[ethmac] bug found?

[davidmertens@freegates.be]

I think I found a bug.
It has something to do with the carrier sense bit in the TxBD when 
working in full duplex.

When using full duplex, the carrier sense line from the PHY will not be 
asserted when transmitting data, only when it is receiving data (in half 
duplex it will be asserted when sending AND receiving data).
In eth_macstatus.v, the last lines of the code:

// CarrierSenseLost
always @ (posedge MTxClk or posedge Reset)
begin
  if(Reset)
    CarrierSenseLost <=#Tp 1'b0;
  else
  if((StatePreamble | (|StateData)) & ~CarrierSense & ~Loopback & 
~Collision)
    CarrierSenseLost <=#Tp 1'b1;
  else
  if(TxStartFrm)
    CarrierSenseLost <=#Tp 1'b0;
end


--> shouldn't there be something like :
if((StatePreamble | (|StateData)) & ~CarrierSense & ~Loopback & 
~Collision) & ~r_FullD )

If you don't use ~r_FullD, you always get an Tx error, because the 
carrier sense of the PHY isn't asserted when transmitting.

Greetings,
David
--
To unsubscribe from ethmac mailing list please visit http://www.opencores.org/mailinglists.shtml