usb协议说明。 第一章至第四章为读者提供了一个纲要，第五章至第十章则提供了USB的所有的具体技术细节。-usb agreement. The first chapter to chapter IV to the reader with an outline of the fifth chapter to the 10th chapter provides a USB all the technical details.

关于USB驱动编写的代码，内容包含USB芯片，电路图，下位机代码和驱动代码以及用户程序代码。（第四部分）-Code written on the USB drive, includes USB chip, circuit, lower computer code and driver code and user code. (Part IV)