说明：  一个在单片机平台的电梯模拟程序，基本实现了电梯的所有基本功能，可供学单片机的同学参考。本程序使用VHDL语言编写。
(A single-chip platform in the elevator simulation program, the basic realization of the elevator all the basic functions, for school students Singlechip reference. This procedure using the VHDL language.)