siong <TSK196@soton.ac.uk> wrote:

> Recently I am trying to write a simple program using 17c44. I tried
> to use portc as my input and portd as my output.
> ....
> when I look at the watch window, the w register is not working.
> .... Does anyone knows the problem?
>
> Below is my main program:-
>
> LOOP    MOVPF   PORTC,0
>         MOVWF   PORTD
>         GOTO    LOOP

Siong:

The 17C4x's instruction set and architecture is very different
from the 16Cxx's... The "MOVPF" instruction's second operand is
a file register, not simply a "0" or "1".

To make your program work, change it as follows:

    WREG    EQU     0x0A    ;Register 0x0A is the W-Register.

    LOOP    MOVPF   PORTC,WREG
            MOVWF   PORTD
            GOTO    LOOP

-Andy

=== Andrew Warren - fastfwd@ix.netcom.com
=== Fast Forward Engineering - Vista, California
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