PURPOSE: To perform effective use of circut by function unification, by processing digital signal with the alloction of the fundamental operation circuit with the time- sharing switch circuit.

CONSTITUTION: The signal input line 1, signal output line 10, functions generator 2 required for the processing of the signal objective, circuit 3 performing digital operation, storage memory 5 memorizing the operation program, time sharing switch 4 connecting and controlling the lines 1, 10, generator 2, and input and output of the circuit 3 in time-sharing manner with the designation of the memory 5, ROM 6 memorizing a plurality of operation programs, and controller 7 transferring the program memorized in ROM 6 to the memory 5 with the designation from external or the output of the ciecuit 3, are provided, so that a plurality of programs executing serially or parallelly the signal processing function of the same or different function can be processed.