User`s manual
BIOS Setup 3-23
Table 3-1: Wake Up Device and Events
The table below describes which devices or specific events can wake the computer from specific states.
These device/events can wake up the computer…… ……from this state
Power switch Sleeping mode or power off mode
RTC alarm Sleeping mode or power off mode
LAN Sleeping mode or power off mode
Modem Sleeping mode or power off mode
IR command Sleeping mode
USB Sleeping mode
PS/2 keyboard Sleeping mode or power off mode
PS/2 mouse Sleeping mode or power off mode
Table 3-2: Effect 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 Less than four seconds Power on
On More than four seconds Fail safe power off
On Less than four seconds Soft off/Suspend
Sleep Less than four seconds Wake up
ACPI Suspend Type:
Three options are available: S1 (PowerOn-Suspend) S3 (Suspend-To-RAM) Auto. The default
setting is S1 (PowerOn-Suspend). 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.
• 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 continue execution where it left off.
To transition into the S1 state, the operating software does not have to flush the processor's cache.
User’s Manual