The Scheme Design And Research Of Set-card Separation In Digital Set-top-box

During information age, development of technology advances our livingstandard. Nowadays, digital televisions bring along brighter future to digitalbroadcasting industry with its efficient utilization of frequency spectrum, vividvision and touching sound. Moreover, the interactive services digital televisionsprovid including Electronic Program Guide (EPG), Video on Demand (VOD) andweb page browsing make the digital broadcasting industry better. Conditional Access(CA) shows as a critical technology for TV operators to provide pay-TV and variousvalue-added services. Meanwhile, the “set-card separation” technology greatlypromotes the development of digital television CA and the large-scale production ofdigital television terminals and, thus, it becomes the main stream of the developmentof CA technology in recent future.After analyzing the digitial television CA and working principles of multicrypttechnologies, this paper compares the characteristics of two main “set-cardseparation” schemes (PCMCIA and USB Schemes). Furthermore, according to thedesign requirements of the “high definition digital television terminal” project, thePCMCIA scheme based on DVB-CI standard which is chosed to be researched inthis paper. Based on the STB326development platform and embedded Linux system,the author demonstrates the hardware and software design methods of “set-cardseparation” scheme which includes the design of bottom driver, stackcommunication and the applications in application layer. In the end, the special CItesting toll--Multicrypt Test Tool--is used to verify the performance of our methodsand the accuracy of results. The user interface directly displaies the performance ofCA and and Man Machine Interface (MMI).Here are the creative features of this project:（1）Considering with embedded Linux operating system, user layer designpattern calls file system operating function in standard drivers lib like poll, ioctl, read,write etc. For the sake of simplifying upper layer design, this pattern provides datagroup receiving and sending, initialization of module, states checking methods whileshielding hardware relativity for upper layer design. （2）Completing the design on STB326platform with protocols in each layeron the theory of message passing and state machine, and offering complementarymethods of this stack design method in software system which is not support thepassing of variable-length messages.（3）Giving an optimized compages of CI stack design method, and completingthe design of communication and applications base on this CI stack design method.The test with “Multicrypt Test Tool” and screen displaies certify the accuracy ofresults.