Research On Integrated Service Set Top Box Based On VxWorks

With the rapid development of digital television, wide band and control technology, eATV integrated service web shows wealthy resource superiority. Digital television Set-Top-Box has applied wider and wider as a bridge popularizing integrated service. With different terminal unit, now customers can accepte IP data access and digital television respectively, but people has bring forward higher demand for information of household application and flexibility of household device and convenience of collecting external information. In order to taking the advantage of HFC network and satisfying people' s increasing information demands, the thesis has devised and realized a integrated service STB based on embedded operating system, which integrated the function of orthodox Cable Modem and common Set Top Box.On the background of development of digital television integrated service and network module of set top box application, the thesis firstly introduces MPEG-2 and DOCSIS protocol for data transfer over Two-way HFC net, as well as the function requirement and interactive standard of integrated service STB. Secondly, based on the analysis of integrated service STB, we build hardware platform of integrated service STB with the CONEXANT interactive STB integration chip CX24430 serving as the core chip, then we study and design its main hardware module.After the study and design of hardware,this thesis analyzes the frame and demand of STB software system, and VxWorks is chosen as the embedded OS, which is famous for its good performance and high reliability. After analysing the makeup of VxWorks and its exploitation environment-Tornado, we emphasis on the design and realization of the following software modules, giving the procedure flow chart and key codes.(i) Cable Modem subsystem ,including design and loading and startup of bottom driver, the link between CM and CMTS.(ii) the demux module of STB subsystem ,including software parsing of PAT and PMT information.(ⅲ)interactive module for user,including initialization, interrupt service and key assignments signal processing of remote control device.(ⅳ) Iinitializtion of integrated service STB and application building-up.The purpose of the thesis is design and realize a integrated service STB, which integrated the function of orthodox Cable Modem and common Set Top Box. After the study, design and debugging of the hardware and software, we perform the application test of integrated service STB over Guangzhou Ration & Television Network, the results of IP data transmission and digital television service are both meet the design technology index, moreover, the system works stably and performs well, it will have a bright future for applications.