In a configuration provided with, for example, sixty four pieces of processor cores, an on-chip-memory, a bus commonly connected thereto, and others, the processor cores are operated by a power supply with low voltage and a clock with low frequency, and the bus is operated by a power supply with high voltage and a clock with high frequency. Each of the processor cores is provided with a bus interface and a frequency divider in order to absorb a power supply voltage difference and a frequency difference between the bus and each of them. The frequency divider generates the clock with low frequency from the clock with high frequency, and the bus interface is provided with a level shifting function, a data width converting function, a hand shaking function between the bus and the bus interface, and the like.