CEDEVICE_POWER_STATE (Compact 2013)

  • Article

3/26/2014

This enumeration describes the device power states. The PwrDeviceUnspecified and PwrDeviceMaximum values are not valid device power states but are used for some Power Manager functions.

Syntax

typedef enum _CEDEVICE_POWER_STATE {
  PwrDeviceUnspecified = -1,
  D0 = 0,
  D1,
  D2,
  D3,
  D4,
  PwrDeviceMaximum
} CEDEVICE_POWER_STATE, *PCEDEVICE_POWER_STATE;

Elements

  • PwrDeviceUnspecified
    System state is unspecified.
  • D0
    Full On. This is the state in which the device is on and running. It is receiving full power from the system and is delivering full functionality to the user.
  • D1
    Low On. This is the state in which the device is fully functional at a lower power state than D0, a lower performance state than D0, or both. This state is applicable when the device is being used, but where peak performance is unnecessary and power is at a premium.
  • D2
    Standby. This is the state in which the device is partially powered with automatic wakeup on request. The device is effectively standing by.
  • D3
    Sleep. This is the state in which the device is partially powered with device-initiated wakeup if available. A device in state D3 is sleeping but capable of raising the system power state on its own. It consumes only enough power to be able to do so; which must be less than or equal to the amount of power used in state D2.
  • D4
    Off. This is the state in which the device is not powered. A device in state D4 should not be consuming any significant power. Some peripheral busses require static terminations that intrinsically use non-zero power when a device is physically connected to the bus; a device on such a bus can still support D4.
  • PwrDeviceMaximum
    Valid device power state values are greater than PwrDeviceUnspecified and less than PwrDeviceMaximum.

Requirements

Header

pm.h

See Also

Reference

Power Management Enumerations