Specifications

Intel® Server Board S3420GPRX TPS Connector/Header Locations and Pin-outs

Revision 1.1

Intel order number E92065-001

Pin Signal Name Pin Signal Name

19 ID_BTN_N 20 INTRUDE_HDR_N

21 LED_NIC5_LINK _N 22 LED_NIC4_LINK _N

23 NMI_BTN_N 24 LED_NIC2_LINK_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.

Note: Control panel features are also routed through the bridge board connector at location

J1C1 as is implemented in Intel

Server Systems configured using a bridge board and a hot-

swap backplane.

6.4.1 Power Button

Server front control panel has a power button. Pressing the power button initiates a request that

the Integrated BMC forwards to the ACPI power state machines in the chipset. Integrated BMC

monitors server power signal but does not directly control power on the power supply. If the

power button is pressed and held for four seconds, the system will power off (S5 state). This

feature is called power button override and is particularly helpful in the case of system hang and

locking up of the system.

 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 processor 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 4 to 5 seconds.

 Power Button — On to Off (Operating system present)

If an ACPI operating system is running, pressing the power button switch generates a

request using 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.

6.4.2 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.