
82371AB (PIIX4)
E
144
4/9/97 2:23 PM PIIX4aDS
INTEL CONFIDENTIAL
(until publication date)
PRELIMINARY
7.2.11.
DEVSTS—DEVICE STATUS REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (1Ch)
00h
Read/Write
Bit
Description
31:30
Reserved.
29:16
Device [0–13] Trap Status Bits (TRP_STS_DEV[0–13])—R/WC.
1=An SMI# was generated by an
I/O trap to the associated device monitor’s enabled address range. 0=No SMI# was generated. Bit
29 corresponds to device monitor 13 and bit 16 corresponds to device monitor 0. This bit is cleared
by writing a 1 to its bit position.
15:12
Reserved.
11:0
Device [0–11] Idle Status Bits (IDL_STS_DEV[0–11])—R/WC.
1=An SMI# was generated by the
expiration of the associated device monitor’s idle timer. 0=No SMI# was generated. Bit 11
corresponds to device monitor 11 and bit 0 corresponds to device monitor 0. This bit is cleared by
writing a 1 to its bit position.
7.2.12.
GLBEN—GLOBAL ENABLE REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (20h)
00h
Read/Write
Bit
Description
15
Battery Low Enable (BATLOW_EN)—R/W.
1=Enable BATLOW# assertion to prevent a system
resume from any suspend state. 0=Disable.
14:12
Reserved.
11
IRQ Resume Enable (IRQ_RSM_EN)—R/W.
1=Enable an unmasked interrupt (IRQ[1, 3:15])
assertion to generate a resume from the Power On Suspend (POS) state. 0=Disable.
10
External SMI Enable (EXTSMI_EN)—R/W.
1=Enable the setting of the EXTSMI_STS bit to
generate an SMI# or resume event. 0=Disable.
9
Reserved.
8
Global Stand By Enable (GSTBY_EN)—R/W.
1=Enable the setting of the GSTBY_STS bit to
generate an SMI# or resume event. 0=Disable.
7:5
Reserved.
4
PIIX4 Master Abort Enable (P4MA_EN)—R/W.
1=Enable the setting of the P4MA_STS bit to
generate an SMI#. 0=Disable.
3
Bus Master Trap Enable (BM_TRP_EN)—R/W.
1=Enable the setting of the BM_STS bit to
generate an SMI#.
2
Reserved.
1
BIOS Enable (BIOS_EN)—R/W.
1=Enable the generation of an SMI# by writing a 1 to the
GBL_RLS bit. 0=Disable.
0
Legacy USB Enable (LEGACY_USB_EN)—R/W.
1=Enable the USB legacy function to generate
an SMI#. 0=Disable.