CS18101X datasheet(19/54 Pages) CIRRUS

19 / 54 page

CobraNet Hardware User’s Manual

Digital Audio Interface

DS651UM23

Version 2.3

6.0 Digital Audio Interface

The CS18101x/CS49611x, CS18102x/CS49612x, and CM-2 support four bi-directional

synchronous serial interfaces. The CS18100x & CS49610x support one bi-directional

synchronous serial interface. All interfaces operate in master mode with DAO1_SCLK as

the bit clock and FS1 as the frame clock. A sample period worth of synchronous serial

data includes two (or four) audio channels. CobraNet supports two synchronous serial bit

rates: 48 Khz and 96 KHz. However, 96 kHz sample rate is not available when using

CS18102x/CS49612x with 16X16 channels. Bit rate is selected by the

modeRateControl

variable. All synchronous serial interfaces operate from a common clock at the same bit

rate.

Figure 4. Channel Structure for Synchronous Serial Audio at 64FS (One Sample Period) - CS18100x/CS49610x &

CS18101x/CS49611x

Figure 5. Channel Structure for Synchronous Serial Audio at 128FS (One Sample Period) - CS18102x/CS49612x

Default channel ordering is shown above. Note that the first channel always begins after

the rising or falling edge of FS1 (depending on the mode).

DAI1_SCLK period depends on the sample rate selected. Up to 32 significant bits are

received and buffered by the DSP for synchronous inputs. Up to 32 significant bits are

transmitted by the DSP for synchronous outputs. Bit 31 is always the most significant

(sign) bit. A 16-bit audio source must drive to bit periods 31-16 with audio data and bits

15-0 should be actively driven with either a dither signal or zeros. Cirrus Logic

recommends driving unused LS bits to zero.

FS 1

D A O 1 _ D A T A 0 / D A I1 _ D A T A 0

*D A O 1 _ D A T A 1 / D A I1 _ D A T A 1

*D A O 1 _ D A T A 2 / D A I1 _ D A T A 2

*D A O 1 _ D A T A 3 / D A I1 _ D A T A 3

* N o t p re s e n t in C S 1 8 1 0 0x or C S 49 610x .

FS1

DAO1_DATA0 / DAI1_DATA0

DAO1_DATA1 / DAI1_DATA1

DAO1_DATA2 / DAI1_DATA2

DAO1_DATA3 / DAI1_DATA3

CS18101X Datasheet(PDF) 19 Page - Cirrus Logic