On Tue, 11 Dec 2001, Andre Abelian wrote:

> Scott,
>
> Thanks for your replay. What about changing duty cycle
> On all of them?

http://www.dattalo.com/technical/software/pic/pwm8.asm


Another technique is to use phased-counters:


    movlw   DELTA_PHASE

    addwf   c0,f
    rlf     ns,f

    addwf   c1,f
    rlf     ns,f

    addwf   c2,f
    rlf     ns,f

    addwf   c3,f
    rlf     ns,w

    xorwf   current_state,w   ; toggle I/O's if the
    andlw   0x0f              ; counters roll over
    movwf   current_state

    movwf   PORTB


If you want to change the relative timing between edges then change the
contents of c0,c1,c2, or c3 individually. E.g.


    ; speed up  c2 by 5 samples:

    movlw   5*DELTA_PHASE

    addwf   c2,f

    movf    current_state,W
    skpnc
     xorlw   00000100b      ; Toggle the state on roll over
    movwf   current_state
    movwf   PORTB



Scott

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