The Design Of Digital Set Top Box

The Digital Set Top Box, also called 1RD (integrated receive decoder), is a terminal receive device of digital television system. It is engendered from the combination of computer technique and the characteristic of Wide Band in the cable TV system. This thesis analyses the whole software design according to the thinking of the software engineering.First, the thesis introduces the technique background of the Digital Set Top Box. Its techniques mainly include digital video technique, embedded operate system technique, Internet and communication technique, information security technique and the system structure of the cable digital TV system. In addition, this thesis expatiates concept of the Set Top Box and analyses elementary services such as digital TV service, TVOD service, NVOD service, STOCK service, browser service and games on-line.Next,the frame of the design is put forward, which include the selection of scheme, the management of software , the distribution of resource, the produce of interface function .The software mamagement includes the hiberarchy,contents,vesion control and criterion of the code.The distribution of resource includes the arrgement of the FLASHROM, SDRAM and SMARTCART.Detailed design includes the drivers part and application part. The drivers part comprises the initialization to the Set Top Box, driving the OSG,realizing the demux,driving the smartcart,driving the keypad and remote control,driving the 1 c bus,Internet interface,driving the NVROM,driving the demodulator with QAM,driving the mcnu.Thc application part consists of the service module management, program navigation ,NVOD,TVOD, browser,digital TV ,games on-line and program loader. In this section , the programme of the Internet interface fuction,the demodulator, initialization of the the Set Top Box, service module management, program navigation and digital TV were considered particularly.In debugging section, the thesis mainly describes the debug method for the demodulator, Internet interface fuction, and the shift of the code from flashrom to sdram in the initializing program. At the end of this section, possible solutions to the problems are provided.Finally, the thesis summarizes advantages and disadvantages of this design, and prospects the foreground of the Set Top Box.