PURPOSE: To attain stable transmission by providing a dead band to phase adjustment of data and a clock in the reproduction of a reception clock at each node to eliminate the clock supply and phase difference adjustment at a specific node.

CONSTITUTION: A reception data changing point detection section 131, a phase comparison section 132 and a clock generating section 133 are provided in a clock synchronizing circuit reproducing a reception clock RXC synchronizing with a reception data RD and the clock RXC adjusted in response to the phase difference θ is outputted. The comparison section 132 detects a phase difference θbetween the data changing point and the clock RXC generated by the generating section 133, which changes the generated frequency (f) by ±Δf around a center value f0 according to the difference θ. Thus, a dead band is provided to the phase synchronizing circuit to absorb the phase difference thereby eliminating the need for the clock supply and phase difference adjustment at the specific node.