DEVICE_POWER_STATE enumeration

The DEVICE_POWER_STATE enumeration type indicates a device power state.

Syntax

typedef enum _DEVICE_POWER_STATE { 
  PowerDeviceUnspecified  = 0,
  PowerDeviceD0           = 1,
  PowerDeviceD1           = 2,
  PowerDeviceD2           = 3,
  PowerDeviceD3           = 4,
  PowerDeviceMaximum      = 5
} DEVICE_POWER_STATE, *PDEVICE_POWER_STATE;

Constants

PowerDeviceUnspecified

Indicates an unspecified device power state.

PowerDeviceD0

Indicates a maximum device power state, which corresponds to device working state D0.

PowerDeviceD1

Indicates a device sleeping state less than PowerDeviceD0 and greater than PowerDeviceD2, which corresponds to device power state D1.

PowerDeviceD2

Indicates a device sleeping state less than PowerDeviceD1 and greater than PowerDeviceD3, which corresponds to device power state D2.

PowerDeviceD3

Indicates the lowest-powered device sleeping state, which corresponds to device power state D3.

PowerDeviceMaximum

The number of device power state values for this enumeration type that represent actual power states. The value of the other device power states is less than this value.

Remarks

A power state indicates the level of power consumption—and thus the extent of computing activity—by the system or by a single device. The power manager sets the power state of the system as a whole, where the system power state is indicated by one of the values of the SYSTEM_POWER_STATE enumeration type. Device drivers set the power state of their individual devices, where the device power state is indicated by one of the values of the DEVICE_POWER_STATE enumeration type.

For more information about system power states, see Handling System Power State Requests. For more information about device power states, see Managing Power for Individual Devices. For more information about power management in general, see Introduction to Power Management.

Requirements

See also

SYSTEM_POWER_STATE

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Build date: 2/11/2014