HP A7818-IE002 - Manual (Page 49)

System Board
Input/output Controller Hub 2 (82801BA)
Chapter 2 49
The CS4299 introduces a new architecture that is different from the one used with the
CS4280-CS4297 pair.
Figure 2-9 CS4280-CS4297 and CS4299 Architecture
Devices On The SMBus
The SMBus is a subset of the I2C bus. It is a two-wired serial bus that runs at a
maximum speed of 100KHz. The SMBus monitors some of the system board’s hardware
functions (for example, voltage levels, temperature, fan speed, memory presence, and
type), both at system boot and during normal run-time. The SMBus controller, located in
the ICH2, controls the SMBus.
The following devices are connected to the SMBus:
• LCD status panel
• One serial EEPROM MaxiLife (also includes backup values of CMOS settings)
• PCI slot 5 ready for Alert-On LAN (AOL) from a hardware level
• ICH2 SMBus master controller 100KHz maximum
• MaxiLife for hardware management, bus master controller
• One LM75 thermal sensor on the system board
• One ADM1024 hardware-monitoring sensor
Previous
Architecture
New
Architecture
North
Bridge
South
Bridge
CS4297
CS4280 digital
controller
PCI Slots
Audio controller link
PCI Bus
North
Bridge
South
Bridge
CS4299
Audio controller link