
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 18: SPDIF Input
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
18-3
Raw capture mode: Subframe bits [31:0] inclusive are selected and stored. All
“biphase” encoded bits are decoded and a binary representation of the IEC60958
subframe is generated. The entire 32-bit binary number is then stored as one unit
in memory.
Section 3.2 provides detailed information regarding use of all functional modes.
2.3 General Operations
2.3.1
Received Serial Format
2.3.2
Memory Formats
The S/PDIF input block will copy the incoming samples into memory in the order that
they occur in the input bitstream. The input bitstream is parsed and audio samples
are captured and packed as 32-bit words prior to being written to memory. The SPDIF
Input decoder always decodes the bi-phase encoded samples into binary prior to
transfer to memory. Refer to
Figure 4 for the memory formatting for each of the
sample sizes supported by the SPDIF Input module.
16-bit mode: The input samples are packed into 32-bit words consisting of two
16-bit samples per 32-bit word. This mode is compatible with the TM1100 and
PNX2700 Audio Out memory formats.
32-bit mode: For 17 through 24-bit audio, the samples are formatted into 32-bit
words and placed in memory at consecutive 32-bit addresses. For these sample
sizes, the sample is rst combined with a programmable bitmask
Figure 2:
Serial Format of an IEC60958 Block
channel 1
M
channel 2
W
channel 1
B
channel 2
W
channel 1
M
channel 2
W
Start of block (indicated by unique B pre-amble)
sub-frame
frame 0
frame 1
channel 1
M
frame 191
0
31
28
24
20
16
12
8
4
Sample data
L
S
B
M
S
B
B, W or M
pre-amble
Aux.
VU C P
Validity flag
User data
Channel status
Parity bit
sub-frame (2 channel PCM)
0
31
28
24
20
16
12
8
4
16 bits data
L
S
B
M
S
B
B, W or M
pre-amble
VU C P
Validity flag
User data
Channel status
Parity bit
sub-frame (non-PCM audio)
unused (0)