PURPOSE: To optimally control in response to purpose such as a high speed drive, a high efficiency or a large output by signal processing based on information of memory means by a digital signal processor.

CONSTITUTION: In a DSP 50, a data bus 51 and a program bus 52 are completely separated in its device. Thus, fetching and execution of a command can be processed in parallel, and a digital signal can be processed at a high speed. A program memory 61 of memory means for storing necessary information to calculate and a data memory 62 for temporarily storing calculated result are connected to the bus 52 of the DSP 50. The DSP 50 is driven in synchronization with an oscillation frequency of a clock 63, and several +MHz of frequency is generally used. The calculated result of the DSP 50 is converted from a digital signal to an analog signal by a D/A converter 65, and output.