USXGMII Ethernet Subsystem v1.0 Product Guide - 1.0 English - Implements an Ethernet Media Access Controller (MAC) with a mechanism to carry a single port of 10M, 100M, 1G, 2.5G, 5G or 10GE over an IEEE 802.3 Clause 49 BASE-R physical coding sublayer/physical layer (PCS/PHY).