国德州仪器公司（TI）的TMS320VC54XX系列DSP芯片与PC机实现异步通信通常有两种方法：第一种是使用通用I／O信号XF和BIO作为串口发送和接收信号，用软件逐位发送和接收数据，即软件异步通信方法，这种方法需要占用很多CPU时间，因此，只能在DSP不太忙、实时性要求不高的情况下采用；第二种是通过扩展异步通信芯片来实现高速串行通信，本文选用的就是此方法。

-State of Texas Instruments (TI) of TMS320VC54XX series DSP chip and PC machines to achieve asynchronous communication there are two methods: the first is the use of general-purpose I/O signal XF and BIO as a serial port to send and receive signals, with software-by-bit send and receive data, or software asynchronous communication method, which take up a lot of CPU time, therefore, can not be too busy in the DSP, real-time nature of the circumstances do not ask for much　the second is through the expansion of asynchronous communication chip to achieve high-speed serial communication, this article is that this method of choice.