PURPOSE: To reduce the power consumption by stopping the drive of the logic circuit which inputs a clock to a dividing circuit based on a reset signal or the clock stop signal supplied from the outside.

CONSTITUTION: A logic circuit 1 works based on a clock signal and inputs a clock to a dividing circuit 2 which divides and outputs the clock. The circuit 2 stops its operation with input of a reset signal 3 and also stops its operation in a reset state when the signal 3 is inputted to the circuit 1. Therefore, the circuit 1 does not work despite the change of the signal 4 so that the power consumption of the circuit 1 can be suppressed.