Hardware Design For Anti-eavesdropping System Of Video Information Based On HDMI

First, this paper describes the development of computer video information leakage prevention and its importance. Then focuses on the research background, the development process of TEMPEST technology as well as domestic and foreign research status. Finally, in the background and theoretical basis that determines the overall research ideas in this paper.Based on features and intercepted principle about HDMI digital video information, I design a leak-proof digital video hardware system——add video processing board inside the shielded computer case, which constitutes a leak-proof video information system. Then this paper analyzes the main structure and working principle of HDMI video system. Because HDMI based on the principle of TMDS encoding, so the TMDS encoding features, signal characteristics and data transfer are also described. Finally, this paper introduces the existence of HDMI interface system in the market. I determine the performance of video processing board according to system requirements, and develop the hardware implementation with the core of FPGA according to the type of video transmission systems and processing speed and other issues. Then I consider the factors such as performance and cost of the hardware system TMDS decoding module, TMDS encoding module, PROM module, configured chips and power chips and other major chip selection and the corresponding peripheral circuit design.After the system schematic design is complete, the next step is to design the processing board PCB. First, I develop a PCB design flow to guide the design of hardware boards. Before PCB layout, it is necessary for its signal integrity problems that may arise, such as video data transmission line reflections, crosstalk analysis and simulation, and based on the simulation results to guide the wiring about data transmission lines. Meanwhile for PCB power integrity issues, I analyze the decoupling principle of decoupling capacitors, and the target impedance is calculated according to the power of the number and specific add capacitor capacitance, and then through the actual simulation to determine the specific capacitance values and numbers. Finally, complete decoupling capacitor placement based on decoupling radius. Then the EMC design about the whole processing boards is introduced, through the power of EMC design and ESD design to protect its electromagnetic compatibility standards. In the final stage of the PCB design, complete the entire processing board PCB layout design according to the theory and some rules of thumb.Finally, I deal with some board-related tests to verify its functionality. And I also raise some further research ideas according to the test results and hardware problems during system implementation.