Abit AT7 User Manual page 57

Introducing the BIOS
on how long the power switch is pressed, depending on how ACPI is configured with an ACPI-aware
operating system.
If you enable the ACPI function in the BIOS setup, the SMI switch function will not work.
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.
The table below describes which devices or specific events can wake the computer from specific states.
These device/events can wake up the computer
Power switch
RTC alarm
LAN
Modem
IR command
USB
PS/2 keyboard
PS/2 mouse
If the system is in this
state......
Off
On
On
Sleep
ACPI Suspend Type:
Two options are available: S1 (POS) ( S3 (STR). The default setting is S1 (POS). POS is "Power On
Suspend", and STR is "Suspend To RAM". Generally, ACPI has six states: System S0 state, S1 state, S2
state, S3 state, S4 state, S5 state. S1 and S3 states are described below:
The S1 (POS) State (POS means Power On Suspend):
While the system is in the S1 sleeping state, its behavior is as described below:
! The processor is not executing instructions. The processor's complex context is maintained.
! Dynamic RAM context is maintained.
! Power Resources are in a state compatible with the system S1 state. All Power Resources that supply a
System Level reference of S0 are in the OFF state.
Table 3-6-1: Wake Up Device and Events
Table 3-6-2: Effect of Pressing the Power Switch
......and the power switch is
pressed for
Less than four seconds
More than four seconds
Less than four seconds
Less than four seconds
Note
from this state
Sleeping mode or power off mode
Sleeping mode or power off mode
Sleeping mode or power off mode
Sleeping mode or power off mode
Sleeping mode
Sleeping mode
Sleeping mode
Sleeping mode
......the system enters this
state
Power on
Soft off/Suspend
Fail safe power off
Wake up
3-27
User's Manual