Design Of Four-channel Camera Link Video Image Acquisition Card Based On PCI-E Bus

Video monitoring is an important component of intelligent building projects which are developing rapidly. With the rapid development of digital video technology and electronic technology, it is developing towards digital and intelligent direction. As the front-end equipment of video monitoring system, video image acquisition card which has become the key research contents is responsible for image acquisition and transmission. With the development trend of the digital camera gradually replacing the analog camera, the high resolution and high quality camera based on the new Camera Link interface is being used. But because of the high price and the redundant functions, the Camera Link image acquisition card matched with camera cannot be accepted by common users. And further more, the products of the multi-channel image acquisition card based on Camera Link interface are less and less, because of the high performance requirements of the large capacity and the high bandwidth. The purpose of this paper is to design a real-time, rapid, economic data acquisition card in order to meet the requirements of efficient image transmission.The paper mainly discusses the design of a4channel digital video acquisition card which is based on PCI Express bus and Camera Link interface. Compared with the traditional acquisition card, the multi-channel Camera Link acquisition card taking FPGA as the core device, not only implements the image acquisition function, but also implements the functions of the camera performance control and the synchronous receiving of multi-channel video source, which simplifies the hardware structure and saves the costs of the system. And then the new Camera Link interface is used to receive the image data of the camera input,which improves the transmission speed and the anti interference ability of the acquisition card. After that, the method of storing the image data to external DDR2SDRAM solves the problem of the low-end FPGA chips which have small capacity and low speed of reading and writing. Finally, the connection between×4lane PCI Express bus and PC, satisfy the engineering of multi-channel image synchronous received to the requirements of high-speed transmission rate.Firstly, this paper introduces the research background and situation of the video image acquisition card, and expounds the key technologies such as Camera Link interface and LVDS technology, FPGA technology and PCI Express bus technology briefly in design. Secondly, thesis analyzes the overall design scheme of the acquisition card, and the hardware circuit and the implementation of each FPGA module, and then detailed introduces the hardware circuit design of the image acquisition interface, and the DDR2SDRAM interface and the PCI Express bus interface, and also study their software modules. Finally, Modelsim SE is used to simulate and test the main modules. According to the results analyzed and discussed, we improve the feasibility and rationality of the design scheme, which meets the requirement of subject design.