Interfacing the MARVEL Chip on DE2-115

I used a lot of trial and error when I got the Cyclone III development kit, because at first no example with Ethernet was delivered with the kit and we were on our own. IIRC contrary to other PHYs the Marvel doesn't generate an automatic reset at power up, and needs a real reset signal from the FPGA or it will be in a strange state. Besides this reset signal needs to be at least as long as what they ask in the datasheet (10ms and 10 valid clock cycles) and you must wait a further 5ms before accessing the MDIO registers.