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AUDIO DATA FORMATS AND TIMING

1/f

S

L−Channel

R−C hannel

LRC K

BC K

(= 48 or 64f

S )

18−Bit Right−Justified

D ATA

DATA

(2) I

2

S D ata Fo rm at: L −C h an n el = L O W , R −Ch an nel = H IG H

(3) L eft−Ju stified D ata Fo rm at: L−C han nel = H IG H , R −C h ann el = L O W

(1) Sta nd ard D ata Fo rm at: L −C h an n el = H IG H , R−C ha nn el = L O W

1/f

S

L−Channel

R−C hannel

LRC K

BC K

(= 32, 48 or 64f

S

)

1

2

3

N−2 N−1

N

1

2

1

2

3

N −2 N −1

N

1/f

S

L−C hannel

R−C hannel

LRC K

BCK

(= 48 or 64f

S

)

2

1

1

2

3

N−2 N−1

N

1

2

3

N−2 N−1

N

14

15

16

16

17

18

18

19

20

14

15

16

1

2

3

DATA

22

23

24

22

23

24

1

2

3

DATA

18

19

20

1

2

3

DATA

16

17

18

1

2

3

DATA

24−Bit Right−Justified

14

15

16

1

2

3

22

23

24

1

2

3

18

19

20

1

2

3

17

18

1

2

20−Bit Right−Justified

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

MSB

14

15

16

14

15

16

1

2

3

DATA

16−Bit Right−Justified, BC K = 32f

S

14

15

16

1

2

3

LSB

MSB

LSB

MSB

16−Bit Right−Justified, BC K = 48f

S

or 64f

S

PCM1742

SBAS176A – DECEMBER 2000 – REVISED APRIL 2005

The PCM1742 supports industry-standard audio data formats, including standard, I

2S, and left-justified, as shown

in Figure 21. Data formats are selected using the format bits, FMT[2:0], in control register 20. The default data

format is 24-bit, left-justified. All formats require binary 2s complement, MSB-first audio data. See Figure 22 for a

detailed timing diagram of the serial audio interface.

Figure 21. Audio Data Input Formats

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