alc658 Realtek Semiconductor Corporation, alc658 Datasheet - Page 18

• Manufacturer Part Number: alc658
• Description: Six-channel Ac?97 2.3 Audio Codec
• Manufacturer: Realtek Semiconductor Corporation

6.1.12. MX1E Record Gain for 2
Default: 8000H
Register 1EH controls the record gain. Each step in bits 3:0 corresponds to a 1.5dB increase/decrease in gain for the right channel,
allowing 16 levels of gain, from 0000 to 1111. Each step in bits 11:8 corresponds to a 1.5dB increase/decrease in gain for the left
channel, allowing 16 levels of gain, from 0000 to 1111.
6.1.13. 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.
Note: Bit 7 enables ADC to front DAC loop-back.
Six-Channel AC’97 2.3 Audio Codec
For LRG/RRG:
15:12
11:10
14:12
6:0
Bit
11:8
9
8
7
7:4
3:0
Bit
15
Type
R/W
R/W
Type
R/W
R/W
R/W
R
-
-
-
-
-
0Fh
00h
Function
Reserved. Read as 0
DRSS[1:0], Double Rate Slot Select
00: PCM(n+1) data is on Slots 10/11
01: PCM(n+1) data is on Slots 7/8 (Default)
10, 11: Reserved
Reserved. Read as 0
MIC Select. 0: MIC1
AD to DA Loop-Back Control 0: Disable 1: Enable
Reserved
Function
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
+22.5 dB Gain
0 dB (No Gain)
Table 17. MX1C Record Gain for 2nd Stereo ADC
Table 18. MX20 General Purpose Register
1: MIC2
1: Mute (-∞ dB)
nd
Stereo ADC
14
Datasheet
ALC658
Rev. 1.3