The Researchment And Development Of HDMI Output Card

HDMI (High-Definition Multimedia Interface), is a new generation of multi-media interface standard and is developed by Hitachi, Matsushita (Panasonic), Philips, Silicon Image, Sony, Thomson and Toshiba. HDMI is one digital interface standard to support the transmission of the all-digital high-definition video without compression, multi-channel audio and control data in a single cable.With the increasingly application of the HDMI interface in the multimedia industry, the related products manufacturers need more standard HDMI signal sources. Now the market has a wide range of equipment with HDMI output, such as DVD, video player and so on, but few products can serve as a standard HDMI signal source.Following market requirements, with the technical advantages, our company officially approved to develop a system-wide digital television test signal generator. The test scope is including of digital televisions, monitors, video display associated with the module and the video interface. I am charge of the development of digital TV HDMI output card .The card is an important part of the test signal generator.This paper introduces HDMI comparative advantages to DVI, has made the decomposition and the explanation to two big technology in theHDMI standard-- data transmission mode and the encoding method;has analyzed the function of HDMI output card circuit modules, and has pointed out the three issues that need to focus on resolving, including:①Carry on the function development to the HDMI output chip and realize audio coding output on the HDMI output card and solve automatic selection mechanism problem of the video pixel coding;②the TMDS differential voltage variable amtitude adjustments of HDMI output;③ clock jitter. For the first two issues, I have carried on research and analysis in view of task requires, finding solutions to the problems. In addition, the paper has made a description of the deep color feature of HDMI1.3, has analyzed the relationship between deep color pixel encoding and pixel clock, TMDS transmission clock, and has proposed one production method based on the actual circuit for deep color test pattern. Finally, I have carried on the test to the HDMI output card, has carried on the analysis to the test result, and proposed a solution method for clock jitter according to the test result. It is worth mentioning that, the generation and test method of deep color pattern has been applied for a patent.