簡要介紹了Blackfin561的DMA功能和BMP文件的格式，敘述了在基于Blackfin561的
嵌入式操作系統(tǒng)uClinux下并行外部接口（PPI）驅(qū)動程序的框架，以及驅(qū)動程序中各個函數(shù)的具體功能與實現(xiàn)方式。完成了虹膜圖像數(shù)據(jù)的采集，并對圖像數(shù)據(jù)進行了預(yù)處理，提取其中所有亮度信息，生成BMP圖像文件。同時指出了調(diào)試過程中常遇的問題以及解決方法。
關(guān)鍵詞：嵌入式系統(tǒng)；設(shè)備驅(qū)動程序；虹膜圖像采集；DMA；PPI
Abstract: In this paper, the DMA function of Blackfin561 and BMP image file are simply
introduced, and the architecture of parallel peripheral interface (PPI) driver based on embedded OS uClinux running on Blackfin561 is given, further more, the functions and achievement of each function in the driver are introduced. The image data is captured and pretreated, in this process, all the brightness signals are pick-up, then generate bmp image file. At the end of the paper, the problems often meet in debug and the solutions are present.
Key words: embedded system；device drivers；iris image sampling；DMA；PPI