PURPOSE: To decrease the number of microinstructions, and to increase the storage capacity of a control memory by using an increment signal, a fetch instruction signal, and an input switching signal from a counter for various kinds of control by a program control circuit.

CONSTITUTION: A mapping memory 9 stores the number M of machine cycles, required for the program control by a control memory, as preset data (f). The mapping memory 9 supplies a counter 12 as preset data with the number of machine cycles which is the frequency of looping of a program constituted so that a control signal Dl and an instruction signal dm form a loop relatively and repeatedly in the control memory 10. The counter 12 sends an increment signal E1 to a program counter 2, a fetch instruction signal E2 to an instruction register 3, and an input switching signal E3 to a multiplexer 5 respectively.