Usb Host Applications In Embedded Systems

As a new technolody in USB field, embedded USB host technolody has been taken more and more notice recent two years. Currently,USB host is PC at most situations. As the quantity of USB equipments becomes large and the style of USB equipment becomes abundant, the users hope that the realization of USB data transmission in embedded system. Based on this, embedded MCU system has widely existed in industrial dominating field. Among them, most are using serial port RS-232 to transmit data.Based on above-mentioned information, the thesis is researching on the realization of document transmission between serial port equipment and U disk in embedded single chip system, In the design of hardware, considering applies simple system to realize complicated USB data transmission, choosing CH375 as USB host interface chip, 8-bit SST89E58 MCU as controlling CPU and extended module to form the single hardware system.This thesis mainly analyzes the realization of the system function from the software side, including the analysis of USB protocol, USB system structure, data communications model and etc. It also anatomizes host controller driver program and constructs the basic communication mechanism between CH375 and MCU. Based on UFI instruction Mass Storage Agreement, it realizes bulk-only data transmission. The creation of simple FAT file system solves the bidirectional data and document transmission between U disk and RS-232 serial port equipment. The thesis also elaborates on the exploring progress of WDM USB driver program and PC communication interface of this system.