Patent ID: 7966507

Claim:
A device for controlling power-supply timings for supplying power from an external power supply unit to a plurality of circuit elements having different power-supply timings, the device comprising: a plurality of power-supply lines configured to supply the power to respective groups of the circuit elements, the respective groups determined based on power-supply timings required by the circuit elements; and a control unit that controls the power-supply timings for supplying the power from the external power supply unit in an order in response to the power-supply timings required by the circuit elements for each of the power-supply lines, wherein the circuit elements include a first circuit element that needs power even in a power-saving mode in which power is saved by stopping a power supplying; and a second circuit element that does not need power in the power-saving mode; the external power supply unit outputs a first power-saving mode power that is supplied even in the power-saving mode, and a second power-saving mode power that is not supplied in the power-saving mode; the power-supply lines include a first power-supply line for supplying the first power-saving mode power to the first circuit element; and a second power-supply for supplying the second power-saving mode power to the second circuit element; and a power-supply timing to supply the second power-saving mode power to each circuit of the second circuit element in the second power-supply line is controlled as a power-supply timing control process at a time of cancelling the power-saving mode.