电话呼叫系统的设计

Design for Telephone Calling System

以单片机与CPLD为核心,设计了电话呼叫系统.其中CPLD完成对各逻辑接口的地址编码,单片机主要用于协调各功能模块,主要包括摘机检测、来电号码显示、拨号处理以及双方通信通道的建立的同时关闭主叫回铃音和断被叫振铃等,实现了两话机点对点的通信.

With MCU and CPLD, a telephone calling system is designed in the paper. The CPLD is responsible for address decoding, then MCU completes system＇s controlling and signal detecting modules design whose functions mainly include the detection of phone-one＇s off-hooking, at the same time showing the number, dialing treatment, sending back ring to calling side, closing the ring and back ring and so on. Ultimately it achieves Peer-to-Peer communication between the two telephones. This system which has the characteristics such as the low cost inexpensively and free call may be widely used in the hospital, the district and some public places.