Datasheet

SRC4392

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SBFS029D –DECEMBER 2005–REVISED DECEMBER 2012

Bit 7 (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 (LSB)

0 0 AUTODEM DEM1 DEM0 DDN IGRP1 IGRP0

IGRP[1:0] SRC Interpolation Filter Group Delay

These bits select the interpolation filter group delay by configuring the number of samples which

are pre-buffered prior to the re-sampler function.

IGRP1 IGRP0 Number of Samples Pre-Buffered

0 0 64 Samples (Default)

0 1 32 Samples

1 0 16 Samples

1 1 8 Samples

DDN SRC Decimation Filter/Direct Down-Sampling Function

This bit selects the mode of the decimation function, either true decimation filter or direct down-

sampling without filtering.

DDN Decimation Function

0 Decimation Filter (Default)

1 Direct Down Sampling

Note: Direct down-sampling should only be used when the output sampling rate is higher than

the input sampling rate. When the output sampling rate is equal to or lower than the input

sampling rate, the Decimation Filter must be used in order to avoid aliasing.

DEM[1:0] Digital De-Emphasis Filter, Manual Configuration

These bits are utilized to enable or disable the digital de-emphasis filter manually. The de-

emphasis filter is intended to process 50/15μs pre-emphasized audio material at the following

input sampling rates:

DEM1 DEM0 De-Emphasis Filter Function

0 0 De-Emphasis Disabled (Default)

0 1 De-Emphasis Enabled for f

= 48kHz

1 0 De-Emphasis Enabled for f

= 44.1kHz

1 1 De-Emphasis Enabled for f

= 32kHz

Note: When the AUTODEM bit is set to 1, the setting of the DEM0 and DEM1 bits are ignored.

AUTODEM Automatic De-Emphasis Configuration

This bit enables or disables the automatic de-emphasis function, which monitors the channel

status bits from the DIR function block and determines whether de-emphasis is enabled and for

which sampling frequency. This function is valid for only 50/15μs pre-emphasized data and one

of the three supported sampling rates (32kHz, 44.1kHz, or 48kHz).

AUTODEM Automatic De-Emphasis Function

0 Disabled (Default)

1 Enabled

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