CIRCUIT WITH POWER SAVING FUNCTION

摘要

PROBLEM TO BE SOLVED: To provide the circuit which eliminates the need to apply a special manufacturing process for the manufacture and can reduce the power consumption at operation time with simple circuit constitution. SOLUTION: Circuit blocks 1-3 operate functionally independently of one another and can be placed in power-down mode independently. An automatic power saving control circuit 4 generates a select signal SEL for selecting the output signal of a circuit block in operation mode between signals S1 and S2 on the basis of access signals AC1 and AC2 and supplies it to a switching circuit 5. For the selection, a power-down indication signal PS1, PS2, or PS3 is outputted to circuit blocks in nonoperation modes, which are placed in power- down mode independently.