82801CA Datasheet, PDF (35/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

Introduction
Manageability
The ICH3 integrates several functions designed to manage the system and lower the total cost of
ownership (TC0) of the system. These system management functions are designed to report errors,
diagnose the system, and recover from system lockups without the aid of an external
microcontroller.
• TCO Timer. The ICH3’s integrated programmable TC0 Timer is used to detect system locks.
The first expiration of the timer generates an SMI# that the system can use to recover from a
software lock. The second expiration of the timer causes a system reset to recover from a
hardware lock.
• Processor Present Indicator. The ICH3 looks for the processor to fetch the first instruction
after reset. If the processor does not fetch the first instruction, the ICH3 will reboot the system
at the safe-mode frequency multiplier.
• ECC Error Reporting. When detecting an ECC error, the host controller has the ability to
send one of several messages to the ICH3. The host controller can instruct the ICH3 to
generate either an SMI#, NMI, SERR#, or TCO interrupt.
• Function Disable. The ICH3 provides the ability to disable the following functions: AC ’97
Modem, AC ’97 Audio, IDE, LAN USB, or SMBus. Once disabled, these functions no longer
decode I/O, memory, or PCI configuration space. Also, no interrupts or power management
events are generated from the disable functions.
• Intruder Detect. The ICH3 provides an input signal (INTRUDER#) that can be attached to a
switch that is activated by the system case being opened. The ICH3 can be programmed to
generate an SMI# or TCO interrupt due to an active INTRUDER# signal.
• SMBus 2.0. The ICH3 integrates an SMBus controller that provides an interface to manage
peripherals (e.g., serial presence detection (SPD) and thermal sensors) with host notify
capabilities.
• Alert On LAN*. The ICH3 supports Alert On LAN* and Alert On LAN* 2. In response to a
TCO event (intruder detect, thermal event, processor not booting) the ICH3 sends a message
over the SMBus. A LAN controller can decode this SMBus message and send a message over
the network to alert the network manager.
Intel^® 82801CA ICH3-S Datasheet
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