Xgmac

Cyclone IV GX in the F484 package support either 4 or 8 serdes transceivers capable of running up to 3.125Gbps in XAUI mode. Four lanes at 3.125Gbps XAUI is what you need for a 10G etherNet interface, assuming an external 10G etherNet PHY. You can't do a 10G etherNet physical interface directly on the Cyclone IV GX, you must have an external 10G PHY connected to four serdes lanes.