1. A method for loading and executing a target program code at a mobile communication device comprising a micro-processor, comprising steps of: (a) entering a monitoring mode from a non-monitoring mode and 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; (c) rebooting the micro-processor to prompt the micro-processor to exit the monitoring mode and enter the non-monitoring mode in which the target program code in the internal memory is to be executed; and (d) after Step (c), setting the micro-processor to enter the monitoring mode in which the monitoring procedure is performed after the micro-processor is next rebooted; and wherein the target program code is one of a plurality of predetermined program codes stored in the external memory, each of which respectively corresponds to a radio frequency identification (RFID) protocol, and wherein the external memory is a flash memory and the external memory is a random access memory.