alc250-lf Realtek Semiconductor Corporation, alc250-lf Datasheet - Page 17

• Manufacturer Part Number: alc250-lf
• Description: Two-channel Ac?97 2.3 Audio Codec With Equalizer
• Manufacturer: Realtek Semiconductor Corporation

6.1.14 MX1E Record Gain for MIC ADC
Default: 8000h
Register 1Eh controls the record gain. Each step in bits 3:0 correspond to 1.5dB in increase/decrease in gain for the right channel,
allowing 16 levels of gain, from 0000 to 1111. Each step in bits 11:8 correspond to 1.5dB in increase/decrease in gain for the left
channel, allowing 16 levels of gain, from 0000 to 1111.
6.1.15 MX20 General Purpose Register
Default: 0000h
This register is used to control several functions. Bit 13 enables or disables 3D control. Bit 9 allows selection of mono output. Bit
8 controls the MIC selector. Bit 7 enables loopback of the AD output to the DA input without involving the AC-Link, allowing
for full system performance measurements.
6.1.16 MX22 3D Control
Default: 0000h
This register is used to control the 3D stereo enhancement function built into the AC’97 component. The register bits, DP2-DP0
are used to control the separation ratios in the analog 3D and digital 3D for both LINE_OUT and HP_OUT.
The 3D stereo function provides for a deeper and wider sound experience. Note that the 3D bit in the MX20.[13] must be set to
1 to enable this function.
Two-Channel AC’97 2.3 Audio Codec
14:12
15:14
11:8
12:9
15:3
Bit
7:4
3:0
Bit
6:0
Bit
2:0
15
13
8
7
3D effect control
For LRG/RRG:
Type
Type
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Mute Control 0: Normal
Reserved
Left Record Gain Select (LMRG[3:0]) in 1.5 dB steps
Reserved
Right Record Gain Select (RMRG[3:0]) in 1.5 dB steps
Reserved, Read as 0
3D Control 1: On
Reserved, Read as 0
MIC Select 0: MIC 1 1: MIC 2
AD to DA Loop-back Control 0: Disable 1: Enable
Reserved
Reserved, Read as 0
Depth Control (DP[2:0])
0Fh
00h
DP[2:0]
000
001
010
011
0: Off
+22.5dB
0 dB (No Gain)
Function
1: Mute (-∞ dB)
0% (off)
12.5%
25%
37.5
12
DP[2:0]
100
101
110
111
Function
Function
Function
Function
67.5%
100%
50%
75%
ALC250 DataSheet
Rev1.3