Specifications

QSSC-S4R Technical Product Specification Processor Presence and Population Check
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24.2.3 Chassis ID LED
The chassis ID LED provides a visual indication of a system being serviced. The state of the chassis ID LED is affected
by the following actions:
x Toggled by turning the chassis ID button on or off.
x Controlled by the IPMI Chassis Identify command.
x Chassis Identify command can be used to blink or deactivate the Chassis ID LED. It cannot be used to set the
LED in the solid-on state.
There is no precedence or lock-out mechanism for the control sources. When a new request arrives, previous requests
are terminated. For example, if the chassis ID LED is blinking and the chassis ID button is pressed, then the chassis ID
LED changes to solid on. If the button is pressed again, then the chassis ID LED turns off.
24.2.4 Front Panel / Chassis Inputs
The BMC monitors the front panel buttons and other chassis signals. The front panel input buttons are momentary
contact switches that are de-bounced by the BMC’s integrated hardware. The de-bounce time is 8 ms. BMC
debouncing does not affect the operation of the power or reset button, since the power and reset buttons are
connected to the chipset. The debouncing is only for BMC monitoring.
24.2.4.1 Chassis Intrusion
QSSC-S4R Support a chassis intrusion sensor.
The BMC monitors the state of the Chassis Intrusion signal and makes the status of the signal available via the Get
Chassis Status command and the Physical Security sensor state. A chassis intrusion state change causes the BMC to
generate a Physical Security sensor event message with a General Chassis Intrusion offset (00h).
The BMC detects chassis intrusion and logs a SEL event when the system is in the on, sleep, or standby state.
Chassis intrusion is not detected when the system is in an AC power-off (AC lost) state.
The BMC hardware cannot differentiate between a missing Chassis Intrusion cable or connector, and a true security
violation. If the Chassis Intrusion cable or connector is removed or damaged, the BMC will treat it as if the chassis
cover is open, and take the appropriate actions.
Fan speeds are affected by the chassis intrusion sensor, all system fans must boost to maximum to ensure sufficient
system cooling.
24.2.4.2 Power Button
See Section 23.1.5.1.
24.2.4.3 Reset Button
An assertion of the Front Panel Reset signal to the BMC causes the system to start the reset and reboot process, as
long as the BMC has not locked-out this input. This assertion is immediate and without the cooperation of software or
the operating system.
See Section 23.3.3 for more information.
24.2.4.4 Diagnostic Interrupt (Front Panel NMI)
A diagnostic interrupt is a non-maskable interrupt or signal for generating diagnostic traces and core dumps from the
operating system. The diagnostic interrupt button is connected to the BMC through a front panel connector. A
diagnostic interrupt button press causes the BMC to do the following:
x Generate a Critical Event sensor event message with a Front Panel NMI /
Diagnostic interrupt offset (00h).
x Generate a system NMI pulse.
Once an NMI has been generated by the BMC, the BMC does not generate another until the system has been reset or
powered down.
24.2.4.5 Chassis Identify
The front panel chassis identify button toggles the state of the Chassis ID LED. If the LED is off, pushing the button
lights the LED. It remains lit until the button is pushed again or until a Chassis Identify command is received that
changes the state of the LED.