YMF744B Datasheet, PDF (48/60 Pages) List of Unclassifed Manufacturers – DS-1S

YMF744B
6. Digital Audio Interface
DS-1S supports each system of the SPDIF input/output port compliant with the IEC958 specification.
6-1. SPDIF IN
DS-1S provides the SPDIF input capability by switch-over operation of the zoomed video port. SPDIF
input sampling frequency is 32.0kHz, 44.1kHz or 48.0kHz.
In DS-1S, sampling rate of the SPDIF signal incoming from the SPDIFIN pin is converted to 48.0kHz in the
frequency rate conversion stage in order to process all the signals at 48.0kHz frequency. If input sampling
frequency is 48.0kHz, however, this is resampled at 96.0kHz, then decimated into 48.0kHz frequency. The
input signal applied to the SPDIFIN pin can be also provided as outputs to the SPDIFOUT pin.
6-2. SPDIF OUT
SPDIF output is selected from three types of data indicated below:
A : Dolby digital (AC-3) encoded data
B : Output data (to be provided to the DAC slot on the AC-link) after digital mixing
C : Input data applied to the SPDIFIN pin
When the above A and B data are supplied as outputs, output sampling frequency is fixed at 48 kHz, and
when the above C data is supplied as an output, output sampling frequency is dependent on the frequency
available from the SPDIFIN input pin.
Control and category codes of the channel status are provided as sampling rate converter, copyright
protection available and commercially available recorded software in accordance with the serial copy
management system. Such a code arrangement allows output data to be digitally copied only to the next
generation ones. When input signal to the SPDIFIN pin is provided as output, no modification is made for
the channel status, etc., and output data is code-dependent available from the SPDIFIN pin.
February 3, 1999
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