由于微电子学和计算机科学的迅速发展，给EDA(电子设计自动化)行业带来了巨大的变化。特别是进入20世纪90年代后，电子系统已经从电路板级系统集成发展成为包括ASIC、FPGA/CPLD和嵌入系统的多种模式。可以说EDA产业已经成为电子信息类产品的支柱产业。EDA之所以能蓬勃发展的关键因素之一就是采用了硬件描述语言(HDL)描述电路系统。就FPGA和CPLD开发而言，比较流行的HDL主要有Verilog HDL、VHDL、ABEL-HDL和 AHDL 等，其中VHDL和Verilog HDL因适合标准化的发展方向而最终成为IEEE标准。-As the microelectronics and the rapid development of computer science, to the EDA (electronic design automation) industry, has brought great changes. Especially the beginning of the 20th century, 90 years, the electronic system has moved from the circuit board-level systems integration to develop into, including ASIC, FPGA/CPLD and embedded systems a variety of modes. Can be said that EDA industry, electronic information products has become a pillar industry. EDA has been able to flourish, one of the key factors is the use of a hardware descr iption language (HDL) descr iption of the electronic circuitry. On the FPGA and CPLD development, the more popular HDL mainly Verilog HDL, VHDL, ABEL-HDL, and AHDL etc., in which VHDL and Verilog HDL because of the direction for the development of standardization eventually become IEEE standard.