Wake Events; Ac Power Failure Recovery; Pci Power Management Support - Intel SE7520BD2 Technical Product Specification

Intel® Server Board SE7520BD2 Technical Product SpecificationPlatform Management Architecture
4.6.10.5 S4 State
The S4 state is called Suspend to Disk. From a hardware perspective, it is equivalent to an S5
state. The operating system is responsible for saving the system context in a special partition on
the hard drive. Although the system must power up and fully boot, boot time to an application is
reduced because the computer is returned to the same system state it had prior to the power-
off.
4.6.10.6 S5 State
This State is the normal off state whether entered through the power button or Soft Off. All
power is shut off except for the logic required to restart. In this state, several "wake-up events"
are supported. The system only remains in the S5 State while the power supply is plugged into
the wall. If the power supply is unplugged from the wall, this is considered a Mechanical OFF or
G3.
4.6.11

Wake Events

The types of wake events and wake up latencies are related to the actual power rails available
to the system in a particular sleep state as well as to the location in which the system context is
stored. Regardless of the Sleep State, wake on the power button is always supported except in
a 'mechanical off' situation. When in a Sleep State the system complies with the PCI 2.2
Specification by supplying the optional 3.3V standby voltage to each PCI slot as well as the
PME signal. This enables any compliant PCI card to wake the system up from any sleep state
except mechanical off.
4.6.11.1 Wake from S1 Sleep State
During S1, the system is fully powered permitting support for wake on USB, wake on PS2
keyboard/mouse, wake on RTC Alarm, and wake on PCI PME. wake on USB, wake on PS2
keyboard/mouse and wake on RTC Alarm are not supported by POE BIOS.
4.6.11.2 Wake from S4 and S5 States
Power button and LAN events are used to wake from S4 and S5.
4.6.12

AC Power Failure Recovery

The design supports two modes of operation with regard to AC power recovery. The user can
select (via a BIOS Setup Screen) whether the system should power back up or remain off after
AC is restored. The ICH5-R does not rely on BIOS to boot and check system status in the case
of AC failure. The ICH contains a register variable named "afterG3" which BIOS can set based
on user configuration input. The ICH internally examines after it detects an AC Recovery.
4.6.13

PCI Power Management Support

The PCI Power Management Specification calls out three areas to be compliant: the system
reset signal must be held low when in a sleep state, the system must support the PCI PME
signal and the system should provide 3.3v standby to the PCI slots. The design complies with
the PCI Power Management Specification and the PCI 2.2 Specification for optional 3.3V
standby voltage to be supplied to each PCI, PCI-X, and PCI Express slots. This support allows
any compliant PCI, PCI-X, and PCI Express adapter card to wake the system up from any sleep
state except mechanical off. Because of the limited amount of power available on 3.3V standby,
the user and the operating system must configure the system carefully following the PCI Power
Management Specification.
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