1 system states and power states – Premio Computer Apollo/Shadowhawk User Manual

Page 62

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Product Description

39

1.14.1.1 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.

Table 9 lists the power states supported by the D845HV and D845WN boards along with the
associated system power targets. See the ACPI specification for a complete description of the
various system and power states.

Table 9.

Power States and Targeted System Power

Global States

Sleeping States

Processor
States

Device States

Targeted System
Power

(Note 1)

G0 – working
state

S0 – working

C0 – working

D0 – working
state.

Full power > 30 W

G1 – sleeping
state

S1 – Processor
stopped

C1 – stop
grant

D1, D2, D3 –
device
specification
specific.

5 W < power < 52.5 W

G1 – sleeping
state

S3 – Suspend to
RAM. Context
saved to RAM.

No power

D3 – no power
except for
wake-up logic.

Power < 5 W

(Note 2)

G1 – sleeping
state

S4 – Suspend to
disk. Context
saved to disk.

No power

D3 – no power
except for
wake-up logic.

Power < 5 W

(Note 2)

G2/S5

S5 – Soft off.
Context not saved.
Cold boot is
required.

No power

D3 – no power
except for
wake-up logic.

Power < 5 W

(Note 2)

G3 –
mechanical off

AC power is
disconnected
from the
computer.

No power to the
system.

No power

D3 – no power for
wake-up logic,
except when
provided by
battery or external
source.

No power to the system so
that service can be
performed.

Notes:

1.

Total system power is dependent on the system configuration, including add-in boards and peripherals powered
by the system chassis’ power supply.

2.

Dependent on the standby power consumption of wake-up devices used in the system.

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