Re: [avrdude-dev] suggest a "programmer"?

[Joerg Wunsch]

As Nicholas Flowers wrote:

> Also, my understanding (which may be wrong) is that USB considers IN 2
> distinct from OUT 2, but that the 16U2 (at least) doesn't allow you to both
> configure IN 2 and OUT 2.  I could have an IN 1/OUT 2 or vice versa.

That's exactly the LUFA problem I mentioned.  USB considers endpoints
0x02 and 0x82 being two distinct EPs (one OUT, one IN), and that's
what the old Philips/NXP PDIUSBD12 chip on the AVRISPmkII does.
However, Atmel controllers don't support this, they require the IN and
OUT endpoint numbers being distinct in the lower 7 bits.  Since the
LUFA implementation wants to be Atmel Studio compliant, they then
switch the endpoint direction dynamically, but that's tricky.
-- 
cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL

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