Filter
Top Products
BIOS Intel® Server Board SE7501WV2 TPS
Revision 1.0
Intel reference number C25653-001
80
The S5 state is equivalent to an operating system shutdown. No system context is saved.
6.12.3 Wake Events
The system BIOS is capable of configuring the system to wake up from several sources under a
non-ACPI configuration, such as when the operating system does not support ACPI. The wake
up sources are described in Table 27. Under ACPI, the operating system programs the
hardware to wake up on the desired event. The BIOS describes various wake sources to the
operating system.
In legacy mode, the BIOS enables or disables wake sources based on a switch in Setup. The
operating system or driver must clear any pending wake up status bits in the associated
hardware, such as the Wake on LAN status bit in the LAN application specific integrated circuit
(ASIC), or PCI power management event (PME) status bit in a PCI device. The legacy wake up
feature is disabled by default.
Table 27. Supported Wake Events
Wake Event Supported via ACPI (by sleep state) Supported Via
Legacy Wake
Power Button Always wakes system Always wakes
system
Ring indicate from COM-A Wakes from S1 and S4. Yes
Ring indicate from COM-B Wakes from S1 and S4. If Serial-B is used for Emergency
Management Port, Serial-B wakeup is disabled.
Yes
PME from PCI cards Wakes from S1 and S4. Yes
RTC Alarm Wakes from S1. Always wakes the system up from S4. Yes
Mouse Wakes from S1 No
Keyboard Wakes from S1 No
USB Wakes from S1 No
6.12.4 Front Panel Switches
The BMC forwards the power button request to the ACPI power state machines in the chipset.
The button signal is monitored by the BMC and does not directly control power on the power
supply.
The power switch behaves differently depending on whether the operating system supports
ACPI. If the operating system supports ACPI the power button can be configured as a sleep
button. The operating system causes the system to transition to the appropriate system state
depending on the user settings.
6.12.4.1 Power Switch Off to On
The chipset may be configured to generate wake up events for several system events: Wake-
on-LAN, PCI Power Management Interrupt, and the Real-Time Clock Alarm are examples of
these events. If the operating system is ACPI-aware, it programs the wake sources before
shutdown. In non-ACPI mode, the BIOS performs the configuration. The BMC monitors the
power button and wake up event signals from the chipset. A transition from either source results