User`s guide

Chapter 2: System Processor Board Description

Keyboard and Mouse

The PS/2-compatible keyboard and mouse connectors are mounted in a single-stacked

housing with the mouse connector over the keyboard. External to the system, they

appear as two connectors.

You can plug in the keyboard and mouse to either connector before powering up the

system. BIOS detects these and conﬁgures the keyboard controller accordingly.

The keyboard controller is functionally compatible with the 8042A microcontroller. The

system can be locked automatically if no keyboard or mouse activity occurs for a

predeﬁned length of time, if speciﬁed through the system setup utility (SSU). Once the

inactivity (lockout)timer hasexpired, the keyboardand mousedo notrespond until the

previously stored password is entered.

Server Management

Server Management features are implemented using one microcontroller on the

processor board known as the Baseboard Management Controller (BMC).

Baseboard Management Controller (BMC)

The BMC and associated circuitry are powered from 5V_Standby, which means this

device remains active even when system power is switched off.

The primary function of the BMC is to autonomously monitor system platform

managementevents and logtheir occurrencein the nonvolatileSystem EventLog (SEL).

Theseevents include overtemperatureand overvoltageconditions,fanfailure,orchassis

intrusion. While monitoring, the BMC maintains the nonvolatile sensor data record

repository (SDRR), from which run-time information can be retrieved. The BMC

provides an ISA host interface to SDRR information, so software running on the server

can poll and retrieve the current status of the platform. A shared register interface is

deﬁned for this purpose.