ST18-AU1 STMICROELECTRONICS [STMicroelectronics], ST18-AU1 Datasheet - Page 31

• Manufacturer Part Number: ST18-AU1
• Description: SIX-CHANNEL DOLBY AC3/MPEG2 AUDIO DECODER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

7
The output serial interface organizes the PCM audio output into the required I
and generates all the DAC control signals.
The PCM output interface can be programmed to meet various data formats and modes of
operation. The following parameters can be configured: word size, clock polarity, WS polarity,
delayed/non-delayed, start/end justified. They are defined by the content of the control register
PCMCR and are described below.
7.1 Output serial interface registers
PCMPRx0-x2 (x = 0, 1, 2): Data in parallel registers
The 9 PCMPR registers are 16-bit PCM parallel registers used for temporary storage of output
data.
Figure 7.1
t
PCMPR00
PCMPR01
PCMPR02
OUTPUT SERIAL INTERFACE - PCM OUTPUT
For 16-bit format, only the PCMPRx0 and PCMPRx1 registers are used
respectively for channel 2 (right) and channel 1 (left).
For formats of greater than 16-bits, the PCMPRx2 registers are used for the
LSB:
PCMPR register example for 18-bit data words
Bit15
channel 2 LSB on bits 7 to 0, left justified.
channel 1 LSB on bits 15 to 8, left justified.
ch2
17
17 16.........
ch1
ch1
1
16.........
0
unused
Bit8
Bit7
ch2
1 0
unused
..... ..2
.....
ch2
ch1
Bit0
2
2
S serial format
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