Cyclone V - EMAC ARP receive error

Altera_Forum · ‎05-14-2016

I have connected a Micrel KSZ8864 PHY (10/100MBit, MII Interface) to the EMAC0 on a MCV Coremodule (Cyclone V). The MII interface of the PHY is routed through the FPGA and the communication with the PHY is done over SPI (not MDIO). For the U-Boot bootloader I have adapted a driver from the Micrel website to communicate with the PHY.

If I send a ping, the transmit process works well but the response is not recognized from the EMAC. Anyway, if a TCP packet is send to the EMAC during ping, this packet is received and detected correct. If I switch back with U-Boot to the default configuration with the GMII Phy and use it with the MCV Development board all works well.

Any idea why the ARP response with the 100MBit Phy is not received ?

Thanks,

Klaus

Altera_Forum · ‎05-16-2016

I have found the problem - there is a bug in the U-Boot Version 2016.03. The following description was copied from the actual Git repository:

Thus far, the socfpga init code had hard-coded the configuration of the ethernet PHY interface to RGMII in the ethernet registers in sysmgr space, so PHYs connected in another modes did not work.