Samsung S5PC110 Manual page 1910

S5PC110_UM
6.4.1.2 Sub-frame Format (IEC 60958)
Each sub-frame is divided into 32 time slot, numbered from 0 to 31. Time slot 0 to 3 carries one of the three
permitted preambles. These are used to affect synchronization of sub-frames, frames and blocks. Time slots 4 to
27 carry the audio sample word in linear 2's complement representation. The most significant bit is carried by time
slot 27. When a 24-bit coding range is used, the least significant bit is in time slot 4. When a 20-bit coding range is
sufficient, the least significant bit is in time slot 8 and time slot 4 to 7 may be used for other application. Under
these circumstances, the bits in the time slot 4 to 7 are designated auxiliary sample bits.
If the source provides fewer bits than the interface allows (24 or 20), the unused least significant bits shall be set
to a logical "0". This procedure supports to connect equipment using different numbers of bits. Time slot 28 carries
the validity flag associated with the audio sample word. This flag is set to logical "0" if the audio sample is reliable.
Time slot 29 carries one bit of the user data associated with the audio channel transmitted in the same sub-frame.
The default value of the user bit is logical "0". Time slot 30 carries one bit of the channel status words associated
with the audio channel transmitted in the same sub-frame. Time slot 31 carries a parity bit such that time slots 4 to
31 inclusive will carry an even number of ones and an even number of zeros.
0
3 4
Sync
S
Preamble
B
7 8
L L
Aux S
B
Figure 6-3
Audio sample word
Validity flag
User data
Channel Status
SPDIF Sub-frame Format
6 SPDIF TRANSMITTER
28
M
S V U C P
B
Parity bit
31
6-4