Advanced Configuration and Power Interface Specification

power transitions and power management states, but the primary requirement for the method should
be low overhead.
State Status Definition
D0 Required This state is equivalent to the “On” state for a DPMS device, but is signaled to the
panel by the correct application of power and/or device specific signaling known to the
controller.
Display is fully on
Video image is active
D1 Optional This state is not required to be physically different than a D3 state if the device is able
to meet the resume requirement and the driver is able to restore state. It is signaled to
the panel by the correct application of power and/or device specific signaling known to
the controller.
Display retains internal state but may be conserving energy
Video image is blank
Latency to return to D0 must be less than 100 milliseconds
D2 Optional This state is not required to be physically different than a D3 state if the device is able
to meet the resume requirement and the driver is able to restore state. It is signaled to
the panel by the correct application of power and/or device specific signaling known to
the controller.
Display retains state but is conserving energy
Video image is blank
Latency to return to D0 is less than 100 milliseconds
D3 Required This state is equivalent to the “Off” state defined in the VESA DPMS specification. It is
signaled by the removal of display output and/or device specific methods known to the
controller.
Display is non-functional
Video image is blank
Latency to return to D0 is less than 250 milliseconds
Although 250 milliseconds is shown here because not all devices in this group are fast now, the
target resume for a new device should be 100 milliseconds.
A.6.1.6 Video Controllers (Graphics Adapters)
State Status Definition
D0 Required Back-end is on
Video controller context is preserved
Video memory contents are preserved
D1 Optional Back-end is off, except for CRT control signaling (DPMS)
Video controller context is preserved
Video memory contents is preserved
Latency to return to D0 is less than 100 milliseconds
D2 Optional Back-end is off, except for CRT control signaling (DPMS)
Video controller context is lost
Video memory contents is lost
Latency to return to D0 is less than 200 milliseconds
Version 6.0 951