TSE 1000BASE-X/SGMII PCS only w/LVDS I/O

You need to write the PHY address in the MDIO_ADDR1 register before you can access the registers themselves. You have 3 ways to find out which address the PHY is using:[list][*]look at the schematic and check the connections to the PHY chip that hard wire the address[*]try all the addresses from 0x00 to 0x1f until you get a response (this is what the Interniche driver does)[*]run a design example with a Nios CPU and the Interniche stack, and look for the address in the console output[/list]