The present invention provides a digital TV. The digital TV comprises a memory, a signal processing module, and a processor. The memory is for storing a regular program code. The signal processing module is for receiving and processing a data signal, and for generating an interruption signal. The processor coupled to the memory and the signal processing module is 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. The memory is divided into a plurality of blocks, and the processor accesses the memory by block. Each block includes a first sub-block storing a specific program code. When the processor receives the interruption signal, the processor reads the specific program code of the first sub-block of the currently-accessed block and executes the specific program code.