1. A method for loading and executing a target program code at a micro-processor, comprising steps of: (a) performing a monitoring procedure for monitoring whether the micro-processor receives a loading request corresponding to the target program code; (b) loading the target program code from an external memory into an internal memory of the micro-processor in response to the loading request; and (c) rebooting the micro-processor to prompt the micro-processor enter a first mode in which the target program code in the internal memory is to be executed.