Hi,

I am fairly new to PIC's and another newbie to this list.

I have a project intended to eventually run on a 16F874.  I am currently
testing using 16F877 engineering samples (all I could get). I am also using
the latest version of MPASM.

I have a question regarding context saving (PUSH/POP) during interrupts, in
particular the method for saving the W register.  The 16F877 has common or
mapped ram at the top of banks 0 and 1 (70h-7Fh) but the 16F874 does not so
I need to eventually modify my code to run correctly on the 874.

Page 8-12 of DS31008A provides a basic example and says that for devices
without common ram the user register for saving W (in their case W_TEMP)
must be defined across all banks and at the same relative location.  Sounds
fair enough, but I can't figure out how this is intended to be done since
trying to define the label twice, even in different banks, will just result
in a "duplicate label" error.

I am sure the answer must be simple and I am being blind to the obvious.
Anyone help?

TIA

Dave Binnington