wm8940gefl-v Wolfson Microelectronics plc, wm8940gefl-v Datasheet - Page 53

• Manufacturer Part Number: wm8940gefl-v
• Description: Mono Codec With Speaker Driver
• Manufacturer: Wolfson Microelectronics plc

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Production Data
Figure 29 DSP/PCM Mode Audio Interface (Mode B, FRAMEP=1)
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 FRAME are outputs. The frequency of BCLK and FRAME in master mode are controlled with
BCLKDIV. These are divided down versions of master clock. This may result in short BCLK pulses
at the end of a frame if there is a non-integer ratio of BCLKs to FRAME clocks.
DACDAT /
R4
Audio interface
control
ADCDAT
BCLK
REGISTER
ADDRESS
LRC
MSB
1
2
1 BCLK
9
8
7
6:5
4:3
3
BIT
Input Word Length (WL)
LEFT CHANNEL
LOUTR
BCP
FRAMEP
WL
FMT
LABEL
n-2 n-1
falling edge can occur anywhere in this area
LSB
n
1
2
0
0
0
10
10
DEFAULT
3
RIGHT CHANNEL
1/fs
LOUTR control
0=normal
1=Input mono channel data output on
both left and right channels
BCLK polarity
0=normal
1=inverted
Frame clock polarity (for RJ, LJ and I
formats)
0=normal
1=inverted
DSP Mode control
1 = Configures interface so that MSB is
available on 1st BCLK rising edge after
FRAME rising edge
0 = Configures interface so that MSB is
available on 2nd BCLK rising edge after
FRAME rising edge
Word length
00 = 16 bits
01 = 20 bits
10 = 24 bits
11 = 32 bits (see note)
Audio interface Data Format Select:
00=Right Justified
01=Left Justified
10=I
11= DSP/PCM mode
n-2 n-1
2
S format
n
DESCRIPTION
PD, Rev 4.2, April 2008
1 BCLK
WM8940
2
S
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