PURPOSE: To control an integrated circuit microprocessor having an extremely large number of instructions, e.g. about 600 instructions or more by means of a control system accordant with each type of instructions.

CONSTITUTION: This microprocessor is provided with a data path device 102 to store and process the data, and controllers which give the instructions of the arithmetic operations, the storage, etc., to the data path device 102 based on a prescribed procedure after decoding the machine word instructions. A 1st controller 203 applies the random logic and a 2nd controller 204 applies a PLA control system respectively. An internal address selecting device 202 gives selectively the control right of the supplied instructions to an instruction decoding device 104 and the controller 203 or 204. Then, an internal address multiplexer device 201 takes out the output of the device having the control right at the side of the device 102.