At 09:11 AM 9/1/2003, Matti Laevaert wrote: >Hello, > >I experience some problems with a usual PIC-delay, written in >assembler (with MPLAB IDE). >I try to make a simple program wich toggles pin RA0. The program >listed bellow is for a period(!) of +/- 6,5ms (but actually it >doesn't mather I guess). When I connect my oscilloscope at pin RA0, >I can see the squarewave, but at regulier times (every second or 2) >there is a little spike (going low). Have you disabled the watchdog timer? If not, this may cause the symptoms you mention. Something to try: add some 'clrwdt' instructions to your code such that a clrwdt happens at least every 5ms or so (assuming prescaler is assigned to TMR0). dwayne -- Dwayne Reid <> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 19 years of Engineering Innovation (1984 - 2003) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email.

Yes it was the watchdog, I already found it. :-) Thx anyway! Matti --- In , "rtstofer" <rstofer@p...> wrote: > > Are you certain you have the watch dog timer turned off? It will do > a PIC reset periodically. > > --- In , "Matti Laevaert" > <matti.laevaert@w...> wrote: > > Hello, > > > > I experience some problems with a usual PIC-delay, written in > > assembler (with MPLAB IDE). > > I try to make a simple program wich toggles pin RA0. The program > > listed bellow is for a period(!) of +/- 6,5ms (but actually it > > doesn't mather I guess). When I connect my oscilloscope at pin RA0, > > I can see the squarewave, but at regulier times (every second or 2) > > there is a little spike (going low). I don't know how it got there. > > When I make the delay longer (0,5s for example), I have a simmilar > > problem: RA0 goes high for 0,5s, back to low for 0,5s, back to high > > for 0,5s and then there is a very small time that RA0 goes low > (only > > vissible at scope). After this very short time, RA0 is back high > for > > 0,5s and the process continues. And I didn't program it that way > (or > > that's what I think). > > > > Can someboby pls take a look at my code below (sorry, comments are > > in dutch)? > > > > Thx in advance, > > Matti, Belgium > > > > > > > > status equ 03h ;statusregister > > porta equ 05h ;poortA > > trisa equ 05h ;poortA input/output register > > portb equ 06h ;poortB > > trisb equ 06h ;poortB input/output register > > delay1 equ 0ch > > delay2 equ 0dh > > delay3 equ 0eh > > #define rp0 status,5 ;rp0 = bit5 > statusreg > > > > > > > > start > > org 05h > > call portdir ;poortA & B > > directions > > bcf rp0 ;bank0 selecteren > > > > ;HOOFDPROGRAMMA > > ;-------------- > > > > main > > bsf porta,0 ;uitgang RA0 aan > > call delay ;vertraging oproepen > > bcf porta,0 ;uitgang RA0 uit > > call delay ;vertraging oproepen > > goto main > > > > ;DELAY SUBROUTINE > > ;---------------- > > > > delay > > movlw b'00001010' > > movwf delay1 > > del1 > > movlw b'00001010' > > movwf delay2 > > del2 > > movlw b'00001010' > > movwf delay3 > > del3 > > decfsz delay3,f ;vertraging > > goto del3 > > decfsz delay2,f > > goto del2 > > decfsz delay1,f > > goto del1 > > return > > > > ;POORT-INITIALISATIES > > ;-------------------- > > > > portdir > > bsf rp0 ;bank1 selecteren > > movlw b'00000001' ;poortB in/out > > movwf trisb > > movlw b'00010000' ;poortA in/out > > movwf trisa > > return > > > > end

Are you certain you have the watch dog timer turned off? It will do a PIC reset periodically. --- In , "Matti Laevaert" <matti.laevaert@w...> wrote: > Hello, > > I experience some problems with a usual PIC-delay, written in > assembler (with MPLAB IDE). > I try to make a simple program wich toggles pin RA0. The program > listed bellow is for a period(!) of +/- 6,5ms (but actually it > doesn't mather I guess). When I connect my oscilloscope at pin RA0, > I can see the squarewave, but at regulier times (every second or 2) > there is a little spike (going low). I don't know how it got there. > When I make the delay longer (0,5s for example), I have a simmilar > problem: RA0 goes high for 0,5s, back to low for 0,5s, back to high > for 0,5s and then there is a very small time that RA0 goes low (only > vissible at scope). After this very short time, RA0 is back high for > 0,5s and the process continues. And I didn't program it that way (or > that's what I think). > > Can someboby pls take a look at my code below (sorry, comments are > in dutch)? > > Thx in advance, > Matti, Belgium > > status equ 03h ;statusregister > porta equ 05h ;poortA > trisa equ 05h ;poortA input/output register > portb equ 06h ;poortB > trisb equ 06h ;poortB input/output register > delay1 equ 0ch > delay2 equ 0dh > delay3 equ 0eh > #define rp0 status,5 ;rp0 = bit5 statusreg > start > org 05h > call portdir ;poortA & B > directions > bcf rp0 ;bank0 selecteren > > ;HOOFDPROGRAMMA > ;-------------- > > main > bsf porta,0 ;uitgang RA0 aan > call delay ;vertraging oproepen > bcf porta,0 ;uitgang RA0 uit > call delay ;vertraging oproepen > goto main > > ;DELAY SUBROUTINE > ;---------------- > > delay > movlw b'00001010' > movwf delay1 > del1 > movlw b'00001010' > movwf delay2 > del2 > movlw b'00001010' > movwf delay3 > del3 > decfsz delay3,f ;vertraging > goto del3 > decfsz delay2,f > goto del2 > decfsz delay1,f > goto del1 > return > > ;POORT-INITIALISATIES > ;-------------------- > > portdir > bsf rp0 ;bank1 selecteren > movlw b'00000001' ;poortB in/out > movwf trisb > movlw b'00010000' ;poortA in/out > movwf trisa > return > > end

Hello, I experience some problems with a usual PIC-delay, written in assembler (with MPLAB IDE). I try to make a simple program wich toggles pin RA0. The program listed bellow is for a period(!) of +/- 6,5ms (but actually it doesn't mather I guess). When I connect my oscilloscope at pin RA0, I can see the squarewave, but at regulier times (every second or 2) there is a little spike (going low). I don't know how it got there. When I make the delay longer (0,5s for example), I have a simmilar problem: RA0 goes high for 0,5s, back to low for 0,5s, back to high for 0,5s and then there is a very small time that RA0 goes low (only vissible at scope). After this very short time, RA0 is back high for 0,5s and the process continues. And I didn't program it that way (or that's what I think). Can someboby pls take a look at my code below (sorry, comments are in dutch)? Thx in advance, Matti, Belgium status equ 03h ;statusregister porta equ 05h ;poortA trisa equ 05h ;poortA input/output register portb equ 06h ;poortB trisb equ 06h ;poortB input/output register delay1 equ 0ch delay2 equ 0dh delay3 equ 0eh #define rp0 status,5 ;rp0 = bit5 statusreg start org 05h call portdir ;poortA & B directions bcf rp0 ;bank0 selecteren ;HOOFDPROGRAMMA ;-------------- main bsf porta,0 ;uitgang RA0 aan call delay ;vertraging oproepen bcf porta,0 ;uitgang RA0 uit call delay ;vertraging oproepen goto main ;DELAY SUBROUTINE ;---------------- delay movlw b'00001010' movwf delay1 del1 movlw b'00001010' movwf delay2 del2 movlw b'00001010' movwf delay3 del3 decfsz delay3,f ;vertraging goto del3 decfsz delay2,f goto del2 decfsz delay1,f goto del1 return ;POORT-INITIALISATIES ;-------------------- portdir bsf rp0 ;bank1 selecteren movlw b'00000001' ;poortB in/out movwf trisb movlw b'00010000' ;poortA in/out movwf trisa return end