Design Of Image Acquisition System With USB2.0 Interface

Image Acquisition major in image data acquire, transfer and storage, it is the basis of image processing. Now, many image collector transfer inamge data to a computer through the computer interface, accomplish their work with the help of high computing speed and large storage capacity of the computer. Traditional computer interface was expensive and discommodious in image data transmission. This dissertation proposes a method to build an image acquisition system with USB2.0 interface.First,some common computer interfaces were discussed, compared and analyzed. Among them, USB2.0 is one of the most popular computer interface, which has the advantages of high transfer-rate,less resource requirement, low cost, expandable and convenientable. After that,the architecture and features of USB2.0 was introduced, including the attributes, definition,technical details, transmission types, device definition, and so on.The scheme being proposed to build an image acquisition system is that: The host computer provide the man-machine interface and deal with the user operation. As the controller of the image collect board,the USB2.0 manage chip decide the operate mode of the board Under the management of the host. CPLD storage the image data in the SRAM, according to the CMOS image sensor's timing.Then the DSP chip read image data from the SRAM, communicate with the GPIF of the comtroller chip by HPI, then send the image data to the host computer to storag and display.This dissertation discusse the schematic diagram of the image acquisition system, the design of the circuit,the select of the chips,the design of the logical relationship in CPLD,the design of PCB,the applicaion of CMOS image sensor OV7620 and so on. How to select a USB2.0 controllor chip was emphasized. The whole software of the image acquisition system was also discussed, include how to program the application in the host computer, the USB2.0 device drivers for Windows, software for the USB2.0 controllor, the program for the DSP chip etc. The firmware framewok, the configuration of end-piont, the design of the GPIF waveform of the USB2.0 controllor CY7C68013 were emphasized.Such works have been done:design the circuit of the Image acquisition system used USB2.0 interface, Design and installation the PCB of an image acquisition board,design and simulation the logic in the CPLD, programming and debugging the USB2.0 firmware, DSP program, USB device driver and the application.