PURPOSE: To make it possible to reduce current consumption for the entire circuit by controlling the supply of a clock according to the type of an instruction from a program memory.

CONSTITUTION: The following parts are provided: a clock signal generation circuit 1 for actuating the entire electronic circuit, a program memory A for memorizing microinstructions, a memory C for holding various types of data, logic arithmetic circuit F and input/output circuit E. It is designed so that a clock signal may be supplied or cancelled by each circuit configuration block depending on the types of microinstructions from the memory A. In addition, the generation of a clock signal is controlled based on the decision of a specific common bits in the memory A.