E
7.2.10.
82371AB (PIIX4)
143
4/9/97 2:23 PM PIIX4aDS
INTEL CONFIDENTIAL
(until publication date)
PRELIMINARY
GLBSTS—GLOBAL STATUS REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (18h)
00h
Read/Write
Bit
Description
15:12
Reserved.
11
IRQ Resume Status (IRQ_RSM_STS)—R/W.
1=System was resumed from a Powered On
Suspend (POS) state due to an interrupt assertion (IRQ[1,3:15]). 0=System was not resumed due to
IRQ. This bit is only set by hardware and can only be reset by writing a 1 to this bit position.
10
External SMI Status (EXTSMI_STS)—R/WC.
1=EXTSMI# signal was asserted. 0=EXTSMI# was
not asserted. This bit is only set by hardware and can only be reset by writing a 1 to this bit position.
9
Reserved.
8
Global Standby Status (GSTBY_STS)—R/WC.
1=Global Standby timer expired (counted down to
0). 0=Global Standby timer did not expire. This bit is only set by hardware and can only be reset by
writing a 1 to this bit position.
7
GP Status (GP_STS)—RO.
1=Indicates that one of the status bits in the GPSTS register is set.
0=All bits in GPSTS register are reset. This bit can only be reset by resetting all bits in the GPSTS
register.
6
PM1 Status (PM1_STS)—RO.
1=Indicates that one of the status bits in the PMSTS register is set.
0=All bits in PMSTS register are reset. This bit can only be reset by resetting all bits in the PMSTS
register.
5
APM Status (APM_STS)—R/WC.
1=A write occurred to the APMC register causing generation of
an SMI#. 0=A write has not occurred to the APMC register causing generation of an SMI#. This bit is
cleared by writing a 1 to this bit position.
4
All Devices Status (DEV_STS)—RO.
1=Indicates that one of the status bits in the DEV_STS
register is set. 0=All bits in DEV_STS register are reset. This bit can only be reset by resetting all
bits in the DEV_STS register.
3
Reserved.
2
P4MA Status (P4MA_STS)—R/WC.
1=An SMI# was generated due to a PIIX4 PCI cycle being
Master Aborted. 0=No SMI# was generated due to PIIX4 PCI cycles having been Master Aborted.
This bit is only set by hardware and can only be reset by writing a 1 to this bit position.
1
Legacy USB Status (LEGACY_USB_STS)—R/WC.
1=USB legacy keyboard logic
generated an
SMI#. 0=USB legacy keyboard logic did not generate an SMI#. This bit is only set by hardware and
can only be reset clearing the children status bits in the USB status register.
0
BIOS Status (BIOS_STS)—R/WC.
1=A write of 1 occurred to the GBL_RLS bit. 0=A write of 1 did
not occur to the GBL_RLS bit. This bit is set by hardware and is cleared by writing a 1 to it.