ASAHI KASEI
[AK4348]
Audio Serial Interface Format
In parallel control mode, the DIF0-1 and TDM0 pins can select eight serial data modes (Table 7). The register value of
DIF0-1 and TDM0bits are ignored. In serial control mode, the DIF0-2 and TDM0-1 bits shown in Table 8 can select 11
serial data modes. The default format is Mode 2 (24-bit MSB justified format in normal mode). The setting of DIF1 pin
is ignored. In all modes the audio data is MSB-first, 2’s complement format and is latched on the rising edge of BICK.
Mode 2 can be used for 16/20-bit MSB justified formats by zeroing the unused LSB’s.
In parallel control mode, when the TDM0 pin = “H”, the audio interface format is TDM256 mode (Table 7). The audio
data of all DACs (eight channels) is input to the SDTI1 pin. The input data to SDTI2-4 pins is ignored. BICK should be
fixed to 256fs. “H” time and “L” time of LRCK should be at least 1/256fs. The audio data is MSB-first, 2’s complement
format. The input data to SDTI1 pin is latched on the rising edge of BICK.
In serial control mode, when the TDM0 bit = “1” and the TDM1 bit = “0”, the audio interface format is TDM256 mode
(Table 8), and the audio data of all DACs (eight channels) is input to the SDTI1 pin. The input data to SDTI2-4 pins is
ignored. BICK should be fixed to 256fs. “H” time and “L” time of LRCK should be at least 1/256fs. The audio data is
MSB-first, 2’s complement format. The input data to SDTI1 pin is latched on the rising edge of BICK. In TDM128 mode
(TDM0 bit = “1” and TDM1 bit = “1”, Table 8), the audio data of DACs (four channels; L1, R1, L2, R2) is input to the
SDTI1 pin. The other four data (L3, R3, L4, R4) is input to the SDTI2 pin. The input data to SDTI3-4 pins is ignored.
BICK should be fixed to 128fs. The audio data is MSB-first, 2’s complement format. The input data to SDTI1-2 pins is
latched on the rising edge of BICK.
Mode
TDM0 DIF1 DIF0 SDTI Format
LRCK BICK Figure
0
1
2
L
L
L
L
L
H
L
H
L
16-bit LSB Justified
20-bit LSB Justified
24-bit MSB Justified
H/L
H/L
H/L
Figure 1
Figure 2
Figure 3
32fs
40fs
48fs
≥
≥
≥
≥
Normal
3
L
H
H
H
H
H
L
H
L
24-bit I2S Compatible
L/H
Figure 4
48fs
N/A
L
H
L
N/A
TDM256
5
6
H
H
24-bit MSB Justified
24-bit I2S Compatible
256fs Figure 5
256fs Figure 6
↑
↓
H
Table 7. Audio Data Formats (Parallel control mode)
Mode
TDM1 TDM0 DIF2 DIF1 DIF0 SDTI Format
LRCK BICK Figure
0
1
2
3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
16-bit LSB Justified
20-bit LSB Justified
24-bit MSB Justified
24-bit I2S Compatible
H/L
H/L
H/L
L/H
Figure 1
Figure 2
Figure 3
Figure 4
32fs
40fs
48fs
48fs
≥
≥
≥
≥
Normal
TDM256
TDM128
4
0
0
0
0
0
0
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
0
0
0
0
1
0
0
0
1
1
0
0
0
1
1
0
0
0
1
0
1
0
0
1
0
1
0
24-bit LSB Justified
N/A
H/L
Figure 2
48fs
≥
N/A
5
6
7
24-bit MSB Justified
24-bit I2S Compatible
24-bit LSB Justified
N/A
256fs Figure 5
256fs Figure 6
256fs Figure 7
↑
↓
↑
N/A
8
9
24-bit MSB Justified
24-bit I2S Compatible
24-bit LSB Justified
128fs Figure 8
128fs Figure 9
128fs Figure 10
↑
↓
↑
10
Table 8. Audio Data Formats (Serial control mode, Default: Mode 2)
MS0532-E-00
2006/07
- 12 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
