WM9713 Datasheet, PDF (46/111 Pages) Wolfson Microelectronics plc – AC 97 AUDIO + TOUCHPANEL CODEC

WM9713L
MONOIN INPUT
PCBEEP INPUT
Preliminary Technical Data
Pin 20 (MONOIN) is a mono input designed to connect to the receive path of a telephony device.The
pin connects directly to the record selector for phone call recording (Note: to record both sides of a
phone call, one ADC channel should record the MONOIN signal while the other channel records the
MIC signal). The record PGA adjusts the recording volume, and is controlled by register 12h or by
the ALC function (see “Record Gain” and “Automatic Level Control” sections).
REGISTER
ADDRESS
14h
Record
Routing
BIT
15:14
13:11
LABEL
R2H
R2HVOL
DEFAULT
11 (mute)
010 (0dB)
10:9 R2M
11 (mute)
8
R2MBST 0 (OFF)
Table 27 Record PGA Routing Control
DESCRIPTION
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
… (3dB steps)
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
To listen to the MONOIN signal, the signal passes through a separate PGA, controlled by register
08h. The signal can be routed into the headphone mixer (for normal phone call operation) and/or the
speaker mixer (for speakerphone operation), but not into the mono mixer (to prevent forming a
feedback loop). When the signal is not selected as an input to any of the mixers the output of the
PGA is muted automatically.
When not in use the MONOIN PGA can be powered down using the Powerdown register bit MOIN
(register 3Eh, bit 4).
MONOIN is biased internally to the reference voltage VREF. Whenever the input is muted or the
device placed into standby mode, the input remains biased to VREF using special anti-thump
circuitry to suppress any audible clicks when changing inputs.
REGISTER
ADDRESS
08h
MONOIN
PGA Vol /
Routing
BIT
15
14
12:8
LABEL
M2H
M2S
MONOIN
VOL
Table 28 Mono PGA Control
DEFAULT
DESCRIPTION
1
1
01000
(0dB)
Mute MONIN path to headphone mixer
1: Mute, 0: No mute (ON)
Mute MONOIN path to speaker mixer
1: Mute, 0: No mute (ON)
MONOIN input gain
00000: +12dB
… (1.5dB steps)
11111: -34.5dB
Pin 19 (PCBEEP) is a mono, line level input intended for externally generated signal or warning
tones. It is routed directly to the record selector and all three output mixers, without an input
amplifier. The signal gain into each mixer can be independently controlled, with a separate mute bit
for each signal path.
1
PTD, March 2004, Rev 2.2
46