Archive: Power Management of USB Host Controllers

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This paper provides information about power capabilities of USB 2.0 host controllers. It outlines the procedure for defining capabilities and explains interpretation of these capabilities by the USB host controller drivers in the Microsoft Windows family of operating systems.

The power capabilities for USB host controllers are conceived by the underlying PCI bus driver. The ACPI driver optionally modifies these capabilities before handing them to the host controller drivers. The drivers retain these capabilities for their hardware entities. This paper provides guidelines for programming these capabilities and demonstrates how incorrect values can cause problems in the power management of the system.

This document assumes familiarity with concepts of system power management and USB host controllers.

This information applies for the following operating systems:
Microsoft Windows Vista
Microsoft Windows Server 2003 SP1
Microsoft Windows XP SP2

Included in this paper:

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