stac9723t ETC-unknow, stac9723t Datasheet - Page 23

• Manufacturer Part Number: stac9723t
• Description: Stereo Ac 97 Codec With Multi-codec Option
• Manufacturer: ETC-unknow

SigmaTel, Inc.
4.4.4 Analog Mixer Input Gain Registers (Index 0Ch - 18h)
4.4.5
04/07/00
These registers control the gain/attenuation for each of the analog inputs. Each step
corresponds to approximately 1.5 dB. The MSB of the register is the mute bit. When
this bit is set to 1 the level for that channel is set at -∞ dB. Register 0Eh (Mic Volume
Register) has an extra bit that is for a 20dB boost. When bit D6 is set to 1, the +20 dB
boost is on. The default value is 8008, which corresponds to 0 dB gain, bost off, and
mute on. The default value for the mono registers is 8008h, which is to 0dB gain with
mute on. The default value for stereo registers is 8808h, which is 0 dB gain with mute
on.
Used to select the record source independently for right and left. The default value is
0000h, which corresponds to MIC in.
Record Select Control Register (Index 1Ah
Table 12
Table 10
SR2…SR0
SL2…SL0
Table 11
Mute
0
0
0
1
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
. Left Record Select Control Registers
. Analog Mixer Input Gain Register
. Record Select Control Registers
Data Sheet
Gx4…Gx0
00000
01000
11111
xxxxx
Right Record Source
Left Record Source
23
Stereo Mix (right)
Video In (right)
Stereo Mix (L)
Line In (right)
CD In (right)
Aux In (right)
Video In (L)
Line In (L)
Mono Mix
Aux In (L)
Mono Mix
CD In (L)
Phone
Phone
MIC
MIC
-34.5 dB gain
)
+12 dB gain
-∞ dB gain
Function
0 dB gain
STAC9721
04/07/00