Jeff D. Pipkins <pipkins@BANGATE.COMPAQ.COM> wrote:

>I'm wondering if any of you have any experience at all with the PIC
>problem that is written about in the fine print footnote on page 3 of
>appnote AN556.  It says that if an "interrupt occurs just before
>the 'movwf PCL' instruction, then the [...] new[ly] computed PC will
>be INCREMENTED and saved on the stack (as the return from interrupt
>address [...] On return from the interrupt the program will go to
>the intended offset of the table PLUS ONE.  This is a very
>undesirable result, so interrupts must be disabled during a
>table read operation." [emphases mine]

Jeff:

The App-Note is WRONG.  There is no need to disable interrupts around
ADDWF PCLs (or around GOTOs, CALLs, or any other instruction that
directly modifies the Program Counter).

-Andy

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