采用USB-UART转换方式实现DSP与PC机的USB通信

Realization of USB Communication of PC with DSP Based on USB-UART Conversion

介绍了异步串行通信芯片SC16C550和USB- UART转换芯片FT232BM的功能、结构特点和内部寄存器.在此基础上设计了通信系统的硬件电路,针对一类应用于运动控制的DSP系统的数据传输需求较低且数据流零散的特点,提出了一种采用USB -UART转换方式实现该类DSP系统与PC机USB通信的方案.这种方案不但满足了USB通信方便快捷的特点,而且继承了传统UART通信占用系统资源少、通信固件开发简单的优势.设计了通信系统程序流程图.选用ADSP- 21992为目标DSP,介绍了其代码开发平台VisualDSP++3. 5及其相关调试工具,并根据流程图简述了DSP内的程序代码组织结构和运行机制.最后说明了PC机上相关驱程的开发步骤和重要函数.

This paper developed functions,structures and inner registers of these two chips SC16C500,a kind of asynchronous serial communication chip and FT232BM,a kind of chip used in USB-UART transition.Based on the specialty of ICs,the hardware circuity and workflow.A unique USB communication method based on USB-UART conversion was put forward,which applied to DSP based MCS (Motion Control System),aimed at the feature of lower data transition request and discontinuous data flow.It not only accorded with the convenience and speediness of the USB communication system,but also inherited the predominance of fewer occupations of system resource and simple communication firmware from traditional UART method.ADSP-21992 was selected as the target DSP;and VisualDSP++3.5 and other debug tools were detailed.According to the workflow,this paper demonstrated the organization of program code and running mechanism in DSP chip.In the end,development steps and some important functions of driver on PC were attached.