Software Design Of PCIe High-speed Data Acquisition Module Based On Embedded Linux

With the continuous development of digital information technolog,people's demand for data is getting higher and higher,thus putting higher requirements on the data transmission performance of embedded systems.While the amount of data transmission continues to increase,not only the data collection system itself is required to have big data real-time processing capabilities with superior performance,but the data transmission performance inside the system is also crucial.The acquisition module based on PCIe bus data researched in this subject is required to achieve high-speed,complete and stable data transmission under the premise of modularization,miniaturization and light weight.This paper relies on the project cooperated with NXP company as the background.Based on the hardware platform composed of ARM main controller and FPGA data acquisition card,the embedded Linux system is used to develop the driver software for PCIe high-speed data acquisition module.First,according to project requirements and theoretical analysis,the overall design plan of the data collection system is given,including hardware design and software design.The hardware introduces the structure and characteristics of the ARM main controller and FPGA data acquisition card in the data acquisition system in detail,and the software describes the development process of the PCIe device driver.Second,for the development of embedded PCIe device drivers,build a hardware and software development environment,including configuring TFTP and NFS services on the host and installing a cross-compiler.In addition,the embedded Linux system was transplanted for the LS1043 A main controller,including the transplantation of U-Boot,Linux kernel and Ubuntu root file system.Next,develop PCIe driver software in the established development environment,and use key technology such as character device driver framework,consistent DMA mapping,ring buffer,and memory mapping to optimize DMA data read and write performance,and then use the driver to provide interface function of the transmission control design application program to read and write data.By separately assigning DMA buffers of different sizes to the transmitted data and adding a speed measurement module,the effect on the data transmission rate of the PCIe bus is tested.Finally,test and verify the various modules of the data acquisition system,including the startup of the embedded Linux system,the loading of the driver module,the reading and writing of the PCIe base address register,the reading and writing function of the driver and the test of the transmission performance,etc.The test results were analyzed in detail.From the test results,the transmission performance of the data acquisition system reached the expected requirements.In the final stage of the thesis,the further development of the data acquisition module is prospected.