Integrated circuit device including wake-up control circuit and electronic device including the same

An electronic system comprising:

• an electronic device;
• and
• at least one integrated circuit device connected to the electronic device through an inter integrated circuit (I2C) interface, the at least one integrated circuit device comprising:
• a central processing unit (CPU) configured to operate in one of a plurality of modes,
• a clock generator configured to generate an internal clock signal,
• a controller configured to control the CPU and the clock generator by receiving serial data and a serial clock signal, and
• a multiplexer configured to select one of the serial clock signal and the internal clock signal and to provide the CPU with the selected signal as an operating clock signal,
• wherein the controller is configured to compare an identification (ID) received from the electronic device with an address of the at least one integrated circuit device.