WM8281 Datasheet, PDF (65/392 Pages) Cirrus Logic – Low Power Audio System with Ambient Noise Cancellation and Echo Cancellation

Rev 4.0
WM8281
The ASRC, ISRC, and DSP Aux Input functions support selectable input sources, but do not
incorporate any digital mixing. The respective input source (*_SRCn) registers are identical to those of
the digital mixers.
The *_SRCn registers select the input source(s) for the respective mixer or signal processing block.
Note that the selected input source(s) must be configured for the same sample rate as the block(s) to
which they are connected. Sample rate conversion functions are available to support flexible
interconnectivity - see “Asynchronous Sample Rate Converter (ASRC)” and “Isochronous Sample
Rate Converter (ISRC)”.
A status bit associated with each of the configurable input sources provides readback for the
respective signal path. If an Underclocked Error condition occurs, then these bits provide readback of
which signal path(s) have been successfully enabled.
The generic register definition for the digital mixers is provided in Table 8.
REGISTER BIT
ADDRESS
LABEL
R1600
(0640h)
15 *_STSn
to
R3000
(0BB8h)
Valid for every
digital core
function input
(digital mixers,
DSP Aux inputs,
ASRC & ISRC
inputs).
7:1 *_VOLn
Valid for every
digital mixer input.
7:0 *_SRCn
Valid for every
digital core
function input
(digital mixers,
DSP Aux inputs,
ASRC & ISRC
inputs).
DEFAULT
DESCRIPTION
0
[Digital Core function] input n status
0 = Disabled
1 = Enabled
40h
[Digital Core mixer] input n volume
-32dB to +16dB in 1dB steps
00h to 20h = -32dB
21h = -31dB
22h = -30dB
... (1dB steps)
40h = 0dB
... (1dB steps)
50h = +16dB
51h to 7Fh = +16dB
00h
[Digital Core function] input n source
select
00h = Silence (mute)
04h = Tone generator 1
05h = Tone generator 2
06h = Haptic generator
08h = AEC loopback
0Ch = Mic Mute Mixer
0Dh = Noise generator
10h = IN1L signal path
11h = IN1R signal path
12h = IN2L signal path
13h = IN2R signal path
14h = IN3L signal path
15h = IN3R signal path
16h = IN4L signal path
17h = IN4R signal path
20h = AIF1 RX1
21h = AIF1 RX2
22h = AIF1 RX3
23h = AIF1 RX4
24h = AIF1 RX5
25h = AIF1 RX6
26h = AIF1 RX7
27h = AIF1 RX8
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