MCF5272 Network Driver Problems

Brett Swimley brett.swimley at
Wed May 1 15:32:18 UTC 2002


Several Months ago I posted a note regarding some problems that I was having
with the MCF5272 Coldfire RTEMS Network Drivers that I was developing.  I
was attributing problems to the instruction cache being enabled, but now I'm
pretty sure that's not the problem.

The MCF5272 Fast Ethernet Controller (FEC) is essentially the same as in the
MPC860T.  I have taken that driver and modified it slightly for use with the

For testing, initially I just thought that I would ping my development board
and get the responses.  Once that was working, I'd dive into more detailed
stress testing.

My problem is that I am regularly missing ping reponse packets.  It
_appears_ that I get the request consistently, but the response just does
not go out the door.  My network driver (I believe) follows the
documentation faithfully.  I have a transmit Daemon task that waits for a
START_TRANSMIT event, and then calls a sendpacket function for each packet
pulled off the queue.  Then sendpacket function loads buffer descriptors
with mbuf data, and then triggers the FEC to transmit the frame.  The buffer
descriptors are retired when the frame has been transmitted. An interrupt
event is generated by the FEC when the frame has been transmitted.

Currently, my test application only initializes the network stack, and then
my Initialization task deletes itself.  Are there any issues with this type
of test?  Should I be doing something more?

I'm not communicating with the PHY on the development board.  It's a
Netburner board and I spoke with their technical staff.  They indicated that
I should not need to do anything.  The PHY autonegotiates, and appears to
set up fine.  I am running Half-Duplex.

I'm not using bootp, so I have initialized the board's IP address, etc.
explicitly per the documentation.

Any insights here would be greatly appreciated.


Brett Swimley
Sr. Design Engineer
Advanced Electronic Designs, Inc.
brett.swimley at
ph: 406-585-8892
fax: 406-585-8893

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