HP Workstation x2000 hp workstation x2000 - Technical Reference and Troublesho - Page 63

System Board The Input/Output Controller Hub 2 (82801BA) 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's name, RIMM speed rating, RIMM type, and so on. You can use the second 128 bytes of the serial EEPROM to store data online. AS98127F The AS98127 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 nonvolatile memory that holds the default values for the CMOS memory (in the event of battery failure).When you install a new system board, the serial EEPROM will have a blank serial number field. The BIOS automatically detects this, and the system prompts you for the serial number printed on the identification label on the back of the workstation. The computer uses 16KB of serial EEPROM implemented within two chips. Serial EEPROM is ROM in which the application of appropriate electrical signals can return one byte at a time to its unprogrammed state. In effect, you can make serial EEPROM behave like very slow, nonvolatile RAM. It is used for storing the tattoo string, the serial number, and the parameter settings for the Setup program as well as MaxiLife firmware. LM75 Temperature Sensor The LM75 temperature sensor and alarm reside on the system board. The sensor measures the temperature in various areas of the system board. The system uses this information to regulate fans. HP MaxiLife Hardware-Monitoring Chip MaxiLife is a hardware-monitoring chip on the system board. Its functions include: • On/off and reset control Chapter 2 63