Rainbow Electronics MAX98089 - Manual (Page 89)

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MAX98089
Low-Power, Stereo Audio Codec
with FlexSound Technology
Passband Filtering
Each digital signal path in the IC includes options for
defining the path bandwidth (Figure 19). The playback
and record paths connected to DAI1 support both voice
and music filtering while the playback path connected to
DAI2 supports music filtering only.
The voice IIR filters provide greater than 70dB stopband
attenuation at frequencies above f
S /2 to reduce aliasing.
Three selectable highpass filters eliminate unwanted low-
frequency signals.
Use music mode when processing high-fidelity audio
content. The music FIR filters reduce power consump-
tion and are linear phase to maintain stereo imaging.
An optional DC-blocking filter is available to eliminate
unwanted DC offset.
In music mode, a second set of FIR filters are available to
support sample rates greater than 50kHz. The filters can
be independently selected for DAI1 and DAI2 and sup-
port both the playback and record audio paths.
Table 13. Sample Rate Converter Register
Figure 19. Digital Passband Filtering Block Diagram
DSTS
SIDETONE
DVST:
0dB TO -60dB
AUTOMATIC
GAIN
CONTROL
EQ1EN EQ2EN
DVEQ1:
0dB TO -15dB
DV1G:
0/6/12/18dB
DV2:
0dB TO -15dB
DCB2
5-BAND
PARAMETRIC
EQ
5-BAND
PARAMETRIC
EQ
DVEQ2:
0dB TO -15dB
MULTI BAND ALC
EXCURSION LIMITER
DV1:
0dB TO -15dB
MODE1
DVFLT
DALEN
MIXDAR
DACL
DAREN
DACR
+
NOISE GATE
MODE1
AVFLT
SRMIX_
MODE
AVLG: 0/6/
12/18dB
AVL:0dB
TO -15dB
AVRG: 0/6/
12/18dB
AVR:0dB
TO -15dB
AUDIO/
VOICE
FILTERS
AUDIO/
FILTERS
AUDIO/
VOICE
FILTERS
MIX
MIX
MIXDAL
MIX
ADREN
ADLEN
ADCR
ADCL
SAMPLE RATE
CONVERTER
REGISTER BIT NAME DESCRIPTION
0x21
4 SRMIX_MODE
Sample Rate Mix Mode. Sets mixing configuration applied to the sample rate con-
verted channel(s).
0 = (DAI1 + DAI2)
1 = (DAI1 + DAI2)/2
3 SRMIX_ENL
Sample Rate Mix Enable. If enabled, mixes data on DAI1 and DAI2. If cleared, SCR
data source is DAI2 only.
0 = SRC mix disable
1 = SRC mix enable
2 SRMIX_ENR
1 SRC_ENL
Sample Rate Converter Enable. Select if the SCR is enabled on a per channel
basis.
0 = Sample rate converter disable
1 = Sample rate converter enable
0 SRC_ENR