Intel SE7501WV2 User Manual

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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