Hello There,
        I'm writing embedded code on a mass storage device and
I'm having a little trouble getting the right specification for
DATA0 / DATA1 packet marking. The USB 1.1 spec doesn't really cover
this and I can't find the part of the 2.6.5 source where this is covered.

My understanding is that after configuration the first packet from the PC
to the device's BULKOUT will be a DATA0 and then a DATA1 and then alternating until any reset when DATA0 is used again. This alternation is carried on without
regard to the different CBW / DATATRANSFERS / CSW transactions.

My lack of understanding is whether the BULKIN endpoint uses the _SAME_ DATA0 / DATA1 sequence or a seperate sequence of it's own. All the diagrams in the specs do not show this sort of activity.
Do I need two variables (one per endpoint) to hold the PID or just one?

i.e.OUT 0 IN 1 IN 0 OUT 1 IN 0 OUT 1 OUT 1 etc
or  OUT 0 IN 0 IN 1 OUT 1 IN 1 OUT 1 OUT 0 etc

So can anyone either direct me to the correct files "/usr/src/linux/drivers/usb/??"
that contain the linux end of things or explain the spec.

Thanks in Advance
Bill


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