摘 要
本文对基于FPGA控制的LED汉字滚动显示器的设计方法进行了探讨。提出了两个实现方案。并对其中一个方案作了详细说明。文中首先介绍了LED发光二极管点阵的控制原理；然后研究了在LED发光二极管点阵上滚动显示汉字的方法；最后，用VHDL语言程序设计了一个完整的LED汉字滚动显示器。
本系统由扫描控制模块、只读存储器ROM和FPGA外面的LED点阵显示模块、一个反相器和两个4-16译码器构成。其中：扫描控制模块和只读存储器ROM集成在FPGA芯片内部。两个4-16译码器(74LS154)和一个反相器配合FPGA中的列扫描控制模块共同完成了两块16×16点阵显示模块的32列的扫描控制。FPGA定义的只读存储器ROM中保存了要显示的汉字的数据，并以16位的数据宽度输出到LED阵显示模块的行端，配合列扫描控制共同完成汉字的滚动显示。
本系统利用数字系统设计自动化(EDA)技术实现了全硬件方式的LED点阵显示。利用FPGA内部的物理资源，将只读存储器ROM和主要功能模块设计在FPGA内部。充分显示了EDA技术设计的灵活性，同时也大大提高了系统的集成度和稳定性。
关键词：FPGA； LED； EDA；动态扫描
Abstract
This article discusses the designing method of FPGA controlled LED Chinese character rolling display. This article also proposes two feasible plans and gives a detailed explanation to one of the plans. The article firstly introduces the LED control principle. Then the article studies rolled the demonstration Chinese character method on the LED light emitter diode lattice. Finally, I design a complete LED Chinese character rolling display with VHDL language program.
This system is composed of a scanning control module, a ROM, an LED plot array module, an inverter and two decoders, with the scanning control module and the ROM installed inside the FPGA chip. The two decoders and the inverter work with the out-scanning control module in the FPGA to exercise 32-array scanning control of the two 16×16 dot-matrix display module. The FPGA-defined ROM preserves the data of the Chinese characters that will be displayed, and it sends the data, by way of a 16-bit data width, to the end of the LED plot array module. With the array-scanning controller, the Chinese characters achieve their rolling display.
This system has realized the entire hardware way LED lattice demonstration using the number system design automation (EDA) technology. Using FPGA internal physics resources, non-erasable storage ROM and major function module design in FPGA. It had demonstrated fully the EDA technical design's flexibility, simultaneously also greatly enhanced system's integration rate and the stability.
Keywords: FPGA; LED; EDA; Dynamic scanning
