I am using the Cisco MGBT1 SFP Transceiver in an SFP Module Interface on a Xilinx ML555 development board. I need to configure the MAC that I am using to talk to the MGBT1, but don’t know what PHY interface the MGBT1 supports. Does it use SGMII, RGMII, GMII, MII or 100Base-X PHY interface? Detailed specifications on the MGBT1 would be very helpful, but I can not find them on your site. Do you use transceivers manufactured by Marvell? If so, which one.