Thomas Sailer (sailer@ife.ee.ethz.ch)
Wed, 09 Dec 1998 09:33:14 +0100
Tim Waugh wrote:
> > Is the peripherial allowed to do this? I thought address transfers
> > are only defined in forward mode...
>
> It is allowed to, if I read the standard correctly. Data and commands can
> both come over the reverse channel, and table 2 lists the reverse channel
> commands as:
Ok, you're right. My doc (1.14) says "Reverse channel addresses are seldom used
and may not be supported in hardware". And I really don't understand
the programmatic interface. ecpAFifo is said to be operational
only in forward direction. What happens if the peripherial wants
to do a reverse channel address? Does the hardware simply stall? Or
do bad things happen?
Tom
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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:18:52 EST