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SERIAL AUDIO DATA INTERFACE

INTERFACE MODE

DATA FORMAT

PCM1807

SLES147 – SEPTEMBER 2005

The PCM1807 interfaces the audio system through LRCK (pin 7), BCK (pin 8), and DOUT (pin 9).

The PCM1807 supports master mode and slave mode as interface modes, which are selected by MD1 and MD0.

MD1 and MD0 are controlled through the serial control port as shown in Table 2.

In master mode, the PCM1807 provides the timing of serial audio data communications between the PCM1807

and the digital audio processor or external circuit. While in slave mode, the PCM1807 receives the timing for data

transfer from an external controller.

Table 2. Interface Modes

MD1

MD0

INTERFACE MODE

0

0

Slave mode (256 fS, 384 fS, 512 fS autodetection) (default)

0

1

Master mode (512 fS)

1

0

Master mode (384 fS)

1

1

Master mode (256 fS)

Master mode

In master mode, BCK and LRCK work as output pins, and these pins are controlled by timing which is generated

in the clock circuit of the PCM1807. The frequency of BCK is fixed at 64 BCK/frame.

Slave mode

In slave mode, BCK and LRCK work as input pins. The PCM1807 accepts 64 BCK/frame or 48 BCK/frame

format (only for a 384 fS system clock), not 32 BCK/frame format.

The PCM1807 supports two audio data formats in both master and slave modes. The data formats are selected

by FMT, which is controlled through the serial control port as shown in Table 3. Figure 21 illustrates the data

formats in slave mode and master mode.

Table 3. Data Format

FORMAT NO.

FMT

FORMAT

0

0

I2S, 24-bit (default)

1

1

Left-justified, 24-bit

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