Audio devices must comply with Audio Device Class Power Management Reference Specification, Version 1.0, which provides definitions of the OnNow device power states (D0–D3) for these devices. The specification also covers the device functionality expected in each power state and the possible wakeup event definitions for the class. The device and driver are required to implement support for power states D0, D2, and D3. Other power states are optional.
PCI Bus Power Management Interface Specification, Revision 1.1 or later, is the only industry specification that ensures compatibility with the power management capabilities of Windows XP and later.