A semiconductor device or an information processing system comprises a plurality of circuit units, and a control unit for controlling a start timing of large-current operations executed by the respective circuit units within a predetermined period, where the large-current operation involves a relatively large current which flows in a power supply system, as compared with other operations. The control unit controls the start timing of the large-current operation from one circuit unit to another such that the waveform of a current flowing from the power supply system is shaped into the waveform of a half cycle of a sinusoidal wave when the circuit units execute large-current operations within the predetermined period.