Design Of Embeded USB Host System Based On ARM

Image signal acquisition and processing is more and more widely applied in scientific research, industrial and agricultural production, medical and public health, public security and other areas. At present, the image processing application is difficult to be applied in embedded systems. There are two main reasons: firstly, compared with common systems, embedded systems have not enough functions and resources to give overall support to complex and high-speed devices; secondly, those simple and inexpensive systems can hardly meet the demands of real time processing and transmission.With the development of technology, the cameras'price has dropped significantly. Most of the camera interface is the USB interface, while the USB interface is used as a device in embedded systems, the application of USB host can not be divorced from computer at present. We will realize the image processing in embedded systems, if we can add a USB host which connects a USB camera device to acquire the image data.The main technical difficulty of this system is the implement of the host controller driver and USB driver. This article provides the embedded USB host platform which is based on ARM7 (lpc2210) +μC /OS-II. On this basis, it completed the following work:(1)Analyzing the partly codes ofμC /OS-II, porting it to ARM development board which is based on LPC2210, and completing the design of the basic work.(2)Achieving the hardware connection between MCU and ISP1160 in PIO mode.(3)Achieving the USB host controller software development based onμC/OS-II to make the system have the characteristics of hot plug, device enumeration and data transmission.