Marco DI LEO wrote:
>
> Hi there,
>
> I am trying to implement 32 bit addition and subtraction routines but I
> have some problems with the carry management.

<SNIP>

> ADD     MOVF    AARGB1,W   ;low byte
>         ADDWF   BARGB1
>
>         MOVF    AARGB0,W   ;Middle low byte
>         BTFSC   _C
>         INCFSZ  AARGB0,W
>         ADDWF   BARGB0
>
        MOVF    AMH,W      ;Middle high byte
        BTFSC   _C
        INCFSZ  AMH,W
        ADDWF   BMH

        MOVF    AH,W       ;High byte
        BTFSC   _C
        INCFSZ  AH,W
        ADDWF   BH

In this case Marco, the Ap note is correct.
Try it out.

Scott