The Application Of PLD Technology In The System Of Computer Video Digital Signal Process

PLD refer to the Programmable Logic Device. It is a kind of chip that can be written the design of Integrated Circuits into its logic arrays. The thesis discusses on how to research and then design the LED video panel system, which is a typical product of computer digital video system, by using the PLD chip as the main control logic.Compared with analog systems, digital video systems of computer have many advantages in the quality of picture, structure and the period of new production. It's the tide that the digital video system will gradually replace the analog one acted as the standard of a new generation. For example, the panel monitor (also called LCD monitor) of computer is replacing the CRT monitor. Video-process chips on display adapters always have the digital interface which can support the panel monitor, the output port of most of display adapters only offer the analog signal interface. Before acting as the input signal of panel monitor, the analog signal must be processed by AD conversion. The conversion inevitably reduces the quality of signal. As a result, the research of full digital system of video signal becomes very important.This design is a video electronic LED Panel. The video picture of computer was scanned to the display board of huge screen. Because of the speciality of LED material, the method of signal control is digital. So the system is a typical application of signal processing of digital video. There is still maturity produce on the market, while most of them are made by method of the custom electronic circuit structure based on the singlechip. Circuits based on singlechip have not only a complex structure, but poor working frequency. Thus, then cannot meet the demand of high quality of video picture. In this system the PLD chip was designed and act as the control chip of signal driving. The structure of circuit are highly integrated. It not only has a simple structure, but obtains a more high frequency of signal processing than thecircuit based on singlechip. (The highest working frequency of sinlechip circuit is about 12M while this system almost reach 50M) A higher speed of signal processing ensure the system achieve a better display quality.The system was component of multimedia video card, driver board and display board. The multimedia video card is the maturity produce purchased on the market. It offers the source of signal. The driver board and display board was designed by our self. Because the structure of display board is very simple, the design is analog to the general produce. The emphasis of design is the driver board. Its driver control logic was realized by means of digital integrated circuit in which the PLD chips utilized as the carrier. The VHDL, which is the IEEE standard design language of integrated circuit, is used as the behavior description language.The compilation, synthesis, simulation and programming are fulfilled in the MAXPLUSII. After being buffered, read by blocks and Plus-width-modulating (also called PWM), the digital video signal will be converted into scanning signal for color moving picture and then be outputted to the display board. The whole system has the many advantage such as the simple structure, high integrated and high picture quality.The system output a clear and stable moving picture in the condition of 60Hz refresh frequency and 32-color degree. The screen can be conveniently combined up to the area of 1024*768. The system achieves the highest level in the homeland market.