The Image Acquisition System Base On USB2.0

With the development of multimedia, image processing is widely used ,at the same time, lay more strict requirements on the image acquisition. The image datum is so large that it's difficult to acquire and transmit. The usual image acquisition system is based on PCI, but there are still some disadvantages, it can't support hot plug and play, it's more difficult for hardware design ,and seize the computer system resources. The USB is a new kind of system bus, because of characteristics of high speed, the usb2.0 speed is up to 480Mbps ,plug and play. So it can meet the requirements of multimedia datum transmission. Now it becomes a trend.So we carry out the high speed image transmission. We design the SAA7111 circuit to convert the PAL to data signal and the USB2.0 interface circuit based on EZ-USB FX2 to transmit datum, and the control unit based on FPGA. The most important for FPGA design is timing. I design the circuit to simulate the I2C timing, and configure the SAA7111 using it. And read datum from SAA7111 and buffer the datum in SRAM and then transmit the datum to host. When we design Printed Circuit Board, we take care of the mixed circuit, and the high speed signal design of USB2.0.To upgrade the transmission speed of USB2.0, I carefully compare the many working modes of EZ-USB FX2, and finish the data transmission. The speed of the image transmission is up to 160Mbps, it can be widely used in image processing system.