Abit WI-2P User Manual page 47

BIOS Setup
•
Devices that are enabled to wake the system and that can do so from their
current device state can initiate a hardware event which transitions the system
state to S0. This transition causes the processor to continue execution where it
left off.
To transition into the S1 state, the operating software does not have to flush the
processor's cache.
The S3(STR) State (Suspend to RAM):
The S3 state is logically lower then the S2 state and is assumed to conserve more
power. The behavior of this state is defined as follows:
•
Processor is not executing instructions. The processor complex context is not
maintained.
•
Dynamic RAM context is maintained.
•
Power Resources are in a state compatible with the system S3 state. All Power
Resources that supply a System Level reference of S0, S1, or S2 are in the
OFF state.
•
Devices states are compatible with the current Power Resource states. Only
devices which solely reference Power Resources which are in the ON state for
a given device state can be in that device state. In all other cases, the device is
in the D3 (off) state.
•
Devices that are enabled to wake the system and that can do so from their
current device state can initiate a hardware event which transitions the system
state to S0. This transition causes the processor to begin execution at its boot
location. The BIOS performs initialization of core functions as required to exit
an S3 state and passes control to the firmware resume vector. Please see the
ACPI Specification Rev. 1.0 book section 9.3.2 for more details on BIOS
initialization.
From the software point of view, this state is functionally the same as the S2 state.
The operational difference can be that some Power Resources that could be left ON in
the S2 state might not be available to the S3 state. As such, additional devices can be
required to be in logically lower D0, D1, D2, or D3 state for S3 than S2. Similarly,
some device wake events can function in S2 but not S3.
Because the processor context can be lost while in the S3 state, the transition to the S3
state requires that the operating software flush all dirty cache to DRAM.
The information above for system S0 & S3 were referring to ACPI
Specification.
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User's Manual