Problems with the MDIO - 16.2 English

• Ensure that the MDIO is driven properly. See MDIO Management Interface for detailed information about performing MDIO transactions.
• Check that the mdc clock is running and that the frequency is 2.5 MHz or less.
• Read from a configuration register that does not have all 0s as a default. If all 0s are read back, the read was unsuccessful. Check that the PHYAD field placed into the MDIO frame matches the value placed on the phyad[4:0] of the core.