Sorry Andy,

I hate to correct you when you are 99.9% right, but...

In the PIC16CXX architecture EVERY instruction that accesses a register
performs a read first, for the exact reason mentioned, simplification of design.

In this case, a MOVWF to PORTB during what would be a change on PORTB
interrupt will in fact clear the interrupt condition.

        best regards,

                Dan Matthews

At 12:03 PM 11/13/95 -0800, you wrote:
>John Payson <supercat@MCS.COM> wrote:
>
>>Does MOVWF perform a read-before-write?
>
>    No.
>
>    -Andy
>
>--
>Andrew Warren - fastfwd@ix.netcom.com
>Fast Forward Engineering, Vista, California
>
>