82801BA Datasheet, PDF (345/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

LPC Interface Bridge Registers (D31:F0)
9.9.8
9.9.9
TCO1_CNT—TCO1 Control Register
I/O Address:
Default Value:
Lockable:
TCOBASE +08h
0000h
No
Attribute:
Size:
Power Well:
R/W, R/WC
16-bit
Core
Bit
15:12
11
10
9
8
7:0
Description
Reserved
TCO Timer Halt (TCO_TMR_HLT)—R/W.
0 = The TCO Timer is enabled to count.
1 = The TCO Timer will halt. It will not count and, thus, cannot reach a value that will cause an
SMI# or set the SECOND_TO_STS bit. When set, this bit prevents rebooting and prevents
Alert On LAN event messages from being transmitted on the SMLINK (but not Alert On LAN
heartbeat messages).
Send Now (SENDNOW)—R/W (special).
1 = Writing a 1 to this bit will cause the ICH to send an Alert On LAN Event message over the
SMLINK interface, with the Software Event bit set.
0 = The ICH will clear this bit when it has completed sending the message. Software must not set
this bit to 1 again until the ICH has set it back to 0.
Setting the SENDNOW bit causes the ICH2 integrated LAN Controller to reset, which can have
unpredictable side-effects. Unless software protects against these side effects, software should not
attempt to set this bit.
NMI to SMI Enable (NMI2SMI_EN)—R/W.
0 = Normal NMI functionality.
1 = Forces all NMIs to instead cause SMIs. The functionality of this bit is dependent upon the
settings of the NMI_EN bit and the GBL_SMI_EN bit as detailed in the following table:
NMI_EN GBL_SMI_EN Description
0
0
No SMI# at all because GBL_SMI_EN = 0
0
1
SMI# will be caused due to NMI events
1
0
No SMI# at all because GBL_SMI_EN = 0
1
1
No SMI# due to NMI because NMI_EN = 1
NMI Now (NMI_NOW)—R/WC.
1 = Writing a 1 to this bit causes an NMI. This allows the BIOS or SMI handler to force an entry to
the NMI handler.
0 = This bit is cleared by writing a 1 to the bit position. The NMI handler is expected to clear this bit.
Another NMI will not be generated until the bit is cleared.
Reserved
TCO2_CNT—TCO2 Control Register
I/O Address:
Default Value:
Lockable:
TCOBASE +0Ah
0000h
No
Attribute:
Size:
Power Well:
R/W
16-bit
Resume
Bit
Description
15:3 Reserved.
INTRUDER# Signal Select (INTRD_SEL)—R/W. Selects the action to take if the INTRUDER# signal
goes active.
00 = No interrupt or SMI#
2:1 _{01 = Interrupt (as selected by TCO_INT_SEL).}
10 = SMI
11 = Reserved
0 Reserved.
82801BA ICH2 and 82801BAM ICH2-M Datasheet
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