Abstract: A jitter attenuation circuit includes a FIFO data register (10) which is operable to receive data that is synchronized with a Write clock output therefrom synchronized with a Read clock. The data is written to the FIFO register (10) from a location determined by a Write pointer (12). The data is read out from the FIFO register (10) from a location determined by a Read pointer (14) which is clocked by a Read clock. The Read clock is synchronized with the Write clock by a phase lock loop (24). The phase lock loop (24) has a phase detector (26) which is operable to accrue phase error over intervals of 2.pi. radians such that the phase lock loop (24) virtually never loses lock as a result of phase jitter on the Write clock.