WM8945
Production Data
AUDIO DATA FORMATS
Three basic audio data formats are supported:
Left justified
I2S
DSP mode
All four of these modes are MSB first. They are described in Audio Data Formats, below. Refer to the
Electrical Characteristic section for timing information.
PCM operation is supported using the DSP mode.
The WM8945 is a mono device. By default, the WM8945 transmits ADCs data on the Left channel
only of the Digital Audio Interface, and receives DAC data on the Left channel. The ADC transmit
configuration can be set using the ADCR_SRC and ADCL_SRC bits; the DAC receive channel can
be selected using the DACL_SRC bit. Digital inversion of the ADC and DAC data is also possible.
The register bits controlling audio data format and channel configuration are described in Table 44.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R4 (04h)
ADCR_SRC
Right Digital Audio interface source
9
1
Audio
Interface
0 = Left ADC data is output on right
channel
1 = No data is output on right
channel
ADCL_SRC
DACL_SRC
Left Digital Audio interface source
8
6
0
0
0 = Left ADC data is output on left
channel
1 = No data is output on left channel
Left DAC Data Source Select
0 = Left DAC outputs left interface
data
1 = Left DAC outputs right interface
data
BCLK_INV
BCLK Invert
5
4
0
0
0 = BCLK not inverted
1 = BCLK inverted
LRCLK_INV
LRCLK Polarity / DSP Mode A-B
select.
Right, left and I2S modes – LRCLK
polarity
0 = Not Inverted
1 = Inverted
DSP Mode – Mode A-B select
0 = MSB is available on 2nd BCLK
rising edge after LRCLK rising edge
(mode A)
1 = MSB is available on 1st BCLK
rising edge after LRCLK rising edge
(mode B)
WL [1:0]
Digital Audio Interface Word Length
00 = 16 bits
3:2
10
01 = 20 bits
10 = 24 bits
11 = 32 bits
Note – see “Companding” for the
selection of 8-bit mode.
PD, May 2011, Rev 4.1
66
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
