ADV7180
Table 90. PAL CCAP Data, Half-Byte Mode
Byte
D[9]
D[8]
D[7]
D[6]
D[5]
D[4]
D[3]
D[2]
D[1]
D[0]
Description
0
0
0
0
0
0
1
1
0
1
0
0
1
1
0
0
0
0
1
1
0
1
0
0
1
1
0
0
1
0
0
Fixed preamble
Fixed preamble
Fixed preamble
DID
1
1
1
1
1
1
1
2
1
1
1
1
1
1
3
0
1
0
1
0
0
4
EP
EP
EP
EP
EP
EP
CS[8]
EP
EP
EP
EP
EP
EP
CS[8]
EF
0
0
0
SDID
5
0
0
0
0
Data count
6
0
0
0
0
CCAP word1[7:4]
CCAP word1[3:0]
CCAP word2[7:4]
CCAP word2[3:0]
User data-words
User data-words
User data-words
User data-words
Checksum
7
0
0
0
0
8
0
0
0
0
9
0
0
0
0
10
CS[7]
CS[6]
CS[5]
CS[4]
CS[3]
CS[2]
CS[1]
CS[0]
Table 91. PAL CCAP Data, Full-Byte Mode
Byte
D[9]
D[8]
D[7]
D[6]
D[5]
D[4]
D[3]
D[2]
D[1]
0
D[0]
Description
0
0
0
0
0
1
1
1
0
0
0
1
1
0
1
0
0
1
1
0
0
0
0
1
1
0
1
0
0
1
1
0
0
1
0
Fixed preamble
Fixed preamble
Fixed preamble
DID
1
1
1
1
1
1
2
1
1
1
1
1
3
0
1
0
0
0
4
EP
EP
EP
EP
EF
0
0
0
SDID
5
0
0
Data count
6
CCAP word1[7:0]
CCAP word2[7:0]
0
0
User data-words
User data-words
UDW padding 0x200
UDW padding 0x200
Checksum
7
0
0
8
1
0
0
0
0
0
0
0
0
0
9
1
0
0
0
0
0
0
0
0
0
10
CS[8]
CS[8]
CS[7]
CS[6]
CS[5]
CS[4]
CS[3]
CS[2]
CS[1]
CS[0]
See the GDECEL[15:0], Gemstar Decoding Even Lines,
Address 0x48 [7:0], Address 0x49 [7:0] section and the
GDECOL[15:0], Gemstar Decoding Odd Lines, Address 0x4A
[7:0], Address 0x4B [7:0] section.
NTSC CCAP Data
Half-byte output mode is selected by setting CDECAD to 0, and
the full-byte mode is enabled by setting CDECAD to 1. See the
GDECAD, Gemstar Decode Ancillary Data Format, Address
0x4C [0] section. The data packet formats are shown in Table 88
and Table 89. Only closed caption data can be embedded in the
output data stream.
GDECEL[15:0], Gemstar Decoding Even Lines,
Address 0x48 [7:0], Address 0x49 [7:0]
The 16 bits of GDECEL[15:0] are interpreted as a collection of
16 individual line decode enable signals. Each bit refers to a line
of video in an even field. Setting the bit enables the decoder
block trying to find Gemstar or closed caption-compatible data
on that particular line. Setting the bit to 0 prevents the decoder
from trying to retrieve data. See Table 92 and Table 93.
NTSC closed caption data is sliced on Line 21d of even and odd
fields. The corresponding enable bit has to be set high. See the
GDECAD, Gemstar Decode Ancillary Data Format, Address
0x4C [0] section and the GDECOL[15:0], Gemstar Decoding
Odd Lines, Address 0x4A [7:0], Address 0x4B [7:0] section.
To retrieve closed caption data services on NTSC (Line 284),
GDECEL[11] must be set.
PAL CCAP Data
Half-byte output mode is selected by setting CDECAD to 0, and
full-byte output mode is selected by setting CDECAD to 1. See
the GDECAD, Gemstar Decode Ancillary Data Format,
Address 0x4C [0] section. Table 90 and Table 91 list the bytes of
the data packet.
To retrieve closed caption data services on PAL (Line 335),
GDECEL[14] must be set.
The default value of GDECEL[15:0] is 0x0000. This setting
instructs the decoder not to attempt to decode Gemstar or
CCAP data from any line in the even field. The user should only
enable Gemstar slicing on lines where VBI data is expected.
Only closed caption data can be embedded in the output data
stream. PAL closed caption data is sliced from Line 22 and
Line 335. The corresponding enable bits must be set.
Rev. A | Page 69 of 112
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