【作者】 刁修慧；

【导师】 吕新民；

【作者基本信息】 西北农林科技大学 ， 机械设计及理论， 2008， 硕士

【摘要】 USB接口具有使用方便,数据传输率高,支持即插即用等特点。但由于USB接口协议复杂,涉及的方面广,特别是软件种类多,USB芯片种类繁多,使得USB设备的开发十分困难。然而随着USB应用领域的逐渐扩大,人们对于USB的期望也越来越高,希望USB能应用在各种计算机领域中,尤其是能应用在移动数据领域中,能通过一些移动设备直接和USB外设通信,使USB能应用在没有PC的领域中。如何将USB应用到嵌入式领域,实现USB的点对点通讯,成为目前USB研究领域的热点。本论文以实现任意波发生器具有USB主口的功能为目的,以ADS1.2/Embest为软件开发环境,采用Hynix的HMS30C7202作为主控芯片,采用Cypress的SL811HS作为USB控制芯片。(1)研究分析了USB1.1协议;在研究USB体系结构、USB总线的拓扑结构、USB总线的物理接口、USB系统的逻辑分层和USB总线数据通信流等基本内容的基础上,重点对USB1.1协议层进行了分析研究。(2)系统地分析了嵌入式系统的开发流程,研究设计了任意波发生器中USB主口设计的硬件系统。分析了干扰因素,并从元器件的选择、对外部电磁辐射进行屏蔽、晶振电路稳定性和PCB板这四个方面,分别采取了抗干扰措施,保证了系统稳定可靠的运行。(3)进行了系统软件设计,研究分析了Bulk-Only传输协议、SCSI命令集和FAT文件系统的构建。该系统完成了USB主机控制器驱动程序、核心驱动程序以及用户软件的设计,实现了设备的枚举、配置等功能;系统支持Mass Storage类协议,建立了与文件系统的接口,通过发送SCSI命令实现了U盘文件的读取。论文研究开发了嵌入式系统中USB主口,实现了嵌入式USB主机系统的构建,在任意波发生器的控制面板上增加USB主机的功能,实现了对存储在U盘里的波形数据进行处理。对于开发嵌入式USB主机,使USB的应用脱离PC机具有重要意义和实用推广价值。更多还原

【Abstract】 USB interface has a variety of features, such as easy to use, high data transmission rate and supporting plug-and-play. However, due to the complexity in USB interface protocol, involving a wide area, especially many sorts in software, a wide range of USB chip, which makes it very difficult in the development of USB devices. However, with gradual expanse in the application areas of USB, people’s expectation for USB is also getting higher and higher. It is hoped that USB be used in various fields of computers, in particular in the field of mobile data, in which USB can be applied in the field with the absence of the PC through direct communication with USB devices. How to apply USB in the field of embedded field and achieve peer-to-peer communications of has become a hot research field.In this paper, we consider it as the purpose to realize that arbitrary wave generator has the function of USB host mode. Besides, we choose ADS1.2/Embest as software development environment, use chip HMS30C7202 as controller chip and select Cypress’s SL811HS as USB controller chip.(1) We analyzed USB1.1 agreement, conducted analysis mainly on USB1.1 agreement on the basis of the research of the architecture of USB, USB bus topology, USB bus physical interface, logic tiers of USB system, data communications flow of USB bus and other basic elements.(2) We conducted systematic analysis of the development process of embedded system, and designed the USB host mode hardware system of arbitrary wave generator. We analyzed interference factors, and took anti-jamming measures separately on the choice of components, shielding the external electromagnetic radiation, crystal stability and PCB circuit boards to guarantee reliable operation of system.(3) We conducted system software design, did research and analysis of the Bulk-Only transfer protocol, SCSI command sets and construction of FAT file system. The system completed design on USB host controller driver program, core driver program and user software, and realized functions of the enumeration of the equipment, configuration, and other functions. System supported Mass Storage class agreement, established a file system interface and achieved reading of USB document through sending SCSI orders. The paper did research and development on of USB host mode in embedded system, realized the construction of embedded USB host system, added USB host functions in the control panel of arbitrary wave generator and achieved processing to the waveform data stored in the U-disk, which is of great significance for the promotion and practical value on the development of embedded USB host and making the application of USB absent form PC.更多还原