I'm doing my first project with the Xmega128AU and just got to the serial port part. It is driving me into an early grave
Has anybody, I implore,
Seen anything like this before?
That is the first three characters of CR, LF, 'OK', CR, LF, sent immediately after reset. You'll perceive that it stars with TXD negative, as it should because it's proper RS232 and not TTL. It gets as far as 'O' and then stops, with TXD HIGH. Nothing will induce it to complete the string.
However, if I back up with the JTAG ICE and run that signon routine again, this is what I get -
Now that is the complete CR, LF, O, K, CR, LF sequence - but it's upside down. Nothing except a hard reset gets the serial port back the right way up, and then it flips again on the third character.
I've tried several of the different ports and they all behave the same way. I suspect that somewhere in one of the multiple manuals I have to keep open with this damn chip there's probably a line or two about it, but I can't find it for looking. I'm starting to deeply regret picking an XMEGA for this project - it's just one thing after another.