PHASE RESTORATION DEVICE OF DIGITAL CIRCUIT

摘要

PURPOSE: To provide a completely integrated digital filter which realizes a phase-locked loop and a data re-timing function by cooperation with a phase comparator. CONSTITUTION: A digital filter 40 includes a prescaler means which divides plural digital pulses into plural digital pulse groups and a counter means which is connected to the prescaler means and counts a 1st increment signal and a 1st decrement signal generated by the prescaler means to generate data signals corresponding to the counts. The digital filter 40 transmits an output to a digital delay element 20 placed between a data signal input and an input of a phase comparator 30 in order to realize the data retiming function. When data are slipped out of the phase for a local clock, the digital filter 40 obtains a polarity of necessary phase correction and feeds it back to the delay element 20. The delay element 20 adjusts the phase of the input data to the phase of the local clock.