82801BA Datasheet, PDF (137/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

Functional Description
remains low until all SCI sources are removed. In the case where the SCI is routed to
IRQ[9, 10, or 11], the interrupt generated internally is active high. The interrupt remains high until
all SCI sources are removed.
Table 5-39 shows which events can cause an SMI# and SCI. Note that some events can be
programmed to cause either an SMI# or SCI. The usage of the event for SCI (instead of SMI#) is
typically associated with an ACPI-based system. Each SMI# or SCI source has a corresponding
enable and status bits.
Table 5-39. Causes of SMI# and SCI
Cause
SCI
PME#
Yes
Power Button Press
Yes
RTC Alarm
Yes
Ring Indicate
Yes
AC’97 wakes
Yes
USB#1 wakes
Yes
USB#2 wakes
Yes
THRM# pin active
Yes
ACPI Timer overflow
(2.34 sec.)
Yes
Any GPI
Yes
TCO SCI Logic
Yes
TCO SCI message
from MCH
Yes
TCO SMI Logic
No
TCO SMI: Year 2000
Rollover
No
TCO SMI: TCO
TIMEROUT
No
TCO SMI: OS writes
to TCO_DAT_IN
No
register
TCO SMI: Message
from MCH
No
TCO SMI: NMI
occurred (and NMI’s
No
mapped to SMI)
TCO SMI:
INTRUDER# signal
No
goes active
SMI Additional Enables
Yes
PME_EN=1
Yes
PWRBTN_EN=1
Yes
RTC_EN=1
Yes
RI_EN=1
Yes
AC97_EN=1
Yes
USB1_EN=1
Yes
USB2_EN=1
Yes
THRM_EN=1
Where Reported
PME_STS
PWRBTN_STS
RTC_STS
RI_STS
AC97_STS
USB1_STS
USB2_STS
THRM_STS
Comment
Can also cause Wake Event
Can also cause Wake Event
The THRM# can cause an
SMI# or SCI on either the
rising or falling edge. Causes
SCI if SCI_EN is set, causes
SMI# if SCI_EN not set.
Yes
TMROF_EN=1
TMROF_STS
GPI[x]_Route=10 (SCI)
Yes GPI[x]_Route=01 (SMI)
GPE1[x]_EN=1
No
TCOSCI_EN=1
GPI[x]_STS
GPE1_STS
TCOSCI_STS
Can also cause IRQ (other
than SCI).
No
none
MCHSCI_STS
Yes
TCO_EN=1
TCO_STS
Can also cause IRQ (other
than SCI).
Yes
none
NEWCENTURY_STS
Yes
none
TIMEOUT
Yes
none
OS_TCO_SMI
Yes
none
MCHSMI_STS
Yes
NMI2SMI_EN=1
NMI2SMI_STS
Yes
INTRD_SEL=10
INTRD_DET
82801BA ICH2 and 82801BAM ICH2-M Datasheet
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