System States And Power States; Effects Of Pressing The Power Switch; Power States And Targeted System Power - Intel S845WD11U Product Manual

Table 5 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 5.

Effects of Pressing the Power Switch

If the system is in this state...
Off
(ACPI G2/G5 – Soft off)
On
(ACPI G0 – working state)
On
(ACPI G0 – working state)
Sleep
(ACPI G1 – sleeping state)
Sleep
(ACPI G1 – sleeping state)

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.
Table 6 lists the power states supported by the S845WD1-E board along with the associated system
power targets. See the ACPI specification for a complete description of the various system and
power states.
Table 6.

Power States and Targeted System Power

Global States Sleeping States
G0 – working S0 – working
state
G1 – sleeping S1 – Processor
state stopped
G1 – sleeping S3 – Suspend to
state RAM. Context
saved to RAM.
G1 – sleeping S4 – Suspend to
state disk. Context
saved to disk.
Description
...and the power switch is
pressed for
Less than four seconds
Less than four seconds
More than four seconds
Less than four seconds
More than four seconds
Processor
States Device States
C0 – working D0 – working
state.
C1 – stop D1, D2, D3 –
grant device
specification
specific.
No power D3 – no power
except for
wake-up logic.
No power D3 – no power
except for
wake-up logic.
...the system enters this state
Power-on
(ACPI G0 – working state)
Soft-off/Standby
(ACPI G1 – sleeping state)
Fail safe power-off
(ACPI G2/G5 – Soft off)
Wake-up
(ACPI G0 – working state)
Power-off
(ACPI G2/G5 – Soft off)
Targeted System
Power (Note 1)
Full power > 30 W
5 W < power < 52.5 W
(Note 2)
Power < 5 W
(Note 2)
Power < 5 W
continued
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