Datasheet

Registers STA309A

26/67 Doc ID 13855 Rev 4

7.2.3 Configuration register C (0x02) - serial output formats

The STA309A features a serial audio output interface that consists of 8 channels. The serial

audio output always acts as a slave to the serial audio input interface and, therefore, all

output clocks are synchronous with the input clocks. The output sample frequency (fs) is

also equivalent to the input sample frequency. In the case of SACD/DSD input, the serial

audio output acts as a master with an output sampling frequency of 176.4 kHz. The output

serial format can be selected independently from the input format and is done via the SAO

and SAOFB bits.

D7 D6 D5 D4 D3 D2 D1 D0

Reserved SAOFB SAO3 SAO2 SAIO SAO0

00000000

Table 18. SAO bits

Bit RW RST Name Description

0RW 0 SAO0

Serial audio output interface format: determines the

interface format of the output serial digital audio

interface.

1RW 0 SAO1

2RW 0 SAO2

3RW 0 SAO3

Table 19. SAOFB bit

Bit RW RST Name Description

4RW 0 SAOFB

Determines MSB or LSB first for all SAO formats:

0: MSB first

1: LSB first

Table 20. SAO serial clock

BICKI = BICKO SAO[3:0] Interface data format

32 * fs

0111 I

S data

1111 Left/right-justified 16-bit data

48 * fs

1110 I

S data

0001 Left-justified data

1010 Right-justified 24-bit data

1011 Right-justified 20-bit data

1100 Right-justified 18-bit data

1101 Right-justified 16-bit data