Hi Scott.

> >         movlw   0xAA            ;high?
> >         subwf   TimerH,W
> >         skpc
> >         goto    EndTime         ;5 cycles
> >
> >         movlw   0x55            ;low?
> >         subwf   TimerL,W
> >         skpc
> >         goto    EndTime         ;5 or 9 clocks to go
Here is mistake either...


What about second example ? (with bug fixed by Bob)
Seems it is correct for 0x00 as well.

        movlw   0xAA    ;high?
        subwf   TimerH,W
        movlw   0x55    ;low?
        skpnz                   ;here it was
        subwf   TimerL,W
        skpc
        goto    EndTime ;8 clocks to go
                        ;7 clocks to pass

WBR Dmitry.


> Well, I obviously can't improve on Dmitry... But if I'm not mistaken, Tony is
> writing some kind of Basic compiler thingy. In which case, the "0xaa55" constant
> may be arbitrary (at compile time). So if the lower byte of the constant is
> "0x00" then Dmitry's code would have to be modified. It's just a special case...
>
> But it turns out that there are several special cases each with their optimum
> solutions. If you want to see how SDCC handles each then look at "gen.c" in the
> PIC SDCC CVS repository:

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