VHDL语法的支持范围是不一样的，以下程序中的某些语句可能不能运行在所有的软件平台之上，因此程序可能要作一些修改，同时务必注意阅读程序中的注释。以下部分程序为txt格式，请自行另存为vdh后缀的文件。有些EDA软件要求ENTITY的名称和文件名要相同，也请自行修改。 如发现错误请来信指正或在BBS上提出。

-VHDL syntax support is not the same as the scope, the following procedures for some of the statements may not be able to run on all of the software platform, so the procedure may have to make some changes, at the same time be sure to pay attention to the footnote reading program. Part of the procedure for the following txt format, please save as vdh suffix documents. Some EDA software requirements ENTITY name and file name should be the same, please amend its own proposal. Found an error please send correction or raised in the BBS.