ADV7180
The data bytes in the ancillary data stream are as follows:
VBI_WORD_4 = Byte 1 [7:0]
Data Bytes
The VBI_WORD_4 to VBI_WORD_N + 3 contains the data-
words that were decoded by the VDP in the transmission order.
The position of bits in bytes is in the inverse transmission order.
VBI_WORD_5 = Byte 2 [7:0]
The number of VBI_WORDS for each VBI data standard and
the total number of UDWs in the ancillary data stream is shown
in Table 74.
For example, closed captioning has two user data bytes, as
shown in Table 78.
Table 73. Framing Code Sequence for Different VBI Standards
Error-Free Framing Code Bits
(In Order of Transmission)
Error-Free Framing Code Reported by VDP
(In Reverse Order of Transmission)
VBI Standard
Length in Bits
TTXT_SYSTEM_A (PAL)
TTXT_SYSTEM_B (PAL)
TTXT_SYSTEM_B (NTSC)
TTXT_SYSTEM_C (PAL and NTSC)
TTXT_SYSTEM_D (PAL and NTSC)
VPS (PAL)
VITC (NTSC and PAL)
WSS (PAL)
GEMSTAR_1× (NTSC)
GEMSTAR_2× (NTSC)
CCAP (NTSC and PAL)
CGMS (NTSC)
8
8
8
8
8
16
1
24
3
11
3
11100111
11100100
11100100
11100111
11100101
10001010100011001
0
000111100011110000011111
001
1001_1011_101
001
0
11100111
00100111
00100111
11100111
10100111
1001100101010001
0
111110000011110001111000
100
101_1101_1001
100
0
1
Table 74. Total User Data-Words for Different VBI Standards1
VBI Standard
ADF Mode
Framing Code UDWs VBI Data-Words No. of Padding Words Total UDWs
TTXT_SYSTEM_A (PAL)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
74
37
84
42
68
34
66
33
68
34
26
13
18
9
4
2
4
2
8
4
4
2
0
0
2
3
2
3
0
2
2
3
0
0
0
0
2
3
2
3
2
1
2
3
0
2
84
44
96
52
80
44
76
42
80
44
36
20
28
16
16
12
16
12
20
12
16
12
16
12
TTXT_SYSTEM_B (PAL)
TTXT_SYSTEM_B (NTSC)
TTXT_SYSTEM_C (PAL and NTSC) 00 (nibble mode)
01,10 (byte mode)
TTXT_SYSTEM_D (PAL and NTSC) 00 (nibble mode)
01,10 (byte mode)
VPS (PAL)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
00 (nibble mode)
01,10 (byte mode)
VITC (NTSC and PAL)
WSS (PAL)
GEMSTAR_1× (NTSC)
GEMSTAR_2× (NTSC)
CCAP (NTSC and PAL)
CGMS (NTSC)
6
3 + 3
1 The first four UDWs are always the ID.
Rev. A | Page 56 of 112
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