Interfacing the MARVEL Chip on DE2-115

There shouldn't be a lot to do to the PHY to get it up running. The Marvel is very picky about its reset signal, but except for that, it should automatically auto-negotiate when going out of reset. Using the MDIO interface you should first interrogate the autonegotiation status and find what speed was negotiated, as the PHY interface will be different between BASE100-TX and gigabit, for example. Then configure the PHY to the correct interface (GMII, RGMII... I don't remember how it is connected on the kit). Also note that there is a clock phase shift option, just check that you use the correct setting, one matching the timing requirements for the project.