LG -P970 Service Manual page 84

• Additional features
– Headset detect capability (GPIO)
– Digital microphone inputs (four microphone inputs, two clocks, and two supplies for two external
digital microphones). Supplies are the microphone biases referred to in the previous sublist.
Data and clock are multiplexed on the PCM port.
– Pop-noise reduction circuitry for all paths
– Side-tone function for the voice paths
– Data scramble function for I2S data received
– Bass boost functions in one stereo audio RX path
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– Automatic gain control on the microphone paths
• The analog input connected to the analog auxiliary input and the microphones
– Independent gains on UL paths
The modem or the OMAP device Bluetooth, voice, and audio interfaces must use
Note:
– Programmable gain amplifier on audio RX and TX
the same clock provider as the device.
– Wide gain programmable range on the microphone input
Figure 14-4 is an architecture overview of the audio subsystem.
– DTMF tone generator
Figure 14-4. Device Audio Subsystem Architectural overview
Device - Audio
BT
voice
serial
port
PCM
voice
serial
port
Audio
TDM/I2S
serial
port
interface
Figure . Device Audio Subsystem Architectural Overview
14.4.1 Data Paths
After the audio submodule is powered up (by the CODECPDZ bit of the CODEC_MODE register, see
Table 14-19), it has two modes of operation:
• Option 1: Four simultaneous multimedia analog channels (four multimedia digital-to-analog converters
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(DACs) and no modem voice path), and two simultaneous analog-to-digital converters or 4 channels
coming from digital microphones.
• Option 2: A dedicated modem voice path (two multimedia DACs plus the ADC/DAC pair used for the
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Voice
DAC
Voice and Bluetooth paths
Four
ADCs
Digital mixing
volume control
filters
Digital mixing
Two
volume control
ADCs
filters
Audio Rx/Tx and voice Tx
Analog
mixing
Analog
volume
control
Audio and voice mixer and drivers
analog amplifiers for
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3. TECHNICAL BRIEF
Functional Description
Analog
drivers
Programmable
the microphones
Digital
microphones
interface
Input interfaces
audio-004
Only for training and service purposes