Re: [avr-gcc-list] RE: Troubles uploading to a Mega103

[Kasper Pedersen]

----- Original Message -----
From: "Heinrich Vermeulen" <address@hidden>
To: <address@hidden>
Sent: Wednesday, March 28, 2001 9:09 AM
Subject: [avr-gcc-list] RE: Troubles uploading to a Mega103


> We had the same problem with both the signature bytes being 1)FF FF FF and
> being 2)00 01 02:
> 1)The ATMega103 loses its signature bytes for some reason after a few
> erase/program cycles.  The workaround is to change the UISP code.  I made
a
> couple of changes already to the software already to accomodate these
> defects (also to read/write fuse bits, correcting srec format downloads,
> etc.).  I can give you or anyone else this code if you so wish.

I am very much interrested; Could you explain what not to do, what to do
instead, and your guess why? I have a similar programming utility, and I'd
like it _not_ to kill off my as-yet-unused 5 samples.

I noticed that there are 16 signature bytes in the 8535. I wonder what all
the remaining ones are - just unused decodes (I doubt it, why then use 4
bits and not 2) or something useful? I think I'll try searching the entire
'8535 ISP command space when I get the time.

/Kasper