82801BA Datasheet, PDF (402/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

AC’97 Audio Controller Registers (D31:F5)
Table 13-2. ICH2 Audio Mixer Register Configuration (Continued)
Primary Secondary
offset
Offset
NAMBAR Exposed Registers (D31:F5)
2Ch
2Eh
30h
32h
34h
36h
38h
3Ah:56h
58h¹
7Ah¹
7Ch¹
7Eh¹
ACh
AEh
B0h
B2h
B4h
B6h
B8h
BAh–F6h
PCM Front DAC Rate
PCM Surround DAC Rate
PCM LFE DAC Rate
PCM LR ADC Rate
MIC ADC Rate
6Ch Vol: C, LFE Mute
6Ch Vol: L, R Surround Mute
Intel RESERVED
Vendor Reserved
Vendor Reserved
Vendor ID1
Vendor ID2
NOTE:
1. Registers in bold are multiplexed between audio and modem functions
2. Software should not try to access reserved registers
The Bus Master registers are located from offset + 00h to offset + 51h and reside in the AC ‘97
controller. Accesses to these registers do NOT cause the cycle to be forwarded over the AC-link to
the codec.
In the case of the split codec implementation accesses to the 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.
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.
Bus Mastering registers exist in I/O space and reside in the AC ‘97 controller. The three channels
(PCM in, PCM out, and Mic in) each have their own set of Bus Mastering registers. The following
register descriptions apply to all three channels. The register definition section titles use a generic
“x_” in front of the register to indicate that the register applies to all three channels. The naming
prefix convention used in Table 13-3 and in the register description I/O address is as follows:
• PI = PCM in channel
• PO = PCM out channel
• MC = Mic in channel.
13-8
82801BA ICH2 and 82801BAM ICH2-M Datasheet