The XG2G20 wrapper allows a 10 Gigabit Ethernet MAC to operate at 1000 and 100 Mb/s data rates in addition to 10 Gb/s. Using the XG2G20 a 10G Ethernet MAC, clocked at 15.625MHz, can be connected to the XAUI20 configured for gigabit operation clocked at 62.5MHz. The XG2G20 performs all the conversions required to map XGMII signalling into double data width GMII signalling and vice versa.