Sounds like your getting bitten by the watchdog. It has a default delay of
2.3s which at 0.25 seconds per led would get you all the way to the end and
one and a bit back before the chip resets and starts again from the beginning.

You need to disable it, either in the source file or via the programmer.

Cheers,
Simon.
---

On Mon, Aug 05, 2002 at 10:12:03PM +0200, jumanji wrote:
> Hi, thanks for the answer, I think I understand, is it the CBLOCK 0x20 <----
> that you mean?
> I didn't put it inthere until today, but it still don't work. (mebbe I have
> put it in the wrong place?)
>
> >From: "Jinx" <joecolquitt@CLEAR.NET.NZ>
> > Could be - RAM starts at 0x0c in the F84 and at 0x20 in the F877.
> > Assuming the delay used RAM counters and the addresses weren't
> > corrected............
>
> > Post the listing for the bit(s) giving you trouble, probably easily fixed.
> > Make sure to include any references to memory, variable and port
> > declarations, the problem may not be where you think it is. Curiously
> > though, it is always in the last place you look
>
> Hmm.. after I have found something, I usually stop searching, so the place
> where I found it is automatically the last place where I have looked ;-)
> I will paste my whole prog inhere, its just a mix from bits & parts found on
> WWW.
> When I compile this source, it results in a semi-success, the LED moves from
> pos1 to pos8, then goes to pos7, quickly to pos6 & then jumps to pos1 &
> starts over again.
>
> ****************************************************************************
> ****************
> ; This is an experimental program, bits & parts are used from examples found
> on WWW.
>         Title "LED flasher."
>         list P = 16F877
>         include "P16f877.inc"  ; use definition file for 16F877
>         org 0x0000      ; start address = 0000h
>
> ; INITIALISE PORTS
> ; binary used to see individual pin level
>
>         movlw b'00000000'       ; all port pins = low
>         movwf PORTA
>         movlw b'00000000'
>         movwf PORTB
>         movlw b'00000000'
>         movwf PORTC
>         movlw b'00000000'
>         movwf PORTD
>         movlw b'00000000'
>         movwf PORTE
>
>         bsf STATUS,RP0   ; set RAM Page 1 for TRIS registers
>
> ; INITIALISE PORTS
> ; binary used to see individual pin IO status
>
>         movlw b'00000000'       ; all IO pins = outputs
>         movwf TRISA
>         movlw b'00000000'
>         movwf TRISB
>         movlw b'00000000'
>         movwf TRISC
>         movlw b'00000000'
>         movwf TRISD
>         movlw b'00000000'
>         movwf TRISE
>
>         movlw b'00000110'       ; all analog pins = digital
>         movwf ADCON1
>
>         bcf STATUS,RP0   ;back to RAM page 0
>
> litLED  BCF STATUS,0  ;Clear the carry flag
>  MOVLW b'00000001'  ;put value in W
>  MOVWF PORTD  ;put W in PORTD
>  CALL Delay
> run RLF PORTD,1  ;Shift the HIGH up the column
>  CALL Delay
>  BTFSS PORTD,7         ;Has it reached the top? (check bit 7 of PORTD)
>  GOTO run  ; if no(0), goto run (if 1 skip 'goto run' performs nop)
> runback RRF PORTD,1            ;YES. Shift the HIGH down
>         CALL Delay
>         BTFSS PORTD,0     ;Has it reached the bottom?
>         GOTO runback   ;if no, goto runback
>         GOTO run    ;YES. Repeat the cycle
>
> ;==============================================================
> ;DELAY GENERATOR CODE HERE
> ;==============================================================
>
> ; Delay = 0.25 seconds
> ; Clock frequency = 4 MHz
>
> ; Actual delay = 0.25 seconds = 250000 cycles
> ; Error = 0 %
>
>  cblock 0x20 ;I have added the 0x20 myself
>  d1
>  d2
>  endc
>
> Delay
>    ;249993 cycles
>  movlw 0x4E
>  movwf d1
>  movlw 0xC4
>  movwf d2
> Delay_0
>  decfsz d1, f
>  goto $+2
>  decfsz d2, f
>  goto Delay_0
>
>    ;3 cycles
>  goto $+1
>  nop
>
>    ;4 cycles (including call)
>  return
>
> ;==============================================================
> ;END OF DELAY GENERATOR CODE
> ;==============================================================
>
>  END
> ****************************************************************************
> ****************
>
>
> Thanks again for your help,
> Best regards.
>
>
> PS: this Re: was a re on [PIC] without the colon, dunno if it would matter,
> but I put one inthere now, just to be sure.
>
> --
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> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

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