BU94501AMUV Datasheet, PDF (23/73 Pages) Rohm – AAC/WMA/MP3 +SD Memory Card + iPod

BU9450xAxxx series
Datasheet
8. Digital audio output (SPDIF)
Digital audio interface
Signal Name I/O
Function
SPDIF O SPDIF output
-
Remarks
SPDIF output become enabled by setting it using the appropriate command.
Figure 23. shows the digital audio signal output format.
Source code
Synchronous
preamble
Source code(4-31)
SPDIF output
0
34
Synchronous
preamble
all 0
(B pattern)
11 12
LSB
Audio data(16bit)
(M pattern)
(W pattern)
00000000101101
Synchronous
preamble
27 28 29 30 31
MSB ^{V U C P}
Figure 23. SPDIF Output Format
One sub frame of SPDIF consists of synchronous preambles, 16-bit audio data, V bit (validity flag), U bit
(user data), C bit (channel status) and P bit (parity bit).
Output rate is fixed to 1X speed.
SPDIF outputs synchronous preambles (source code 0-3) as they are, and other elements (source code
4-31) as the biphase output. While the operation stops, L output is enabled.
Synchronous preambles and C bit use 32 frames (≈4.4 ms) for one cycle. The data formats are shown in
Tables.2 and 3 V bit is fixed to L. U bit uses 98 frames (≈13.3 ms) for one cycle
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2012.12.10 Rev.003