Power supply control device, semiconductor device and method of driving semiconductor device

Abstract

A power supply voltage control apparatus including an input signal generation circuit of wide uses or a small-sized monitor circuit of a novel configuration, and a semiconductor circuit and a method for driving the same, having a semiconductor circuit, an input signal generation circuitable to change the phase difference i of a reference signal outφi and an input signal outφin accordance with a control signal Si when generating the two signals from a clock, a monitor circuithaving a characteristic between a power supply voltage and delay the same as that of a critical path of the semiconductor circuit, propagating the input signal outφ, and outputting a delayed signal outφ' to be delayed exactly by a time equivalent to a delay of the critical path (or smaller by a constant ratio), a delay detection circuitfor detecting a delay of the delayed signal outφ′ relative to the reference signal outφi, and a power supply voltage control circuitfor controlling a power supply voltage Vsupplied to the semiconductor deviceand the monitor circuitbased on the detection result.