Hardware Design Of The Video Model In Integrated Services Terminal

With the development of economy and technology, it will be the trend of the times that the telecommunications network,CATV network and computer communication network infiltrate each other,and realize the unity of the three nets to offer integrated services for users. New HFC network can overcome the serious impact of the original one which has funnel noise,and it can provide integrated services to users, including digital TV, IP telephone, data transmission. The integrated services terminal (IST) is a device which is based on the new pattern HFC network and offers integrated services for family users, and it provides family users to realize the Internet access, digital TV and IP phone etc, from a network, and the family users also can enjoy the various value-added services for video on-demand, home shopping, internet games and distance education etc.The task of the subject is the hardware design of the A/V model in integrated services terminal.The thesis introduces the feature and transmission method of digital video firstly, and then the DVB-C transmission mechanism and MPEG-2 compression standard about digital TV in brief . MPEG-2 is information sources's decode standard used in digital TV ,and the MPEG-2 transport stream is the main receiving data format in the subject; Europe DVB-C protocol adopted in China is channel transmission decoding standard.In this thesis, the requirement of IST is analyzed from the aspects of function, interface and performance request. On the basis of it, functional requirements, performance index requirement and interface method of IST's A/V model is brought forward.According to video model demand analysis and video data processing, program design of IST'video model is presented including six its major functional models: the main control interface model, audio and video decoding model,memory module,external interface module,video output model and power model. By comparing with the existing audio and video decoding chips, STi5518 is selected as the MPEG-2 decoding chip in A/V model .After the technical characteristics of the chips are analysised in detail, all the IST'audio and video circuits are designed, including audio and video decoding model hardware circuit,memory circuit,the main control model interface circuit, audio and video output circuit,power circuit and common interface which is used to connect to the smart card reader or memory card.The development of appliance Integrated Service Terminal is a more complex and huge workload project. As time is limited, it is be further optimized to meet the needs of the market, since audio and video model designed can realize the required functions.