Wed Apr 6 21:25:06 EDT 2011

USB endpoint register access

The simplest approach seems to be to create a word for setting the a
register to the correct endpoint window, and have an ep-command word
that sets the size and flags.

The buffers only need to be set once at startup.  The good thing is
that the status and count are right next to each other.


So this is really just a!! followed by !a+ !a+ for the basic count &
status access.  Probably need to write CNT first though, since STAT
can cause an action: setting UOWN transfers the buffer to the USB
hardware, which causes a transmit on an IN endpoint.