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Register Index
A-16
82801AA and 82801AB Datasheet
AC’97 Modem I/O Registers at MBAR + Offset
MBAR is set in Section 13.1.11, “MBAR—Modem Base Address Register (Modem—D31:F6)” on
page 13-5
Modem In Buffer Descriptor List Base
Address Register
00h
Section 13.2.1, “x_BDBAR—Buffer Descriptor List
Base Address Register” on page 13-10
Modem In Current Index Value
Register
04h
Section 13.2.2, “x_CIV—Current Index Value
Register” on page 13-10
Modem In Last Valid Index Register
05h
Section 13.2.3, “x_LVI—Last Valid Index Register” on
page 13-10
Modem In Status Register
06h
Section 13.2.4, “x_SR—Status Register” on
page 13-11
Modem In Position In Current Buffer
Register
08h
Section 13.2.5, “x_PICB—Position In Current Buffer
Register” on page 13-12
Modem In Prefetch Index Value
Register
0Ah
Section 13.2.6, “x_PIV—Prefetch Index Value
Register” on page 13-12
Modem In Control Register
0Bh
Section 13.2.7, “x_CR—Control Register” on
page 13-13
Modem Out Buffer Descriptor List
Base Address Register
10h
Section 13.2.1, “x_BDBAR—Buffer Descriptor List
Base Address Register” on page 13-10
Modem Out Current Index Value
Register
14h
Section 13.2.2, “x_CIV—Current Index Value
Register” on page 13-10
Modem Out Last Valid Register
15h
Section 13.2.3, “x_LVI—Last Valid Index Register” on
page 13-10
Modem Out Status Register
16h
Section 13.2.4, “x_SR—Status Register” on
page 13-11
Modem In Position In Current Buffer
Register
18h
Section 13.2.5, “x_PICB—Position In Current Buffer
Register” on page 13-12
Modem Out Prefetched Index
Register
1Ah
Section 13.2.6, “x_PIV—Prefetch Index Value
Register” on page 13-12
Modem Out Control Register
1Bh
Section 13.2.7, “x_CR—Control Register” on
page 13-13
Global Control
3Ch
Section 13.2.8, “GLOB_CNT—Global Control
Register” on page 13-14
Global Status
40h
Section 13.2.9, “GLOB_STA—Global Status Register”
on page 13-14
Codec Access Semaphore Register
44h
Section 13.2.10, “CAS—Codec Access Semaphore
Register” on page 13-15
Table A-3. ICH Variable I/O Registers (Sheet 5 of 5)
Register Name
Offset
Datasheet Section and Location