Why don«t we go back to elementary math:

Starting with HIGH MID LOW, we would have:

LOW = LOW - 1
IF LOW < 0 THEN LOW = &HFF   MID=MID - 1
IF MID < 0 THEN HIGH = HIGH - 1

I«m just starting with PIC programming but it seems easy to convert this to
PIC commands.

Felipe Kwiecinski Fernandez
IBM Brasil - Filial Porto Alegre

> De:   Fehrenbach, Robert J [SMTP:FehreRJ@CH.ETN.COM]
> Enviado:      Jueves 13 de Agosto de 1998 02:20 PM
> Para: PICLIST@MITVMA.MIT.EDU
> Asunto:       Re: 3 byte decrement
> 
> From:
>          "Peter L. Peres" <plp@ACTCOM.CO.IL>
> 
>                                    high  mid  low
>                                        ff    ff      01  - 1  =  ff  ff
> 00
> 
>    decf    mid, F               ff    fe     01
>    decf    mid, F               ff    fd     01
>    decfsz  low, F              ff    fd    00
>    incf    mid, F                    skip
>    incfsz  mid, F               ff    fe    00
>    decf    high, F              fe    fe    00  !
> 
> Am I missing something here?