Systems and methods for individually controlling power supply voltage to circuits in a semiconductor device

A semiconductor device comprising:

• a CPU electrically connected to a first switch;
• a memory electrically connected to a second switch;
• a signal processing circuit electrically connected to a third switch;
• and
• a controller,
• wherein the CPU comprises a first memory circuit and a second memory circuit, the first memory circuit and the second memory circuit being different from the memory,
• wherein the first memory circuit is configured to be supplied with a first signal from the controller,
• wherein the second memory circuit is configured to store a data immediately before power supply to the CPU stops,
• wherein the data stored in the second memory circuit is configured to input to the first memory circuit immediately after power supply starts,
• wherein the signal processing circuit is configured to convert an operation data signal of the CPU to an output signal which is input to an output device,
• wherein each of the first switch, the second switch, and the third switch is electrically connected to a power supply line,
• wherein the CPU is configured to output a second signal which is input to the controller,
• wherein the controller is configured to control the first switch in accordance with the second signal,
• wherein the signal processing circuit is configured to output a third signal which is input to the controller,
• wherein the controller is configured to control the third switch in accordance with the third signal, and
• wherein the controller is configured to control the first switch, the second switch, and the third switch individually.