Semiconductor integrated circuit device, data processing system and mobile body communication terminal apparatus

In the invention, an optimal control without having error is performed on the stopping operation and bias voltage control with respect to the built-in circuit block in accordance with the state of the corresponding circuit block. The invented control circuits (3, 9, 11) individually stop the clock to reduce the operation current and add substrate biased-voltage to decrease the leakage current for the first computation processing circuit (1) such as the CPU portion, and the second computation processing circuit (2) such as the DSP portion. In order to transfer the workable state from the first and the second computation processing circuits to the second computation processing circuit for terminating operation, the first computation processing circuit is easily prevented from inputting/outputting signal to the second computation processing circuit from the moment of receiving the instruction and after the instruction, so as to prevent from the erroneous operation of the second computation processing circuit caused by inputting/outputting the signal. Regardless of stopping the operation of the first computation processing circuit or both computation processing circuits, when execution is proceeded in accordance with the instruction of the first computation processing circuit, the erroneous operation of the first computation processing circuit caused by inputting/outputting the unexpected signal also can be prevented.