HP Compaq dc7100 DT Technical Reference Manual page 120

Input/Output Interfaces
Audio Control
The audio subsystem is controlled through a set of indexed registers that physically reside in the
audio codec . The register addresses are decoded by the audio controller and forwarded to the
audio codec over the AC97 Link Bus previously described. The audio codec's control registers
(Table 5-25) are mapped into 64 kilobytes of variable I/O space.
Offset Address or
Register
00h Reset
02h Master Vol.
04h Reserved
06h Mono Mstr. Vol.
08h Reserved
0Ah PC Beep Vol.
0Ch Phone In Vol.
0Eh Mic Vol.
10h Line In Vol.
12h CD Vol.
5-34
Table 5-25.
AC97 Audio Codec Control Registers
Value
On Offset Address or
Reset Register
0100h 14h Video Vol.
8000h 16h Aux Vol.
-- 18h PCM Out Vol.
8000h 1Ah Record Sel.
-- 1Ch Record Gain
8000h 1Eh Reserved
8008h 20h Gen. Purpose
8008h 22h 3D Control
8808h 24h Reserved
8808h 26h Pwr Mgnt.
361834-002
Value
On Offset Address or
Reset Register
8808h 28h Ext. Audio ID.
8808h 2Ah Ext. Audio Ctrl/Sts
8808h 2Ch PCM DAC SRate
0000h 32h PCM ADC SRate
8000h 34h Reserved
-- 72h Reserved
0000h 74h Serial Config.
0000h 76h Misc. Control Bits
-- 7Ch Vender ID1
000xh 7Eh Vender ID2
Technical Reference Guide
Value
On
Reset
0001h
0000h
BB80h
BB80h
--
--
7x0xh
0404h
4144h
5340h