Power Button; Reset Button; Nmi Button - Intel S5500WB Technical Product Specification

Intel® Server Board S5500WB TPS
Pin
11 FP_PWR_BTN_N
13 GND (Power Button GND)
15 BMC_RST_BTN_N
17 GND (Reset GND)
19 FP_ID_BTN_N
21 NC
23 FP_NMI_BTN_N
Combined system BIOS and the Integrated BMC support provide the functionality of the various
supported control panel buttons and LEDs. The following sections describe the supported
functionality of each control panel feature.
7.3.1

Power Button

The BIOS supports a front control panel power button. Pressing the power button initiates a
request that the Integrated BMC forwards to the ACPI power state machines in the chipset. It is
monitored by the Integrated BMC and does not directly control power on the power supply.
Power Button — Off to On
The Integrated BMC monitors the power button and the wake-up event signals from the
chipset. A transition from either source results in the Integrated BMC starting the power-
up sequence. Since the processors are not executing, the BIOS does not participate in
this sequence. The hardware receives the power good and reset signals from the
Integrated BMC and then transitions to an ON state.
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, if the BIOS fails to service the request, the Integrated BMC
automatically powers off the system in four to five seconds.
Power Button — On to Off (operating system present)
If an ACPI operating system is running, pressing the power button switch generates a
request via SCI to the operating system to shut down the system. The operating system
retains control of the system and the operating system policy determines the sleep state
into which the system transitions, if any. Otherwise, the BIOS turns off the system.
7.3.2

Reset Button

The platform supports a front control panel reset button. Pressing the reset button initiates a
request forwarded by the Integrated BMC to the chipset. The BIOS does not affect the behavior
of the reset button.
7.3.3

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
Revision 1.3
Signal Name
Intel order number E53971-004
Connector / Header Locations and Pin-out
Pin
12 NIC1_ACT_LED_N
14 NIC1_LINK_LED_N
16 SMB_SENSOR_3V3STB_DATA
18 SMB_SENSOR_3V3STB_CLK
20 FP_CHASSIS_INTRU
22 NIC2_ACT_LED_N
24 NIC2_LINK_LED_N
Signal Name
55