7 — — 5.5 5.5 V V FOSC < = 20 MHz FOSC < = 48 MHz RAM Data Retention Voltage(1) D002* VPOR* Typ† Supply Voltage D001 D002* Min PIC18LF1XK50 1.5 — — V Device in Sleep mode PIC18F1XK50 1.7 — — V Device in Sleep mode — 1.6 — V Power-on Reset Release Voltage VPORR* Power-on Reset Rearm Voltage — 0.8 — V VFVR Fixed Voltage Reference Voltage (calibrated) 0.974 1.968 3.736 1.024 2.048 4.096 1.064 2.158 4.226 V SVDD VDD Rise Rate to ensure internal Power-on Reset signal 0.05 — — V/ms FVR1S<1:0> = 00 (1x) FVR1S<1:0> = 01 (2x) FVR1S<1:0> = 10 (4x), VDD > = 4.75V * † These parameters are characterized but not tested. Data in “Typ” column is at 3.3V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered in Sleep mode without losing RAM data. DS41350D-page 366 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 27-1: POR AND POR REARM WITH SLOW RISING VDD VDD VPOR VPORR VSS NPOR POR REARM VSS TVLOW(2) Note 1: 2: 3: TPOR(3) When NPOR is low, the device is held in Reset. TPOR 1 s typical. TVLOW 2.7 s typical. 2010 Microchip Technology Inc. Preliminary DS41350D-page 367 PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics Conditions Min Typ† Max Units — 30 — A — — 5 — A — LP Clock mode and Sleep (requires FVR and BOR to be disabled) — 6.0 9 A 1.8 — 7 12 A 3.0 FOSC = 32 kHz LP Oscillator(4), -40°C TA +85°C — 6 11 A 1.8 — 7 17 A 3.0 VDD Note Supply Current (IDD)(1, 2) D009 LDO Regulator D010 D010 D011* D011* D011* D011* D011* D011* — 12 20 A 5.0 — 6.0 12 A 1.8 — 9.0 16 A 3.0 — 8.0 15 A 1.8 — 11 25 A 3.0 — 12 35 A 5.0 — 170 220 A 1.8 — 280 370 A 3.0 — 200 250 A 1.8 — 310 400 A 3.0 — 380 490 A 5.0 — 75 110 A 1.8 — 130 190 A 3.0 — 90 130 A 1.8 — 140 210 A 3.0 — 160 250 A 5.0 FOSC = 32 kHz LP Oscillator(4), -40°C TA +85°C FOSC = 32 kHz LP Oscillator -40°C TA +125°C FOSC = 32 kHz LP Oscillator (4) -40°C TA +125°C FOSC = 1 MHz XT Oscillator FOSC = 1 MHz XT Oscillator FOSC = 1 MHz XT Oscillator CPU Idle FOSC = 1 MHz XT Oscillator CPU Idle * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. DS41350D-page 368 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics Min Typ† — — — — Conditions Max Units 300 700 A 1.8 500 1200 A 3.0 330 700 A 1.8 530 1200 A 3.0 VDD Note Supply Current (IDD)(1, 2) D012 D012 D012A D012A D013 D013 D013A D013A D014 D014 — 730 1400 A 5.0 — 240 300 A 1.8 — 440 550 A 3.0 — 230 300 A 1.8 — 400 550 A 3.0 — 470 640 A 5.0 — 140 180 A 1.8 — 230 300 A 3.0 — 160 210 A 1.8 — 250 310 A 3.0 — 290 380 A 5.0 — 50 64 A 1.8 — 86 110 A 3.0 — 70 100 A 1.8 — 100 150 A 3.0 — 120 170 A 5.0 — 500 640 A 1.8 — 830 1100 A 3.0 — 520 660 A 1.8 — 860 1100 A 3.0 — 1000 1300 A 5.0 FOSC = 4 MHz XT Oscillator FOSC = 4 MHz XT Oscillator FOSC = 4 MHz, XT Oscillator CPU Idle FOSC = 4 MHz XT Oscillator CPU Idle FOSC = 1 MHz EC Oscillator (medium power) FOSC = 1 MHz EC Oscillator (medium power)(5) FOSC = 1 MHz EC Oscillator (medium power) CPU Idle FOSC = 1 MHz EC Oscillator (medium power) CPU Idle(5) FOSC = 4 MHz EC Oscillator (medium power) FOSC = 4 MHz EC Oscillator (medium power)(5) * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. 2010 Microchip Technology Inc. Preliminary DS41350D-page 369 PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics Conditions Min Typ† Max Units — 200 250 A 1.8 — 340 440 A 3.0 — 210 280 A 1.8 — 360 470 A 3.0 — 430 570 A 5.0 — 820 1000 A 1.8 — 1500 1900 A 3.0 VDD Note Supply Current (IDD)(1, 2) D014A D014A D015 D015 D015A D015A — 830 1100 A 1.8 — 1500 1900 A 3.0 — 1700 2300 A 5.0 — 300 370 A 1.8 — 510 660 A 3.0 — 320 430 A 1.8 — 530 690 A 3.0 FOSC = 4 MHz EC Oscillator (medium power) CPU Idle FOSC = 4 MHz EC Oscillator (medium power) CPU Idle(5) FOSC = 6 MHz EC Oscillator (high power) FOSC = 6 MHz EC Oscillator (high power)(5) FOSC = 6 MHz EC Oscillator (high power) CPU Idle FOSC = 6 MHz EC Oscillator (high power) CPU Idle(5) — 640 840 A 5.0 D015B — 4.7 6.0 mA 3.0 FOSC = 24 MHz 6 MHz EC Oscillator (high power) PLL enabled D015B — 4.7 6.1 mA 3.0 — 5.6 7.4 mA 5.0 FOSC = 24 MHz 6 MHz EC Oscillator (high power) PLL enabled(5) D015C — 2.0 2.5 mA 3.0 FOSC = 24 MHz 6 MHz EC Oscillator (high power) PLL enabled, CPU Idle D015C — 2.0 2.5 mA 3.0 — 2.3 3.0 mA 5.0 FOSC = 24 MHz 6 MHz EC Oscillator (high power) PLL enabled, CPU Idle(5) * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. DS41350D-page 370 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics Conditions Min Typ† Max Units D016 — 2.6 3.3 mA 3.0 FOSC = 12 MHz EC Oscillator (high power) D016 — 2.6 3.3 mA 3.0 — 3.1 4.1 mA 5.0 FOSC = 12 MHz EC Oscillator (high power)(5) D017 — 1.0 1.3 mA 3.0 FOSC = 12 MHz EC Oscillator (high power) CPU Idle D017 — 1.0 1.3 mA 3.0 — 1.2 1.6 mA 5.0 FOSC = 12 MHz EC Oscillator (high power) CPU Idle(5) D017A — 9 12 mA 3.0 FOSC = 48 MHz 12 MHz EC Oscillator (high power) PLL enabled D017A — 8.9 12 mA 3.0 — 11 14 mA 5.0 FOSC = 48 MHz 12 MHz EC Oscillator (high power) PLL enabled(5) D017B — 3.9 5.0 mA 3.0 FOSC = 48 MHz 12 MHz EC Oscillator (high power) PLL enabled, CPU Idle D017B — 3.9 5.0 mA 3.0 — 4.7 6.0 mA 5.0 FOSC = 48 MHz 12 MHz EC Oscillator (high power) PLL enabled, CPU Idle(5) — 19 38 A 1.8 — 23 44 A 3.0 — 21 40 A 1.8 — 25 46 A 3.0 VDD Note Supply Current (IDD)(1, 2) D018 D018 D019 D019 — 26 48 A 5.0 — 16 33 A 1.8 — 18 38 A 3.0 — 18 35 A 1.8 — 20 40 A 3.0 — 21 42 A 5.0 FOSC = 32 kHz LFINTOSC Oscillator mode(3, 5) FOSC = 32 kHz LFINTOSC Oscillator mode(3, 5) FOSC = 32 kHz LFINTOSC Oscillator CPU Idle FOSC = 32 kHz LFINTOSC Oscillator CPU Idle(5) Supply Current (IDD)(1, 2) * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. 2010 Microchip Technology Inc. Preliminary DS41350D-page 371 PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics D020 D020 D021 D021 D021A D021A Conditions Min Typ† Max Units — 320 430 A 1.8 — 460 600 A 3.0 — 350 460 A 1.8 — 490 630 A 3.0 — 540 710 A 5.0 — 380 530 A 1.8 — 550 770 A 3.0 — 410 530 A 1.8 — 580 770 A 3.0 VDD — 650 900 A 5.0 — 290 400 A 1.8 — 410 560 A 3.0 — 320 420 A 1.8 — 440 570 A 3.0 — 490 680 A 5.0 D022 — 1.2 1.6 mA 1.8 — 2.1 2.9 mA 3.0 D022 — 1.2 1.6 mA 1.8 — 2.1 2.9 mA 3.0 — 2.4 3.5 mA 5.0 — 2.0 2.7 mA 1.8 — 3.5 4.8 mA 3.0 — 2.0 2.7 mA 1.8 — 3.5 4.8 mA 3.0 D023 D023 D023A D023A — 4.0 6.0 mA 5.0 — 0.9 1.3 mA 1.8 — 1.5 2.1 mA 3.0 — 0.9 1.3 mA 1.8 — 1.5 2.1 mA 3.0 — 1.7 2.6 mA 5.0 Note FOSC = 500 kHz LFINTOSC Oscillator FOSC = 500 kHz LFINTOSC Oscillator(5) FOSC = 1 MHz HFINTOSC Oscillator FOSC = 1 MHz HFINTOSC Oscillator(5) FOSC = 1 MHz HFINTOSC Oscillator CPU Idle FOSC = 1 MHz HFINTOSC Oscillator CPU Idle(5) FOSC = 8 MHz HFINTOSC Oscillator FOSC = 8 MHz HFINTOSC Oscillator(5) FOSC = 16 MHz HFINTOSC Oscillator FOSC = 16 MHz HFINTOSC Oscillator(5) FOSC = 16 MHz HFINTOSC Oscillator CPU Idle FOSC = 16 MHz HFINTOSC Oscillator CPU Idle(5) Supply Current (IDD)(1, 2) * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. DS41350D-page 372 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.2 DC Characteristics: PIC18F/LF1XK50-I/E (Industrial, Extended) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics D024 D024 D025 D025 Conditions Min Typ† Max Units — 0.5 0.7 mA 1.8 — 0.9 1.1 mA 3.0 — 0.5 0.7 mA 1.8 — 0.9 1.1 mA 3.0 — 1.0 1.4 mA 5.0 — 1.0 1.1 mA 1.8 — 2.1 2.0 mA 3.0 — 1.0 1.1 mA 1.8 — 2.1 2.0 mA 3.0 VDD Note FOSC = 4 MHz EXTRC Oscillator mode FOSC = 4 MHz EXTRC Oscillator mode(5) FOSC = 6 MHz HS Oscillator FOSC = 6 MHz HS Oscillator(5) — 3.5 2.5 mA 5.0 D025A — 5.4 6.0 mA 3.0 FOSC = 24 MHz 6 MHz HS Oscillator PLL enabled D025A — 5.4 6.0 mA 3.0 — 7.4 7.6 mA 5.0 FOSC = 24 MHz 6 MHz HS Oscillator PLL enabled(5) D026 — 3.2 3.3 mA 3.0 FOSC = 12 MHz HS Oscillator D026 — 3.2 3.3 mA 3.0 — 4.8 4.2 mA 5.0 FOSC = 12 MHz HS Oscillator(5) D026A — 10 12 mA 3.0 FOSC = 48 MHz, 12 MHz HS Oscillator PLL enabled D026A — 10 12 mA 3.0 — 13 15 mA 5.0 FOSC = 48 MHz, 12 MHz HS Oscillator PLL enabled(5) * These parameters are characterized but not tested. Legend: TBD = To Be Determined Note 1: 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 disabled. 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. 3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended by the formula IR = VDD/2REXT (mA) with REXT in k 4: FVR and BOR are disabled. 5: 330 nF capacitor on VUSB pin. 2010 Microchip Technology Inc. Preliminary DS41350D-page 373 PIC18F/LF1XK50 27.3 DC Characteristics: PIC18F/LF1XK50-I/E (Power-Down) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Device Characteristics Power-down Base Current Conditions Typ† Max +85°C Max +125°C Units — 0.024 0.7 6.7 A 1.8 — 0.078 1.9 8.5 A 3.0 — 6.0 7.0 13 A 1.8 — 7.0 10 15 A 3.0 — 8.0 12 19 A 5.0 — 0.45 1.3 4.4 A 1.8 — 0.75 2.0 6.0 A 3.0 — 6.5 7.0 10.5 A 1.8 — 9.6 10.6 17.6 A 3.0 — 10.5 16.5 20 A 5.0 — 12 17 23 A 1.8 — 22 19 25 A 3.0 — 28 42 50 A 1.8 — 35.6 45.6 55 A 3.0 — 38.5 49 60 A 5.0 — — — — A 1.8 — — 21 27 A 3.0 — — — — A 1.8 — 27 48 51 A 3.0 — 36.5 51 55 A 5.0 — 0.79 3.6 5.3 A 1.8 — 1.8 2.9 6.9 A 3.0 — 8.0 7.5 10 A 1.8 — 8.5 10.5 15 A 3.0 — 10.5 12.5 24 A 5.0 Min VDD Note (IPD)(2) D027 D027 WDT, BOR, FVR, Voltage Regulator and T1OSC disabled, all Peripherals Inactive WDT, BOR, FVR and T1OSC disabled, all Peripherals Inactive Power-down Module Current D028 D028 D029 D029 D030 D030 D031 D031 Legend: * † Note 1: 2: 3: 4: 5: LPWDT Current(1) LPWDT Current(1) FVR current (3) FVR current(3, 5) BOR Current(1, 3) BOR Current(1, 3, 5) T1OSC Current(1) T1OSC Current(1) TBD = To Be Determined These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max values should be used when calculating total current consumption. 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 high-impedance state and tied to VDD. Fixed Voltage Reference is automatically enabled whenever the BOR is enabled A/D oscillator source is FRC 330 f capacitor on VUSB pin. DS41350D-page 374 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.3 DC Characteristics: PIC18F/LF1XK50-I/E (Power-Down) (Continued) PIC18LF1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended PIC18F1XK50 Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Param No. Min Typ† Max +85°C Max +125°C Units — — 1.8 8 — — 3 — — — — D033 — — D033 — — Device Characteristics Conditions VDD Note A 1.8 10 A 3.0 A/D Current(1, 4), no conversion in progress 6 12 A 1.8 — 10 17 A 3.0 — 11.5 22 A 5.0 — 38 44 A 1.8 — 40 47 A 3.0 30 40 49 A 2.0 34 44 53 A 3.0 — 36 50 60 A 5.0 — — 239 244 A 1.8 — — 242 249 A 3.0 — 144 243 250 A 2.0 — 146 247 256 A 3.0 Power-down Module Current D032 D032 D033A D033A D034 D034 Legend: * † Note 1: 2: 3: 4: 5: — 151 253 264 A 5.0 — — 18 23 A 1.8 — — 30 35 A 3.0 — 35 36 44 A 2.0 — 43 44 60 A 3.0 — 55 65 74 A 5.0 A/D Current(1, 4), no conversion in progress Comparator Current, low power Comparator Current, low power Comparator Current, high power Comparator Current, high power Voltage Reference Current Voltage Reference Current TBD = To Be Determined These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max values should be used when calculating total current consumption. 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 high-impedance state and tied to VDD. Fixed Voltage Reference is automatically enabled whenever the BOR is enabled A/D oscillator source is FRC 330 f capacitor on VUSB pin. 2010 Microchip Technology Inc. Preliminary DS41350D-page 375 PIC18F/LF1XK50 27.4 DC Characteristics: PIC18F/LF1XK50-I/E DC CHARACTERISTICS Param No. Sym VIL Characteristic Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Min Typ† Max Units — — with Schmitt Trigger buffer with I2C levels Conditions — 0.8 V 4.5V VDD 5.5V — 0.15 VDD V 1.8V VDD 4.5V — — 0.2 VDD V 1.8V VDD 5.5V — — 0.3 VDD V Input Low Voltage I/O PORT: D036 with TTL buffer D036A D037 D038 MCLR, OSC1 (RC mode)(1) — — 0.2 VDD V D039A OSC1 (HS mode) — — 0.3 VDD V — — 2.0 — — V 4.5V VDD 5.5V 0.25 VDD + 0.8 — — V 1.8V VDD 4.5V with Schmitt Trigger buffer 0.8 VDD — — V 1.8V VDD 5.5V with I2C levels 0.7 VDD — — V VIH Input High Voltage I/O ports: D040 with TTL buffer D040A D041 D042 MCLR 0.8 VDD — — V D043A OSC1 (HS mode) 0.7 VDD — — V D043B OSC1 (RC mode) 0.9 VDD — — V (Note 1) — ±5 ± 100 nA VSS VPIN VDD, Pin at high-impedance IIL Input Leakage Current(2) D060 I/O ports D061 MCLR(3) — ± 50 ± 200 nA VSS VPIN VDD D063 OSC1 — ±5 ± 100 nA VSS VPIN VDD, XT, HS and LP oscillator configuration 50 250 400 A VDD = 5.0V, VPIN = VSS — — VSS+0.6 VSS+0.6 VSS+0.6 V IOH = 8mA, VDD = 5V IOH = 6mA, VDD = 3.3V IOH = 3mA, VDD = 1.8V VDD-0.7 VDD-0.7 VDD-0.7 — — V IOL = 3.5mA, VDD = 5V IOL = 3mA, VDD = 3.3V IOL = 2mA, VDD = 1.8V IPUR PORTB Weak Pull-up Current VOL Output Low Voltage(4) D070* D080 I/O ports VOH D090 Output High Voltage(4) I/O ports Legend: * † Note 1: 2: 3: 4: TBD = To Be Determined These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended to use an external clock in RC mode. Negative current is defined as current sourced by the pin. 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. Including OSC2 in CLKOUT mode. DS41350D-page 376 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.4 DC Characteristics: PIC18F/LF1XK50-I/E (Continued) DC CHARACTERISTICS Param No. Sym Characteristic Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +85°C for industrial -40°C TA +125°C for extended Min Typ† Max Units Conditions — — 15 pF — — 50 pF Cell Endurance 10K 100K — — E/W VDD for Read VMIN — — V VDD + 1.5 — 9.0 V Temperature during programming: -40°C TA 85°C VDD for Bulk Erase TBD 2.1 — V Temperature during programming: 10°C TA 40°C VPEW VDD for Write or Row Erase VMIN — — V VMIN = Minimum operating voltage VMAX = Maximum operating voltage IPPPGM Current on MCLR/VPP during Erase/Write — — 5.0 mA 5.0 mA Capacitive Loading Specs on Output Pins D101* COSC2 OSC2 pin D101A* CIO All I/O pins In XT, HS and LP modes when external clock is used to drive OSC1 Flash Memory D130 EP D131 Voltage on MCLR/VPP during Erase/Program D132 IDDPGM Current on VDD during Erase/Write — D133 TPEW Erase/Write cycle time — D134 TRETD Characteristic Retention 40 — 4.0 ms — Year Program Flash Memory Data Flash Memory Provided no other specifications are violated VUSB Capacitor Charging D135 Charging current — 200 — A D135A Source/sink capability when charging complete — 0.0 — mA Legend: * † Note 1: 2: 3: 4: TBD = To Be Determined These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended to use an external clock in RC mode. Negative current is defined as current sourced by the pin. 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. Including OSC2 in CLKOUT mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 377 PIC18F/LF1XK50 27.5 USB Module Specifications Operating Conditions-40°C TA +85°C (unless otherwise state) Param No. Sym Characteristic Min Typ Max Units Conditions D313 VUSB USB Voltage 3.0 — 3.6 V D314 IIL Input Leakage on pin — — ±1 A D315 — — 0.8 V 2.0 — — V For VUSB range D318 VILUSB Input Low Voltage for USB Buffer VIHUSB Input High Voltage for USB Buffer VDIFS Differential Input Sensitivity Voltage on VUSB pin must be in this range for proper USB operation VSS VPIN VDD pin athigh impedance For VUSB range — — 0.2 V The difference between D+ and D- must exceed this value while VCM is met D319 VCM D316 Differential Common Mode 0.8 — 2.5 V Range Driver Output Impedance(1) 28 — 44 D320 ZOUT D321 VOL Voltage Output Low 0.0 — 0.3 V 1.5 kload connected to 3.6V D322 VOH Voltage Output High 2.8 — 3.6 V 1.5 kload connected to ground Note 1: The D+ and D- signal lines have been built-in impedance matching resistors. No external resistors, capacitors or magnetic components are necessary on the D+/D- signal paths between the PIC18F1XK50/PIC18LF1XK50 family device and USB cable. DS41350D-page 378 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.6 Thermal Considerations Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +125°C Param No. TH01 TH02 TH03 TH04 TH05 Sym Characteristic JA Thermal Resistance Junction to Ambient JC TJMAX PD Thermal Resistance Junction to Case Maximum Junction Temperature Power Dissipation PINTERNAL Internal Power Dissipation Typ Units Conditions 62.4 C/W 20-pin PDIP package 85.2 C/W 20-pin SOIC package 108.1 C/W 20-pin SSOP package TBD C/W 20-pin QFN 5x5mm package 31.4 C/W 20-pin PDIP package 24 C/W 20-pin SOIC package 24 C/W 20-pin SSOP package 150 C — W PD = PINTERNAL + PI/O — W PINTERNAL = IDD x VDD(1) TH06 PI/O I/O Power Dissipation — W PI/O = (IOL * VOL) + (IOH * (VDD - VOH)) TH07 PDER Derated Power — W PDER = PDMAX (TJ - TA)/JA(2) Legend: Note 1: 2: 3: TBD = To Be Determined IDD is current to run the chip alone without driving any load on the output pins. TA = Ambient Temperature TJ = Junction Temperature 2010 Microchip Technology Inc. Preliminary DS41350D-page 379 PIC18F/LF1XK50 27.7 Timing Parameter Symbology The timing parameter symbols have been created with one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKOUT cs CS di SDI do SDO dt Data in io I/O PORT mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (High-impedance) L Low FIGURE 27-2: T Time osc rd rw sc ss t0 t1 wr OSC1 RD RD or WR SCK SS T0CKI T1CKI WR P R V Z Period Rise Valid High-impedance LOAD CONDITIONS Load Condition Pin CL VSS Legend: CL = 50 pF for all pins, 15 pF for OSC2 output DS41350D-page 380 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 27.8 AC Characteristics: PIC18F1XK50/PIC18LF1XK50-I/E FIGURE 27-3: CLOCK TIMING Q4 Q1 Q2 Q3 Q4 Q1 OSC1/CLKIN OS02 OS04 OS04 OS03 OSC2/CLKOUT (LP,XT,HS Modes) OSC2/CLKOUT (CLKOUT Mode) PIC18F1XK50 VOLTAGE FREQUENCY GRAPH, -40°C TA +85°C FIGURE 27-4: 5.5 VDD (V) 3.6 2.7 1.8 0 10 20 40 48 Frequency (MHz) Note 1: The shaded region indicates the permissible combinations of voltage and frequency. 2: Refer to Table 27-1 for each Oscillator mode’s supported frequencies. 2010 Microchip Technology Inc. Preliminary DS41350D-page 381 PIC18F/LF1XK50 PIC18LF1XK50 VOLTAGE FREQUENCY GRAPH, -40°C TA +125°C FIGURE 27-5: VDD (V) 3.6 2.7 1.8 0 10 20 40 48 Frequency (MHz) Note 1: The shaded region indicates the permissible combinations of voltage and frequency. 2: Refer to Table 27-1 for each Oscillator mode’s supported frequencies. FIGURE 27-6: HFINTOSC FREQUENCY ACCURACY OVER DEVICE VDD AND TEMPERATURE 125 + 5% Temperature (°C) 85 60 ± 2% 25 0 -20 -40 1.8 ± 5% 2.0 2.5 3.0 3.3(2) 3.5 4.0 4.5 5.0 5.5 VDD (V) Note 1: This chart covers both regulator enabled and regulator disabled states. 2: Regulator Nominal voltage DS41350D-page 382 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 27-1: CLOCK OSCILLATOR TIMING REQUIREMENTS Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +125°C Param No. OS01 Sym FOSC Characteristic External CLKIN Frequency(1) Oscillator Frequency(1) OS02 TOSC External CLKIN Period(1) Oscillator Period(1) Min Typ† Max Units Conditions DC — 37 kHz DC — 4 MHz EC Oscillator mode (medium) DC — 48 MHz EC Oscillator mode (high) EC Oscillator mode (low) — 32.768 33 kHz LP Oscillator mode 0.1 — 4 MHz XT Oscillator mode 1 — 20 MHz HS Oscillator mode DC — 4 MHz RC Oscillator mode 27 — s LP Oscillator mode 250 — ns XT Oscillator mode 50 — ns HS Oscillator mode 20.80 — ns EC Oscillator mode — 30.5 — s LP Oscillator mode 250 — 10,000 ns XT Oscillator mode 50 — 1,000 ns HS Oscillator mode 250 — — ns RC Oscillator mode TCY = 4/FOSC OS03 TCY Instruction Cycle Time(1) 83 TCY DC ns OS04* TosH, TosL External CLKIN High, External CLKIN Low 2 — — s LP oscillator 100 — — ns XT oscillator 20 — — ns HS oscillator TosR, TosF External CLKIN Rise, External CLKIN Fall 0 — ns LP oscillator 0 — ns XT oscillator 0 — ns HS oscillator OS05* * † These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. 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 OSC1 pin. When an external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices. 2010 Microchip Technology Inc. Preliminary DS41350D-page 383 PIC18F/LF1XK50 TABLE 27-2: OSCILLATOR PARAMETERS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param No. OS08 Sym HFOSC OS10* Characteristic Internal Calibrated HFINTOSC Frequency(2) TIOSC ST HFINTOSC Wake-up from Sleep Start-up Time Freq. Tolerance Min Typ† Max Units 2% — 16.0 — MHz 0°C TA +85°C 5% — 16.0 — MHz -40°C TA +125°C — — 5 7 s VDD = 2.0V, -40°C to +85°C — — 5 7 s VDD = 3.0V, -40°C to +85°C — — 5 7 s VDD = 5.0V, -40°C to +85°C Conditions * † These parameters are characterized but not tested. 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: Instruction cycle period (TCY) equals four times the input oscillator time base period. 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 pin. When an external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices. 2: To ensure these oscillator frequency tolerances, VDD and VSS must be capacitively decoupled as close to the device as possible. 0.1 F and 0.01 F values in parallel are recommended. 3: By design. TABLE 27-3: Param No. PLL CLOCK TIMING SPECIFICATIONS (VDD = 42.7V TO 5.5V) Min Typ† Max Units FOSC Oscillator Frequency Range 4 — 12 MHz F11 FSYS On-Chip VCO System Frequency 16 — 48 MHz F12 trc PLL Start-up Time (Lock Time) — — 2 ms CLK CLKOUT Stability (Jitter) -0.25% — +0.25% % F10 F13* Sym Characteristic Conditions * These parameters are characterized but not tested. † Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. DS41350D-page 384 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 27-7: CLKOUT AND I/O TIMING Cycle Write Fetch Read Execute Q4 Q1 Q2 Q3 FOSC OS12 OS11 OS20 OS21 CLKOUT OS19 OS18 OS16 OS13 OS17 I/O pin (Input) OS14 OS15 I/O pin (Output) New Value Old Value OS18, OS19 TABLE 27-4: CLKOUT AND I/O TIMING PARAMETERS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param No. OS11 OS12 Sym TosH2ckL Characteristic Fosc to CLKOUT (1) TosH2ckH Fosc to CLKOUT (1) (1) OS13 TckL2ioV CLKOUT to Port out valid OS14 OS15 OS16 TioV2ckH TosH2ioV TosH2ioI OS17 TioV2osH OS18 TioR Port input valid before CLKOUT(1) Fosc (Q1 cycle) to Port out valid Fosc (Q2 cycle) to Port input invalid (I/O in hold time) Port input valid to Fosc(Q2 cycle) (I/O in setup time) Port output rise time(2) OS19 TioF Port output fall time(2) Typ† Max Units Conditions — — 70 ns VDD = 3.3-5.0V — — 72 ns VDD = 3.3-5.0V — — 20 ns TOSC + 200 ns — 50 — 50 — — 70* — ns ns ns 20 — — ns — — — — 25 TCY 40 15 28 15 — — 72 32 55 30 — — ns OS20* Tinp OS21* Trbp * † Min INT pin input high or low time PORTB interrupt-on-change new input level time These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25C unless otherwise stated. ns VDD = 3.3-5.0V VDD = 3.3-5.0V VDD = 2.0V VDD = 3.3-5.0V VDD = 2.0V VDD = 3.3-5.0V ns ns Note 1: Measurements are taken in RC mode where CLKOUT output is 4 x TOSC. 2: Includes OSC2 in CLKOUT mode. 2010 Microchip Technology Inc. Preliminary DS41350D-page 385 PIC18F/LF1XK50 FIGURE 27-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR 33 PWRT Time-out 32 OSC Start-Up Time Internal Reset(1) Watchdog Timer Reset(1) 31/ 31A 34 34 I/O pins Note 1: Asserted low. FIGURE 27-9: BROWN-OUT RESET TIMING AND CHARACTERISTICS VDD VBOR and VHYST VBOR (Device in Brown-out Reset) (Device not in Brown-out Reset) TBORREJ 37 Reset 33(1) (due to BOR) Note 1: 64 ms delay only if PWRTE bit in the Configuration Word register is programmed to ‘0’. 2 ms delay if PWRTE = 0. DS41350D-page 386 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 27-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER, AND BROWN-OUT RESET PARAMETERS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param No. Sym Characteristic Min Typ† Max Units Conditions 30 TMCL MCLR Pulse Width (low) 2 5 — — — — s s VDD = 3.3-5V, -40°C to +85°C VDD = 3.3-5V 31 TWDT Standard Watchdog Timer Time-out Period(5) 10 10 17 17 27 30 ms ms VDD = 3.3V-5V, -40°C to +85°C VDD = 3.3V-5V 31A TWDTLP Low Power Watchdog Timer Time-out Period 10 10 18 18 27 33 ms ms VDD = 3.3V-5V, -40°C to +85°C VDD = 3.3V-5V 32 TOST Oscillator Start-up Timer Period(1), (2) — 1024 — 33* TPWRT Power-up Timer Period, PWRTE = 0 40 65 140 ms 34* TIOZ I/O high-impedance from MCLR Low or Watchdog Timer Reset — — 2.0 s 35 VBOR Brown-out Reset Voltage TBD TBD TBD TBD 1.9 2.2 2.7 2.85 TBD TBD TBD TBD V V V V 36* VHYST Brown-out Reset Hysteresis 25 50 75 mV -40°C to +85°C 37* TBORDC Brown-out Reset DC Response Time 1 3 5 10 s VDD VBOR, -40°C to +85°C VDD VBOR Tosc (Note 3) BORV = 1.9V BORV = 2.2V BORV = 2.7V BORV = 2.85V Legend: TBD = To Be Determined * These parameters are characterized but not tested. † Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. 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 pin. When an external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices. 2: By design. 3: Period of the slower clock. 4: To ensure these voltage tolerances, VDD and VSS must be capacitively decoupled as close to the device as possible. 0.1 F and 0.01 F values in parallel are recommended. 5: Design Target. If unable to meet this target, the maximum can be increased, but the minimum cannot be changed. 2010 Microchip Technology Inc. Preliminary DS41350D-page 387 PIC18F/LF1XK50 FIGURE 27-10: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS T0CKI 40 41 42 T1CKI 45 46 49 47 TMR0 or TMR1 TABLE 27-6: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param No. 40* Sym TT0H Characteristic T0CKI High Pulse Width Min No Prescaler With Prescaler TT0L 41* T0CKI Low Pulse Width No Prescaler With Prescaler 42* TT0P T0CKI Period 45* TT1H T1CKI High Synchronous, No Prescaler Time Synchronous, with Prescaler Asynchronous TT1L 46* T1CKI Low Time Max Units 0.5 TCY + 20 — — ns 10 — — ns 0.5 TCY + 20 — — ns 10 — — ns Greater of: 20 or TCY + 40 N — — ns 0.5 TCY + 20 — — ns 15 — — ns 30 — — ns Synchronous, No Prescaler 0.5 TCY + 20 — — ns Synchronous, with Prescaler 15 — — ns Asynchronous 30 — — ns Greater of: 30 or TCY + 40 N — — ns 47* TT1P T1CKI Input Synchronous Period 48 FT1 Timer1 Oscillator Input Frequency Range (oscillator enabled by setting bit T1OSCEN) 49* TCKEZTMR1 Delay from External Clock Edge to Timer Increment Asynchronous * † Typ† 60 — — ns 32.4 32.768 33.1 kHz 2 TOSC — 7 TOSC — Conditions N = prescale value (2, 4, ..., 256) N = prescale value (1, 2, 4, 8) Timers in Sync mode These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. DS41350D-page 388 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 27-11: CAPTURE/COMPARE/PWM TIMINGS (CCP) CCPx (Capture mode) CC01 CC02 CC03 Note: Refer to Figure 27-2 for load conditions. TABLE 27-7: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP) Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param No. Sym Characteristic CC01* TccL CCPx Input Low Time CC02* TccH CCPx Input High Time CC03* TccP * † Min Typ† Max Units 0.5TCY + 20 — — ns With Prescaler 20 — — ns No Prescaler 0.5TCY + 20 — — ns With Prescaler 20 — — ns 3TCY + 40 N — — ns No Prescaler CCPx Input Period Conditions N = prescale value (1, 4 or 16) These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. TABLE 27-8: PIC18F1XK50/PIC18LF1XK50 A/D CONVERTER (ADC) CHARACTERISTICS: Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +125°C Param Sym No. Characteristic Min Typ† Max Units Conditions AD01 NR Resolution — — 10 AD02 EIL Integral Error — — ±2 LSb VREF = 5.0V AD03 EDL Differential Error — — 1.5 LSb No missing codes VREF = 5.0V AD04 EOFF Offset Error — — ±3 LSb VREF = 5.0V LSb VREF = 5.0V AD05 EGN — — ±3 AD06 VREF Change in Reference Voltage = VREF+ - VREF-(3) 1.8 — VDD AD07 VAIN Full-Scale Range VSS — VREF AD08 ZAIN Recommended Impedance of Analog Voltage Source — — 2.5 AD09* IREF * † Note 1: 2: 3: 4: Gain Error VREF Input Current (3) bit V 1.8 VREF+ VDD + 0.3V VSS - 0.3V VREF- VREF+ - 1.8V V k Can go higher if external 0.01F capacitor is present on input pin. 10 — 1000 A During VAIN acquisition. Based on differential of VHOLD to VAIN. — — 10 A During A/D conversion cycle. These parameters are characterized but not tested. Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Total Absolute Error includes integral, differential, offset and gain errors. The A/D conversion result never decreases with an increase in the input voltage and has no missing codes. ADC VREF is from external VREF, VDD pin or FVR, whichever is selected as reference input. When ADC is off, it will not consume any current other than leakage current. The power-down current specification includes any such leakage from the ADC module. 2010 Microchip Technology Inc. Preliminary DS41350D-page 389 PIC18F/LF1XK50 FIGURE 27-12: A/D CONVERSION TIMING BSF ADCON0, GO (Note 2) 131 Q4 130 132 A/D CLK 9 A/D DATA 8 7 .. . ... 2 1 0 NEW_DATA OLD_DATA ADRES TCY ADIF GO DONE SAMPLING STOPPED SAMPLE 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. TABLE 27-9: A/D CONVERSION REQUIREMENTS Param Symbol No. 130 TAD Characteristic A/D Clock Period Min Max Units 0.7 25.0(1) s TOSC based, VREF 3.0V TBD 1 s A/D RC mode 11 12 TAD 1.4 TBD — — s s 131 TCNV Conversion Time (not including acquisition time)(2) 132 TACQ Acquisition Time(3) 135 TSWC Switching Time from Convert Sample — (Note 4) TBD TDIS Discharge Time 0.2 — Legend: Note 1: 2: 3: 4: Conditions -40C to +85C 0C to +85C s TBD = To Be Determined The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. ADRES register may be read on the following TCY cycle. The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50 . On the following cycle of the device clock. DS41350D-page 390 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 27-10: COMPARATOR SPECIFICATIONS Operating Conditions: 1.8V < VDD < 3.6V, -40°C < TA < +125°C (unless otherwise stated). Param No. Sym Characteristics Input Offset Voltage Min Typ Max Units Comments — — ±7.5 — ±50 ±80 mV mV High Power Mode Low Power Mode CM01 VIOFF CM02 VICM Input Common Mode Voltage 0 — VDD V CM03 CMRR Common Mode Rejection Ratio 55 — — dB CM04 TRESP Response Time — 150 400 ns CM05 TMC2OV Comparator Mode Change to Output Valid* — — 10 s CM06 CHYSTER Comparator Hysteresis — 65 — mV * Note 1: Note 1 These parameters are characterized but not tested. Response time measured with one comparator input at VDD/2, while the other input transitions from VSS to VDD. TABLE 27-11: CVREF VOLTAGE REFERENCE SPECIFICATIONS Operating Conditions: 1.8V < VDD < 3.6V, -40°C < TA < +125°C (unless otherwise stated). Param No. Sym Characteristics Min Typ Max Units Comments CV01* CLSB Step Size(2) — — VDD/24 VDD/32 — — V V Low Range (VRR = 1) High Range (VRR = 0) CV02* CACC Absolute Accuracy — — — — 1/4 1/2 LSb LSb Low Range (VRR = 1) High Range (VRR = 0) CV03* CR Unit Resistor Value (R) — 2k — CV04* CST Settling Time(1) — — 10 s * Note 1: These parameters are characterized but not tested. Settling time measured while CVRR = 1 and CVR3:CVR0 transitions from ‘0000’ to ‘1111’. TABLE 27-12: FIXED VOLTAGE REFERENCE (FVR) SPECIFICATIONS Operating Conditions: 1.8V < VDD < 3.6V, -40°C < TA < +125°C (unless otherwise stated). VR Voltage Reference Specifications Param No. Sym Characteristics Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C TA +125°C Min Typ Max Units TBD 1.2 TBD V VR01 VROUT VR voltage output VR02 TCVOUT Voltage drift temperature coefficient — TBD TBD ppm/C VR03 VROUT/ VDD Voltage drift with respect to VDD regulation — TBD — V/V VR04 TSTABLE Settling Time — TBD TBD s Comments Legend: TBD = To Be Determined * These parameters are characterized but not tested. 2010 Microchip Technology Inc. Preliminary DS41350D-page 391 PIC18F/LF1XK50 FIGURE 27-13: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING CK US121 US121 DT US122 US120 Note: Refer to Figure 27-2 for load conditions. TABLE 27-13: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param. No. Symbol Characteristic Min. Max. Units US120 TCKH2DTV SYNC XMIT (Master and Slave) Clock high to data-out valid 3.0-5.5V — 80 ns 1.8-5.5V — 100 ns US121 TCKRF Clock out rise time and fall time (Master mode) 3.0-5.5V — 45 ns 1.8-5.5V — 50 ns Data-out rise time and fall time 3.0-5.5V — 45 ns 1.8-5.5V — 50 ns US122 TDTRF FIGURE 27-14: Conditions USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING CK US125 DT US126 Note: Refer to Figure 27-2 for load conditions. TABLE 27-14: USART SYNCHRONOUS RECEIVE REQUIREMENTS Standard Operating Conditions (unless otherwise stated) Operating Temperature -40°C TA +125°C Param. No. Symbol Characteristic US125 TDTV2CKL SYNC RCV (Master and Slave) Data-hold before CK (DT hold time) US126 TCKL2DTL DS41350D-page 392 Data-hold after CK (DT hold time) Preliminary Min. Max. Units 10 — ns 15 — ns Conditions 2010 Microchip Technology Inc. PIC18F/LF1XK50 FIGURE 27-15: SPI MASTER MODE TIMING (CKE = 0, SMP = 0) SS SP70 SCK (CKP = 0) SP71 SP72 SP78 SP79 SP79 SP78 SCK (CKP = 1) SP80 bit 6 - - - - - -1 MSb SDO LSb SP75, SP76 SDI MSb In bit 6 - - - -1 LSb In SP74 SP73 Note: Refer to Figure 27-2 for load conditions. FIGURE 27-16: SPI MASTER MODE TIMING (CKE = 1, SMP = 1) SS SP81 SCK (CKP = 0) SP71 SP72 SP79 SP73 SCK (CKP = 1) SP80 SDO MSb SP78 bit 6 - - - - - -1 LSb SP75, SP76 SDI MSb In bit 6 - - - -1 LSb In SP74 Note: Refer to Figure 27-2 for load conditions. 2010 Microchip Technology Inc. Preliminary DS41350D-page 393 PIC18F/LF1XK50 FIGURE 27-17: SPI SLAVE MODE TIMING (CKE = 0) SS SP70 SCK (CKP = 0) SP83 SP71 SP72 SP78 SP79 SP79 SP78 SCK (CKP = 1) SP80 MSb SDO LSb bit 6 - - - - - -1 SP77 SP75, SP76 SDI MSb In bit 6 - - - -1 LSb In SP74 SP73 Note: Refer to Figure 27-2 for load conditions. FIGURE 27-18: SS SPI SLAVE MODE TIMING (CKE = 1) SP82 SP70 SP83 SCK (CKP = 0) SP71 SP72 SCK (CKP = 1) SP80 SDO MSb bit 6 - - - - - -1 LSb SP77 SP75, SP76 SDI MSb In bit 6 - - - -1 LSb In SP74 Note: Refer to Figure 27-2 for load conditions. DS41350D-page 394 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 27-15: SPI MODE REQUIREMENTS Param No. Symbol Characteristic SP70* TSSL2SCH, SS to SCK or SCK input TSSL2SCL Min Typ† Max Units Conditions TCY — — ns SP71* TSCH SCK input high time (Slave mode) TCY + 20 — — ns SP72* TSCL SCK input low time (Slave mode) TCY + 20 — — ns SP73* TDIV2SCH, Setup time of SDI data input to SCK edge TDIV2SCL 100 — — ns SP74* TSCH2DIL, TSCL2DIL Hold time of SDI data input to SCK edge 100 — — ns SP75* TDOR SDO data output rise time — 10 25 ns SP76* TDOF SDO data output fall time 3.0-5.5V 1.8-5.5V — 25 50 ns — 10 25 ns SP77* TSSH2DOZ SS to SDO output high-impedance 10 — 50 ns SP78* TSCR SCK output rise time (Master mode) 3.0-5.5V — 10 25 ns 1.8-5.5V — 25 50 ns SP79* TSCF SCK output fall time (Master mode) — 10 25 ns 3.0-5.5V — — 50 ns 1.8-5.5V — — 145 ns SP81* TDOV2SCH, SDO data output setup to SCK edge TDOV2SCL Tcy — — ns SP82* TSSL2DOV — — 50 ns 1.5TCY + 40 — — ns SP80* TSCH2DOV, SDO data output valid after TSCL2DOV SCK edge SDO data output valid after SS edge SP83* TSCH2SSH, SS after SCK edge TSCL2SSH * These parameters are characterized but not tested. † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. FIGURE 27-19: I2C™ BUS START/STOP BITS TIMING SCL SP93 SP91 SP90 SP92 SDA Stop Condition Start Condition Note: Refer to Figure 27-2 for load conditions. 2010 Microchip Technology Inc. Preliminary DS41350D-page 395 PIC18F/LF1XK50 TABLE 27-16: I2C™ BUS START/STOP BITS REQUIREMENTS Param No. Symbol Characteristic SP90* TSU:STA SP91* THD:STA SP92* TSU:STO SP93 THD:STO Stop condition Start condition Typ 4700 — Max Units — Setup time 400 kHz mode 600 — — Start condition 100 kHz mode 4000 — — Hold time 400 kHz mode 600 — — Stop condition 100 kHz mode 4700 — — Setup time Hold time * 100 kHz mode Min 400 kHz mode 600 — — 100 kHz mode 4000 — — 400 kHz mode 600 — — Conditions ns Only relevant for Repeated Start condition ns After this period, the first clock pulse is generated ns ns These parameters are characterized but not tested. FIGURE 27-20: I2C™ BUS DATA TIMING SP103 SCL SP100 SP90 SP102 SP101 SP106 SP107 SP91 SDA In SP92 SP110 SP109 SP109 SDA Out Note: Refer to Figure 27-2 for load conditions. DS41350D-page 396 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 TABLE 27-17: I2C™ BUS DATA REQUIREMENTS Param. No. Symbol SP100* THIGH Characteristic Clock high time Min Max Units 100 kHz mode 4.0 — s Device must operate at a minimum of 1.5 MHz 400 kHz mode 0.6 — s Device must operate at a minimum of 10 MHz 1.5TCY — 100 kHz mode 4.7 — s Device must operate at a minimum of 1.5 MHz 400 kHz mode 1.3 — s Device must operate at a minimum of 10 MHz SSP Module SP101* TLOW Clock low time SSP Module SP102* TR SP103* TF SP90* SP91* TSU:STA THD:STA SP106* THD:DAT SP107* TSU:DAT SP92* TSU:STO SP109* TAA SP110* SP * Note 1: 2: TBUF CB Conditions 1.5TCY — SDA and SCL rise time 100 kHz mode — 1000 ns 400 kHz mode 0.1CB 300 ns SDA and SCL fall time 100 kHz mode — 250 ns 400 kHz mode 20 + 0.1CB 250 ns CB is specified to be from 10-400 pF Only relevant for Repeated Start condition 20 + 100 kHz mode 4.7 — s 400 kHz mode 0.6 — s Start condition hold 100 kHz mode time 400 kHz mode 4.0 — s 0.6 — s Data input hold time 100 kHz mode 0 — ns 400 kHz mode 0 0.9 s 100 kHz mode 250 — ns 400 kHz mode 100 — ns Start condition setup time Data input setup time Stop condition setup time Output valid from clock Bus free time 100 kHz mode 4.7 — s 400 kHz mode 0.6 — s 100 kHz mode — 3500 ns 400 kHz mode — — ns 100 kHz mode 4.7 — s 400 kHz mode 1.3 — s — 400 pF Bus capacitive loading CB is specified to be from 10-400 pF After this period the first clock pulse is generated (Note 2) (Note 1) Time the bus must be free before a new transmission can start These parameters are characterized but not tested. 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. A Fast mode (400 kHz) I2C bus device can be used in a Standard mode (100 kHz) 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 397 PIC18F/LF1XK50 NOTES: DS41350D-page 398 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 28.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES Graphs and tables are not available at this time. 2010 Microchip Technology Inc. Preliminary DS41350D-page 399 PIC18F/LF1XK50 NOTES: DS41350D-page 400 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 29.0 PACKAGING INFORMATION 29.1 Package Marking Information 20-Lead PDIP Example XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN PICXXFXXXX-I/P 0810017 20-Lead SSOP Example XXXXXXXXXXX XXXXXXXXXXX YYWWNNN PICXXFXXXX -I/SS 0810017 20-Lead SOIC (.300”) Example XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX PICXXFXXXX-I /SO 0810017 YYWWNNN 20-Lead QFN Example XXXXXXX XXXXXXX YYWWNNN Legend: XX...X Y YY WW NNN e3 * Note: 18F14K50 -I/ML 0810017 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package. 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. 2010 Microchip Technology Inc. Preliminary DS41350D-page 401 PIC18F/LF1XK50 29.2 Package Details The following sections give the technical details of the packages. /HDG3ODVWLF'XDO,Q/LQH3±PLO%RG\>3',3@ 1RWH )RUWKHPRVWFXUUHQWSDFNDJHGUDZLQJVSOHDVHVHHWKH0LFURFKLS3DFNDJLQJ6SHFLILFDWLRQORFDWHGDW KWWSZZZPLFURFKLSFRPSDFNDJLQJ N E1 NOTE 1 1 2 3 D E A2 A L c A1 b1 b eB e 8QLWV 'LPHQVLRQ/LPLWV 1XPEHURI3LQV ,1&+(6 0,1 1 120 0$; 3LWFK H 7RSWR6HDWLQJ3ODQH $ ± ± 0ROGHG3DFNDJH7KLFNQHVV $ %DVHWR6HDWLQJ3ODQH $ ± ± 6KRXOGHUWR6KRXOGHU:LGWK ( 0ROGHG3DFNDJH:LGWK ( 2YHUDOO/HQJWK ' 7LSWR6HDWLQJ3ODQH / /HDG7KLFNQHVV F E E H% ± ± 8SSHU/HDG:LGWK /RZHU/HDG:LGWK 2YHUDOO5RZ6SDFLQJ %6& 1RWHV 3LQYLVXDOLQGH[IHDWXUHPD\YDU\EXWPXVWEHORFDWHGZLWKLQWKHKDWFKHGDUHD 6LJQLILFDQW&KDUDFWHULVWLF 'LPHQVLRQV'DQG(GRQRWLQFOXGHPROGIODVKRUSURWUXVLRQV0ROGIODVKRUSURWUXVLRQVVKDOOQRWH[FHHGSHUVLGH 'LPHQVLRQLQJDQGWROHUDQFLQJSHU$60(<0 %6& %DVLF'LPHQVLRQ7KHRUHWLFDOO\H[DFWYDOXHVKRZQZLWKRXWWROHUDQFHV 0LFURFKLS 7HFKQRORJ\ 'UDZLQJ &% DS41350D-page 402 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 /HDG3ODVWLF6KULQN6PDOO2XWOLQH66±PP%RG\>6623@ 1RWH )RUWKHPRVWFXUUHQWSDFNDJHGUDZLQJVSOHDVHVHHWKH0LFURFKLS3DFNDJLQJ6SHFLILFDWLRQORFDWHGDW KWWSZZZPLFURFKLSFRPSDFNDJLQJ D N E E1 NOTE 1 1 2 e b c A2 A φ A1 L1 8QLWV 'LPHQVLRQ/LPLWV 1XPEHURI3LQV L 0,//,0(7(56 0,1 1 120 0$; 3LWFK H 2YHUDOO+HLJKW $ ± %6& ± 0ROGHG3DFNDJH7KLFNQHVV $ 6WDQGRII $ ± ± 2YHUDOO:LGWK ( 0ROGHG3DFNDJH:LGWK ( 2YHUDOO/HQJWK ' )RRW/HQJWK / )RRWSULQW / 5() /HDG7KLFNQHVV F ± )RRW$QJOH /HDG:LGWK E ± 1RWHV 3LQYLVXDOLQGH[IHDWXUHPD\YDU\EXWPXVWEHORFDWHGZLWKLQWKHKDWFKHGDUHD 'LPHQVLRQV'DQG(GRQRWLQFOXGHPROGIODVKRUSURWUXVLRQV0ROGIODVKRUSURWUXVLRQVVKDOOQRWH[FHHGPPSHUVLGH 'LPHQVLRQLQJDQGWROHUDQFLQJSHU$60(<0 %6& %DVLF'LPHQVLRQ7KHRUHWLFDOO\H[DFWYDOXHVKRZQZLWKRXWWROHUDQFHV 5() 5HIHUHQFH'LPHQVLRQXVXDOO\ZLWKRXWWROHUDQFHIRULQIRUPDWLRQSXUSRVHVRQO\ 0LFURFKLS 7HFKQRORJ\ 'UDZLQJ &% 2010 Microchip Technology Inc. Preliminary DS41350D-page 403 PIC18F/LF1XK50 /HDG3ODVWLF6PDOO2XWOLQH62± :LGHPP%RG\>62,&@ 1RWH )RUWKHPRVWFXUUHQWSDFNDJHGUDZLQJVSOHDVHVHHWKH0LFURFKLS3DFNDJLQJ6SHFLILFDWLRQORFDWHGDW KWWSZZZPLFURFKLSFRPSDFNDJLQJ D N E E1 NOTE 1 1 2 3 e b α h h A A2 c φ L A1 8QLWV 'LPHQVLRQ/LPLWV 1XPEHURI3LQV β L1 0,//,0(7(56 0,1 1 120 0$; 3LWFK H 2YHUDOO+HLJKW $ ± %6& ± 0ROGHG3DFNDJH7KLFNQHVV $ ± ± 6WDQGRII $ ± 2YHUDOO:LGWK ( 0ROGHG3DFNDJH:LGWK ( %6& 2YHUDOO/HQJWK ' %6& %6& &KDPIHURSWLRQDO K ± )RRW/HQJWK / ± )RRWSULQW / 5() )RRW$QJOH ± /HDG7KLFNQHVV F ± /HDG:LGWK E ± 0ROG'UDIW$QJOH7RS ± 0ROG'UDIW$QJOH%RWWRP ± 1RWHV 3LQYLVXDOLQGH[IHDWXUHPD\YDU\EXWPXVWEHORFDWHGZLWKLQWKHKDWFKHGDUHD 6LJQLILFDQW&KDUDFWHULVWLF 'LPHQVLRQV'DQG(GRQRWLQFOXGHPROGIODVKRUSURWUXVLRQV0ROGIODVKRUSURWUXVLRQVVKDOOQRWH[FHHGPPSHUVLGH 'LPHQVLRQLQJDQGWROHUDQFLQJSHU$60(<0 %6& %DVLF'LPHQVLRQ7KHRUHWLFDOO\H[DFWYDOXHVKRZQZLWKRXWWROHUDQFHV 5() 5HIHUHQFH'LPHQVLRQXVXDOO\ZLWKRXWWROHUDQFHIRULQIRUPDWLRQSXUSRVHVRQO\ 0LFURFKLS 7HFKQRORJ\ 'UDZLQJ &% DS41350D-page 404 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 20-Lead Plastic Quad Flat, No Lead Package (MQ) 5x5x0.9 mm Body [QFN] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Microchip Technology Drawing C04-120A 2010 Microchip Technology Inc. Preliminary DS41350D-page 405 PIC18F/LF1XK50 NOTES: DS41350D-page 406 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 APPENDIX A: REVISION HISTORY Revision A (May 2008) Original data sheet for PIC18F1XK50/PIC18LF1XK50 devices. Revision B (June 2008) Revised 27.4 DC Characteristics table. Revision C (04/2009) Revised data sheet title; Revised Features section; Revised Table 1-2; Revised Table 3-1, Table 3-2; Added Note 3 in Section 9.1; Revised Register 14-1; Revised Example 16-1; Revised Section 18.8.4; Revised Register 18-3; Revised Table 20-2; Revised Sections 22.2.1, 22.2.2, 22.5.1.1, 22.7; Revised Tables 23-4, 27-1, 27-2, 27-3 27-4, 27-8. Revision D (05/2010) Revised the 20-pin PDIP, SSOP, SOIC Diagram; Added the 20-pin QFN Diagram; Revised Table 1, Table 1-1; Revised Figure 2-1; Added Note below Section 2.11.1 (Low Speed Operation); Revised Table 3-1, Table 3-2; Revised Section 4 (Flash Program Memory) and Section 5 (Data EEPROM Memory); Revised Example 5-2, Table 5-1; Deleted Note 1 from Registers 7-4, 7-8; Revised Tables 9-1, 9-3; Revised Sections 14.1 (ECCP Outputs and Configuration), 14.4.4 (Enhanced PWM Auto-Shutdown Mode); Added Note 4 below Register 14-2; Revised Figure 14-10; Revised Equation 17-1; Revised Table 18-3 and Table 20-3; Revised Equation 21-1; Deleted Section 21.1.3 (Output Clamped to VSS); Revised Figure 21-1; Revised Table 21-1, Table 23-4 and Table 24-1; Added Note 2 to Table 24-1; Revised Register 24-6; Deleted Note 1 from Table 24-3; Revised Section 27 (tables); Added 20Lead QFN Package Marking Information and Package Details; Revised the Product Identification System Section; Other minor corrections. 2010 Microchip Technology Inc. Preliminary DS41350D-page 407 PIC18F/LF1XK50 APPENDIX B: DEVICE DIFFERENCES The differences between the devices listed in this data sheet are shown in Table B-1. TABLE B-1: Features DEVICE DIFFERENCES PIC18F13K50 PIC18F14K50 PIC18LF13K50 PIC18F26K20 PIC18LF14K50 PIC18F44K20 PIC18F45K20 PIC18F46K20 Program Memory (Bytes) 8192 16384 32768 65536 8192 16384 32768 65536 Program Memory (Instructions) 4096 8192 16384 32768 4096 8192 16384 32768 19 19 20 20 20 Interrupt Sources I/O Ports Ports A, B, C, Ports A, B, C, (E) (E) 19 19 20 Ports A, B, C, (E) Ports A, B, C, (E) Ports A, B, C, D, E Ports A, B, C, Ports A, B, C, Ports A, B, C, D, E D, E D, E Capture/Compare/ PWM Modules 1 1 1 1 1 1 1 1 Enhanced Capture/Compare/ PWM Modules 1 1 1 1 1 1 1 1 Parallel Communications (PSP) No No No No Yes Yes Yes Yes 10-bit Analog-toDigital Module 11 input channels 11 input channels 11 input channels 11 input channels 14 input channels 14 input channels 14 input channels 14 input channels 20-pin PDIP 20-pin SOIC 20-pin SSOP 20-pin QFN 20-pin PDIP 20-pin SOIC 20-pin SSOP 20-pin QFN 20-pin PDIP 20-pin SOIC 20-pin SSOP 20-pin QFN 28-pin PDIP 28-pin SOIC 28-pin SSOP 28-pin QFN 20-pin PDIP 20-pin SOIC 20-pin SSOP 20-pin QFN 40-pin PDIP 44-pin TQFP 44-pin QFN 40-pin PDIP 44-pin TQFP 44-pin QFN 40-pin PDIP 44-pin TQFP 44-pin QFN Packages DS41350D-page 408 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 INDEX A A/D Analog Port Pins, Configuring .................................. 223 Associated Registers ............................................... 223 Conversions ............................................................. 214 Discharge ................................................................. 215 Selecting and Configuring Acquisition Time ............ 212 Specifications ........................................................... 389 Absolute Maximum Ratings ............................................. 365 AC Characteristics Industrial and Extended ........................................... 381 Load Conditions ....................................................... 380 Access Bank Mapping with Indexed Literal Offset Mode ................. 50 ACKSTAT ........................................................................ 171 ACKSTAT Status Flag ..................................................... 171 ADC ................................................................................. 211 Acquisition Requirements ........................................ 221 Block Diagram .......................................................... 211 Calculating Acquisition Time .................................... 221 Channel Selection .................................................... 212 Configuration ............................................................ 212 Conversion Clock ..................................................... 212 Conversion Procedure ............................................. 216 Internal Sampling Switch (RSS) IMPEDANCE ............. 221 Interrupts .................................................................. 213 Operation ................................................................. 214 Operation During Sleep ........................................... 215 Port Configuration .................................................... 212 Power Management ................................................. 215 Reference Voltage (VREF) ........................................ 212 Result Formatting ..................................................... 213 Source Impedance ................................................... 221 Special Event Trigger ............................................... 215 Starting an A/D Conversion ..................................... 213 ADCON0 Register ............................................................ 217 ADCON1 Register .................................................... 218, 219 ADDFSR .......................................................................... 354 ADDLW ............................................................................ 317 ADDULNK ........................................................................ 354 ADDWF ............................................................................ 317 ADDWFC ......................................................................... 318 ADRESH Register (ADFM = 0) ........................................ 220 ADRESH Register (ADFM = 1) ........................................ 220 ADRESL Register (ADFM = 0) ......................................... 220 ADRESL Register (ADFM = 1) ......................................... 220 Analog Input Connection Considerations ......................... 233 Analog-to-Digital Converter. See ADC ANDLW ............................................................................ 318 ANDWF ............................................................................ 319 ANSEL (PORT Analog Control) ......................................... 98 ANSEL Register ................................................................. 98 ANSELH Register .............................................................. 99 Assembler MPASM Assembler .................................................. 362 B Bank Select Register (BSR) ............................................... 35 Baud Rate Generator ....................................................... 167 BAUDCON Register ......................................................... 194 BC .................................................................................... 319 BCF .................................................................................. 320 BF .................................................................................... 171 2010 Microchip Technology Inc. BF Status Flag ................................................................. 171 Block Diagrams ADC ......................................................................... 211 ADC Transfer Function ............................................ 222 Analog Input Model .......................................... 222, 233 Baud Rate Generator .............................................. 167 Capture Mode Operation ......................................... 119 Clock Source ............................................................. 16 Comparator 1 ........................................................... 226 Comparator 2 ........................................................... 227 Crystal Operation ....................................................... 17 EUSART Receive .................................................... 184 EUSART Transmit ................................................... 183 External POR Circuit (Slow VDD Power-up) ............ 281 External RC Mode ..................................................... 18 Fail-Safe Clock Monitor (FSCM) ................................ 26 Generic I/O Port ......................................................... 83 Interrupt Logic ............................................................ 68 MSSP (I2C Master Mode) ........................................ 165 MSSP (I2C Mode) .................................................... 148 MSSP (SPI Mode) ................................................... 139 On-Chip Reset Circuit .............................................. 279 PIC18F1XK50/PIC18LF1XK50 .................................. 12 PWM (Enhanced) .................................................... 121 Reads from Flash Program Memory ......................... 55 Resonator Operation ................................................. 18 Table Read Operation ............................................... 51 Table Write Operation ............................................... 52 Table Writes to Flash Program Memory .................... 58 Timer0 in 16-Bit Mode ............................................. 103 Timer0 in 8-Bit Mode ............................................... 102 Timer1 ..................................................................... 106 Timer1 (16-Bit Read/Write Mode) ............................ 106 Timer2 ..................................................................... 112 Timer3 ..................................................................... 114 Timer3 (16-Bit Read/Write Mode) ............................ 115 USB Interrupt Logic ................................................. 267 USB Peripheral and Options ................................... 253 Voltage Reference ................................................... 248 Voltage Reference Output Buffer Example ............. 249 Watchdog Timer ...................................................... 304 BN .................................................................................... 320 BNC ................................................................................. 321 BNN ................................................................................. 321 BNOV .............................................................................. 322 BNZ ................................................................................. 322 BOR. See Brown-out Reset. BOV ................................................................................. 325 BRA ................................................................................. 323 Break Character (12-bit) Transmit and Receive .............. 202 BRG. See Baud Rate Generator. Brown-out Reset (BOR) ................................................... 282 Detecting ................................................................. 282 Disabling in Sleep Mode .......................................... 282 Software Enabled .................................................... 282 Specifications .......................................................... 387 Timing and Characteristics ...................................... 386 BSF .................................................................................. 323 BTFSC ............................................................................. 324 BTFSS ............................................................................. 324 BTG ................................................................................. 325 BZ .................................................................................... 326 Preliminary DS41350D-page 409 PIC18F/LF1XK50 C C Compilers MPLAB C18 ............................................................. 362 CALL ................................................................................ 326 CALLW ............................................................................. 355 Capture (CCP Module) ..................................................... 119 CCP Pin Configuration ............................................. 119 CCPRxH:CCPRxL Registers ................................... 119 Prescaler .................................................................. 119 Software Interrupt .................................................... 119 Timer1/Timer3 Mode Selection ................................ 119 Capture/Compare/PWM (CCP) Capture Mode. See Capture. CCP Mode and Timer Resources ............................ 118 Compare Mode. See Compare. CCP1CON Register ......................................................... 117 Clock Accuracy with Asynchronous Operation ................ 192 Clock Sources Associated registers ................................................... 27 External Modes HS ...................................................................... 17 LP ....................................................................... 17 XT ...................................................................... 17 CLRF ................................................................................ 327 CLRWDT .......................................................................... 327 CM1CON0 Register ......................................................... 231 CM2CON0 Register ......................................................... 232 CM2CON1 Register ......................................................... 235 Code Examples 16 x 16 Signed Multiply Routine ................................ 66 16 x 16 Unsigned Multiply Routine ............................ 66 8 x 8 Signed Multiply Routine .................................... 65 8 x 8 Unsigned Multiply Routine ................................ 65 A/D Conversion ........................................................ 216 Changing Between Capture Prescalers ................... 119 Clearing RAM Using Indirect Addressing ................... 46 Computed GOTO Using an Offset Value ................... 32 Data EEPROM Read ................................................. 63 Data EEPROM Refresh Routine ................................ 64 Data EEPROM Write ................................................. 63 Erasing a Flash Program Memory Row ..................... 57 Fast Register Stack .................................................... 32 Implementing a Timer1 Real-Time Clock ................. 109 Initializing PORTA ...................................................... 84 Initializing PORTB ...................................................... 89 Initializing PORTC ...................................................... 94 Loading the SSPBUF (SSPSR) Register ................. 142 Reading a Flash Program Memory Word .................. 56 Saving Status, WREG and BSR Registers in RAM ... 79 Writing to Flash Program Memory ....................... 59–60 Code Protection ............................................................... 293 COMF ............................................................................... 328 Comparator Associated Registers ............................................... 236 Operation ................................................................. 225 Operation During Sleep ........................................... 230 Response Time ........................................................ 228 Comparator Module ......................................................... 225 C1 Output State Versus Input Conditions ................ 228 Comparator Specifications ............................................... 391 Comparator Voltage Reference (CVREF) Associated Registers ............................................... 251 Effects of a Reset ............................................. 230, 247 Operation During Sleep ........................................... 247 Overview .................................................................. 247 DS41350D-page 410 Comparator Voltage Reference (CVREF) Response Time ........................................................ 228 Comparators Effects of a Reset .................................................... 230 Compare (CCP Module) .................................................. 120 CCPRx Register ...................................................... 120 Pin Configuration ..................................................... 120 Software Interrupt .................................................... 120 Special Event Trigger ...................................... 116, 120 Timer1/Timer3 Mode Selection ................................ 120 Computed GOTO ............................................................... 32 CONFIG1H Register ................................................ 295, 296 CONFIG1L Register ........................................................ 295 CONFIG2H Register ........................................................ 298 CONFIG2L Register ........................................................ 297 CONFIG3H Register ........................................................ 299 CONFIG4L Register ........................................................ 299 CONFIG5H Register ........................................................ 300 CONFIG5L Register ........................................................ 300 CONFIG6H Register ........................................................ 301 CONFIG6L Register ........................................................ 301 CONFIG7H Register ........................................................ 302 CONFIG7L Register ........................................................ 302 Configuration Bits ............................................................ 294 Configuration Register Protection .................................... 309 Context Saving During Interrupts ....................................... 79 CPFSEQ .......................................................................... 328 CPFSGT .......................................................................... 329 CPFSLT ........................................................................... 329 Customer Change Notification Service ............................ 419 Customer Notification Service ......................................... 419 Customer Support ............................................................ 419 CVREF Voltage Reference Specifications ........................ 391 D Data Addressing Modes .................................................... 46 Comparing Addressing Modes with the Extended Instruction Set Enabled ..................... 49 Direct ......................................................................... 46 Indexed Literal Offset ................................................ 48 Instructions Affected .......................................... 48 Indirect ....................................................................... 46 Inherent and Literal .................................................... 46 Data EEPROM Code Protection ....................................................... 309 Data EEPROM Memory ..................................................... 61 Associated Registers ................................................. 64 EEADR Register ........................................................ 61 EECON1 and EECON2 Registers ............................. 61 Operation During Code-Protect ................................. 64 Protection Against Spurious Write ............................. 64 Reading ..................................................................... 63 Using ......................................................................... 64 Write Verify ................................................................ 63 Writing ....................................................................... 63 Data Memory ..................................................................... 35 Access Bank .............................................................. 39 and the Extended Instruction Set .............................. 48 Bank Select Register (BSR) ...................................... 35 General Purpose Registers ....................................... 39 Map for PIC18F13K50/PIC18LF13K50 ..................... 36 Map for PIC18F14K50/PIC18LF14K50 ..................... 37 Special Function Registers ........................................ 39 USB RAM .................................................................. 35 DAW ................................................................................ 330 DC and AC Characteristics Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 Graphs and Tables .................................................. 399 DC Characteristics Extended and Industrial ........................................... 376 Industrial and Extended ........................................... 366 DCFSNZ .......................................................................... 331 DECF ............................................................................... 330 DECFSZ ........................................................................... 331 Development Support ...................................................... 361 Device Differences ........................................................... 407 Device Overview .................................................................. 9 Details on Individual Family Members ....................... 10 Features (28-Pin Devices) ......................................... 11 New Core Features ...................................................... 9 Other Special Features .............................................. 10 Device Reset Timers ........................................................ 283 Oscillator Start-up Timer (OST) ............................... 283 PLL Lock Time-out ................................................... 283 Power-up Timer (PWRT) ......................................... 283 Time-out Sequence .................................................. 283 DEVID1 Register .............................................................. 303 DEVID2 Register .............................................................. 303 Direct Addressing ............................................................... 47 E ECCPAS Register ............................................................ 129 EECON1 Register ........................................................ 53, 62 Effect on Standard PIC Instructions ................................. 358 Electrical Specifications ................................................... 365 Enhanced Capture/Compare/PWM (ECCP) .................... 117 Associated Registers ............................................... 138 Enhanced PWM Mode ............................................. 121 Auto-Restart ..................................................... 131 Auto-shutdown ................................................. 129 Direction Change in Full-Bridge Output Mode . 127 Full-Bridge Application ..................................... 125 Full-Bridge Mode ............................................. 125 Half-Bridge Application .................................... 124 Half-Bridge Application Examples ................... 132 Half-Bridge Mode ............................................. 124 Output Relationships (Active-High and Active-Low) .............................................. 122 Output Relationships Diagram ......................... 123 Programmable Dead Band Delay .................... 132 Shoot-through Current ..................................... 132 Start-up Considerations ................................... 128 Outputs and Configuration ....................................... 118 Specifications ........................................................... 389 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................. 183 Equations Estimating USB Transceiver Current Consumption . 275 Errata ................................................................................... 7 EUSART .......................................................................... 183 Asynchronous Mode ................................................ 185 12-bit Break Transmit and Receive ................. 202 Associated Registers, Receive ........................ 191 Associated Registers, Transmit ....................... 187 Auto-Wake-up on Break .................................. 200 Baud Rate Generator (BRG) ........................... 195 Clock Accuracy ................................................ 192 Receiver ........................................................... 188 Setting up 9-bit Mode with Address Detect ...... 190 Transmitter ....................................................... 185 Baud Rate Generator (BRG) Associated Registers ....................................... 195 Auto Baud Rate Detect .................................... 199 2010 Microchip Technology Inc. Baud Rate Error, Calculating ........................... 195 Baud Rates, Asynchronous Modes ................. 196 Formulas .......................................................... 195 High Baud Rate Select (BRGH Bit) ................. 195 Clock polarity Synchronous Mode .......................................... 203 Data polarity Asynchronous Receive .................................... 188 Asynchronous Transmit ................................... 185 Synchronous Mode .......................................... 203 Interrupts Asynchronous Receive .................................... 189 Asynchronous Transmit ................................... 186 Synchronous Master Mode .............................. 203, 207 Associated Registers, Receive ........................ 207 Associated Registers, Transmit ............... 205, 208 Reception ........................................................ 205 Transmission ................................................... 203 Synchronous Slave Mode Associated Registers, Receive ........................ 209 Reception ........................................................ 208 Transmission ................................................... 207 Extended Instruction Set ADDFSR .................................................................. 354 ADDULNK ............................................................... 354 and Using MPLAB Tools ......................................... 360 CALLW .................................................................... 355 Considerations for Use ............................................ 358 MOVSF .................................................................... 355 MOVSS .................................................................... 356 PUSHL ..................................................................... 356 SUBFSR .................................................................. 357 SUBULNK ................................................................ 357 Syntax ...................................................................... 353 F Fail-Safe Clock Monitor ............................................. 26, 293 Fail-Safe Condition Clearing ...................................... 27 Fail-Safe Detection .................................................... 26 Fail-Safe Operation ................................................... 26 Reset or Wake-up from Sleep ................................... 27 Fast Register Stack ........................................................... 32 Firmware Instructions ...................................................... 311 Flash Program Memory ..................................................... 51 Associated Registers ................................................. 60 Control Registers ....................................................... 52 EECON1 and EECON2 ..................................... 52 TABLAT (Table Latch) Register ........................ 54 TBLPTR (Table Pointer) Register ...................... 54 Erase Sequence ........................................................ 57 Erasing ...................................................................... 57 Operation During Code-Protect ................................. 60 Reading ..................................................................... 55 Table Pointer Boundaries Based on Operation ....................... 55 Table Pointer Boundaries .......................................... 54 Table Reads and Table Writes .................................. 51 Write Sequence ......................................................... 58 Writing To .................................................................. 58 Protection Against Spurious Writes ................... 60 Unexpected Termination ................................... 60 Write Verify ........................................................ 60 G General Call Address Support ......................................... 164 GOTO .............................................................................. 332 Preliminary DS41350D-page 411 PIC18F/LF1XK50 H Hardware Multiplier ............................................................ 65 Introduction ................................................................ 65 Operation ................................................................... 65 Performance Comparison .......................................... 65 I I/O Ports ............................................................................. 83 I2C Associated Registers ............................................... 180 I2C Mode (MSSP) Acknowledge Sequence Timing ............................... 174 Baud Rate Generator ............................................... 167 Bus Collision During a Repeated Start Condition .................. 178 During a Stop Condition ................................... 180 Clock Arbitration ....................................................... 168 Clock Stretching ....................................................... 160 10-Bit Slave Receive Mode (SEN = 1) ............. 160 10-Bit Slave Transmit Mode ............................. 160 7-Bit Slave Receive Mode (SEN = 1) ............... 160 7-Bit Slave Transmit Mode ............................... 160 Clock Synchronization and the CKP bit (SEN = 1) .. 161 Effects of a Reset ..................................................... 175 General Call Address Support ................................. 164 I2C Clock Rate w/BRG ............................................. 167 Master Mode ............................................................ 165 Operation ......................................................... 166 Reception ......................................................... 171 Repeated Start Condition Timing ..................... 170 Start Condition Timing ..................................... 169 Transmission .................................................... 171 Multi-Master Communication, Bus Collision and Arbitration .................................................. 175 Multi-Master Mode ................................................... 175 Operation ................................................................. 152 Read/Write Bit Information (R/W Bit) ............... 152, 153 Registers .................................................................. 148 Serial Clock (RC3/SCK/SCL) ................................... 153 Slave Mode .............................................................. 152 Addressing ....................................................... 152 Reception ......................................................... 153 Transmission .................................................... 153 Sleep Operation ....................................................... 175 Stop Condition Timing .............................................. 174 ID Locations ............................................................. 293, 309 INCF ................................................................................. 332 INCFSZ ............................................................................ 333 In-Circuit Debugger .......................................................... 309 In-Circuit Serial Programming (ICSP) ...................... 293, 309 Indexed Literal Offset Addressing and Standard PIC18 Instructions ............................. 358 Indexed Literal Offset Mode ............................................. 358 Indirect Addressing ............................................................ 47 INFSNZ ............................................................................ 333 Initialization Conditions for all Registers .................. 287–291 Instruction Cycle ................................................................. 33 Clocking Scheme ....................................................... 33 Instruction Flow/Pipelining ................................................. 33 Instruction Set .................................................................. 311 ADDLW .................................................................... 317 ADDWF .................................................................... 317 ADDWF (Indexed Literal Offset Mode) .................... 359 ADDWFC ................................................................. 318 ANDLW .................................................................... 318 DS41350D-page 412 Preliminary ANDWF .................................................................... 319 BC ............................................................................ 319 BCF ......................................................................... 320 BN ............................................................................ 320 BNC ......................................................................... 321 BNN ......................................................................... 321 BNOV ...................................................................... 322 BNZ ......................................................................... 322 BOV ......................................................................... 325 BRA ......................................................................... 323 BSF .......................................................................... 323 BSF (Indexed Literal Offset Mode) .......................... 359 BTFSC ..................................................................... 324 BTFSS ..................................................................... 324 BTG ......................................................................... 325 BZ ............................................................................ 326 CALL ........................................................................ 326 CLRF ....................................................................... 327 CLRWDT ................................................................. 327 COMF ...................................................................... 328 CPFSEQ .................................................................. 328 CPFSGT .................................................................. 329 CPFSLT ................................................................... 329 DAW ........................................................................ 330 DCFSNZ .................................................................. 331 DECF ....................................................................... 330 DECFSZ .................................................................. 331 Extended Instruction Set ......................................... 353 General Format ........................................................ 313 GOTO ...................................................................... 332 INCF ........................................................................ 332 INCFSZ .................................................................... 333 INFSNZ .................................................................... 333 IORLW ..................................................................... 334 IORWF ..................................................................... 334 LFSR ....................................................................... 335 MOVF ...................................................................... 335 MOVFF .................................................................... 336 MOVLB .................................................................... 336 MOVLW ................................................................... 337 MOVWF ................................................................... 337 MULLW .................................................................... 338 MULWF .................................................................... 338 NEGF ....................................................................... 339 NOP ......................................................................... 339 Opcode Field Descriptions ....................................... 312 POP ......................................................................... 340 PUSH ....................................................................... 340 RCALL ..................................................................... 341 RESET ..................................................................... 341 RETFIE .................................................................... 342 RETLW .................................................................... 342 RETURN .................................................................. 343 RLCF ....................................................................... 343 RLNCF ..................................................................... 344 RRCF ....................................................................... 344 RRNCF .................................................................... 345 SETF ....................................................................... 345 SETF (Indexed Literal Offset Mode) ........................ 359 SLEEP ..................................................................... 346 SUBFWB ................................................................. 346 SUBLW .................................................................... 347 SUBWF .................................................................... 347 SUBWFB ................................................................. 348 SWAPF .................................................................... 348 2010 Microchip Technology Inc. PIC18F/LF1XK50 TBLRD ..................................................................... 349 TBLWT ..................................................................... 350 TSTFSZ ................................................................... 351 XORLW .................................................................... 351 XORWF .................................................................... 352 INTCON Register ............................................................... 69 INTCON Registers ....................................................... 69–71 INTCON2 Register ............................................................. 70 INTCON3 Register ............................................................. 71 Inter-Integrated Circuit. See I2C. Internal Oscillator Block INTOSC Specifications ........................................... 384, 385 Internal RC Oscillator Use with WDT .......................................................... 304 Internal Sampling Switch (RSS) IMPEDANCE ..................... 221 Internet Address ............................................................... 419 Interrupt Sources ............................................................. 293 ADC ......................................................................... 213 Capture Complete (CCP) ......................................... 119 Compare Complete (CCP) ....................................... 120 Interrupt-on-Change (RB7:RB4) .......................... 83, 89 INTn Pin ..................................................................... 79 PORTB, Interrupt-on-Change .................................... 79 TMR0 ......................................................................... 79 TMR0 Overflow ........................................................ 103 TMR1 Overflow ........................................................ 105 TMR3 Overflow ................................................ 113, 115 Interrupts ............................................................................ 67 INTOSC Specifications ............................................ 384, 385 IOCA Register .................................................................... 86 IOCB Register .................................................................... 91 IORLW ............................................................................. 334 IORWF ............................................................................. 334 IPR Registers ..................................................................... 76 IPR1 Register ..................................................................... 76 IPR2 Register ..................................................................... 77 L LATA Register .................................................................... 86 LATB Register .................................................................... 91 LATC Register ................................................................... 95 LFSR ................................................................................ 335 Load Conditions ............................................................... 380 Low-Voltage ICSP Programming. See Single-Supply ICSP Programming M Master Clear (MCLR) ....................................................... 281 Master Synchronous Serial Port (MSSP). See MSSP. Memory Organization ......................................................... 29 Data Memory ............................................................. 35 Program Memory ....................................................... 29 Microchip Internet Web Site ............................................. 419 MOVF ............................................................................... 335 MOVFF ............................................................................ 336 MOVLB ............................................................................ 336 MOVLW ........................................................................... 337 MOVSF ............................................................................ 355 MOVSS ............................................................................ 356 MOVWF ........................................................................... 337 MPLAB ASM30 Assembler, Linker, Librarian .................. 362 MPLAB Integrated Development Environment Software . 361 MPLAB PM3 Device Programmer ................................... 364 MPLAB REAL ICE In-Circuit Emulator System ................ 363 MPLINK Object Linker/MPLIB Object Librarian ............... 362 2010 Microchip Technology Inc. MSSP ACK Pulse ....................................................... 152, 153 I2C Mode. See I2C Mode. Module Overview ..................................................... 139 SPI Mode. See SPI Mode. SSPBUF Register .................................................... 144 SSPSR Register ...................................................... 144 MULLW ............................................................................ 338 MULWF ............................................................................ 338 N NEGF ............................................................................... 339 NOP ................................................................................. 339 O OSCCON Register ....................................................... 20, 21 Oscillator Module ............................................................... 15 Oscillator Parameters ...................................................... 384 Oscillator Selection .......................................................... 293 Oscillator Specifications ................................................... 383 Oscillator Start-up Timer (OST) ....................................... 283 Specifications .......................................................... 387 Oscillator Switching Fail-Safe Clock Monitor ............................................. 26 Oscillator, Timer1 ..................................................... 105, 115 Oscillator, Timer3 ............................................................. 113 OSCTUNE Register ........................................................... 22 P P1A/P1B/P1C/P1D.See Enhanced Capture/Compare/ PWM (ECCP) .......................................................... 121 Packaging Information ..................................................... 401 Marking .................................................................... 401 PIE Registers ..................................................................... 74 PIE1 Register .................................................................... 74 PIE2 Register .................................................................... 75 Pinout Descriptions PIC18F1XK50/PIC18LF1XK50 .................................. 13 PIR Registers ..................................................................... 72 PIR1 Register .................................................................... 72 PIR2 Register .................................................................... 73 POP ................................................................................. 340 POR. See Power-on Reset. PORTA Associated Registers ................................................. 88 LATA Register ........................................................... 83 PORTA Register ........................................................ 83 Specifications .......................................................... 385 TRISA Register .......................................................... 83 PORTA Register ................................................................ 85 PORTB Associated Registers ................................................. 93 LATB Register ........................................................... 89 PORTB Register ........................................................ 89 TRISB Register .......................................................... 89 PORTB Register .......................................................... 90, 94 PORTC Associated Registers ................................................. 97 LATC Register ........................................................... 94 PORTC Register ........................................................ 94 RC3/SCK/SCL Pin ................................................... 153 Specifications .......................................................... 385 TRISC Register ......................................................... 94 Power Managed Modes ................................................... 237 and A/D Operation ................................................... 215 and PWM Operation ................................................ 137 Preliminary DS41350D-page 413 PIC18F/LF1XK50 and SPI Operation ................................................... 147 Entering .................................................................... 237 Exiting Idle and Sleep Modes .................................. 241 by Interrupt ....................................................... 241 by Reset ........................................................... 242 by WDT Time-out ............................................. 241 Without a Start-up Delay .................................. 242 Idle Modes ............................................................... 239 PRI_IDLE ......................................................... 240 RC_IDLE .......................................................... 241 SEC_IDLE ........................................................ 240 Multiple Sleep Functions .......................................... 238 Run Modes ............................................................... 238 PRI_RUN ......................................................... 238 RC_RUN .......................................................... 238 SEC_RUN ........................................................ 238 Selecting .................................................................. 237 Sleep Mode .............................................................. 239 Summary (table) ...................................................... 237 Power-on Reset (POR) .................................................... 281 Power-up Timer (PWRT) ......................................... 283 Time-out Sequence .................................................. 283 Power-up Timer (PWRT) Specifications ........................................................... 387 Precision Internal Oscillator Parameters .......................... 385 Prescaler, Timer0 ............................................................. 103 PRI_IDLE Mode ............................................................... 240 PRI_RUN Mode ............................................................... 238 Program Counter ................................................................ 30 PCL, PCH and PCU Registers ................................... 30 PCLATH and PCLATU Registers .............................. 30 Program Memory and Extended Instruction Set ..................................... 50 Code Protection ....................................................... 307 Instructions ................................................................. 34 Two-Word .......................................................... 34 Interrupt Vector .......................................................... 29 Look-up Tables .......................................................... 32 Map and Stack (diagram) ........................................... 29 Reset Vector .............................................................. 29 Program Verification and Code Protection ....................... 305 Associated Registers ............................................... 307 Programming, Device Instructions ................................... 311 PSTRCON Register ......................................................... 134 Pulse Steering .................................................................. 134 PUSH ............................................................................... 340 PUSH and POP Instructions .............................................. 31 PUSHL ............................................................................. 356 PWM (ECCP Module) Effects of a Reset ..................................................... 137 Operation in Power Managed Modes ...................... 137 Operation with Fail-Safe Clock Monitor ................... 137 Pulse Steering .......................................................... 134 Steering Synchronization ......................................... 136 PWM Mode. See Enhanced Capture/Compare/PWM ..... 121 PWM1CON Register ........................................................ 133 R RAM. See Data Memory. RC_IDLE Mode ................................................................ 241 RC_RUN Mode ................................................................ 238 RCALL .............................................................................. 341 RCON Register .......................................................... 78, 280 Bit Status During Initialization .................................. 286 RCREG ............................................................................ 190 RCSTA Register ............................................................... 193 DS41350D-page 414 Reader Response ............................................................ 420 RECON0 (Reference Control 0) Register ........................ 249 RECON1 (Reference Control 1) Register ........................ 250 RECON2 (Reference Control 2) Register ........................ 250 Register RCREG Register ..................................................... 199 Register File ....................................................................... 39 Register File Summary ...................................................... 41 Registers ADCON0 (ADC Control 0) ....................................... 217 ADCON1 (ADC Control 1) ............................... 218, 219 ADRESH (ADC Result High) with ADFM = 0) ......... 220 ADRESH (ADC Result High) with ADFM = 1) ......... 220 ADRESL (ADC Result Low) with ADFM = 0) ........... 220 ADRESL (ADC Result Low) with ADFM = 1) ........... 220 ANSEL (Analog Select 1) .......................................... 98 ANSEL (PORT Analog Control) ................................. 98 ANSELH (Analog Select 2) ........................................ 99 ANSELH (PORT Analog Control) .............................. 99 BAUDCON (EUSART Baud Rate Control) .............. 194 BDnSTAT (Buffer Descriptor n Status, CPU Mode) 263 BDnSTAT (Buffer Descriptor n Status, SIE Mode) .. 264 CCP1CON (Enhanced Capture/Compare/PWM Control) .......................................................................... 117 CM1CON0 (C1 Control) ........................................... 231 CM2CON0 (C2 Control) ........................................... 232 CM2CON1 (C2 Control) ........................................... 235 CONFIG1H (Configuration 1 High) .................. 295, 296 CONFIG1L (Configuration 1 Low) ........................... 295 CONFIG2H (Configuration 2 High) .......................... 298 CONFIG2L (Configuration 2 Low) ........................... 297 CONFIG3H (Configuration 3 High) .......................... 299 CONFIG4L (Configuration 4 Low) ........................... 299 CONFIG5H (Configuration 5 High) .......................... 300 CONFIG5L (Configuration 5 Low) ........................... 300 CONFIG6H (Configuration 6 High) .......................... 301 CONFIG6L (Configuration 6 Low) ........................... 301 CONFIG7H (Configuration 7 High) .......................... 302 CONFIG7L (Configuration 7 Low) ........................... 302 DEVID1 (Device ID 1) .............................................. 303 DEVID2 (Device ID 2) .............................................. 303 ECCPAS (Enhanced CCP Auto-shutdown Control) 129 EECON1 (Data EEPROM Control 1) ................... 53, 62 INTCON (Interrupt Control) ........................................ 69 INTCON2 (Interrupt Control 2) ................................... 70 INTCON3 (Interrupt Control 3) ................................... 71 IOCA (Interrupt-on-Change PORTA) ......................... 86 IOCB (Interrupt-on-Change PORTB) ......................... 91 IPR1 (Peripheral Interrupt Priority 1) ......................... 76 IPR2 (Peripheral Interrupt Priority 2) ......................... 77 LATA (PORTA Data Latch) ........................................ 86 LATB (PORTB Data Latch) ........................................ 91 LATC (PORTC Data Latch) ....................................... 95 OSCCON (Oscillator Control) .............................. 20, 21 OSCTUNE (Oscillator Tuning) ................................... 22 PIE1 (Peripheral Interrupt Enable 1) .......................... 74 PIE2 (Peripheral Interrupt Enable 2) .......................... 75 PIR1 (Peripheral Interrupt Request 1) ....................... 72 PIR2 (Peripheral Interrupt Request 2) ....................... 73 PORTA ...................................................................... 85 PORTB ................................................................ 90, 94 PSTRCON (Pulse Steering Control) ........................ 134 PWM1CON (Enhanced PWM Control) .................... 133 RCON (Reset Control) ....................................... 78, 280 RCSTA (Receive Status and Control) ..................... 193 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 REFCON0 ................................................................ 249 REFCON1 ................................................................ 250 REFCON2 ................................................................ 250 SLRCON (PORT Slew Rate Control) ....................... 100 SRCON0 (SR Latch Control 0) ................................ 244 SRCON1 (SR Latch Control 1) ................................ 245 SSPADD (MSSP Address and Baud Rate, SPI Mode) ........................................................ 159 SSPCON1 (MSSP Control 1, I2C Mode) ................. 150 SSPCON1 (MSSP Control 1, SPI Mode) ................. 141 SSPCON2 (MSSP Control 2, I2C Mode) ................. 151 SSPMSK (SSP Mask) .............................................. 158 SSPSTAT (MSSP Status, SPI Mode) .............. 140, 149 STATUS ..................................................................... 45 STKPTR (Stack Pointer) ............................................ 31 T0CON (Timer0 Control) .......................................... 101 T1CON (Timer1 Control) .......................................... 105 T2CON (Timer2 Control) .......................................... 111 T3CON (Timer3 Control) .......................................... 113 TRISA (Tri-State PORTA) .......................................... 85 TRISB (Tri-State PORTB) .................................... 90, 94 TXSTA (Transmit Status and Control) ..................... 192 UCFG (USB Configuration) ...................................... 256 UCON (USB Control) ............................................... 254 UEIE (USB Error Interrupt Enable) .......................... 272 UEIR (USB Error Interrupt Status) ........................... 271 UEPn (USB Endpoint n Control) .............................. 259 UIE (USB Interrupt Enable) ...................................... 270 UIR (USB Interrupt Status) ...................................... 268 USTAT (USB Status) ............................................... 258 WDTCON (Watchdog Timer Control) ...................... 305 WPUA (Weak Pull-up PORTA) .................................. 86 WPUB (Weak Pull-up PORTB) .................................. 91 RESET ............................................................................. 341 Reset State of Registers .................................................. 286 Resets ...................................................................... 279, 293 Brown-out Reset (BOR) ........................................... 293 Oscillator Start-up Timer (OST) ............................... 293 Power-on Reset (POR) ............................................ 293 Power-up Timer (PWRT) ......................................... 293 RETFIE ............................................................................ 342 RETLW ............................................................................ 342 RETURN .......................................................................... 343 Return Address Stack ........................................................ 30 Return Stack Pointer (STKPTR) ........................................ 31 Revision History ............................................................... 407 RLCF ................................................................................ 343 RLNCF ............................................................................. 344 RRCF ............................................................................... 344 RRNCF ............................................................................ 345 S SCK .................................................................................. 139 SDI ................................................................................... 139 SDO ................................................................................. 139 SEC_IDLE Mode .............................................................. 240 SEC_RUN Mode .............................................................. 238 Serial Clock, SCK ............................................................ 139 Serial Data In (SDI) .......................................................... 139 Serial Data Out (SDO) ..................................................... 139 Serial Peripheral Interface. See SPI Mode. SETF ................................................................................ 345 Shoot-through Current ..................................................... 132 Single-Supply ICSP Programming. Slave Select (SS) ............................................................. 139 Slave Select Synchronization .......................................... 145 2010 Microchip Technology Inc. SLEEP ............................................................................. 346 Sleep Mode ..................................................................... 239 SLRCON Register ........................................................... 100 Software Simulator (MPLAB SIM) ................................... 363 SPBRG ............................................................................ 195 SPBRGH ......................................................................... 195 Special Event Trigger ...................................................... 215 Special Event Trigger. See Compare (ECCP Mode). Special Features of the CPU ........................................... 293 Special Function Registers ................................................ 39 Map ............................................................................ 40 SPI Mode Typical Master/Slave Connection ............................ 143 SPI Mode (MSSP) Associated Registers ............................................... 147 Bus Mode Compatibility ........................................... 147 Effects of a Reset .................................................... 147 Enabling SPI I/O ...................................................... 143 Master Mode ............................................................ 144 Operation ................................................................. 142 Operation in Power Managed Modes ...................... 147 Serial Clock ............................................................. 139 Serial Data In ........................................................... 139 Serial Data Out ........................................................ 139 Slave Mode .............................................................. 145 Slave Select ............................................................. 139 Slave Select Synchronization .................................. 145 SPI Clock ................................................................. 144 Typical Connection .................................................. 143 SR Latch .......................................................................... 243 Associated Registers ............................................... 245 SRCON0 Register ........................................................... 244 SRCON1 Register ........................................................... 245 SS .................................................................................... 139 SSP Typical SPI Master/Slave Connection ..................... 143 SSPADD Register ............................................................ 159 SSPCON1 Register ................................................. 141, 150 SSPCON2 Register ......................................................... 151 SSPMSK Register ........................................................... 158 SSPOV ............................................................................ 171 SSPOV Status Flag ......................................................... 171 SSPSTAT Register .................................................. 140, 149 R/W Bit ............................................................ 152, 153 Stack Full/Underflow Resets .............................................. 32 Standard Instructions ....................................................... 311 STATUS Register .............................................................. 45 STKPTR Register .............................................................. 31 SUBFSR .......................................................................... 357 SUBFWB ......................................................................... 346 SUBLW ............................................................................ 347 SUBULNK ........................................................................ 357 SUBWF ............................................................................ 347 SUBWFB ......................................................................... 348 SWAPF ............................................................................ 348 T T0CON Register .............................................................. 101 T1CON Register .............................................................. 105 T2CON Register .............................................................. 111 T3CON Register .............................................................. 113 Table Pointer Operations (table) ........................................ 54 Table Reads/Table Writes ................................................. 32 TBLRD ............................................................................. 349 TBLWT ............................................................................ 350 Thermal Considerations ................................................... 379 Preliminary DS41350D-page 415 PIC18F/LF1XK50 Time-out in Various Situations (table) .............................. 283 Timer0 .............................................................................. 101 Associated Registers ............................................... 103 Operation ................................................................. 102 Overflow Interrupt .................................................... 103 Prescaler .................................................................. 103 Prescaler Assignment (PSA Bit) .............................. 103 Prescaler Select (T0PS2:T0PS0 Bits) ..................... 103 Prescaler. See Prescaler, Timer0. Reads and Writes in 16-Bit Mode ............................ 102 Source Edge Select (T0SE Bit) ................................ 102 Source Select (T0CS Bit) ......................................... 102 Specifications ........................................................... 388 Switching Prescaler Assignment .............................. 103 Timer1 .............................................................................. 105 16-Bit Read/Write Mode ........................................... 107 Associated Registers ............................................... 110 Interrupt .................................................................... 108 Operation ................................................................. 106 Oscillator .......................................................... 105, 107 Oscillator Layout Considerations ............................. 108 Overflow Interrupt .................................................... 105 Resetting, Using the CCP Special Event Trigger ..... 108 Specifications ........................................................... 388 TMR1H Register ...................................................... 105 TMR1L Register ....................................................... 105 Use as a Real-Time Clock ....................................... 109 Timer2 .............................................................................. 111 Associated Registers ............................................... 112 Interrupt .................................................................... 112 Operation ................................................................. 111 Output ...................................................................... 112 Timer3 .............................................................................. 113 16-Bit Read/Write Mode ........................................... 115 Associated Registers ............................................... 116 Operation ................................................................. 114 Oscillator .......................................................... 113, 115 Overflow Interrupt ............................................ 113, 115 Special Event Trigger (CCP) .................................... 116 TMR3H Register ...................................................... 113 TMR3L Register ....................................................... 113 Timing Diagrams A/D Conversion ........................................................ 390 Acknowledge Sequence .......................................... 174 Asynchronous Reception ......................................... 190 Asynchronous Transmission .................................... 187 Asynchronous Transmission (Back to Back) ........... 187 Auto Wake-up Bit (WUE) During Normal Operation 201 Auto Wake-up Bit (WUE) During Sleep ................... 201 Automatic Baud Rate Calculator .............................. 199 Baud Rate Generator with Clock Arbitration ............ 168 BRG Reset Due to SDA Arbitration During Start Condition ................................................. 177 Brown-out Reset (BOR) ........................................... 386 Bus Collision During a Repeated Start Condition (Case 1) ........................................................... 178 Bus Collision During a Repeated Start Condition (Case 2) ........................................................... 179 Bus Collision During a Start Condition (SCL = 0) .... 177 Bus Collision During a Stop Condition (Case 1) ...... 180 Bus Collision During a Stop Condition (Case 2) ...... 180 Bus Collision During Start Condition (SDA only) ..... 176 Bus Collision for Transmit and Acknowledge ........... 175 CLKOUT and I/O ...................................................... 385 Clock Synchronization ............................................. 161 DS41350D-page 416 Clock Timing ............................................................ 381 Clock/Instruction Cycle .............................................. 33 Comparator Output .................................................. 225 Enhanced Capture/Compare/PWM (ECCP) ............ 389 Fail-Safe Clock Monitor (FSCM) ................................ 27 First Start Bit Timing ................................................ 169 Full-Bridge PWM Output .......................................... 126 Half-Bridge PWM Output ................................. 124, 132 I2C Bus Data ............................................................ 396 I2C Bus Start/Stop Bits ............................................ 395 I2C Master Mode (7 or 10-Bit Transmission) ........... 172 I2C Master Mode (7-Bit Reception) .......................... 173 I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 156 I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 163 I2C Slave Mode (10-Bit Transmission) .................... 157 I2C Slave Mode (7-bit Reception, SEN = 0) ............ 154 I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 162 I2C Slave Mode (7-Bit Transmission) ...................... 155 I2C Slave Mode General Call Address Sequence (7 or 10-Bit Address Mode) ............................ 164 I2C Stop Condition Receive or Transmit Mode ........ 174 Internal Oscillator Switch Timing ............................... 23 PWM Auto-shutdown Auto-restart Enabled ........................................ 131 Firmware Restart ............................................. 130 PWM Direction Change ........................................... 127 PWM Direction Change at Near 100% Duty Cycle .. 128 PWM Output (Active-High) ...................................... 122 PWM Output (Active-Low) ....................................... 123 Repeat Start Condition ............................................ 170 Reset, WDT, OST and Power-up Timer .................. 386 Send Break Character Sequence ............................ 202 Slave Synchronization ............................................. 145 Slow Rise Time (MCLR Tied to VDD, VDD Rise > TPWRT) .......................................... 285 SPI Master Mode (CKE = 1, SMP = 1) .................... 393 SPI Mode (Master Mode) ......................................... 144 SPI Mode (Slave Mode, CKE = 0) ........................... 146 SPI Mode (Slave Mode, CKE = 1) ........................... 146 SPI Slave Mode (CKE = 0) ...................................... 394 SPI Slave Mode (CKE = 1) ...................................... 394 Synchronous Reception (Master Mode, SREN) ...... 206 Synchronous Transmission ..................................... 204 Synchronous Transmission (Through TXEN) .......... 204 Time-out Sequence on POR w/PLL Enabled (MCLR Tied to VDD) ........................................ 285 Time-out Sequence on Power-up (MCLR Not Tied to VDD, Case 1) ................................. 284 Time-out Sequence on Power-up (MCLR Not Tied to VDD, Case 2) ................................. 284 Time-out Sequence on Power-up (MCLR Tied to VDD, VDD Rise < TPWRT) ..................... 284 Timer0 and Timer1 External Clock .......................... 388 Transition for Entry to Sleep Mode .......................... 239 Transition for Wake from Sleep (HSPLL) ................ 239 Transition Timing for Entry to Idle Mode .................. 240 Transition Timing for Wake from Idle to Run Mode . 240 USART Synchronous Receive (Master/Slave) ........ 392 USART Synchronous Transmission (Master/Slave) 392 Timing Diagrams and Specifications A/D Conversion Requirements ................................ 390 PLL Clock ................................................................ 384 Timing Parameter Symbology ......................................... 380 Timing Requirements I2C Bus Data ............................................................ 397 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 I2C Bus Start/Stop Bits ............................................ 396 SPI Mode ................................................................. 395 Top-of-Stack Access .......................................................... 30 TRISA Register .................................................................. 85 TRISB Register ............................................................ 90, 94 TSTFSZ ........................................................................... 351 Two-Speed Start-up ......................................................... 293 Two-Word Instructions Example Cases .......................................................... 34 TXREG ............................................................................. 185 TXSTA Register ............................................................... 192 BRGH Bit ................................................................. 195 Serial Interface Engine (SIE) ..................................... 35 USB. See Universal Serial Bus. U W Universal Serial Bus Address Register (UADDR) ..................................... 260 Associated Registers ............................................... 276 Buffer Descriptor Table ............................................ 261 Buffer Descriptors .................................................... 261 Address Validation ........................................... 264 Assignment in Different Buffering Modes ........ 266 BDnSTAT Register (CPU Mode) ..................... 262 BDnSTAT Register (SIE Mode) ....................... 264 Byte Count ....................................................... 264 Example ........................................................... 261 Memory Map .................................................... 265 Ownership ........................................................ 261 Ping-Pong Buffering ......................................... 265 Register Summary ........................................... 266 Status and Configuration ................................. 261 Class Specifications and Drivers ............................. 278 Descriptors ............................................................... 278 Endpoint Control ...................................................... 259 Enumeration ............................................................. 278 External Pull-up Resistors ........................................ 257 Eye Pattern Test Enable .......................................... 257 Firmware and Drivers ............................................... 276 Frame Number Registers ......................................... 260 Frames ..................................................................... 277 Internal Pull-up Resistors ......................................... 257 Internal Transceiver ................................................. 255 Interrupts .................................................................. 267 and USB Transactions ..................................... 267 Layered Framework ................................................. 277 Oscillator Requirements ........................................... 276 Overview .......................................................... 253, 277 Ping-Pong Buffer Configuration ............................... 257 Power ....................................................................... 277 Power Modes ........................................................... 273 Bus Power Only ............................................... 273 Dual Power with Self-Power Dominance ......... 274 Self-Power Only ............................................... 273 RAM ......................................................................... 260 Memory Map .................................................... 260 Speed ....................................................................... 278 Status and Control ................................................... 254 Transfer Types ......................................................... 277 UFRMH:UFRML Registers ...................................... 260 USART Synchronous Master Mode Requirements, Synchronous Receive ............. 392 Requirements, Synchronous Transmission ..... 392 Timing Diagram, Synchronous Receive .......... 392 Timing Diagram, Synchronous Transmission .. 392 USB Module Electrical Specifications .............................. 378 USB RAM Wake-up on Break ........................................................... 200 Watchdog Timer (WDT) ........................................... 293, 304 Associated Registers ............................................... 305 Control Register ....................................................... 305 Programming Considerations .................................. 304 Specifications .......................................................... 387 WCOL ...................................................... 169, 170, 171, 174 WCOL Status Flag ................................... 169, 170, 171, 174 WDTCON Register .......................................................... 305 WPUA Register .................................................................. 86 WPUB Register .................................................................. 91 WWW Address ................................................................ 419 WWW, On-Line Support ...................................................... 7 2010 Microchip Technology Inc. V Voltage Reference (VR) Specifications .......................................................... 391 Voltage Reference. See Comparator Voltage Reference (CVREF) Voltage References Fixed Voltage Reference (FVR) .............................. 248 VR Stabilization ....................................................... 248 VREF. SEE ADC Reference Voltage X XORLW ........................................................................... 351 XORWF ........................................................................... 352 Preliminary DS41350D-page 417 PIC18F/LF1XK50 NOTES: DS41350D-page 418 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 THE MICROCHIP WEB SITE CUSTOMER SUPPORT Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: Users of Microchip products can receive assistance through several channels: • Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s guides and hardware support documents, latest software releases and archived software • General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing • Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives • • • • • Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Development Systems Information Line Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.com CUSTOMER CHANGE NOTIFICATION SERVICE Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions. 2010 Microchip Technology Inc. Preliminary DS41350D-page 419 PIC18F/LF1XK50 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. 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. Please list the following information, and use this outline to provide us with your comments about this document. To: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Device: PIC18F/LF1XK50 Y N Literature Number: DS41350D Questions: 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? DS41350D-page 420 Preliminary 2010 Microchip Technology Inc. PIC18F/LF1XK50 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. Device X Packaging Option X /XX XXX Temperature Range Package Pattern Examples: a) b) Device: PIC18F13K50(1), PIC18F14K50(1), PIC18LF13K50(1), PIC18LF14K50 Packaging Option: Blank = Standard packaging (tube or tray) T = Tape and Reel(1) d) Temperature Range: E I e) Package: P SO SS MQ c) = -40C to +125C (Extended) = -40°C to +85°C (Industrial) = = = = PIC18F14K50-E/P 301 = Extended temp., PDIP package, Extended VDD limits, QTP pattern #301. PIC18LF14K50-E/SO = Extended temp., SOIC package. PIC18LF14K50-E/P = Extended temp., PDIP package. PIC18LF14K50-E/MQ = Extended temp., QFN package. PIC18F14K50-I/P = Industrial temp., PDIP package. PDIP SOIC SSOP QFN Note 1: Pattern: QTP, SQTP, Code or Special Requirements (blank otherwise) 2010 Microchip Technology Inc. Preliminary Tape and Reel option is available for ML, MV, PT, SO and SS packages with industrial Temperature Range only. DS41350D-page 421 WORLDWIDE SALES AND SERVICE AMERICAS ASIA/PACIFIC ASIA/PACIFIC EUROPE Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://support.microchip.com Web Address: www.microchip.com Asia Pacific Office Suites 3707-14, 37th Floor Tower 6, The Gateway Harbour City, Kowloon Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431 India - Bangalore Tel: 91-80-3090-4444 Fax: 91-80-3090-4123 India - New Delhi Tel: 91-11-4160-8631 Fax: 91-11-4160-8632 Austria - Wels Tel: 43-7242-2244-39 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 India - Pune Tel: 91-20-2566-1512 Fax: 91-20-2566-1513 France - Paris Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Japan - Yokohama Tel: 81-45-471- 6166 Fax: 81-45-471-6122 Germany - Munich Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Atlanta Duluth, GA Tel: 678-957-9614 Fax: 678-957-1455 Boston Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088 Chicago Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075 Cleveland Independence, OH Tel: 216-447-0464 Fax: 216-447-0643 Dallas Addison, TX Tel: 972-818-7423 Fax: 972-818-2924 Detroit Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260 Kokomo Kokomo, IN Tel: 765-864-8360 Fax: 765-864-8387 Los Angeles Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608 Santa Clara Santa Clara, CA Tel: 408-961-6444 Fax: 408-961-6445 Toronto Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509 Australia - Sydney Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Tel: 86-10-8528-2100 Fax: 86-10-8528-2104 Korea - Daegu Tel: 82-53-744-4301 Fax: 82-53-744-4302 China - Chengdu Tel: 86-28-8665-5511 Fax: 86-28-8665-7889 China - Chongqing Tel: 86-23-8980-9588 Fax: 86-23-8980-9500 Korea - Seoul Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934 China - Hong Kong SAR Tel: 852-2401-1200 Fax: 852-2401-3431 Malaysia - Kuala Lumpur Tel: 60-3-6201-9857 Fax: 60-3-6201-9859 China - Nanjing Tel: 86-25-8473-2460 Fax: 86-25-8473-2470 Malaysia - Penang Tel: 60-4-227-8870 Fax: 60-4-227-4068 China - Qingdao Tel: 86-532-8502-7355 Fax: 86-532-8502-7205 Philippines - Manila Tel: 63-2-634-9065 Fax: 63-2-634-9069 China - Shanghai Tel: 86-21-5407-5533 Fax: 86-21-5407-5066 Singapore Tel: 65-6334-8870 Fax: 65-6334-8850 China - Shenyang Tel: 86-24-2334-2829 Fax: 86-24-2334-2393 Taiwan - Hsin Chu Tel: 886-3-6578-300 Fax: 886-3-6578-370 China - Shenzhen Tel: 86-755-8203-2660 Fax: 86-755-8203-1760 Taiwan - Kaohsiung Tel: 886-7-536-4818 Fax: 886-7-536-4803 China - Wuhan Tel: 86-27-5980-5300 Fax: 86-27-5980-5118 Taiwan - Taipei Tel: 886-2-2500-6610 Fax: 886-2-2508-0102 China - Xian Tel: 86-29-8833-7252 Fax: 86-29-8833-7256 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 Italy - Milan Tel: 39-0331-742611 Fax: 39-0331-466781 Netherlands - Drunen Tel: 31-416-690399 Fax: 31-416-690340 Spain - Madrid Tel: 34-91-708-08-90 Fax: 34-91-708-08-91 UK - Wokingham Tel: 44-118-921-5869 Fax: 44-118-921-5820 China - Xiamen Tel: 86-592-2388138 Fax: 86-592-2388130 China - Zhuhai Tel: 86-756-3210040 Fax: 86-756-3210049 01/05/10 DS41350D-page 422 Preliminary 2010 Microchip Technology Inc.