User`s guide

Firmware Configuration
6-48 AT85C51SND3Bx Firmware User’s Guide
7691A–MP3–08/07
Table 6-6. Audio output settings
Table 6-7. Audio input settings
Definition Label Description Values
AUDIO_OUT_TYPE Internal (on-chip) or external
audio DAC
INTERNAL_DAC
[EXTERNAL_DAC]
AUDIO_OUT_DRIVE Impedance drive of the
internal audio DAC:
- high impedance (50kΩ)
- low impedance (32Ω)
LINE_OUT_DRIVE (50kΩ)
[INTERNAL_HEADSET_DRIVE] (32Ω)
EXTERNAL_HEADSET_DRIVE (50kΩ)
AUDIO_EXT_HEAD_AMP_ON Output enabling the switch
on/off of the external
headphone amplifier
[P1_6]
I/O pins mnemonics are defined in
mcu.h file (See Section 3.1.5).
EXT_DAC_OVERSAMP External audio DAC
oversampling ratio
OVERSAMP_128X
[OVERSAMP_256X]
OVERSAMP_348X
EXT_DAC_IF_TYPE Interface type of the external
audio DAC
[DAC_IF_I2S]
DAC_IF_PCM
EXT_DAC_NB_BITS Bit number of the external
audio DAC
From [16] up to 32
Definition Label Description Values
MIC_BIAS_CTRL Microphone output bias
voltage: 1.5V or 2.0V.
Related to the power level
voltage or forced
NO_MIC_BIAS (no microphone)
[POWER_SELECTED_BIAS] (related)
V2_0_BIAS (forced)
V1_5_BIAS (forced)
AUDIO_IN_MIC_GAIN Microphone input analog
amplifier gain
AUP_INPUT_GAIN_0DB
AUP_INPUT_GAIN_6DB
AUP_INPUT_GAIN_12DB
AUP_INPUT_GAIN_18DB
[AUP_INPUT_GAIN_24DB]
AUDIO_IN_MIC_DIGITAL_GAI
N
Microphone input digital
amplifier gain
AUP_INPUT_GAIN_DIG_1
AUP_INPUT_GAIN_DIG_2
AUP_INPUT_GAIN_DIG_4
AUP_INPUT_GAIN_DIG_8
AUP_INPUT_GAIN_DIG_12
AUP_INPUT_GAIN_DIG_16
AUP_INPUT_GAIN_DIG_20
AUP_INPUT_GAIN_DIG_24
AUDIO_IN_LINE_GAIN Input line analog amplifier
gain
AUP_INPUT_GAIN_0DB
AUP_INPUT_GAIN_6DB
[AUP_INPUT_GAIN_12DB]
AUP_INPUT_GAIN_18DB
AUP_INPUT_GAIN_24DB
AUDIO_IN_LINE_DIGITAL_GA
IN
Input line digital amplifier
gain
AUP_INPUT_GAIN_DIG_1
AUP_INPUT_GAIN_DIG_2
AUP_INPUT_GAIN_DIG_4
AUP_INPUT_GAIN_DIG_8
AUP_INPUT_GAIN_DIG_12
AUP_INPUT_GAIN_DIG_16
AUP_INPUT_GAIN_DIG_20
AUP_INPUT_GAIN_DIG_24
AUDIO_LINE_BACK_GAIN Input line preamplifier gain [AUP_INPUT_GAIN_6DB]
AUP_INPUT_GAIN_12DB