ADSP-21368 SHARC Processor Hardware Reference 9-21
S/PDIF Transmitter/Receiver
can be detected by adding the sync detection logic in software by
using a software counter to check for the DTS header every 2048
and 4096 frames respectively.
Emphasized Audio Data
The receiver must indicate to the program whether the received audio data
is emphasized using the channel status bits as detailed below.
• In professional mode, (bit 0 of byte 0 = 1), channel status bits 2–4
of byte 0 indicate the audio data is emphasized if they are equal to
110 or 111.
• In consumer mode, (bit 0 of byte 0 = 0), channel status bits 3–5
indicate the audio data is emphasized if they are equal to 100, 010
or 110.
If emphasis is indicated in the channel status bits, the receiver asserts the
EMPHASIS bit flag. This bit flag is used to generate an interrupt as shown in
“Error Handling” on page 9-22.
Single-Channel, Double-Sampling Frequency
Mode
Single-channel, double-frequency mode (SCDF) is selected with the
DIR_SCDF and DIR_SCDF_LR bits in the DIRCTL register. The DIR_B0CHANL/R
bits in the
DIRSTAT register also contain information about the SCDF
mode. When the DIR_B0CHANL/R indicates single-channel, double-fre-
quency mode, the two subframes of a frame carry successive audio samples
of the same signal.
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