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FLT: Digital Filter Rolloff Control

FMT[2:0]: Audio Interface Data Format

SRST: Reset

ZREV: Zero-Flag Polarity Select

PCM1680

SLES133 – MARCH 2005

B15

B14

B13

B12

B11

B10

B9

B8

B7

B6

B5

B4

B3

B2

B1

B0

REGISTER 9

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

RSV

RSV

FLT

RSV

RSV

FMT2

FMT1

FMT0

Default value: 0

FLT = 0

Sharp rolloff (default)

FLT = 1

Slow rolloff

The FLT bit allows users to select the digital filter rolloff that is best suited to their application. Two filter rolloff

selections are available: sharp or slow. The filter responses for these selections are shown in the Typical

Performance Curves section of this data sheet.

Default value: 101b

FMT[2:0]

Audio Data Format Selection

000

24-bit right-justified format, standard data

001

20-bit right-justified format, standard data

010

18-bit right-justified format, standard data

011

16-bit right-justified format, standard data

100

101

Left-justified format, 16- to 24-bit (default)

110

Reserved

111

Reserved

The FMT[2:0] bits are used to select the data format for the serial audio interface.

B15

B14

B13

B12

B11

B10

B9

B8

B7

B6

B5

B4

B3

B2

B1

B0

REGISTER 10

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

SRST

ZREV

DREV

DMF1

DMF0

RSV

RSV

DMC

Default value: 0

SRST = 0

Reset disabled (default)

SRST = 1

Reset enabled

The SRST bit is used to enable or disable the soft reset function. The operation is the same as the

power-on-reset function with the exception of the reset period, which is 1024 system clocks for the SRST

function. All registers are initialized.

Default value: 0

ZREV = 0

Zero-flag pins high at a zero detect (default)

ZREV = 1

Zero-flag pins low at a zero detect

The ZREV bit allows the user to select the polarity of the zero-flag pins.

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