2 System Board

The Input/Output Controller Hub (82801AA)

ICH SMBus Master

The ICH provides a processor-to-SMBus controller. All access performed to

Controller

the SMBus is done through the ICH SMBus interface. Typically, the

 

processor has access to all the devices connected to the SMBus.
DIMM Sockets

Each DIMM socket is connected to the SMBus. The 168-pin DIMM modules

 

include a 256 byte I2C Serial EEPROM. The first 128 bytes contain general

 

information, including the DRAM chips’ manufacturer name, DIMM speed

 

rating, DIMM type, etc. The second 128 bytes of the Serial EEPROM can be

 

used to store data online.
RIMM Sockets

Each RIMM socket is connected to the SMBus. The 168-pin RIMM modules

 

include a 256 byte I2C Serial EEPROM. The first 128 bytes contain general

 

information, including the DRAM chips’ manufacturer name, RIMM speed

 

rating, RIMM type, etc. The second 128 bytes of the Serial EEPROM can be

 

used to store data online.

ADM1024The ADM1024 chip is a hardware monitoring sensor dedicated to the

 

processor temperature. This chip uses the thermal diodes integrated into

 

each processor cartridge and makes the temperature information available

 

through the SMBus. It also monitors processor power supply voltages.
Serial EEPROM

This is the non-volatile memory which holds the default values for the CMOS

 

memory (in the event of battery failure).When installing a new system

 

board, the Serial EEPROM will have a blank serial number field. This will be

 

detected automatically by the BIOS, which will then prompt the user for the

 

serial number which is printed on the identification label on the back of the

 

PC Workstation. The computer uses 16KBytes of Serial EEPROM

 

implemented within two chips. Serial EEPROM is ROM in which one byte at

 

a time can be returned to its unprogrammed state by the application of

 

appropriate electrical signals. In effect, it can be made to behave like very

 

slow, non-volatile RAM. It is used for storing the tatoo string, the serial

 

number, and the parameter settings for the Setup program as well as

 

MaxiLife firmware.
LM75 Temperature

The LM75 temperature sensor and alarm are located on the system board.

SensorThe sensor is used to measure the temperature in various areas of the

 

system board. This information is used to regulate fans.

57