After a week or so of coding, the firmware changes to support programming the latest range of ATTiny CPUs using the uPDI protocol are almost ready for prime time.
Also nearly ready is a patch for avrdude to add support for uPDI over jtagMKII.
There’s just one small remaining hurdle to overcome – the target’s fuses are proving troublesome to write – but I’m sure this will be sorted soon.
The good news is that uPDI support will be offered as a free firmware update to existing owners. If your uPDI target’s programming header conforms to the recommended 6-pin header pinout then wAVR should Just Work with the supplied ribbon cable.