AK4635 AKM [Asahi Kasei Microsystems], AK4635 Datasheet - Page 33

• Manufacturer Part Number: AK4635
• Description: 16-Bit Mono CODEC with ALC & MIC/SPK/Video-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

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Four types of data formats are available and are selected by setting the DIF1-0 bits.
is MSB first, 2’s complement format. Audio interface formats can be used in both master and slave modes. FCK and
BICK are output from the AK4635 in master mode, but must be input to the AK4635 in slave mode.
In Mode 1-3, the SDTO is clocked out on the falling edge of BICK and the SDTI is latched on the rising edge.
In Mode0 (DSP mode), the audio I/F timing is changed by BCKP and MSBS bits.
When BCKP bit is “0”, SDTO data is output by rising edge of BICK, SDTI data is latched by falling edge of BICK.
When BCKP bit is “1”, SDTO data is output by falling edge of BICK, SDTI data is latched by rising edge of BICK.
MSB data position of SDTO and SDTI can be shifted by MSBS bit. The shifted period is a half of BICK.
If 16-bit data, the output of ADC, is converted to 8-bit data by removing LSB 8-bit, “−1” at 16bit data is converted to “−1”
at 8-bit data. And when the DAC playbacks this 8-bit data, “−1” at 8-bit data will be converted to “−256” at 16-bit data
and this is a large offset. This offset can be removed by adding the offset of “128” to 16-bit data before converting to 8-bit
data.
Rev. 0.6
BICK(32fs)
SDTO(o)
SDTI(i)
BICK(64fs)
SDTO(o)
SDTI(i)
FCK
Audio Interface Format
Mode
0
1
2
3
0
0
DIF1
15:MSB, 0:LSB
15
15 14
15
0
0
1
1
1
1
14
14
2
2
Don’t Care
13
13
13
DIF0
3
3
0
1
0
1
8
MSBS bit
8
7
7
2
I
0
0
1
1
SDTO (ADC)
MSB justified
MSB justified
9
14
Data
2
S compatible
DSP Mode
Table 17. Audio Interface Format in Mode 0
6
6
1
10
15
5
5
0
Table 16. Audio Interface Format
11
16
BCKP bit
15 14
4
4
Figure 29. Mode 1 Timing
12
17
0
1
0
1
3
3
13
18
I
2
2
MSB justified
MSB justified
SDTI (DAC)
2
S compatible
14
DSP Mode
- 33 -
1
1
1
15
31
Audio Interface Format
0
0
0
1/fs
0
0
1
1
Figure 32
Figure 33
Figure 34
Figure 35
2
2
≥ 16fs
≥ 32fs
≥ 32fs
≥ 32fs
BICK
3
3
8
(Table
9
14
Don’t Care
Don’t Care
See
10
15
Figure 29
Figure 30
Figure 31
16) In all modes, the serial data
Figure
Table 17
(default)
11
16
12
17
13
18
14
(default)
15
31
[AK4635]
2007/10
0
0
15
15
15
1
1