Intel SE7520AF2 Technical Product Specification page 173

Intel® Server Board SE7520AF2 TPS
deasserting SLEEP_S5 to the CPU configuration circuitry. If the configuration is good,
PS_PWRON is asserted to the power supply. The supply then asserts POWERGOOD back to
the mBMC.
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.
6.3.4.2 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 mBMC, 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 mBMC causes the mBMC 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.
6.3.4.3 Diagnostic Interrupt Button (Front Panel NMI)
As stated in the IPMI 1.5 Specification, a Diagnostic Interrupt is a non-maskable interrupt or
signal for generating diagnostic traces and core dumps from the operating system. The mBMC
generates the NMI, which can be used as an OEM-specific diagnostic front panel interface.
The Diagnostic Interrupt button is connected to the mBMC through the front panel connector. A
Diagnostic Interrupt button press causes the mBMC to generate a 200 ms system NMI pulse.
This generates an event (NMI button sensor); the NMI is actually generated by a factory defined
PEF filter.
6.3.4.4 Chassis ID Button and LED
The front panel interface supports a Chassis Identify Button and a corresponding Blue Chassis
Identify LED (both available only on the rack version of the Server Chassis SC5300). A second
Blue Chassis Identify LED is mounted on the back edge of the baseboard where it may be
visible when viewed from the back of an integrated system.
The LED can provide a mechanism for identifying one system out of a group of identical
systems in a rack environment
Revision 1.2
Intel order number C77866-003
Platform Management
173