>-----Original Message-----
>From: Matt Marsh [mailto:matt@MATTMARSH.NET]

>So, the program should start and light the LED by default.
>When I press the button for the first time the LED should go
>out and stay out until the system is reset. However, the LED
>just comes on and stays on.
>
>Here is the code:
>ISR
>        clrwdt
>        bcf     INTCON,3        ; Reset timer interrupt
>
>        movlw   d'1'            ; Subtract 1 from sequence number to
>        subwf   SEQ,w           ; make it zero based
>        addwf   PCL,f
>        goto    Sequence1
>        goto    Sequence2

The first thing I noticed about this is that you are not performing any
context saving!  You are modifying W both here and in the main loop (when a
button is pressed).  You should be saving any registers that the main loop
isn't expecting to get clobbered before doing anything else in your ISR.
The datasheet for the PIC you are using should have some example code that
shows how to save STATUS and W which are generaly the most important two.

Regards

Mike




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