Research On Embedded USB HOST System Based On ARM

As a BUS interface technique, USB is widely applied in PC field, In some embedded system, people hope USB device can be used to extend mass storage ability. But in general USB topology structure, an USB device cannot be separated from the host PC.In this thesis, aimed on the application limitation of USB device, analyzed the USB host system and made a design plan. Then the hardware and software requirement for an embedded USB host, other than host PC, and some design hints are determined. Furthermore, considering the most popular U disk as USB device target, an USB host demo is designed and realized by using interface chip CH376 to communicate with U disk. Through this module, the USB host is realized in embedded system. This makes it possible to communicate directly with traditional USB peripheral in an embedded device without PC.In this solution, a very popular and easy to be debugged micro controller STM32F103 is selected as the core MCU of embedded system. The whole module is accomplished and verified. The interrupt task schedule mechanism is realized in firmware design and a set of API is given. This makes the module with high universality and easy to be migrated to other embedded system with different processors. It can be used in different applications which need large storage. According to the method proposed in this thesis, an USB host system can be constructed. This contributes a universal significance to the development of embedded USB host and USB application without PC.