Datasheet

www.ti.com
AUDIO DATA FORMATS AND TIMING
1/f
S
L−Channel
R−Channel
LRCK
BCK
(= 48 or 64f
S
)
18−Bit Right−Justified
DATA
DATA
(2) I
2
S Data Form at: L−Channel = LOW, R−Channel = HIGH
(3) Left−Justified Data Format: L−Channel = HIGH, R−Channel = LOW
(1) Standard Data Format: L−Channel = HIGH, R−Cha nnel = LO W
1/f
S
L−Channel
R−Channel
LRCK
BCK
(= 32, 48 or 64f
S
)
1 2 3 N−2 N−1 N 1 2 1 23 N−2 N−1 N
1/f
S
L−Channel
R−Channel
LRCK
BCK
(= 48 or 64f
S
)
211 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 15 161 2 3DATA
22 23 24 22 23 241 2 3
DATA
18 19 201 2 3DATA
16 17 181 2 3
DATA
24−Bit Right−Justified
14 15 161 2 3
22 23 241 2 3
18 19 201 2 3
17 181 2
20−Bit Right−Justified
LSBMSB LSBMSB
LSBMSB
LSBMSBLSBMSB
LSBMSB LSBMSB
LSBMSB
LSBMSB
LSBMSB
LSBMSB
LSBMSB
14 15 16 14 15 161 2 3
DATA
16−Bit Right−Justified, BCK = 32f
S
14 15 161 2 3
LSBMSB LSBMSB
16−Bit Right−Justified, BCK = 48f
S
or 64f
S
PCM1742
SBAS176A – DECEMBER 2000 – REVISED APRIL 2005
The PCM1742 supports industry-standard audio data formats, including standard, I
2
S, 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
13