[En-Nut-Discussion] changes in nicrtl driver

Stephen Noftall stephenn at lcsaudio.com
Fri Jul 2 16:19:24 CEST 2004


> What I was saying is that I cannot believe full duplex can be set in a way
> it is done in nicrtl.c. Attempt is done, but bit will remain unchanged.
> Anyway I think that half duplex should be set there, not full duplex.

Actually, with Ethernut hardware and the Realtek chip, it is set to full
duplex all the time.

There is no way (other than a hardware modification to simulate the EEPROM)
to turn it to half duplex.

This is where the problem comes from. The Ethernut is in full duplex, and
the switch has "auto-negotiated" down to half duplex.

Since you want the two to match, the best choice is to upgrade to the new
Ethernet controller (which is what I have done, and it works great!), or to
somehow get the switch into full duplex. You can only do this if you have a
managed switch, and manually set it to 10BaseT-FullDuplex. If you do that,
it works well. That is what we have done with our previous Realtek stuff, so
that the collisions never occur. There is a really cheap ($150?) managed
switch out there that we used, forget the model number, but it was locally
stocked with a computer supplier.

SN




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