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82801AA and 82801AB Datasheet
8-59
LPC Interface Bridge Registers (D31:F0)
8.8.3.2
PM1_EN—Power Management 1 Enables Register
I/O Address:
PMBASE + 02h
(
ACPI PM1a_EVT_BLK + 2)
0000h
No
Bits 0
:
7: Core,
Bits 8
:
15: Resume
Attribute:
Size:
Usage:
R/W
16 bits
ACPI or Legacy
Default Value:
Lockable:
Power Well:
5
GBL _STS.
1 = This bit is set when an SCI is generated due to BIOS wanting the attention of the SCI handler.
BIOS has a corresponding bit, BIOS_RLS, which will cause an SCI and set this bit.
0 = The SCI handler should then clear this bit by writing a 1 to it.
4:1
Reserved
0
TMROF_STS.
This is the timer overflow status bit.
1 = This bit gets set anytime the 22
nd
bit of the 24 bit timer goes high (bits are counted from 0 to 23).
This will occur every 2.3435 seconds. When the TMROF_EN bit is set, then the setting of the
TMROF_STS bit will additionally generate an SCI or SMI# (depending on the SCI_EN).
0 = The SCI or SMI# handler clears this bit by writing a 1 to this bit.
Bit
Description
Bit
Description
15:11
Reserved.
10
RTC_EN.
1 = Enable. An SCI (or SMI#) or wake event will occur when this bit is set and the RTC_STS bit
goes active. If this bit is not set, then setting the RTC_STS bit does not cause an SCI (or
SMI#)or wake event.
0 = This bit is not cleared by any reset other than RTCRST# and a power button override event.
NOTE:
This bit is in the RTC well to allow an RTC event to wake after a power failure.
9
Reserved
8
PWRBTN_EN.
This bit is used to enable the setting of the PWRBTN_STS bit to generate a power
management event (SMI#, SCI). PWRBTN_EN has no effect on the PWRBTN_STS bit being set by
the assertion of the power button. The Power Button is always enabled as a Wake event.
1 = Enable
0 = Disable
7:6
Reserved.
5
GBL_EN.
The Global Enable bit. When both the GBL_EN and the GBL_STS are set, an SCI is
raised.
1 = Enable
0 = Disable
4:1
Reserved.
0
TMROF_EN.
This is the timer overflow interrupt enable bit and works in conjunction with the
SCI_EN bit:
TMROF_EN
SCI_EN
Effect when TMROF_STS is set
0
x
No SMI# or SCI
1
0
SMI#
1
1
SCI