On Mon, 22 Jul 1996, NEIL GANDLER wrote:

>  I just finished my first interrupt routine for a PIC 16c74 and looked at
> p. 2-639 of the microntoller databook. They suggest a routine
> to save the current value of the STATUS and W register before
> procedding through the interrupt routine and restoring these values
> upon completion of the routine. What I don't understand is why
> they swap the nibbles of the status register. I would appreciate
> any advice.
>
>                 Neil Gandler

Neil,

Because the SWAPF instruction does not affect the Z bit in the STATUS
register. If you save STATUS using MOVF STATUS,temp_STATUS, you end up
affecting the Z bit in the process. They swap it back in the restore part
so no information is lost.

Sherif