System Management Controller (Smc)/Keyboard Controller (Kbc); Clocks; Real Time Clock; Thermal Monitoring - Intel BX80580Q9400 - Core 2 Quad 2.66 GHz Processor User Manual

Development Board Features
3.6.20 System Management Controller (SMC)/Keyboard
Controller (KBC)
A Renesas* H8S/2117 (U9G2) serves as both System Management Controller (SMC)
and Keyboard Controller (KBC) for the development board. The SMC/KBC controller
supports two PS/2 ports, battery monitoring and charging, wake/runtime SCI events,
CPU thermal monitoring/Fan control, GMCH thermal throttling support, LPC docking
support and power sequencing control.
The two PS/2 ports on the development board are for legacy keyboard and mouse.
The keyboard plugs into the bottom jack and the mouse plugs into the top jack at
J1A1. Scan matrix keyboards can be supported via an optional connector at J9E1.
3.6.21

Clocks

The system clocks and spread spectrum clocks are provided by the CK505D (EU6H1)
clock synthesizer.
The FSB frequency is determined from decoding the processor BSEL settings. The
BSEL settings can be manually changed via jumpers J1G5, J1G3, and J1G1 (Refer to
Table 17).
The development board also supports PCIE CLKREQ through the DB800 SRC clock
buffer (U7C2). In addition this CRB also supports one dual 1x8 PCI fan-out buffer
(U7E4).
3.6.22

Real Time Clock

An on-board battery at BT5H1 maintains power to the real time clock (RTC) when in a
mechanical off state. A CR2032 battery is installed on the development board.
3.6.23

Thermal Monitoring

The processor has a thermal diode for temperature monitoring (the thermal sensor is
located at U3B3). The SMC throttles the processor if it becomes hot. If the
temperature of the processor rises too high, the SMC alternately blinks the CAPS lock
LED (located at CR9G2) and NUM lock LED (located at CR9G1) on the board, and the
board shuts down.
The development board supports PWM based FAN speed control. As part of the
thermal measurement, speed of the fan is varied based on the temperature
measurement. 3-pin fan headers J2B3 and J3C2 are provided to support FAN Tacho
output measurement for CPU and GMCH respectively.
Development Kit User's Manual 39