Jim Main <PICLIST@MITVMA.MIT.EDU> wrote:

> This is the start of my interrupt service routine - it saves W,
> STATUS, FSR and PCLATH.  I'm thinking however that there'll be a
> problem if an interrupt occurs when STATUS,RP0 is set.... temp_w is
> then in the wrong register bank, and it'll overwrite whatever that
> location's being used for..
>
> The only way round it is to leave the corresponding bank1 register
> free, so that it doesn't matter - but then you'd have to know which
> bank to look in when it comes time to restore the registers at the
> end of the routine..  eg you'd have to restore the STATUS register
> before restoring the W register
>
> Does this sound ok, or is there a simpler method?

Jim:

The method you describe is the commonly-accepted one (it's even in
the 16C7x data book).  It'll work just fine.

-Andy

Andrew Warren - fastfwd@ix.netcom.com
Fast Forward Engineering, Vista, California
http://www.geocities.com/SiliconValley/2499