Product Description
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Table 6 lists the system states based on how long the power switch is pressed,
depending on how ACPI is configured with an ACPI-aware operating system.
Table 6. Effects of Pressing the Power Switch
If the system is in this
state…
…and the power switch is
pressed for
…the system enters this state
Off
(ACPI G2/G5 – Soft off)
Less than four seconds Power-on
(ACPI G0 – working state)
On
(ACPI G0 – working state)
Less than four seconds Soft-off/Standby
(ACPI G1 – sleeping state)
On
(ACPI G0 – working state)
More than six seconds Fail safe power-off
(ACPI G2/G5 – Soft off)
Sleep
(ACPI G1 – sleeping state)
Less than four seconds Wake-up
(ACPI G0 – working state)
Sleep
(ACPI G1 – sleeping state)
More than six seconds Power-off
(ACPI G2/G5 – Soft off)
1.13.1.1 System States and Power States
Under ACPI, the operating system directs all system and device power state
transitions. The operating system puts devices in and out of low-power states based
on user preferences and knowledge of how devices are being used by applications.
Devices that are not being used can be turned off. The operating system uses
information from applications and user settings to put the system as a whole into a
low-power state.