十年專注單片機方案開發(fā)的方案公司英銳恩，分享PIC16F84單片機產(chǎn)生兩組PWM輸出實例。英銳恩現(xiàn)提供服務產(chǎn)品涉及主控芯片：8位單片機、16位單片機、32位單片機及各類運算放大器等。

list p=16F84 ; list directive to define processor
#include ; processor specific variable definitions

__CONFIG _CP_OFF & _WDT_OFF & _PWRTE_OFF & _RC_OSC

; '__CONFIG' directive is used to embed configuration data within .asm file.
; The lables following the directive are located in the respective .inc file.
; See respective data sheet for additional information on configuration word.

;********************** CONST DEFINITIONS******************************
FULL_WORK = 10 ; 程
DEF_WORK2 = 8 ; PWM2
PORT_OUT = PORTB ;
PIN_PWM1 = 0 ; P
PIN_PWM2 = 1 ;
;********************** VARIABLE DEFINITIONS***************************
CBLOCK 0x0C
w_temp ; variable used for context saving
status_temp ; variable used for context saving
PWM_FULL ; 程
PWM_WORK_CFG1 ; PWM1 
PWM_WORK_CFG2 ; PWM2 

PWM_WORK_CNT1 ; PWM1 
PWM_WORK_CNT2 ; PWM2 
ENDC
;**********************************************************************
;****************** *******************
;**********************************************************************
ORG 0x000 ; processor reset vector
ResetStart
goto main ; go to beginning of program
;**********************************************************************
;**************************************
;**********************************************************************
ORG 0x004 ; interrupt vector location
movwf w_temp ; save off current W register contents
movf STATUS,w ; move status register into W register
movwf status_temp ; save off contents of STATUS register

bsf STATUS,RP0
bcf INTCON,T0IF ;
bcf STATUS,RP0 

decfsz PWM_FULL,F ;
goto ISR_PWM1
bsf PORT_OUT,PIN_PWM1 ; PWM1/PWM2
bsf PORT_OUT,PIN_PWM2
movlw FULL_WORK ; 
movwf PWM_FULL
movf PWM_WORK_CFG1,W
movwf PWM_WORK_CNT1
movf PWM_WORK_CFG2,W
movwf PWM_WORK_CNT2
goto ISR_EXIT
ISR_PWM1
decfsz PWM_WORK_CNT1,F ;
goto ISR_PWM2
bcf PORT_OUT,PIN_PWM1 ; 
ISR_PWM2

decfsz PWM_WORK_CNT2,F ;
goto ISR_EXIT
bcf PORT_OUT,PIN_PWM2 ; 
ISR_EXIT
movf status_temp,w ; retrieve copy of STATUS register
movwf STATUS ; restore pre-isr STATUS register contents
swapf w_temp,f
swapf w_temp,w ; restore pre-isr W register contents
retfie ; return from interrupt
;**********************************************************************
;****************** ﹍てPWM *******************************
;**********************************************************************
InitPWM
bsf STATUS,RP0 ;
bcf PORT_OUT,PIN_PWM1
bcf PORT_OUT,PIN_PWM2
bcf STATUS,RP0
bsf PORT_OUT,PIN_PWM1 ;
bsf PORT_OUT,PIN_PWM2
movlw FULL_WORK ;
movwf PWM_FULL
movlw DEF_WORK1

movwf PWM_WORK_CFG1
movwf PWM_WORK_CNT1
movlw DEF_WORK2
movwf PWM_WORK_CFG2
movwf PWM_WORK_CNT2
retlw 0
;**********************************************************************
;************************************************
;**********************************************************************
InitTimer
bsf STATUS,RP0
bsf OPTION_REG,T0CS ;
bsf OPTION_REG,PSA ;
bsf INTCON,GIE ;
bcf INTCON,T0IF ;
bcf STATUS,RP0
retlw 0
;********************************************************************

**
;********************
;**********************************************************************
StartTimer
bsf STATUS,RP0
bcf OPTION_REG,T0CS ;
bsf INTCON,T0IE ;
bcf STATUS,RP0
retlw 0
;**********************************************************************
;****************** *******************************
;**********************************************************************
StopTimer
bsf STATUS,RP0
bsf OPTION_REG,T0CS ;
bcf INTCON,T0IE ;
bcf STATUS,RP0
retlw 0
;**********************************************************************
;****************** *******************************

;**********************************************************************
main
bcf STATUS,RP0 ; select Page 0 for Port Access
call InitPWM
call InitTimer
call StartTimer
goto $
;**********************************************************************
END ; directive 'end of program'