USB主机在嵌入式系统中的应用

【作者】 董杨生；

【导师】 方斌；

【作者基本信息】 南京理工大学 ， 检测技术与自动化装置， 2008， 硕士

【摘要】 嵌入式USB主机技术作为一项USB领域新的发展技术,最近两年,得到越来越多的关注,目前,USB主机的角色大多数情况下都是由PC机担当,随着USB设备数量的不断扩大以及USB设备形式的不断丰富,人们希望能在嵌入式系统中实现USB数据传输。同时,在工业控制领域中,嵌入式单片机系统广泛存在,其中大部分还是通过串口RS-232进行数据通信。在上述背景下,本文研究在嵌入式单片机系统中,如何实现串口设备与U盘之间进行文件传输的通信过程,在硬件设计上,考虑以简单的系统实现复杂的USB数据传输为切入点,选用CH375作为USB主机接口芯片,8位单片机SST89E58作为控制CPU,加上扩展模块构成了简单的硬件系统。本文主要从软件上剖析了本系统功能的实现:认真研究了USB协议,对USB体系结构、数据通信模型、USB协议栈设备框架、USB标准描述符等进行了深入分析。仔细研究了主控制器驱动程序,建立了CH375与单片机之间的底层通信机制。基于MassStorage类协议UFI子类指令集,实现了Bulk-Only单批量数据传输。创建简单的FAT文件系统,解决了U盘与RS-232串口设备间双向文件数据传输的问题。本文还详细说明了WDM型USB设备驱动程序开发过程,并开发了本系统PC端的通信界面,以便于系统的调试与功能测试环节。更多还原

【Abstract】 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.更多还原