In one preferred embodiment, a boot control apparatus of an MCU includes a register, a reset signal generating circuit, and a controlling circuit. The register includes a first pin to receive a reset signal output from the reset signal generating circuit, and a second pin to receive a signal output from the controlling circuit. The controlling circuit includes a signal detecting circuit, and a delay circuit for delaying a signal output from the signal detecting circuit. The register is capable of sending a command to the MCU to allow the MCU to execute a warm boot if the first pin receives a reset signal and the second pin is at a low level, and sending another command to the MCU to allow the MCU to execute a cold boot if the first pin receives a reset signal and the second pin is at a high level.