Advanced Configuration and Power Interface Specification

A.6.1.2 Internal Flat Panel Devices
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 controller specific signaling.
Display is fully on
Backlight (if present) is fully on(subject to performance state requirements – see below)
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.
Display retains internal state but may be conserving energy
Backlight(if present) is fully off
Video image is blank
Latency to return to D0 must be less than 500 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.
Display retains state but is conserving energy
Backlight (if present) is fully off;
Video image is blank
Latency to return to D0 is less than 500 milliseconds
D3 Required This state is equivalent to the “Off” state defined in the VESA DPMS specification. It is
signaled by the removal of power or possibly by controller-specific signaling.
Display is non-functional
Backlight (if present) is fully off.
Video image is blank
Latency to return to D0 is less than 500 milliseconds
Internal flat panels (also known as local flat panels or sometimes as LCDs) do not normally support
or require DPMS signaling to change power states. Instead, controllers capable of managing such
panels tend to provide vendor-specific methods to control internal flat panels, often involving
special sequencing of power signals to the panel. Some may be managed only by the application or
removal of power.
Backlight control for power management states is likewise controller and even platform specific.
Note that on-off backlight control for power management states is often unrelated to backlight
intensity or brightness control that is used while in the D0 state.
The 500 milliseconds is only to allow some existing hardware to function . The target for new
devices should be 100 milliseconds.
A.6.1.3 DVI Displays (Digital Flat Panels and DVI Monitors)
State Status Definition
D0 Required This state is equivalent to the “On” state for a DPMS device, but is signaled to the
display by the correct application of power and/or controller specific signaling.
Display is fully on
Video image is active
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