AK4635 datasheet(33/81 Pages) AKM

33 / 81 page

[AK4635]

Rev. 0.6

2007/10

- 33 -

■ Audio Interface Format

Four types of data formats are available and are selected by setting the DIF1-0 bits. (Table 16) In all modes, the serial data

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.

Mode

DIF1

DIF0

SDTO (ADC)

SDTI (DAC)

BICK

Figure

DSP Mode

≥ 16fs

See Table 17

MSB justified

≥ 32fs

Figure 29

MSB justified

≥ 32fs

Figure 30

(default)

I2S compatible

≥ 32fs

Figure 31

Table 16. Audio Interface Format

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.

MSBS bit

BCKP bit

Audio Interface Format

Figure 32

(default)

Figure 33

Figure 34

Figure 35

Table 17. Audio Interface Format in Mode 0

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.

FCK

BICK(32fs)

SDTO(o)

BICK(64fs)

SDTO(o)

SDTI(i)

15:MSB, 0:LSB

Data

1/fs

Don’t Care

15 14

SDTI(i)

Don’t Care

Figure 29. Mode 1 Timing

AK4635 Datasheet(PDF) 33 Page - Asahi Kasei Microsystems

AK4635 Datasheet(HTML) 33 Page - Asahi Kasei Microsystems

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81

Datasheet Download

Link URL