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LPC Interface Bridge Registers (D31:F0)
8-60
82801AA and 82801AB Datasheet
8.8.3.3
PM1_CNT—Power Management 1 Control
I/O Address:
PMBASE + 04h
(
ACPI PM1a_CNT_BLK)
0000h
No
Bits 0
:
7: Core,
Bits 8
:
15: Resume
Attribute:
Size:
Usage:
R/W
32 bits
ACPI or Legacy
Default Value:
Lockable:
Power Well:
8.8.3.4
PM1_TMR—Power Management 1 Timer Register
I/O Address:
PMBASE + 08h
(
ACPI PMTMR_BLK)
Attribute:
Size:
Usage:
RO
32 bits
ACPI
Default Value:
Lockable:
Power Well:
xx000000h
No
Core
Bit
Description
13
SLP_EN — WO.
This is a write-only bit and reads to it always return a zero.
1 = Setting this bit causes the system to sequence into the Sleep state defined by the SLP_TYP
field.
12:10
SLP_TYP.
This 3-bit field defines the type of Sleep the system should enter when the SLP_EN bit is
set to 1.
000 = ON
001 = Just assert STPCLK#. Puts processor in Stop-Grant state. Also assert CPUSLP#, to put
processor in sleep state.
010 = Reserved
011 = Reserved
100 = Reserved
101 = Suspend-To-RAM. Assert SLP_S3#.
110 = Suspend-To-Disk. Assert SLP_S3# and , SLP_S5#.
111 = Soft Off. Assert SLP_S3#, and SLP_S5#
2
GBL_RLS.
This bit is used by the ACPI software to raise an event to the BIOS. BIOS software has a
corresponding enable and status bits to control its ability to receive ACPI events. This bit always
reads as 0.
1
Reserved
0
SCI_EN.
Selects the SCI interrupt or the SMI interrupt for various events including the bits in the
PM1_STS register (bit 10, 8, 0), and bits in GPE0_STS.
1 = These events will generate an SCI interrupt.
0 = These events will generate an SMI#.
Bit
Description
31:24
Reserved
23:0
TMR_VAL.
This read-only field returns the running count of the PM timer. This counter runs off a
3.579545 MHz clock (14.31818 MHz divided by 4). It is reset to zero during a PCI reset, and then
continues counting as long as the system is in the S0 state.
Anytime the 22
nd
bit of the timer goes HIGH to LOW (bits referenced from 0 to 23), the TMROF_STS
bit is set. The High-to-Low transition will occur every 2.3435 seconds. If the TMROF_EN bit is set,
an SCI interrupt is also generated. Writes to this register have no effect.