Design Of The Small Digital Program Controlled Exchange Used In Electric Power Communication

In electric power system,Digital Program Controlled Exchange has been used broadly because communications requests high reliability. This Article gives brief introduction about exchange technics firstly,then expatiates on the theory of digital exchange technics. Based on the theory ,the article introduces the design of the small digital program exchange emphaticly which uses MT8980D as its main device,and introduce the interface design of the hardware circuit using MT8980D and AT89C51 and their channel switching under software control.PCM code and decode system use LSIC called TP3067 as its Codec,DTMF signals receiving uses the chip of MT8870. The clock circuit needed in the design can be supplied by FPGA.Finally ,the article introduces the design of software system .The hard core of the software design is the call processing.