Patent ID: 6873669

Claim:
A clock signal reproduction device provided with: an oscillation device for generating a clock signal at a frequency corresponding to a control signal input; a first comparison device for comparing the phases of an input data signal and said clock signal, and generating a first control signal for correcting a phase difference between said input data signal and said clock signal; a second comparison device for comparing the phases of a signal divided from said clock signal and a reference signal, and generating a second control signal for correcting a frequency discrepancy of said clock signal; a switching device for selecting either said first control signal or second control signal, and outputting a control signal for applying to said oscillation device; and a control device for controlling such that said switching device selects said first control signal depending on a detection signal from a first detecting device for detecting by use of analog methods whether a phase difference between the signal divided from said clock signal and said reference signal is within a first predetermined range, and also for controlling such that said switching device selects said second control signal depending on a detection signal from a second detecting device for detecting by use of digital methods whether a phase difference between the signal divided from said clock signal and said reference signal is outside of a second predetermined range that is wider than said first predetermined range.