82801CA Datasheet, PDF (437/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

AC ’97 Modem Controller Registers (D31:F6)
14.2 AC ’97 Modem I/O Space (D31:F6)
In the case of the split codec implementation accesses to the modem mixer registers in different
codecs are differentiated by the controller by using address offsets 00h–7Fh for the primary codec
and address offsets 80h–FEh for the secondary codec. Table 14-2 shows the register addresses for
the modem mixer registers.
Table 14-2. Intel^® ICH3 Modem Mixer Register Configuration
Register
MMBAR Exposed Registers (D31:F6)
Pri.
00h:38h
3Ch
3Eh
40h
42h
44h
46h
48h
4Ah
4Ch
4Eh
50h
52h
54h
56h
58h
7Ah
7Ch
7Eh
Sec.
Name
80h:B8h
BCh
BEh
C0h
C2h
C4h
C6h
C8h
CAh
CCh
CEh
D0h
D2h
D4h
D6h
D8h
FAh
FCh
FEh
Intel RESERVED
Extended Modem ID
Extended Modem Stat/Ctrl
Line 1 DAC/ADC Rate
Line 2 DAC/ADC Rate
Handset DAC/ADC Rate
Line 1 DAC/ADC Level Mute
Line 2 DAC/ADC Level Mute
Handset DAC/ADC Level Mute
GPIO Pin Configuration
GPIO Polarity/Type
GPIO Pin Sticky
GPIO Pin Wake Up
GPIO Pin Status
Misc. Modem AFE Stat/Ctrl
Vendor Reserved
Vendor Reserved
Vendor ID1
Vendor ID2
NOTE:
1. Registers in bold are multiplexed between audio and modem functions.
2. Registers in italics are for functions not supported by the ICH3.
3. Software should not try to access reserved registers.
4. The ICH3 supports a modem codec as either primary or secondary, but does not support two modem codecs.
The Global Control (GLOB_CNT) and Global Status (GLOB_STA) registers are aliased to the
same global registers in the audio and modem I/O space. Therefore a read/write to these registers in
either audio or modem I/O space affects the same physical register.
These registers exist in I/O space and reside in the AC ’97 controller. The two channels, Modem in
and Modem out, each have their own set of Bus Mastering registers. The following register
descriptions apply to both channels. The naming prefix convention used is as follows:
MI = Modem in channel
MO = Modem out channel
Intel^® 82801CA ICH3-S Datasheet
437