WM8985_07 WOLFSON [Wolfson Microelectronics plc], WM8985_07 Datasheet - Page 77

• Manufacturer Part Number: WM8985_07
• Description: Multimedia CODEC With Class D Headphone and Line Out
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Pre-Production
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Table 43 Audio Interface Control
Note: Right Justified Mode will only operate with a maximum of 24 bits. If 32-bit mode is selected the
device will operate in 24-bit mode.
AUDIO INTERFACE CONTROL
The register bits controlling audio format, word length and master / slave mode are summarised
below.
Register bit MS selects audio interface operation in master or slave mode. In Master mode BCLK,
and LRC are outputs. The frequency of BCLK in master mode can be controlled with BCLKDIV. The
frequencies of BCLK and LRC are also controlled by MCLKDIV. The LRC sample rate is set to the
required values by MCLKDIV and the BCLK rate will be set accordingly to provide sufficient BCLKs
for that chosen sample rate. These clocks are divided down versions of master clock.
R4 (04h)
Audio
Interface
Control
R5
REGISTER
ADDRESS
0
1
2
4:3
6:5
7
8
0
BIT
MONO
ALRSWAP
DLRSWAP
FMT
WL
LRP
BCP
LOOPBACK
LABEL
0
0
0
10
10
0
0
0
DEFAULT
Selects between stereo and mono
device operation:
0 = Stereo device operation
1 = Mono device operation. Data
appears in ‘left’ phase of LRC only.
Controls whether ADC data appears in
‘right’ or ‘left’ phases of LRC clock:
0 = ADC left data appear in ‘left’ phase
of LRC and right data in 'right' phase
1 = ADC left data appear in ‘right’ phase
of LRC and right data in 'left' phase
Controls whether DAC data appears in
‘right’ or ‘left’ phases of LRC clock:
0 = DAC left data appear in ‘left’ phase
of LRC and right data in 'right' phase
1 = DAC left data appear in ‘right’ phase
of LRC and right data in 'left' phase
Audio interface Data Format Select:
00 = Right Justified
01 = Left Justified
10 = I
11 = DSP/PCM mode
Word length
00 = 16 bits
01 = 20 bits
10 = 24 bits
11 = 32 bits (see note)
LRC clock polarity
0 = normal
1 =inverted
DSP Mode – mode A/B select
0 = MSB is available on 2
edge after LRC rising edge (mode A)
1 = MSB is available on 1
edge after LRC rising edge (mode B)
BCLK polarity
0 = normal
1 = inverted
Digital loopback function
0 = No loopback
1 = Loopback enabled, ADC data output
is fed directly into DAC data input.
2
S format
DESCRIPTION
PP, Rev 3.5, January 2007
nd
st
BCLK rising
BCLK rising
WM8985
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