WM9713L_06 WOLFSON [Wolfson Microelectronics plc], WM9713L_06 Datasheet - Page 28

• Manufacturer Part Number: WM9713L_06
• Description: AC 97 Audio + Touchpanel CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9713L
RECORD GAIN
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The amplitude of the signal that enters the audio ADC is controlled by the Record PGA
(Programmable Gain Amplifier). The PGA gain can be programmed either by writing to the Record
Gain register, or by the Automatic Level Control (ALC) circuit (see next section). When the ALC is
enabled, any writes to the Record Gain register have no effect.
Two different gain ranges can be implemented: the standard gain range defined in the AC’97
standard, or an extended gain range with smaller gain steps. The ALC circuit always uses the
extended gain range, as this has been found to result in better sound quality.
Table 12 Record Gain Register
The output of the Record PGA can also be mixed into the phone and/or headphone outputs (see
“Audio Mixers”). This makes it possible to use the ALC function for the microphone signal in a
smartphone application.
Table 13 Record PGA Routing Control
12h
Record Gain
14h
Record
Routing
REGISTER
REGISTER
ADDRESS
ADDRESS
15
14
13:8
7
6
5:0
15:14
13:11
10:9
8
BIT
BIT
RMU
GRL
RECVOLL
ZC
GRR
RECVOLR
R2H
R2HVOL
R2M
R2MBST
LABEL
LABEL
1
0
000000
0
0
000000
11 (mute)
010 (0dB)
11 (mute)
0 (OFF)
DEFAULT
DEFAULT
Mute Audio ADC (both channels)
1: Mute (OFF)
0: No Mute (ON)
Gain range select (left)
0: Standard (0 to 22.5dB, 1.5dB step size)
1: Extended (-17.25 to +30dB, 0.75dB steps)
Record Volume (left)
Standard (GRL=0)
XX0000: 0dB
XX0001: +1.5dB
… (1.5dB steps)
XX1111: +22.5dB
Zero Cross Enable
0: Record Gain changes immediately
1: Record Gain changes when signal is zero
or after time-out
Gain range select (right)
Similar to GRL
Record Volume (right)
Similar to RECVOLR
Controls record mux to headphone mixer
paths. 00=stereo, 01=left rec mux only,
10=right rec mux only, 11=mute left and
right
Controls gain of record mux l/r to headphone
mixer paths.
000: +6dB
001: +3dB
... (3dBsteps)
111: -15dB
Controls record mux to mono mixer path.
00=stereo, 01=left rec mux only, 10=right
rec mux only, 11=mute left and right
Enables 20dB gain boost for record mux to
mono mixer path
DESCRIPTION
DESCRIPTION
Extended (GRL=1)
000000: -17.25dB
000001: -16.5dB
… (0.75dB steps)
111111: +30dB
PP Rev 3.0 June 2006
Pre-Production
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