在图像处理中图像数据交换量大, 图像数据传输是图像采集处理系统的关键环节。EDMA 是DSP中用于实现数据快速交换的重要技术, 具有独立于CPU的后台批量数据传输的能力。文章基于TI公司TMS320DM642芯片的图像采集处理系统, 利用EDMA的数据传输方式实现视频数据信号高速实时传输。介绍了DSP的外部存储器接口与FPGA的FIFO存储器有机结合进行数据传输, 分析了其设计的整体结构与逻辑控制的功能, 并着重分析了基于EDMA Ping-Pong数据传输方式的原理及其应用。另外, EDMA 中断服务程序调用CPU对已搬移完成的图像数据块进行处理, 不仅提高了数据的传输效率, 而且节约了CPU资源, 使DSP的高性能得到了充分发挥, 从而为视频信号处理的实时性奠定了基础。

In image processing, large image data need be exchanged among memories, so the transmission of image data is key link in image capture and processing system. EDMA is important technology in DSP that is used to realize the rapid exchange data, and it has the ability of transmission data that isnt dependent on CPU. In this paper, the video signal capture and processing system is designed based on TMS320DM642 chip of TI company. And in the system the EDMA data transmission mode is utilized to realize the high-speed and real-time transmission for the video signal data. The combination with the EMIFA of DSP and FIFO storage of the FPGA which is used in the data transmission is introduced in this paper, and the design of overall structure and the function of logic control are analyzed. Especially the principle, realization method and application based on the EDMA Ping-Pong data transmission mode is analyzed. In addition, the program of EDMA interrupt service is used in the image to process the moved image data, and the CPU is mainly used in video signal proce-ssing and system function control. This method not only improved the transmission efficiency of the data but also make the high-speed performance of DSP get full application, so as to lay a foundation for the real-time performance of video signal processing.