The ET5401A-LR is an “intelligent” optical module which incorporates the complete physical layer functionality from the 10.3125Gb/s 64B/66B encoded optical interface to a XAUI compliant (4 channel x 3.125 Gb/s) 8B/10B encoded electrical interface and vice versa. The control interface (MDIO) is also integrated. The receiver subassembly includes a highly reliable PIN photodiode. The MUX/DEMUX, XAUI interface and MDIO management functions are all integrated into the module, as is a precision oscillator that removes any need for an external reference clock.