The TLK3118 is a flexible, redundant XAUI serial transceiver that is compliant to 10-Gbps Ethernet XAUI specification. The TLK3118 provides high-speed bi-directional point-to-point data transmissions with up to 12.5 Gbps of raw data transmission capacity. The primary application of this device for use in backplanes and front panel connections requiring redundant 10Gbps connections over controlled impedance media of approximately 50 . The transmission media can be printed circuit board (PCB) traces, copper cables or fiber-optical media. The ultimate rate and distance of data transfer is dependent upon the attenuation characteristics of the media and the noise coupling into the lines. The TLK3118 performs the parallel-to-serial, serial-to-parallel conversion, and clock extraction functions for a physical layer interface. The TLK3118 provides two complete XGXS/PCS functions defined in Clause 47/48 of the IEEE P802.3ae 10Gbps Ethernet standard. The serial transmitter is implemented using differential Current Mode Logic (CML) with integrated termination resistors. The TLK3118 can be configured as a redundant XAUI transceiver or a full duplex XAUI re-timer. TLK3118 supports a 32-bit data path, 4-bit control, 10 Gigabit Media Independent Interface (XGMII) to the protocol device. Figure 1 shows an example system block diagram for TLK3118 used to provide the 10-Gbps Ethernet Physical Coding Sublayer to Coarse Wave-length Division Multiplexed optical transceiver or parallel optics.