60 CP9*, CR9*, CT9* Celeron M/Pentium M
Publication No. HRMCP9 Rev. B
7.17.2
SMBus Devices
The CR9 uses a serial 2-wire I
2
C bus to communicate with several onboard devices:
Table 7-5 SMBus Devices
Device
Designators
SMBus address a
Clock synthesizer *
U1000
1101 001Xb
User Serial EEprom (24C04)
U1980
1010 00XXb
Optional big User EEprom
U1983
1010 010Xb
SPD EEprom Bank 0 *
U1981
1010 100Xb
SPD EEprom Bank 1 *
U1981
1010 101Xb
Factory EEprom *
U1984
1010 11XXb
Temperature sensor LM83
U1982
0011 001Xb
Temperature sensor LM75-1
U1985
1001 110Xb
Temperature sensor LM75-2
U1986
1001 111Xb
Analog Digital Converter
U1953
1001 000Xb
IPMI Controller
U8000
0010 XXXXb
Northbridge E7501
U1300
0011 000Xb
Southbridge ICH4 (slave)
U1600
1000 100Xb
PCI Bridge P64H2 *
U6000
1110 011Xb
Devices marked by * are handled by BIOS. It is strongly recommended not to access these devices by user
software.
An X at bit 0 represents the R/#W bit.
7.17.3
SMBus External (IPMB)
The Intelligent Platform Management Bus (IPMB) is available on the J7002 CPCI
connector for external use. External access via IPMB to the onboard SMBus devices
can only be done via the IPMI controller. For more information please see the IPMB
within the IPMI controller section.
7.17.4
Temperature Sensor LM83
A National Semiconductor LM83 temperature sensor is implemented on the CR9
board. The sensor is located close to the CPU and shows the die-temperature of the
CPU and the local onboard temperature. The sensor has an over-temperature output
integrated, which can be used to take actions like reducing the CPU speed. For
programming information please see the 'AMI-BIOS for CR9, CP9, CT9 User’s and
Programmer’s Manual'.
More information on the LM83 can be found in the data sheet from National
Semiconductors.