[avrdude-dev] ATxmega A4U support

[Brian Mayton]

I'm starting a new project that involves an ATxmega128A4U and it would be
great if I could program this part with avrdude (running Atmel Studio 6 in a
VM just to program parts is a real pain.)

Recent SVN versions of avrdude seem to be able to read the device signature
just fine over PDI, but programming the device results in an error when the
first byte of flash reads back as 0xFF during verification (implying it was
never programmed.)  

I found this in an earlier thread on this list:

>> The new XMEGAs A3Us and A4Us don't seem to work with the existing
>> JTAG code; I think the protocol may have changed in some
>> incompatible way.
>
> If someone who owns such a device were about providing an USB sniffer
> trace of the Atmel Studio JTAGICE communication, I'm willing to have
> a look at it.

I've captured USB traffic from Atmel Studio 6 programming an ATxmega128A4U via
PDI on a jtagice mkii with Wireshark, and another trace of the flash being
read back.  The files are here:

http://bdm.cc/u/atxmega128a4u_dumps.tar.bz2

I can take a look and try to figure out what's going wrong myself, but if
someone who already has some familiarity with the jtagice mkii usb protocol
and the avrdude codebase might be able to spot the differences, that would
save me a bit of time.

Brian