Technical Product Specification

Table Of Contents
Connector/Header Locations and Pin-outs Intel
®
Server Board S5400SF TPS
Revision 2.02
Intel order number: D92944-007
122
Power Button — On to Off (operating system absent)
The System Control Interrupt (SCI) is masked. The BIOS sets up the power button event
to generate an SMI and checks the power button status bit in the ACPI hardware
registers when an SMI occurs. If the status bit is set, the BIOS sets the ACPI power
state of the machine in the chipset to the OFF state. The Integrated BMC monitors
power state signals from the chipset and de-asserts PS_PWR_ON to the power supply.
As a safety mechanism, the Integrated BMC automatically powers off the system in 4 to
5 seconds if the BIOS fails to service the request.
Power Button — On to Off (operating system present)
If an ACPI operating system is running, pressing the power button switch generates a
request to the operating system via SCI to shut down the system. The operating system
retains control of the system and operating system policy determines the sleep state into
which the system transitions, if any. Otherwise, the BIOS turns off the system.
6.5.2 Reset Button
The platform supports a front control panel reset button. Pressing the reset button initiates a
request that is forwarded by the Integrated BMC to the chipset. The BIOS does not affect the
behavior of the reset button.
6.5.3 NMI Button
The BIOS supports a front control panel NMI button. The NMI button may not be provided on all
front panel designs. Pressing the NMI button initiates a request that causes the Integrated BMC
to generate an NMI (non-maskable interrupt). The NMI is captured by the BIOS during boot
services time, and by the operating system during runtime. During boot services time, the BIOS
halts the system upon detection of the NMI.
6.5.4 Chassis Identify Button
The front panel chassis identify button toggles the state of the chassis ID LED. If the LED is off,
then pushing the ID button lights the LED. It remains lit until the button is pushed again or until a
Chassis Identify or a Chassis Identify LED command is received to change the state of the LED.
6.5.5 Power LED
The green power LED is active when system DC power is on. The power LED is controlled by
the BIOS. The power LED reflects a combination of the state of system (DC) power and the
system ACPI state. The following table shows the states that can be assumed.
Table 64. Power LED Indicator States
State ACPI Power LED
Power off No Off
Power on No Solid on
S4/S5 Yes Off
S1 Sleep Yes ~1 Hz blink
S0 Yes Solid on