The VSC8228 is a dual repeater/retimer for Fibre Channel, Gigabit Ethernet, SONET/SDH, and Infiniband applications. The VSC8228 contains dual FibreTimerTM clock recovery units (CRU) for bidirectional signal conditioning in system interconnect and serial backplane applications. The device supports rates from 125 Mbps up to 4.25G. Using a single reference clock for acquisition, the VSC8228 retransmits the incoming serial data synchronously to the reference clock in retimer mode or to the incoming data in repeater mode. In the retimer mode, add/drop elasticity buffers insert/delete Fibre Channel fill words to account for timing differences in the incoming data and local reference clock.