Design Of CMOS High-definition Camera Acquisition And Transmission System Based On FPGA

With the improvement of the level of integrated circuit technology,CMOS image sensor has made a leap-style development.In particular,CMOS can be integrated within the A / D converter,the level conversion circuit characteristics,so that the direct output of digital signals.HD,high frame rate digital camera,can greatly enhance the image data transfer rate,but also bring great challenges to the hardware circuit design.In this paper,based on the actual engineering requirements,in order to reduce the difficulty of hardware design,simplify the hardware circuit for the purpose of designing a FPGA-based CMOS high-definition camera data acquisition and transmission system,the camera in the 200 Mbps high-speed transmission process can take a resolution of 2048 × 1088 high-definition images,is conducive to the capture of transient phenomenon evidence.The design of the collection and transmission system is divided into three parts: the visible area of the target image acquisition unit,control and processing unit,high-speed data transmission unit.For the level conversion circuit at the interface between the acquisition unit and the control unit,the LVDS level of the CMOS output is converted to TTL level by using the VHDL hardware description language,and the software design is implemented instead of the hardware circuit design.For the high speed transmission problem,Language in the transmission process of the image transmission channel timing design,so that it can multi-channel output,in order to achieve high-speed transmission function;for data transmission in high-speed transmission can ensure that the correct byte,this paper uses FPGA chip field programmable function,Design and implementation of the image data acquisition word alignment and bit alignment,greatly improving the integrity of the data sampling.Finally,through the board-level test and imaging experiments to verify the hardware circuit in the software under the logic of the function,indicating that the design of the acquisition and transmission system can be achieved in the higher frame rate 230 fps to capture high-definition images,a resolution of 2048 × 1088,to meet the project needs.