用VHDL语言模拟完成程控交换技术的实验，已经通过仿真验收-Simulation using VHDL language to complete the experimental program-controlled switching technology has been acceptance by simulation

CPLD程控交换综合实验程序，附有源代码，和最终下载文件-CPLD program-controlled exchange of comprehensive experimental program, with source code, and eventually download