Design And Research Of Digital Switching System Based On ARM9

Since Bell invented the telephone at1876, the science and technology improve constantly along with the improvement of the society, and people's requirements for the technology grow day by day. Telephone exchange and communication technologies have made remarkable achievements in this process. Telephone switching technology now completely finished the change from artificial to the programmable. In recent years, with the rapid development of modern communication technology, the program-controlled digital switching technology is also tending to be mature. The exchange contents changes greatly and expands from a simple voice communication to video, images, files and instant messages and so on. Facing the age of information explosion, people benefit from these technologies, in addition to the convenience, at the same time, learning and knowing well exchanging technology has become not only a new challenge but also an urgent need to engineers and related majors. This paper, which is supported by the basic theory of exchange principle and related technologies and literatures, gives the design of a system based on ARM9which combines the original MCU control digital exchange system. This system gives a comprehensive upgrade of the original system by solving the problems including the small capacity and can not incapability to be connected to the Internet.This system consists of two parts named including software and hardware. The part of hardware was designed by modularity, including the clock module, transmit and receive module circuit, the network interface circuit, the CPU processing module circuit and display circuit. Two parts of the software section are the embedded client software and gateway applications. Embedded terminal gives choice and connection to the gateway, so that we can achieve a real-time monitoring the state of the entire system of communication.Within the system we use the ST-BUS protocol to transmit signals, and can finish the functions of32-channel intelligent digital interphone's (call station) call set-up, meeting, override, and broadcasting in one council and can also be directly connected to the Internet via an Ethernet interface to establish between the Bureau and the Bureau of interconnection. The entire system can be monitored while the gateway client is connecting network, and then achieve the functions of the communication voice recording, the recording of the landing station, the interconnection with other words stand and outbound traffic priority. The principle machine of this system has been achieved. System testing has shown that the indicators of interconnection between the council and the council between the stations are meeting the design requirements.