这个是个人心得，在学习usb的过程中遇到的问题，有选择的摘录下来，适合学习者。-This is a personal experience in learning the process of usb problems have a choice excerpt from, suitable for learners.

The causation is that the USB kernal uses the base memory at POST stage, and the base memory is conflicted with these programs. To solve these problems, the USB kernal will use the shadow RAM at whole time.

本文简单介绍USB的接口的特点和philips公司的USB接口芯片PDIUSBD12，并详细说明USB软硬件开发过程中注意的问题-This article briefly the characteristics of USB interface and USB interface philips chip companies PDIUSBD12, and detailed descr iption of the process of developing the USB hardware and

短信猫USB驱动，解决通讯的问题，比较实用-SMS cat USB drive, to resolve communication problems, more practical