fpga4fun.com

I'm curious about a couple of aspects of this project. Is the output from a couple of fpga pins enough to send data over ethernet?

For receiving packets, I'm wondering how safe it is to send the input to the fpga? Am I likely to see a lot of spikes and the like on a typical ethernetwork? I'm doing a project at school that I'd like to use ethernet for I/O, but my professor won't let me do anything likely to blow one of the (8) boards we have, and after having spent about $200 (canadian) on my setup, I have the same fear at home.

yes, the outputs of the FPGA are able to send data. Usually it is done through an isolation transformer, but I tried without and had no problem.

There is not a "lot of spikes" on the network. Anyway the IOs should be protected, since they are exposed to the outside. My guess is that a series resistor plus a zener diode should do the trick.

Hello,

The ethernet i/o is only electrically connected to your own local hub/switch or pc directly so it should not have to deal with anything too weird outside this small domain. I think this is right anyway. I'm sure any "spikes" that were out there would not make it through the hub/switch...

But I'm very curious about the signal standard so I guess I should go read the IEEE stuff about that.

Chris

You can always 'steal' Ethernet magnetics from an old Ethernet NIC, too

(New life for those old ISA 10baseT NICs in your closet).

-mrac