
82801AA and 82801AB Datasheet
8-65
LPC Interface Bridge Registers (D31:F0)
8.8.3.10
GPE1_EN—General Purpose Event 1 Enable Register
I/O Address:
PMBASE + 2Eh
(
ACPI GPE1_BLK + 2)
0000h
No
Resume
Attribute:
Size:
Usage:
R/W
16 bits
ACPI
Default Value:
Lockable:
Power Well:
Note:
This register is symmetrical to the General Purpose Event 1 Status Register. GPIOs that are not
implemented do not have the corresponding bits implemented in this register.
8.8.3.11
SMI_EN—SMI Control and Enable Register
I/O Address:
Default Value:
Lockable:
Power Well:
PMBASE + 30h
0000h
No
Core
Attribute:
Size:
Usage:
R/W
16 bit
ACPI or Legacy
Bit
Description
15:0
GPI[n]_EN.
These bits enable the corresponding GPI[n]_STS bits being set to cause an SMI#, SCI,
and/or wake event.
Bit
Description
15
Reserved
14
1MIN_EN.
1 = Enables the ICH to generate an SMI# when the 1MIN_STS bit is set in the SMI_STS register.
13
TCO_EN.
1 = Enables the TCO logic to generate SMI#.
0 = Disables TCO logic generating an SMI#.
NOTE:
If the NMI2SMI_EN bit is set, SMIs that are caused by re-routed NMIs will not be gated by
the TCO_EN bit. Even if the TCO_EN bit is 0, NMIs will still be routed to cause SMIs.
12:8
Reserved
7
BIOS_RLS.
1 = Enables the generation of an SCI interrupt for ACPI software when a one is written to this bit
position by BIOS software. This bit always reads a zero.
6
SWSMI_TMR_EN.
1 = Starts Software SMI# Timer. When the 64 ms timer expires (±4ms), it will generate an SMI# and
set the SWSMI_TMR_STS bit. The SWSMI_TMR_EN bit will remain at 1 until software sets it
back to 0.
0 = Disable. Clearing the SWSMI_TMR_EN bit before the timer expires will reset the timer and the
SMI# will not be generated. The default for this bit is 0.
5
APMC_EN.
1 = Enables writes to the APMC register to cause an SMI#
4
SLP_SMI_EN.
1 = When this bit is set, any write of a 1 to the SLP_EN bit (bit 13 in PM1_CNT register) generates
an SMI#, and the system does not transition to the sleep state based on that write to the
SLP_EN bit.
0 = Disables the generation of SMI# on SLP_EN.
NOTE:
This bit must be 0 before the software attempts to transition the system into a sleep state
by writing a 1 to the SLP_EN bit.