WM8994 Datasheet, PDF (192/359 Pages) Wolfson Microelectronics plc – Multi-Channel Audio Hub CODEC for Smartphones

WM8994
Production Data
Note that the audio interface cannot support every possible combination of input and output sample
rate simultaneously, but only where the ratio of the sample rates matches the available AIF2ADC_DIV
or AIF2DAC_DIV divider settings.
Note that the WM8994 performs sample rate conversion, where necessary, to provide digital mixing
and interconnectivity between the Audio Interfaces and the DSP Core functions. One stereo Sample
Rate Converter (SRC) is provided for audio input; a second stereo SRC is provided for audio output.
Each SRC is automatically configured on AIF1 or AIF2, depending on the selected Clocking and
Sample Rate settings. The WM8994 cannot support configurations that would require SRC on the
input or output paths of both interfaces simultaneously. See “Sample Rate Conversion” for further
details.
REGISTER BIT
ADDRESS
R517
5:3
(0205h)
AIF 2
Clocking
(2)
2:0
R529
7:4
(0211h)
AIF2
Rate
LABEL
DEFAULT
DESCRIPTION
AIF2DAC_DIV
AIF2ADC_DIV
AIF2_SR
000
000
1000
Selects the AIF2 input path sample rate relative
to the AIF2 output path sample rate.
This field should only be changed from default in
modes where the AIF2 input path sample rate is
slower than the AIF2 output path sample rate.
000 = Divide by 1
001 = Divide by 1.5
010 = Divide by 2
011 = Divide by 3
100 = Divide by 4
101 = Divide by 5.5
110 = Divide by 6
111 = Reserved
Selects the AIF2 output path sample rate
relative to the AIF2 input path sample rate.
This field should only be changed from default in
modes where the AIF2 output path sample rate
is slower than the AIF2 input path sample rate.
000 = Divide by 1
001 = Divide by 1.5
010 = Divide by 2
011 = Divide by 3
100 = Divide by 4
101 = Divide by 5.5
110 = Divide by 6
111 = Reserved
Selects the AIF2 Sample Rate (fs)
0000 = 8kHz
0001 = 11.025kHz
0010 = 12kHz
0011 = 16kHz
0100 = 22.05kHz
0101 = 24kHz
0110 = 32kHz
0111 = 44.1kHz
1000 = 48kHz
1001 = 88.2kHz
1010 = 96kHz
All other codes = Reserved
Note that 88.2kHz and 96kHz modes are
supported for AIF2 input (DAC playback) only.
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PD, April 2012, Rev 4.4
192