Samsung S5PC110 Manual page 1912

S5PC110_UM
6.4.4 NON-LINEAR PCM ENCODED SOURCE (IEC 61937)
The non-linear PCM encoded audio bit stream is transferred using the basic 16-bit data area of the IEC 60958 sub
frames, that is, in time slots 12 to 27. Each IEC 60958 frame can transfer 32 bits of the non-PCM data in
consumer application mode.
When the SPDIF bit stream conveys linear PCM audio, the symbol frequency is 64 times the PCM sampling
frequency (32 time slots per PCM sample time's two channels). When a non-linear PCM encoded audio bit stream
is transmitted by the interface, the symbol frequency shall be 64 times the sampling rate of the encoded audio
within that bit stream. If a non-linear PCM encoded audio bit stream is transmitted by the interface containing
audio with low sampling frequency, the symbol frequency shall be 128 times the sampling rate of the encoded
audio within that bit stream.
Each data burst contains a burst-preamble consisting of four 16-bit words (Pa, Pb, Pc, Pd), followed by the burst-
payload which contains data of an encoded audio frame.
The burst-preamble consists of four mandatory fields. Pa and Pb represent a synchronization word; Pc gives
information about the type of data and some information/control for the receiver; Pd gives the length of the burst-
payload, limited to 216(=65,535) bits.
The four preamble words are contained in two sequential SPDIF frames. The frame beginning the data-burst
contains preamble word Pa in subframe 1 and Pb in subframe 2. The next frame contains Pc in subframe 1 and
Pd in subframe 2. When placed into a SPDIF subframe, the MSB of a 16-bit burst-preamble is placed into time
slot 27 and the LSB is placed into time slot 12.
Data-burst
Pa Pb
Preamble word
Pa
Pb
Pc
Pd
Stuffing Data-burst
Pc Pd Burst-payload
Repetition period between two data-bursts
Figure 6-5
Table 6-1
Length of field
16 bits
16 bits
16 bits
16 bits
Stuffing Data-burst
Format of Burst Payload
Burst Preamble Words
Contents
Sync word 1
Sync word 2
Burst-info
Length-code
6 SPDIF TRANSMITTER
Stuffing Data-burst
Pa Pb Pc Pd
Value MSB.. LSB
0xF872
0x4E1F
Refer to SPDBSTAS_SHD[15:0]
Refer to SPDBSTAS_SHD[31:16]
...
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