| 摘要 |
PURPOSE:To reduce the power consumption of a semiconductor integrated circuit under a standby state, by providing a switching circuit which selects one out of the 1st and 2nd power supply courses in accordance with the operating state of the semiconductor integrated circuit. CONSTITUTION:Each control signal phi0 and phi3 is set to a level corresponding to the states of devices, namely, standby states and active states of the devices in accordance with commands from a CPU, with the devices being made to correspond to the control signals phi0 and phi3. A switch which is controlled by such control signals supplies voltages of the 1st and 2nd power sources V1 and V2 to one of the devices which is to be set to its active state by the CPU and the voltage of the 1st power source V1 to the other device which is to be set to a standby state b the CPU. The voltage of the 1st power source V1 is sufficient to guarantee the necessary minimum operations of the device under the standby state. Therefore, the power consumption can be reduced without hindering the stability of the system operation.
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