Big discussion via email yesterday motivated by Chuck about whether we can add
a capability to use the Can-Do modules as a bit pipe between a CPU in the
experiment module and the IHU.  The end result is that yes, we can do it. 

My proposal is that we implement byte-wide in and out busses.  Two of the 
"spare" outputs and two of the analog input channels get taken over to serve
as request/acknowledge handshake lines.  The remaining analog inputs and the
remaining two digital outputs continue to behave as they would in "normal"
mode.  Data is always sent in blocks of 8 bytes.  The module's stream addresses
for this capability are the same as for the command/control protocol but with
the high order bit flipped, so that this bit-pipe function runs at lower
priority than command and telemetry.

[[!tag tags/amsat]]