为解决计算机外设种类的日益增加与有限的主板插槽和端口之间的矛盾,IBM、Inter、DEC、ComPaq、Microsoft、NEC和NorthTlecom等厂商于1994年底制定了一种新的PC外设接口标准——USB。USB具有传输速度快,支持热插拔和即插即用,易于扩展,占用的系统资源少等优点。USB1.1支持两种传输速率:1.5Mbps和12Mbps ,而USB2.0将速度提高了40倍(即480Mbps),能够满足高速外设的需要,但价格也随之提高。
本课题重点介绍了USB总线的体系结构和特点,包括总线特征、信号环境、传输类型等;并针对传统的PCI、ISA、EPP/ECP等接口的数据采集卡的不足,我们们提出了一种基于USB1.1接口技术和DSP(Digital signal processing 数字信号处理器)的数据采集卡的实现方案。设计并制作了基于USB接口的数据采集卡的硬件系统,编写USB1.1接口芯片的固件程序。最后,为了实现主机软件和数据采集卡之间的通信,编写了数据采集卡的USB设备驱动程序。
基于课题的研究内容,本论文先对USB总线技术进行了介绍,然后以设计一种基于USB1.1接口技术的数据采集卡为例,详细地介绍了USB的硬件设计、固件设计和驱动程序设计。在硬件设计部分,论文首先介绍了USB1.1接口芯片的性能和特点,然后给出了具体的硬件设计方案;固件设计是USB设计的重点;驱动程序开始部分先论述了驱动程序开发工具的选择,然后介绍了本数据采集系统的USB设备驱动程序的设计。
关键词 USB; 数据采集; USB1.1
ABSTRACT
In order to resolve the conflict between the increase of PC peripheral devices and the limited board slot and port, IBM, Intel,ComPaq, DEC, Microsoft, NEC and North Tlecom have developed a new interface standard of PC-- USB (Universial Serial Bus) in 1994. USB has the advantage of high speed, HotPlugIn, Plug and Play, easily to expand and engrossing less system resource, etc. USB1. 1 has two kinds of speed: 1.5Mbps and 12Mbps, but USB2.0 has the speed of 480Mbps, which can meet with the demands of high speed peripheral devices.
This subject discusses the architecture and feature of USB, including bus attributes, signal environment, data flow model, and so on. After that, it brings forward a design scheme of data acquisition card with USB1.1 interface and digital signal processing, which is based upon the defects of traditional industry bus, such as ISA, PCI. Then it designs and realizes the hardware system of the data acquisition card with the USB interface. At last, it programs the USB device driver of data acquisition card.
Base d on the subject, this paper introduces the USB bus technology at first and then shows the design of data acquisition system, which in cluds four segments: hardware design, firm ware design, device driver and application program. In driver program segment, the paper shows how to choose the driver develop tools and introduce the USB deviced river of this data acqusition card. At last, a summary will be presented as the end of the paper.