在测控类电子产品中,常需要主控制器提供多个异步串口对接外设单元,但主控制器的片上串口资源十分有限,因此产生了串口扩展器的场景需求。本文采用WK2114芯片设计了一款UART接口四通道异步串口扩展器,该扩展器利用主控制器的一个标准3线异步串口扩展得到4个增强型子串口,芯片内部自带256级FIFO,且子串口的波特率、数据位长度、校验格式均可单独设定,最高通信速率可达2 Mb/s。功能验证和样机测试结果表明,该款扩展器具有一定的实用价值。

In measurement and control electronic products,it is often necessary for the main controller to provide multiple asynchronous serial port docking peripheral units.However,the on-chip serial port resources of the main controller are very limited,resulting in the scenario demand for serial port extenders.In this paper,WK2114 chip is used to design a four channel UART interface asynchronous serial port expander.The expander uses a standard 3-wire asynchronous serial port of the main controller to expand to obtain four enhanced sub serial ports.The chip has 256 level FIFO inside,and the baud rate,data bit length,and verification format of the sub serial port can be set separately.The maximum communication rate can reach 2 Mb/s.The functional verification and prototype test results prove that this extender has certain practical value.