综合测试系统中串口扩展的设计与实现

Design of the serial port expansion in comprehensive test system

在实际的应用中,往往需要多个异步串行接口去连接不同的测试设备。为了解决处理器LPC2294串口数量不足的问题,使用了两片TI公司的4通道异步串行收发器集成芯片TL16C554,以总线方式扩展了八个异步串行接口。完成了串口扩展的硬件电路设计,对软件设计进行了详细的说明。该设计在某组合导航综合测试系统中应用可靠,通过串口实现了LPC2294与八个测试设备的数据接收与发送。

In practical applications,multiple asynchronous serial interfaces were often needed to connect the different test devices.Two TL16C554 chips which have 4 channel asynchronous serial transceivers were adopted to solve the insufficient number of LPC2294 serial ports problem.Eight bus asynchronous serial interfaces were extended by bus mode.The serial port expansion circuit was designed and the software was described in detail.The proposed design has been used in an integrated navigation test system reliably,and the communication between the LPC2294 and eight test devices was achieved through the serial port.