wm8903 Wolfson Microelectronics plc, wm8903 Datasheet - Page 78

• Manufacturer Part Number: wm8903
• Description: Ultra Low Power Codec For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

WM8903
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The register bits controlling audio data format and word length are summarised in Table 53.
Table 53 Audio Data Format Control
In Left Justified mode, the MSB is available on the first rising edge of BCLK following a LRCLK
transition. The other bits up to the LSB are then transmitted in order. Depending on word length,
BCLK frequency and sample rate, there may be unused BCLK cycles before each LRCLK transition.
Figure 38 Left Justified Audio Interface (assuming n-bit word length)
R25 (19h)
Audio
Interface 1
REGISTER
ADDRESS
BIT
3:2
1:0
7
4
AIF_BCLK_INV
AIF_LRCLK_INV
AIF_WL [1:0]
AIF_FMT [1:0]
LABEL
DEFAULT
00
10
0
0
BCLK Invert
0 = BCLK not inverted
1 = BCLK inverted
LRC Polarity / DSP Mode A-B
select.
Right, left and I
polarity
0 = Not Inverted
1 = Inverted
DSP Mode – Mode A-B select
0 = MSB is available on 2nd BCLK
rising edge after LRC rising edge
(mode A)
1 = MSB is available on 1st BCLK
rising edge after LRC rising edge
(mode B)
Digital Audio Interface Word Length
00 = 16 bits
01 = 20 bits
10 = 24 bits
11 = 32 bits
Digital Audio Interface Format
00 = Right Justified
01 = Left Justified
10 = I2S
11 = DSP
PP, Rev 3.1, August 2009
DESCRIPTION
2
S modes – LRC
Pre-Production
78