【作者】 胥洋央；

【导师】 王景存；

【作者基本信息】 武汉科技大学 ， 计算机应用技术， 2002， 硕士

【摘要】 PLD是指可编程逻辑器件，是一种可将集成电路的设计用编程的方式写入到其逻辑阵列结构中的一种芯片。本论文讨论用PLD芯片作为主要控制逻辑来设计计算机数字视频系统的一个典型应用型产品——LED视频电子显示屏系统的研制方法。 与模拟系统相比，计算机数字视频系统在图像质量、结构和新产品开发周期等方面有许多优势。数字视频系统有一种逐渐替代模拟系统的趋势，并将成为新一代标准。例如，现在数字接口的平板显示器(panel，亦称液晶显示器)正在取代传统的模拟接口CRT显示器。虽然当前计算机显卡视频处理芯片中一般都有支持平板显示器的数字视频接口，但现在大部分的计算机显卡的输出仍然只提供模拟信号接口。这种模拟视频信号必须要经过AD转换后，才能成为平板显示器的输入信号。这个转换过程不可避免地降低了信号的质量。所以，对完全数字化的视频信号系统的研究变得非常重要。 本系统将计算机视频图像扫描到大屏幕显示板上，LED器件特性决定了信号的控制是全数字式的，是数字视频信号处理系统的一个典型应用。现在市场上已经有成型产品，但其牛大多数还是基于单片机的传统电子电路结构。单片机电路不仅结构复杂，且工作频率很低，不能适应高质量的视频图像的要求。本系统将PLD芯片设计成系统信号驱动的控制芯片，实现了电路结构的高度集成化，不仅结构简单，而且信号处理的频率大大高于单片机电路(普通单片机电路最高工作频率为12M左右，而本系统控制芯片达到50M以上)，更快速的信号处理速度保证了系统产生更优良的图像质量。 本系统由计算机多媒体视频卡、驱动板和显示板组成。多媒体视频卡是购买的现成产品，从50针接口输出数字视频信号，为系统提供信号源。驱动板和显示板是自行研制的，显示板是由红绿两色LED材料组成的发光阵列。由于显示板本身结构简单，所以本系统的设计与通用产品相类似。设计的重点是驱动板，其驱动控制逻辑以PLD芯片为载体通过数字集成电路方式实现，控制逻辑的功能设计是用IEEE标准的集成电路设计语言VHDL作为行为描述语言，在MAXPLUSⅡ 武汉科技大学硕士学位论文 环境中进行编译、综合、仿真和芯片编程。系统将多媒体视频卡输出的数字视频 信号进行数据缓存、分块读取和脉宽调制等处理，形成符合显示板结构的彩色运 动图像扫描信号，输出到显示板。整个系统具有结构简单、集成度高、图像性能 优越等特点。 本系统在显示刷新频率为60HZ，灰度级别为32级的条件下，图像显示清晰 稳定。屏幕可支持1024＊768以下任何面积组态，拼接方便。达到国内市场上成 型产品的水平。更多还原

【Abstract】 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.更多还原