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Altera_Forum's avatar
Altera_Forum
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15 years ago

Strange Ethernet behaviour

We currently have a a design which is based heavily upon the Cyclone 3 FPGA dev kit. However, at this point it is very difficult to return to the Dev Kit to test the software some am hoping someone h...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Do you have a point to point connection or are you connected to a LAN?

DHCP or fixed IP?

I don't know if your case could be related to this:

Last year I had a problem with iniche+tse: in presence of concurrent tx and rx, some frames were lost. If tx and rx were not overlapped there was no problem.

After long investigation, I discovered the problem was in sgdma driver: sometimes rx and tx frames got corrupted because dma data was allocated in the same memory area.

I never found if I myself was making some error or if this is an undocumented driver bug: if you use TCP this behaviour is somehow hidden, since TCP would recover the lost frames and you get only a minimal performance loss.

I only needed 100Mbps, so I solved the problem using the opencores mac in sync mode.