I have re-read the errata sheet, and remember seeing it before.
It doesn't say you need a stub routine between your main and sub.

You have to insert a FFFFh at the *target* of any jump over the
4000h "boarder line" :

  1. Insert a data word of value FFFFh as the first
  instruction in the destination of a CALL or GOTO.

  2. Insert a data word of value FFFFh immediately
  following any RETURN, RETLW, or RETFIE instruction.

So, whenever the PIC jumps over the 4000h boarder (from
executing a CALL or GOTO), it has to see a FFFFh instruction
as the first one.

Note also that the RETURN (if it "returns" over the 4000h
boarder) needs FFFFh directly *after* the RETURN instruction,
not at the *target* of the RETURN ! Could easily be fixed with
a "458_RETURN" macro that inserts both the RETURN and the FFFFh.

Or is it be something with "C" that makes this harder
to implement ?

Jan-Erik.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body