Desktop Board Features
21
Power Management
Power management is implemented at several levels, including software support
through the Advanced Configuration and Power Interface (ACPI) and the following
hardware support:
•
Power connectors
•
Fan headers
•
LAN wake capabilities
•
Instantly Available PC technology (Suspend to RAM)
•
+5 V standby power indicator LED
•
Wake from USB
•
PCI Power Management Event signal (PME#) wakeup support
•
PCI Express WAKE# signal support
•
Wake from PS/2 devices
•
Wake from serial port
Software Support
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 Board requires an
operating system that provides full ACPI support.
Hardware Support
Power Connectors
ATX12V-compliant power supplies can turn off the computer power through system
control. When an ACPI-enabled computer receives the correct command, the power
supply removes all non-standby voltages.
When resuming from an AC power failure, the computer returns to the power state it
was in before power was interrupted (either on or off). The computer’s response can
be set by using the Last Power State feature in the BIOS Setup program’s Boot menu.
The Desktop Board has two power connectors. See Figure 23 on page 49 for the
location of the power connectors.
Fan Headers
The function/operation of the fans is as follows:
•
The fans are on when the board is in the ACPI S0 or S1 state.
•
The fans are off when the computer is in the ACPI S3, S4, or S5 state.
•
Each fan header is wired to a tachometer input.
•
All fan headers support closed-loop fan control that can adjust the fan speed or
switch the fan on or off as needed.
