LRR-TUM-Logo Department of Informatics
Technische Universität München
Informatik X: Rechnertechnik und Rechnerorganisation / Parallelrechnerarchitektur
Prof. Dr. Arndt Bode , Prof. Dr. Hans Michael Gerndt
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Next: Standard Descriptors Up: The Universal Serial Bus Previous: Data Flow Types   Contents   Index


Enumeration and Device Descriptors

Whenever a USB device is attached to the bus it will be enumerated by the USB subsystem - i.e an unique device number (1-127) is assigned and then the device descriptor is read. Such a desciptor is a data structure which contains information about the device and its properties. The USB standard defines a hierarchy of descriptors (see figure 2).

Figure 2: USB Descriptor Hierarchy
\includegraphics [width=\linewidth]{descr}



Subsections

Detlef Fliegl
2001-01-08
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