;********************************************************** ;* fc005_compare.asm - CCP Compare tryout to generate a waveform. ;* modified from fc004.asm - Event Logger ;* ;* It does not do anything except demo CCP compare mode. ;* ;* Author: Doug Rice ;* Copyright 2018 ;* ;* Description: ;* ;* Set up CCP for compare ;* Turn on TMR1 to increment, do not touch it once running to ensure stable count. ;* if you start and stop TMR1 and do TMR1 += constant, ;* the prescaler tend to be reset on write and add jitter. ;* ;* the CCP compare reduces processing jitter. ;* ;* Toggle the CCP compare mode to toggle between SET and CLEAR of the CCP pin. ;* ;* If you use the prescale. ;* ;* You have to set CCPR1 so that TMR1 has to catch up. ;* ;* CCPR1 += TMR1ticksToNextMatch ;* ;* In service routing, increment CCPR1 by different amounts for Hi and Low ;* CCPR1 has to be set to ahead or TMR1 so TMR1 catches up ;* ;* To see the software jitter, toggle another output in the service routine so that the software jitter can be seen. ;* ;* On first compare copy TMR1 to CCPR1 and add increment. ;* ;* ;* ideas:- ;* with CCP pin set to output, capture TMR1 by changing the mode to capture and changing pin level. ;* Not sure what happens if pin is output and CCP is in Capture mode - it triggers a capture. ;* convert to compare mode to set CCP pin. ;* Now Add timeout to CCP ;* Let it time out ;* convert to compare mode to CLEAR CCP pin. ;* Now Add next timeout to CCP ;* Let it time out ;********************************************************** ;* ;* Copyright 2018 Douglas Rice ;* ;* http://www.dougrice.plus.com/hp/freqCounter/freqCounter.html ;* ;********************************************************** ;* ;* Modify this to use compare. ;* ;* init ;* TMR1 started ;* CCP set up for compare. ;* ;* while(1){ ;* ;* wait for TMRR1 == CCPH ;* toggle mode so output toggles. ;* increment CCPR1H so it is ahead of TMR1. TMR1 catches up and in ISR increment CCPR1 by required timeout. ;* ;* Note: use modulo 2^16 in TMR1 and CCPH to keep TMR1 < CCPH ;*} ;* ;* ;* 12F683 pins ; 1 U 8 ; 2 7 ; 3 6 ; 4 5 ;Pins for 12F683 ;1 VDD ;2 GP5/TICKI/OSC1/CLKIN ;2 GP4/AN3/TIG/OSC2/CLKOUT ;4 GP3/MCLR/VPP ; ;8 VSS ;7 GP0/AN0/CIN+/ICSPDAT/ULPWU ;6 GP1/AN1/CIN-/VREF/ICSPCLK ;5 GP2/AN2/T0CKI/INT/COUT/CCP1 ;* ; ;********************************************************** ;-------------------------------------------------------------------------- ; Sec 1.0 Build support for 12F683 ;------------------------------------------------------------------------- ; uncomment this below or define it on the command line ; #define using12F683 ;configure the GPIO bits ( not device pin ) #define RS232pin 4 #define CCPpin 2 #define swCCPpin 5 #ifdef using12F683 list p=12f683 ; Include file, change directory if needed include "p12f683.inc" __idlocs 0xF683 ; NOTE:- 12F683 has failsafe clock so can run off internal clock or external clock. ; MORE WORK IS REQUIRED TO SET THIS UP. ; Need to set up OSCON to select external oscillator. ; Using internal 4Mhz Osc if FCMEM_ is not diabled explicitly. ; ;_FCMEN_ON EQU H'3FFF' ;_FCMEN_OFF EQU H'37FF' __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _INTRC_OSC_NOCLKOUT ; __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _INTRC_OSC_CLKOUT ; Using 10Mhz External clock with ; __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _EC_OSC & _FCMEN_OFF & _IESO_OFF ; Using 10Mhz XT OSC with External clock, works Set 10Mhz to 9.4 Mhz then 10.3Mhz and serial was readable. ; __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _XT_OSC & _FCMEN_OFF & _IESO_OFF ; Using 10Mhz HS OSC with External clock, did not work with sine wave output. ; __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _HS_OSC & _FCMEN_OFF & _IESO_OFF ; Using 10Mhz LP OSC with External clock, works 4Vpp on scope - NOT DESIGNED FOR 10MHz ; __config _PWRTE_ON & _WDT_OFF & _BOD_OFF & _MCLRE_OFF & _LP_OSC & _FCMEN_OFF & _IESO_OFF ; ; 12F683 has extra CMCON1 for TMR1 sync ; #define CMCON CMCON0 #endif #ifdef using16F690 ; TBD #endif ;-------------------------------------------------------------------------- ; Sec 1.2 Variables ;----1--------------------------------------------------------------------- cblock 0x20 ; variables used for context saving w_temp status_temp SRtxTemp SRtxCnt SRout SRdel compareInc endc ;-------------------------------------------------------------------------- ; Sec 1.4 MACRO for tables straddling memory page ;------------------------------------------------------------------------- TEST_STRADDLE MACRO START if high( $ ) != high( START ) Error "Table straddles Page Boundary " endif endm ; Start at the reset vector org 0x000 goto Init ;-------------------------------------------------------------------------- ; Sec 2.0 Code ;------------------------------------------------------------------------- Init org 0x010 #ifdef using12F683 nop ;TBD #endif movlw 0 movwf GPIO banksel TRISIO ;make CCP1 pin output otherwise it does not work. ;#define RS232pin 4 ;#define CCPpin 2 ;#define swCCPpin 1 ; set upoutputs movlw ~( 1<: CCP Mode Select bits ;0000 = Capture/Compare/PWM off (resets CCP module) ;0001 = Unused (reserved) ;0010 = Unused (reserved) ;0011 = Unused (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, set output on match (CCP1IF bit is set) ;1001 = Compare mode, clear output on match (CCP1IF bit is set) ;1010 = Compare mode, generate software interrupt on match (CCP1IF bit is set, CCP1 pin is unaffected) ;1011 = Compare mode, trigger special event (CCP1IF bit is set, TMR1 is reset and A/D ;conversion is started if the ADC module is enabled. CCP1 pin is unaffected.) ;110x = PWM mode active-high ;111x = PWM mode active-low ; ; If measuring 50Hz, period os 20ms which fits in the 16bit ; goto StartCCP ; output CRLF movlw 0x0D call SRtxChar movlw 0x0A call SRtxChar movlw 1 movwf compareInc ; skip goto StartCCP ; ; try and capture TMR1 by setting the CCP pin to output and setting up capture. ; This sets pin so may not be wanted ; So skip this code after testing it! ; bcf GPIO,CCPpin banksel CCP1CON ; turn off - output cleared movlw 0<