![ST STA309A Скачать руководство пользователя страница 26](http://html1.mh-extra.com/html/st/sta309a/sta309a_operation-manual_1355499026.webp)
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
0
0
0
0
0
0
0
0
Table 18.
SAO bits
Bit
RW
RST
Name
Description
0
RW
0
SAO0
Serial audio output interface format: determines the
interface format of the output serial digital audio
interface.
1
RW
0
SAO1
2
RW
0
SAO2
3
RW
0
SAO3
Table 19.
SAOFB bit
Bit
RW
RST
Name
Description
4
RW
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
2
S data
1111
Left/right-justified 16-bit data
48 * fs
1110
I
2
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