Power Management; Acpi; Effects Of Pressing The Power Switch - Intel D865PERLX Specification

Intel Desktop Board D865PERC/D865PESO Technical Product Specification

1.13 Power Management

Power management is implemented at several levels, including:
•
Software support through Advanced Configuration and Power Interface (ACPI)
•
Hardware support:
 Power connector
 Fan connectors
 LAN wake capabilities
 Instantly Available PC technology
 Resume on Ring
 Wake from USB
 Wake from PS/2 devices
 Power Management Event signal (PME#) wake-up support

1.13.1 ACPI

ACPI gives the operating system direct control over the power management and Plug and Play
functions of a computer. The use of ACPI with the Desktop Boards D865PERC and D865PESO
requires an operating system that provides full ACPI support. ACPI features include:
•
Plug and Play (including bus and device enumeration)
•
Power management control of individual devices, add-in boards (some add-in boards may
require an ACPI-aware driver), video displays, and hard disk drives
•
Methods for achieving less than 15-watt system operation in the power-on/standby
sleeping state
•
A Soft-off feature that enables the operating system to power-off the computer
•
Support for multiple wake-up events (see Table 12 on page 44)
•
Support for a front panel power and sleep mode switch
Table 10 lists the system states based on how long the power switch is pressed, depending on how
ACPI is configured with an ACPI-aware operating system.
Table 10.

Effects of Pressing the Power Switch

If the system is in this state...
Off
(ACPI G2/G5 – Soft off)
On
(ACPI G0 – working state)
On
(ACPI G0 – working state)
Sleep
(ACPI G1 – sleeping state)
Sleep
(ACPI G1 – sleeping state)
For information about
The Desktop Boards' compliance level with ACPI
42
...and the power switch is
pressed for
Less than four seconds
Less than four seconds
More than four seconds
Less than four seconds
More than four seconds
...the system enters this state
Power-on
(ACPI G0 – working state)
Soft-off/Standby
(ACPI G1 – sleeping state)
Fail safe power-off
(ACPI G2/G5 – Soft off)
Wake-up
(ACPI G0 – working state)
Power-off
(ACPI G2/G5 – Soft off)
Refer to
Section 1.5, page 18