XAUI
From Wikipedia, the free encyclopedia
XAUI (pronounced "zowie", a concatenation of the Roman numeral X, meaning ten, and the initials of "Attachment Unit Interface") is a standard for connecting 10 Gigabit Ethernet (10GbE) PHY to Ethernet MAC on a printed circuit board. It is also known by the acronym XGXS (ten gigabit extender sublayer). It used as an off chip MAC/PHY interface as the 72-pin 10 Gigabit Media-Independent Interface (XGMII) is not a practical interface to use on a circuit board.
XAUI is specified in Clause 48 of the IEEE 802.3ae 10GbE specification. It is a 16-pin interface consisting of four differential lanes in both the transmit and receive directions. Data is 8b10b encoded resulting in a data-rate of 3.125GHz per lane. Data is driven and received by SerDes which are capable of clock and data recovery (CDR). The XAUI transmit path converts idles to three types of control character: regular comma characters, skips and alignment characters. The XAUI receive path uses the commas for synchronization, the skips for clock tolerance compensation and the alignment characters to remove skew between the lanes.
XAUI is the interface used by XENPAK optical modules.
