The Study And Implement Of Key Technology In Embedded Stock Service

Stock analysis system is a kind of real-time service, which presents both the real-time exchange information and historic data analysis. After the introduction of basic stock knowledge and program developing environment, a design of stock analysis software running in embedded system is put forward in this paper, and the crucial techniques solving the conflicts between set top box resource's limit and stock service high demanding are described in details. The whole stock analysis service is divided into three parts: front data broadcasting server, data transmitting block, terminal data receiving and presentation module. After extracting real-time exchange data from DBF (Data Base Found), the front broadcast server, according to different data demands, transforms real-time data into various data. And then following job are packing various data into transmit stream, sending data to terminal through cable TV network. As one of child services in data broadcast, stock service has its description in MPEG-2 (Moving Picture Expert Group) PSI (Program Special Information), which contains PAT (Program Association Table), PMT (Program Map Table), CAT (Conditional Access Table) etc. And the mainly parts of stock data transmit through DVB (Digital Video Broadcast) private sections packages. If STB (Set Top Box) terminal main task finds out the stock service description in PSI information, it can extract the exact stock data from all of received data found according this service description, and presents data as demand. Because hardware resource is relatively scarce, it is hard to ensure stock service running properly without any data reducing and receiving strategies. The satisfying stock function needs the cooperation between data broadcasting server and termination. In this design, the adaptable data sending and receiving tactic, special memory managing skills and peculiar stock data compression help the stock software working better and much efficient.