AK4955 Datasheet, PDF (33/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
■ Audio Interface Format
Four types of data formats are available and selected by setting the DIF1-0 bits (Table 17). In all modes, the serial data is
MSB first, 2’s complement format. Audio interface formats are supported in both master and slave modes. LRCK and
BICK are output from the AK4955 in master mode, but must be input to the AK4955 in slave mode. The SDTO is clocked
out on the falling edge (“↓”) of BICK and the SDTI is latched on the rising edge (“↑”) of BICK.
Mode
0
1
2
3
DIF1 bit
0
0
1
1
DIF0 bit
0
1
0
1
SDTO (ADC)
24bit MSB justified
24bit MSB justified
24bit MSB justified
I²S Compatible
SDTI (DAC)
24bit LSB justified
16bit LSB justified
24bit MSB justified
I²S Compatible
Table 17. Audio Interface Format
BICK
≥ 48fs
≥ 32fs
≥ 48fs
=32fs or
≥ 48fs
Figure
Figure 25
Figure 26
Figure 27
(default)
Figure 28
LRCK
01 2
BICK(64fs)
8 9 10
20 21
SDTO(o)
23 22
16 15 14
0
31 0 1 2
8 9 10
20 21
23 22
16 15 14
0
31 0 1
23
SDTI(i)
Don’t Care 23 22
12 11
23:MSB, 0:LSB
Lch Data
1 0 Don’t Care
Figure 25. Mode 0 Timing
23 22
12 11
Rch Data
10
LRCK
0 1 2 3 7 8 9 10 12 13 14 15 0 1 2 3 8 9 10 11 12 13 14 15 0 1
BICK(32fs)
SDTO(o)
23 22 21
15 14 13 12 11 10 9 8 23 22 21
15 14 13 12 11 10 9 8 23
SDTI(i)
15 14 13
7 6 5 4 3 2 1 0 15 14 13
7 6 5 4 3 2 1 0 15
BICK(64fs)
0 1 2 3 15 16 17 18 23 24 30 31 0
12
3 15 16 17 18 23 24 25 30
31 1
SDTO(o)
23 22 21
87 6 5 0
23 22 21
87 6 5 0
23
SDTI(i)
Don’t Care
15 14 13 8 2 1 0 Don’t Care
24bit: 23:MSB, 0:LSB
16bit: 15: MSB, 0:LSB
Lch Data
15 14 13 8 2 1 0
Rch Data
Figure 26. Mode 1 Timing
MS1343-E-00
- 33 -
2011/12