MAC-NET not sending eth frames

hmijail — Thu, 03 Apr 2014 18:05:46 GMT

I am trying to use the MAC-NET core in the Vybrid uC in a TWR-VF65GS10 board (connected to a TWR-SER2 board). And I believe I have done everything that should be done to be able to send a random ethernet frame:

clocks ungated and multiplexers set to use the external RMII clock,
IO pins configured and multiplexers set,
FIFO descriptors and buffers created and aligned with better-than-recommended alignment,
disabled ENET, set registers to my liking (store&forward, CRC added by MAC-NET, RMII mode)
initialized the PHY and set its registers to my liking,
got the PHY to autonegotiate and detect the link conditions forced by the other side and report good link,
fed back the negotiated speed to ENET,
re-enabled ENET,
prepared an ethernet frame into one of the buffers, set its flags,
and set ENET0->TDAR = ENET_TDAR_TDAR_MASK.

If I understand correctly, now DMA should take over and either send the frame or signal any error, and then set TDAR to 0.

But nothing is happening. TDAR stays ==1 indefinitely. No changes in EIR either. And Wireshark also doesn't see anything.

I have tried using enhanced buffers and requested interrupt flags to see if any error flags appeared on their status fields. Nothing.

I have tried checking what the BSP does, and I don't see anything I could be missing.

I have tried different alignment sizes, either the minimum required ones or much bigger than recommended.

I have tried ungating all the CCGR clocks just in case I was missing something..., setting the MII_SPEED in MSCR slower than necessary..., tried different sizes of ethernet frames, ... nothing happens.

U-boot in the accelerometer demo boot disk does manage to ping the network, so the hardware is functional.

The RAM I am using is set to be non-cached.

Does anyone have any idea of what could be wrong?

Re: MAC-NET not sending eth frames

karina_valencia — Mon, 07 Apr 2014 18:37:50 GMT

timesyssupport can you attend this case?

Re: MAC-NET not sending eth frames

hmijail — Thu, 10 Apr 2014 11:14:54 GMT

Just in case someone finds him/herself in this situation, my problem was that the MMU had been activated and I was passing virtual addresses to the MAC-NET. The moment I passed the physical addresses it started working.

A colleague says the Vybrid USB controller did something similar because of alignment problems, so in general, looks like the module-private DMA engines have this tendency to just sit there if there is any problem with their work parameters. For the MAC-NET case, I expected at the very least that the EIR[EBERR] bit would flag a problem with the DMA transaction (as its description says), but... no.

topic Re: MAC-NET not sending eth frames in Vybrid Processors

MAC-NET not sending eth frames

Re: MAC-NET not sending eth frames

Re: MAC-NET not sending eth frames