原创 About USB

Today I get some useful information about USB on the web site below.

http://www.usb.org/

First,I know the concepts about USB On-The-Go.

Due to its widespread acceptance, USB is becoming the de facto industry standard for connecting peripherals to PCs and laptops. Many of the new peripherals now using USB are also portable devices.

As these portable devices increase in popularity, there is a growing need for them to communicate directly with each other when a PC is not available. The On-The-Go Supplement addresses this need for mobile interconnectivity by allowing a USB peripheral to have the following enhancements:

• 
  
• Limited host capability to communicate with selected other USB peripherals
  
• A small USB connector to fit the mobile form factor
  
• Low power features to preserve battery life

http://www.usb.org/developers/onthego/USB_OTG_Intro.pdf

USB 2.0 Specification

That's great.If someone want to develop usb devices,he must read usb 2.0 spec first.

http://www.usb.org/developers/docs/usb_20_040908.zip