EDA技术以EDA软件工具为开发环境，以可编程逻辑器件为实验载体，实现源代码编程和仿真功能。VHDL作为一种标准化的硬件描述语言用于描述数字系统的结构、行为、功能和接口。本设计提出了一种基于VHDL语言的编码器和译码器的实现方法。编码器与译码器是计算机电路中基本的器件，本课程设计采用EDA技术设计编码和译码器。编码器由8线-3线优先编码器作为实例代表，译码器则包含3线-8线译码器和2线-4线译码器两个实例模块组成。课程设计采用硬件描述语言VHDL把电路按模块化方式进行设计，然后进行编程、时序仿真和分析等。课程设计结构简单，使用方便，具有一定的应用价值。

-EDA technology take the EDA software as tools for the development of the environment,programmable logic devices in experimental carrier,the realiztion of the source code programming and simulation. The VHDL as a standardized hardware descr iption language used to describe the struction of digital systems,behavior,function and interface.　　 The paper proposes a method for encoder and decoder based on the VHDL language.Encoder and decoder is a basic computer circuit devices.This Curriculum design by EDA design encoder and decoder.Encoders from 8- 3 priority encoder for example,and decoder includes 3- 8 decoder and the 2- 4 examples of the two decoder modules.And then to program, the timing simulation and analysis.Curriculum design, simple structure, easy to use and has a value.