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Unread 08-03-2006, 10:51
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ericand ericand is offline
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AKA: Eric Anderson
FRC #3765 (Terrabots)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2004
Location: St. Paul, MN
Posts: 148
ericand is a jewel in the roughericand is a jewel in the roughericand is a jewel in the rough
Re: The 8.2 (or 8.3) Battery Voltage Bug

Quote:
Originally Posted by Kevin Watson
Can those folks who are having problems please try building your code with the attached 18f8722beta.lkr link script and testing your code. If you still have problems, then try the attached 18f8722_2.44.lkr script and test again. Please report back here with the outcome.

-Kevin
Our problems seem to be helped by changing the linker script. The symptoms
indicate that txdata and/or rxdata are being corrupted. In our robot,
the .map file indicates that txdata is at 0xf00 (gpr15 right above the stack).

Normally I would suspect a stack overflow into the txdata, but the PIC
addressing modes can't allow the stack to escape its bank.

On the theory that there is something strange about the memory in gpr15,
we changed our linker script to disallow data in gpr15. This seemed to fix
things, but we were out of time so we don't have enough testing to be 100%
sure. My fear is that we have just changed the symptom, but not eliminated
the problem.