USB composite device VS compound device

chley

Composite USB devices expose multiple functions to a host by
using multiple interfaces.
A compound device is an external hub that is combined with
other
devices. Compound devices appear to the host as a hub with one or more
non-removable devices that are connected to the hub’s ports.
对于compound device，它内置的hub和其它设备都会有各自的device address， 而compoiste device只有一个device address。实际上，从host的角度来看，compound device与一个hub上挂多个设备是等效的。
WUSB不推荐将device实现为compound device，参见WUSB AM FAQ。
               
               
               

本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u/24393/showart_459745.html

happen23

学到了，多谢！