3
36
Power Management Setup
ACPI (Advanced Configuration and Power Interface) is an open industry standard that defines
power and configuration management interfaces between an operating system and the BIOS.
In other words, it is a standard that describes how computer components work together
to manage system hardware. In order to use this function the ACPI specification must be
supported by the OS (for example, Windows2000 or WindowsXP).
ACPI defines five sleeping states, they are :
S1 - The S1 sleeping state is a low wake latency sleeping state. In this state, no system
context is lost (CPU or chip set) and hardware maintains all system context. (also called
Power on Suspend
)
S2 - The S2 sleeping state is a low wake latency sleeping state. This state is similar to
the S1 sleeping state except that the CPU and system cache context is lost (the OS
is responsible for maintaining the caches and CPU context). Control starts from the
processor’s reset vector after the wake event.
S3 - The S3 sleeping state is a low wake latency sleeping state where all system context is lost
except system memory. CPU, cache, and chip set context are lost in this state. Hardware
maintains memory context and restores some CPU and L2 configuration context. Control
starts from the processor’s reset vector after the wake event. (also called
Suspend to
RAM
)
S4 - The S4 sleeping state is the lowest power, longest wake latency sleeping state supported
by ACPI. In order to reduce power to a minimum, it is assumed that the hardware platform
has powered off all devices. Platform context is maintained. (also called
Suspend to
Disk
)
S5 - The S5 state is similar to the S4 state except that the OS does not save any context. The
system is in the “soft” off state and requires a complete boot when it wakes. Software
uses a different state value to distinguish between the S5 state and the S4 state to allow
for initial boot operations within the BIOS to distinguish whether or not the boot is going to
wake from a saved memory image.
Phoenix - AwardBIOS CMOS Setup Utility
Power Management Setup
ACPI Function
[Enabled]
Item Help
ACPI Suspend Type
[S3(STR)]
Power Button
[Instant-off]
Menu Level ►
PWRON After PWR-Fail
[Off]
HPET Support
[Enabled]
**
Power Management Events **
Resume by PCI Card
[Disabled]
USB KB/MS Resume from S3
[Disa
bled]
Resume by Alarm
[Di
sabled]
x Date of Month Alarm
0
x Time(hh:mm:ss) Alarm
0 : 0 : 0
x Power On by Button
Enabled
PS/2 Mouse Resume from S3
[Disabled]
PS/2 KB Resume from S3
[Disabled]
x KB Resume Password
Enter
x Hot Key Resume
Ctrl-F1
↑↓→←:Move Enter:/-/PU/PD:Value F10:Save
ESC:Exit F1:General Help
←:Move Enter:/-/PU/PD:Value F10:Save
ESC:Exit F1:General Help
:Move Enter:Select +/-/PU/PD:Value F10:Save ESC:Exit F1:General Help
F5:Previous Values F7:Optimized Defaults
Enabled
