22

DS626F2

CS5366

4.5

Serial Audio Interface (SAI) Format

The SAI port consists of two timing pins (SCLK, LRCK/FS) and four audio data output pins (SDOUT1/TDM,

SDOUT2, SDOUT3/TDM and SDOUT4). The CS5366 output is serial data in I²S, Left-Justified (LJ), or Time

Division Multiplexed (TDM) digital audio interface formats. These formats are available to the user in both

Stand-Alone Mode and Control Port Mode.

4.5.1 I²S and LJ Format

The I²S and LJ formats are both two-channel protocols. During one LRCK period, two channels of data are

transmitted, odd channels first, then even. The MSB is always clocked out first.

In Slave Mode, the number of SCLK cycles per channel is fixed as described under “Serial Audio Interface

- I²S/LJ Timing” on page 15. In Slave Mode, if more than 32 SCLK cycles per channel are received from a

master controller, the CS5366 will fill the longer frame with trailing zeros. If fewer than 24 SCLK cycles per

channel are received from a master, the CS5366 will truncate the serial data output to the number of SCLK

cycles received. For a complete overview of serial audio interface formats, please refer to Cirrus Logic Ap-

plication Note AN282.

Figure 10. I²S Format

Figure 11. LJ Format

Odd Channels 1,3, ...

Even Channels 2,4, ...

LRCK

receiver latches data on rising edges of SCLK

SDOUT

SCLK

MSB

...

LSB

MSB

...

LSB

MSB

Odd Channels 1,3, ...

Even Channels 2,4, ...

LRCK

receiver latches data on rising edges of SCLK

MSB

...

LSB

MSB

MSB

...

LSB

SDOUT

SCLK