I have a problem on the continuity of my PWM module.

The PWM runs at 1kHz, 5% duty cycle

The PWM module works fine for 9.48ms (10 cycles) and then it stop for=20
31.43ms and then it start again

I can't find the reason why it stop for this 31.43ms.....

eg.

_1111111111__________________1111111111__________


Regards

Francois


Here is my code.

 list      p=3D16f88           ; list directive to define processor
 #include <p16F88.inc>  ; processor specific variable definitions
 errorlevel  -302   ; suppress message 302 from list file

;=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
;       Configuration Bits
;=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

;Program Configuration Register 1
  __CONFIG    _CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF & _WRT_PROTECT_OFF=
=20
& _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_ON & _PWRTE_OFF & _WDT_OFF &=20
_XT_OSC

;Program Configuration Register 2
  __CONFIG    _CONFIG2, _IESO_OFF & _FCMEN_OFF


;**************************************************************************=
**
;     PORT Assingments
;**************************************************************************=
**
;         PORT A
;**************************************************************************=
**
;  #Define         xxx    PORTA,0  ;pin17
;  #Define        xxx    PORTA,1  ;pin18
;  #Define        RxData   PORTA,2  ;pin1
;  #Define         Trigger   PORTA,3  ;pin2
;       #Define         xxx    PORTA,4  ;pin3
;**************************************************************************=
**
;         PORT B
;**************************************************************************=
**
  #Define        Light   PORTB,0  ;pin6  PWM Output - must be digital outpu=
t
  #Define         LED    PORTB,1  ;pin7
;  #Define         xxx    PORTB,2  ;pin8
;  #Define         xxx    PORTB,3  ;pin9
  #Define         KeyUp   PORTB,4  ;pin10
  #Define         KeyDown   PORTB,5  ;pin11
;  #Define         xxx    PORTB,6  ;pin12
;  #Define         xxx    PORTB,7  ;pin13

;**************************************************************************=
**
;         GENERAL PURPOSE REGISTERS
;**************************************************************************=
**
CounterA  equ     0x23
CounterB  equ     0x24
CounterC  equ     0x25

ADDR   equ  0x2B
VALUE   equ  0x2C

Time3KReg  equ     0x36
Time3M1Reg  equ     0x37
Time3M2Reg  equ     0x38

w_temp         EQU     0x71        ; variable used for context saving
status_temp    EQU     0x72        ; variable used for context saving
pclath_temp    EQU     0x73    ; variable used for context saving
timer   equ  0x74
timer1   equ  0x75
;**************************************************************************=
**
;      START
;**************************************************************************=
**

  ORG     0x000             ; processor reset vector
  goto    setup             ; go to beginning of setup 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
  movf PCLATH,W      ; move PCLATH register into W register
  movwf pclath_temp       ; save off contents of PCLATH register

; isr code can go here or be located as a call subroutine elsewhere
  call Inthandler

  movf    pclath_temp,w     ; retrieve copy of PCLATH register
  movwf PCLATH            ; restore pre-isr PCLATH register contents
  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

;**************************************************************************=
**
;   SETUP
;**************************************************************************=
**
setup

  clrwdt

   bcf  INTCON, GIE

  BANKSEL CMCON
  movlw  0x07
     movwf  CMCON              ; CMCON=3D7 set comperators off
         ; CMCOM=3D5 set single comparator RA1=3DVin-, RA2=3DVin+(ref)
  BANKSEL OPTION_REG
  bsf  OPTION_REG, 0x07 ; Disable Pull Up on PORTB - RBPU (OPTION_REG<7>).

  BANKSEL PORTA     ; select bank of PORTA
  MOVLW B'00000000'
  MOVWF PORTA    ; Initialize PORTA by
         ; clearing output
         ; data latches
  BANKSEL ANSEL     ; Select Bank of ANSEL
  MOVLW  0x00     ; Configure all pins
  MOVWF  ANSEL     ; as digital inputs

  MOVLW  b'11111111'   ; Value used to
         ; initialize data
         ; direction
  BANKSEL TRISA
  MOVWF  TRISA     ; Set RA<7:0> as inputs

  BANKSEL PORTB     ; select bank of PORTB
  movlw B'00000000'   ; (RB0:RB1) =3D 0 - OTHERS =3D 1
   movwf   PORTB     ; Initialize PORTA by
         ; clearing output
  BANKSEL TRISB    ; data latches
  MOVLW  B'11111100'   ; Value used to
         ; initialize data
         ; direction

  MOVWF  TRISB     ; Set RB<7:0> as inputs

; * PWM registers configuration
; * Fosc =3D 4000000 Hz
; * Fpwm =3D 1000.00 Hz (Requested : 250 Hz)
; * Duty Cycle =3D 5 %
; * Resolution is 10 bits
; * Prescaler is 4
; * Ensure that your PWM pin is configured as digital output
; * see more details on http://www.micro-examples.com/
; * this source code is provided 'as is',
; * use it at your own risks

;PR2 =3D 0b11111001
 BANKSEL PR2
 movlw b'11111001'
 movwf PR2

;T2CON =3D 0b00000111
 BANKSEL T2CON
 movlw b'00000101'
 movwf T2CON

;CCPR1L =3D 0b01111100
 BANKSEL CCPR1L
 movlw b'00001100'
 movwf CCPR1L

;CCP1CON =3D 0b00111100
 BANKSEL CCP1CON
 movlw b'00011100'
 movwf CCP1CON


;**************************************************************************=
**
;   START OF MAIN PROGRAM
;**************************************************************************=
**
main
  CLRF STATUS    ; Do initialization, Select bank 0
  CLRF PCLATH    ; Keep in lower 2KByte

  CALL Delay_1s   ; allow for settle time


main1 clrwdt

  decf timer,f
  btfsc STATUS,Z
  call togled

  goto main1

togled
  decfsz timer1,f
  return

  movlw B'00000010'
  xorwf PORTB,f

  return


;PIC Time Delay =3D 1.0000020 s with Osc =3D 4.000000 MHz
Delay_1s
 movlw D'6'
 movwf CounterC
 movlw D'24'
 movwf CounterB
 movlw D'168'
 movwf CounterA
loop_1s
  decfsz CounterA,1
 goto loop_1s
 decfsz CounterB,1
 goto loop_1s
 decfsz CounterC,1
 goto loop_1s
 return

;*******************************************************

Inthandler

;  movf D8, w
;  movwf MasterHighByte
;  movwf VALUE
;  movlw 0x00
;  movwf ADDR
;  call PicEeWrite

;  movf D9, w
;  movwf MasterLowByte
;  movwf VALUE
;  movlw 0x01
;  movwf ADDR
;  call PicEeWrite

  return

 END           ; directive 'end of program'

--=20
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