关键字:Maxplus2 VHDL 计数器 Abstract VHDL is a circuit design for the high-level language. In the late 1980s emerged. Initially by the United States Department of Defense developed for the . troops used to improve the reliability and reduce the development cycle of use smaller language. However, to the extent that it satisfies the design requirements of the time. He then became the 1987 ANSI / IEEE standard (IEEE STD 1076-1987). Further amended in 1993, has e plete, as ANSI / IEEE ANSI / IEEE 1076-1993 standard STD. At present, most of the CAD manufacturers produce the EDA patibility of such standards. VHDL is the brief description of VHSIC (Very High Speed Integrated Circuit Hardware Description Language). The translation into Chinese is ultra-high speed integrated circuits hardware description language. So it is primarily used in digital circuit design. Currently, it is used mostly in FPGA / CPLD / EPLD design in China. , This article mainly to explain the use VHDL to achieve eight two-decimal counter asynchronous method。 Keywords:Maxplus2 VHDL Counter 1 MAX+plusⅡ简介 输入 1)原理图输入(Graphic Editor):MAX+PLUSII软件具有图形输入能力,用户可以方便的使用图形编辑器输入电路图,图中的元器件可以调用元件库中元器件,除调用库中的元件以外,还可以调用该软件中的符号功能形成的功能块. 2)硬件描述语言输入(Text Editor):MAX+PLUSII软件中有一个集成的文本编辑器,该编辑器支持VH