| Information technology has been coming into digital era. As a high quality multimedia player and high performance network information terminal, digital television, which is based on embedded system, is a new hotspots of next generation consumer electronics and has broad market perspective. Based on the deep analysis of Digital TV Standards,embedded software and hardware technology, solution of digital television is studied.According to the method binding two subsystems on system level, digital television, consists of Decoding Subsystem and Display Subsystem, in which Decoding subsystem is developed on decoder chip dedicated for Set Top Box application, while Display subsystem on HD-Ready television solution. On the one hand, each subsystem has its own embedded processor and heterogeneous software architecture to achieve different functions. On the other hand, the two subsystems cooperate with each other by communication——Audio and video signals are transferred from Decoding Subsystem to Display Subsystem through audio and video interfaces; Commands, data and status information are transmitted through communication interface to synchronize the operations of two processors. In user's perspective, the whole system runs as a single one, that is to say, Single System Image is implemented.A design instance is shown in this paper. The design of hardware circuit of Decoding Subsystem in which Dtti5516 is chosen as the processor is elaborated,since it is the foundation of the whole system. HD-Ready television solution supplied by Trident Multimedia is adopted for Display Subsystem, in which M16C/62 is the main controller. Dtti5516 communicate with M16C/62 through UART interface accorded with our communication protocols. According to the characteristics of digital TV applications, communication protocols between two processors and status machine model of application layer are designed. These are the key techniques to achieve single system image.In the end, the system is tested. The results show the functions of digital television are completely achieved. Front-end performance is analysed. Concerning scalability, the system could be improved to implement more functional and practical application in the future. |
