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Communication Over the USB

This section provides an abridged description of the logical communication model on USB. Refer to the Universal Serial Bus Specification for complete technical details. A simplified diagram of the USB communication flow is shown in Figure 2-2.

The USB driver software maintains an abstract view of the logical and physical topology of the bus when it communicates with USB devices. Drivers look for the interface(s) of interest that are available in devices on the USB.

Figure 2-2 USB communication flow

USB Interface

USB Devices

Endpoints

Pipes

A Look At USB Devices with USB Prober

© 1998 Apple Computer, Inc. – (Last Updated 23 Nov 98)

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