SE7210TP1-E Datasheet, PDF (107/145 Pages) Intel Corporation – Intel® Server Board Technical Product Specification

Intel® Server Board SE7210TP1-E TPS
Platform Management Architecture
5.2.4
Front Panel Control
The National Semiconductor PC87431 integrated management controller provides the main
front panel control functions. These include control of the system Power Button, Reset Button,
Diagnostic Interrupt (Front Panel NMI) Button, System Identify Button, System ID LED,
Status/Fault LED, and Chassis Intrusion Switch. Front panel control also includes the front
panel lockout features.
5.2.4.1
Power Button
After de-bouncing the front panel Power Button signal, the National Semiconductor PC87431
integrated management controller routes the signal state directly to the chipset Power Button
signal input. If the chipset has been initialized by the BIOS, the chipset responds to the
assertion of the signal by requesting a power state change. It reacts to the press of the switch,
not the release of it.
The Power Button signal toggles the system power. The Power Button signal to the National
Semiconductor PC87431 integrated management controller is activated by a momentary
contact switch on the front panel assembly. The National Semiconductor PC87431 integrated
management controller de-bounces the signal. After de-bouncing the signal, the National
Semiconductor PC87431 integrated management controller routes it directly to the chipset via
the Power Button signal. The chipset responds to the assertion of the signal. It responds to the
press of the switch, not the release of it.
If the system is in Secure Mode or the Power Button is forced protected, then when the power
switch is pressed, a Platform Security Violation Attempt event message is generated and no
power control action is taken.
In the case of simultaneous button presses, the Power Button action takes priority over all other
buttons. For example, if the sleep button is depressed for one second and then the Power
Button is pressed and released, the system powers down. Due to the routing of the de-bounced
Power Button signal to the chipset, the power signal action overrides the action of the other
switch signals.
5.2.4.2
Reset Button
The reset button is a momentary contact button on the front panel. Its signal is routed through
the front panel connector to the National Semiconductor PC87431 integrated management
controller, which monitors and de-bounces it. The signal must be stable for at least 25ms before
a state change is recognized.
An assertion of the front Panel Reset signal to the National Semiconductor PC87431 integrated
management controller causes the National Semiconductor PC87431 integrated management
controller to start the reset and reboot process. This action is immediate and without the
cooperation of any software or operating system running on the system.
If Secure Mode is enabled or the button is forced protected, the reset button does not reset the
system, but instead a Platform Security Violation Attempt event message is generated. The
reset button is disabled in sleep mode.
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