CLOCK REGENERATING APPARATUS

PROBLEM TO BE SOLVED: To provide a clock regenerating apparatus for regenerating a clock for data reception from received data that can quickly correct a phase error between the received data and a regenerated clock and correct the frequency of the regenerated clock corresponding to a clock of a transmitter side. SOLUTION: A phase error detection section 4 calculates the phase error between the regenerated data and the regenerated clock, a feedback amount calculation section 6 obtains a feedback amount in proportion to the phase error, and a clock generating section 2 uses the feedback amount to correct sum data outputted from a center frequency calculation section 8 and accumulates the sum after the correction to generate the recovery clock. Further, the feedback amount calculation section 6 generates a feedback amount only once when an edge change of the received data takes place and holds the feedback amount to be '0' in other cases. Moreover, the center frequency calculation section 8 averages the sum of an adder 12 of the clock generating section 2 to update the summation data denoting the center frequency of the recovered clock. COPYRIGHT: (C)2004,JPO