Patent attributes
A signal processing apparatus of an electronic device not only cuts off supply of power to a hardware unit from a power supply unit when a control signal associated with a power OFF command is supplied from an instruction input unit, but also turns OFF a switching circuit of an oscillation circuit unit, thereby cutting off supply of power to the oscillation circuit unit. The switching circuit is configured to be turned ON according to input of a signal from an interrupt port unit, and resumes supply of the power to the oscillation circuit unit upon supply of a control signal from the instruction input unit. When supply of a clock signal to a CPU circuit unit from the oscillation circuit unit is resumed, the CPU circuit unit resumes supply of power to the hardware unit from the power supply unit after operation of the CPU circuit unit is stabilized.
