82801FB Datasheet, PDF (175/786 Pages) Intel Corporation – Intel I/O Controller Hub 6 (ICH6) Family

Functional Description
If the INTRUDER# signal goes inactive some point after the INTRD_DET bit is written as a 1,
then the INTRD_DET signal will go to a 0 when INTRUDER# input signal goes inactive. Note
that this is slightly different than a classic sticky bit, since most sticky bits would remain active
indefinitely when the signal goes active and would immediately go inactive when a 1 is written to
the bit.
Note:
The INTRD_DET bit resides in the ICH6’s RTC well, and is set and cleared synchronously with
the RTC clock. Thus, when software attempts to clear INTRD_DET (by writing a 1 to the bit
location) there may be as much as two RTC clocks (about 65 µs) delay before the bit is actually
cleared. Also, the INTRUDER# signal should be asserted for a minimum of 1 ms to guarantee that
the INTRD_DET bit will be set.
Note:
If the INTRUDER# signal is still active when software attempts to clear the INTRD_DET bit, the
bit remains set and the SMI is generated again immediately. The SMI handler can clear the
INTRD_SEL bits to avoid further SMIs. However, if the INTRUDER# signal goes inactive and
then active again, there will not be further SMIs, since the INTRD_SEL bits would select that no
SMI# be generated.
5.15.1.3
Detecting Improper Firmware Hub Programming
The ICH6 can detect the case where the Firmware Hub is not programmed. This results in the first
instruction fetched to have a value of FFh. If this occurs, the ICH6 sets the BAD_BIOS bit, which
can then be reported via the Heartbeat and Event reporting using an external, Alert on LAN*
enabled LAN controller (See Section 5.15.2).
5.15.2
Heartbeat and Event Reporting via SMBus
The ICH6 integrated LAN controller supports ASF heartbeat and event reporting functionality
when used with the 82562EM or 82562EX Platform LAN Connect component. This allows the
integrated LAN controller to report messages to a network management console without the aid of
the system processor. This is crucial in cases where the processor is malfunctioning or cannot
function due to being in a low-power state.
All heartbeat and event messages are sent on the SMBus interface. This allows an external LAN
controller to act upon these messages if the internal LAN controller is not used.
The basic scheme is for the ICH6 integrated LAN controller to send a prepared Ethernet message
to a network management console. The prepared message is stored in the non-volatile EEPROM
that is connected to the ICH6.
Messages are sent by the LAN controller either because a specific event has occurred, or they are
sent periodically (also known as a heartbeat). The event and heartbeat messages have the exact
same format. The event messages are sent based on events occurring. The heartbeat messages are
sent every 30 to 32 seconds. When an event occurs, the ICH6 sends a new message and increments
the SEQ[3:0] field. For heartbeat messages, the sequence number does not increment.
Intel^® I/O Controller Hub 6 (ICH6) Family Datasheet
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