1. A digital TV, comprising: a memory, for storing a regular program code; a signal processing module, for receiving and processing a data signal and generating an interruption signal, and a processor coupled to the memory and the signal processing module, for receiving the interruption signal and reading the regular program code from the memory, and for executing the regular program code to realize functions of the digital TV; wherein, the memory is divided into a plurality of blocks, and the processor accesses the memory by block; each block comprises a first sub-block storing a specific program code, and when the processor receives the interruption signal, the processor reads the specific program code from the first sub-block of the currently-accessed block and executes the specific program code.