82801CA Datasheet, PDF (436/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

AC ’97 Modem Controller Registers (D31:F6)
14.1.12
SVID—Subsystem Vendor ID (Modem—D31:F6)
Address Offset:
Default Value:
Lockable:
2C–2Dh
0000h
No
Attribute:
Size:
Power Well:
Read/Write-Once
16 bits
Core
The SVID register, in combination with the Subsystem ID register, enable the operating
environment to distinguish one audio subsystem from the other(s).
This register is implemented as write-once register. Once a value is written to it, the value can be
read back. Any subsequent writes will have no effect.
Bit
15:0 Subsystem Vendor ID—R/WO.
Description
14.1.13
SID—Subsystem ID (Modem—D31:F6)
Address Offset:
Default Value:
Lockable:
2E–2Fh
0000h
No
Attribute:
Size:
Power Well:
Read/Write-Once
16 bits
Core
The SID register, in combination with the Subsystem Vendor ID register make it possible for the
operating environment to distinguish one audio subsystem from another.
This register is implemented as write-once register. Once a value is written to it, the value can be
read back. Any subsequent writes will have no effect.
Bit
15:0 Subsystem ID—R/WO.
Description
14.1.14
INTR_LN—Interrupt Line Register (Modem—D31:F6)
Address Offset: 3Ch
Default Value: 00h
Lockable:
No
Attribute:
Size:
Power Well:
R/W
8 bits
Core
This register indicates which PCI interrupt line is used for the AC ’97 module interrupt.
Bit
Description
7:0
Interrupt Line (INT_LN)—R/W. This data is not used by the ICH3. It is used to communicate to
software the interrupt line that the interrupt pin is connected to.
14.1.15
INT_PIN—Interrupt Pin (Modem—D31:F6)
Address Offset: 3Dh
Default Value: 02h
Lockable:
No
Attribute:
Size:
Power Well:
RO
8 bits
Core
This register indicates which PCI interrupt pin is used for the AC ’97 modem interrupt. The AC ’97
interrupt is internally ORed to the interrupt controller with the PIRQB# signal.
Bit
Description
7:3 Reserved.
2:0 Interrupt Pin (INT_PN)—RO. Hardwired to 010b to select PIRQB#.
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Intel^® 82801CA ICH3-S Datasheet