Re: [avr-chat] Struggling to write usersig with avrdude on an xmega256a3

[Joerg Wunsch]

Travis Griggs <address@hidden> wrote:

> It fails at the verify step. Using the read variant of the above
> (which works fine), I can see that it somehow mashed new write with
> the old contents, ending up with something in between. So the verify
> fails.

Obviously, writes to the user signature area require it to be erased
before.  This can happen through a chip erase (naturally), or through
a page erase.

The current (well, quite old now) released version of AVRDUDE did not
support page erases.  The SVN version (to be released as 6.0 really
soon now) does, and if I read the code correctly, is supposed to
automatically perform a page erase for the usersig before programming
it.  If you can, give it a try.

If you are stuck with the old version, just program the user signature
only once after a chip erase.
-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)