The MC10/100EP445 is an integrated 8bit differential serial to parallel data converter with asynchronous data synchronization. The device has two modes of operation. CKSEL HIGH mode is designed to operate NRZ data rates of up to 3.3 Gb/s, while CKSEL LOW mode is designed to operate at twice the internal clock data rate of up to 5.0 Gb/s. The conversion sequence was chosen to convert the first serial bit to Q0, the second bit to Q1, etc. Two selectable differential serial inputs, which are selected by SINSEL, provide this device with loop-back testing capability. The MC10/100EP445 has a SYNC pin which, when held high for at least two consecutive clock cycles, will swallow one bit of data shifting the start of the conversion data from Dn to Dn+1. Each additional shift requires an additional pulse to be applied to the SYNC pin.