PURPOSE: To provide a digital signal processor capable of drastically reducing the load of user's program development, reducing the load of a microcomputer, unnecessitating an external memory device, and drastically reducing total cost.

CONSTITUTION: The digital signal processor is provided with a program ROM 30 for storing plural module programs for digital signal processing, the microcomputer 10 for outputting start address data corresponding to a necessary module program out of the plural module programs stored in the ROM 30, a module sequence RAM 23 for storing start address data, and a means for controlling the successive reading of module programs corresponding to the start address data stored in the RAM 23 from the ROM 30.