Patent ID: 7659761

Claim:
An operation mode setting apparatus, comprising: an operation mode setting control unit configured to discriminate the phase of a reference clock from the phase of a feedback clock to generate a locking suspension signal; and an operation mode setting unit configured to generate a locking completion signal in response to a phase comparison signal and a pulse signal under the control of a reset signal and the locking suspension signal, wherein the operation mode setting control unit includes: a latch configured to latch the locking completion signal and generate an output; a first detector configured to detect whether the phase of the feedback clock leads the phase of the reference clock by a first time, and to generate a first detection signal; a second detector configured to detect whether the phase of the reference clock leads the phase of the feedback clock by a second time, and to generate a second detection signal; and a signal combining unit configured to combine an output signal of the latch, the first detection signal, and the second detection signal to generate the locking suspension signal.