Abit AT7-MAX2 User Manual page 51

4-26
ACPI Function (Advanced Configuration and Power Interface):
ACPI gives the operating system direct control over the power management and Plug and Play functions
of a computer. The BIOS is fully support the ACPI functions. If you want ACPI functions to work
normally, you should notice two things. One is your operating system must support ACPI, as of now only
® ®
Microsoft Windows
thing is that all devices and add-on cards in your system must fully support ACPI, both hardware and
software (drivers). If you want to know if your devices or add-on cards support ACPI or not, please
contact the device or add-on card manufacture for more information. If you want to know more about
ACPI specifications, please go to the address below for more detailed information:
ACPI requires an ACPI-aware operating system. ACPI features include:
Plug and Play (including bus and device enumeration) and APM functionality normally contained in
the BIOS.
Power management control of individual devices, add-in cards (some add-in cards may require an
ACPI-aware driver), video displays, and hard disk drives.
A Soft-off feature that enables the operating system to power off the computer.
Support for multiple wake-up events (see Table 4-6-1).
Support for a front panel power and sleep mode switch. Table 4-6-2 describes the system states based
on how long the power switch is pressed, depending on how ACPI is configured with an ACPI-aware
operating system.
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
PCI Card (PME)
USB
If the system is in this
state......
Off
On
On
Sleep
ACPI Suspend Type:
Three options are available: S1 (PowerOn-Suspend)
AT7-MAX2
®
2000, Windows ME and Windows
Table 4-6-1: Wake Up Device and Events
Table 4-6-2: 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
®
XP supports these functions. The second
from this state
Sleeping mode or power off mode
Sleeping mode or power off mode
Sleeping mode or power off mode
Sleeping mode
......the system enters this
state
Power on
Fail safe power off
Soft off/Suspend
Wake up
S3 (Suspend-To-RAM)
Chapter 4
http://www.acpi.info/
Auto. The default