82801BA Datasheet, PDF (341/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

LPC Interface Bridge Registers (D31:F0)
9.9
System Management TCO Registers (D31:F0)
The TCO logic is accessed via registers mapped to the PCI configuration space
(Device 31:Function 0) and the system I/O space. For TCO PCI Configuration registers, see LPC
Device 31:Function 0 PCI Configuration registers.
9.9.1 TCO Register I/O Map
The TCO I/O registers reside in a 32-byte range pointed to by a TCOBASE value, which is,
ACPIBASE + 60h in the PCI configuration space. The following table shows the mapping of the
registers within that 32-byte range. Each register is described in the sections below.
Table 9-11. TCO I/O Register Map
Offset
00h
01h
02h
03h
04h–05h
06h–07h
08h–09h
0Ah–0Bh
0Ch–0Dh
0Eh
0Fh
10h
11h–1Fh
Mnemonic
TCO_RLD
TCO_TMR
TCO_DAT_IN
TCO_DAT_OUT
TCO1_STS
TCO2_STS
TCO1_CNT
TCO2_CNT
TCO_MESSAGE1,
TCO_MESSAGE2
TCO_WDSTATUS
SW_IRQ_GEN
Register Name: Function
TCO Timer Reload and Current Value
TCO Timer Initial Value
TCO Data In
TCO Data Out
TCO Status
TCO Status
TCO Control
TCO Control
Used by BIOS to indicate POST/Boot progress
Watchdog Status Register
Reserved
Software IRQ Generation Register
Reserved
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
RO
R/W
RO
9.9.2
TCO1_RLD—TCO Timer Reload and Current Value Register
I/O Address:
Default Value:
Lockable:
TCOBASE +00h
0000h
No
Attribute:
Size:
Power Well:
R/W
8-bit
Core
Bit
Description
7:0
TCO Timer Value. Reading this register will return the current count of the TCO timer. Writing any
value to this register will reload the timer to prevent the time-out. Bits 7:6 will always be 0.
82801BA ICH2 and 82801BAM ICH2-M Datasheet
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