As Colin O'Flynn wrote: > > Is the dW interface also capable of flashing an entire ROM?
> Hmm.. while it's similar to JTAG. One of the differences is though > that you need to enable DW mode first, which requires SPI if the > fuse isn't set. So you use the limited SPI interface of the MK-II to > enable the DW fuse then use DW to download code, then disable the DW > fuse. Btw., I've meanwhile got some explanation from one of those Atmel Noway guys about how dW works. That ``limited SPI interface'' is basically limited in that it can only transfer a single reply byte from the ISP protocol back to the host. Good enough for programming a fuse byte, and that's all it is intented for. debugWire is somehow still on my agenda, but probably first as a debugging protocol, not as a method to download something. Back to the 5.0-BETA: using Colin's USB hack (for the JTAG ICE mkII) on Linux, I recently ran into reproducible troubles when trying to read back the flash of something I just had downloaded. It always hung at the same percentange, accompanied by a message that it received a preposterous packet length indication. The reason for this is not yet quite clear to me, perhaps it's even an ICE firmware bug where the ICE is intermixing two packets (a regular reply and an event packet for a break event). I've got a suspicion that that could occasionally happen (and if that's reproducible, I'll report it to Atmel), however, upon reviewing that code, the receiver tries to ignore the preposterous number of bytes it's just being told -- which of course makes no sense, as it will wait forever then. Instead, it should simply re-enter the state machine, looking for yet another start-of-frame indication. I'll have to fix that, it's a showstopper as it is right now. -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-) _______________________________________________ avrdude-dev mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avrdude-dev
