ADV7180_15 Datasheet, PDF (59/114 Pages) Analog Devices – 10-Bit, 4 Oversampling SDTV Video Decoder

Data Sheet
ADV7180
Table 75. Ancillary Data in Byte Output Format¹
Byte
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
Description
0
0
0
0
0
0
0
0
0
0
0
Ancillary data preamble
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
3
EP
EP
0
I²C_DID6_2[4:0]
0
0
DID
4
EP
EP
I²C_SDID7_2[5:0]
0
0
SDID
5
EP
EP
0
DC[4:0]
0
0
Data count
6
EP
EP
Padding[1:0]
VBI_DATA_STD[3:0]
0
0
ID0 (User Data-Word 1)
7
EP
EP
0
LINE_NUMBER[9:5]
0
0
ID1 (User Data-Word 2)
8
EP
EP
EVEN_FIELD
LINE_NUMBER[4:0]
0
0
ID2 (User Data-Word 3)
9
EP
EP
0
0
0
0
VDP_TTXT_TYPE[1:0] 0
0
ID3 (User Data-Word 4)
10
VBI_WORD_1[7:0]
0
0
ID4 (User Data-Word 5)
11
VBI_WORD_2[7:0]
0
0
ID5 (User Data-Word 6)
12
VBI_WORD_3[7:0]
0
0
ID6 (User Data-Word 7)
13
VBI_WORD_4[7:0]
0
0
ID7 (User Data-Word 8)
14
VBI_WORD_5[7:0]
0
0
ID8 (User Data-Word 9)
Pad 0x200; these
padding words may be
present, depending on
ancillary data type; user
data-word
n−3
1
0
0
0
0
0
0
0
0
0
n−2
1
0
0
0
0
0
0
0
0
0
n−1
B8
Checksum
0
0
CS (checksum word)
1 _{This mode does not fully comply with ITU-R BT.1364.}
Structure of VBI Words in the Ancillary Data Stream
Each VBI data standard has been split into a clock-run-in
(CRI), a framing code (FC), and a number of data bytes (n).
The data packet in the ancillary stream includes only the FC
and data bytes. Table 76 shows the format of VBI_WORD_x in
the ancillary data stream.
Table 76. Structure of VBI Data-Words in the Ancillary Stream
Ancillary Data Byte No. Byte Type Description
VBI_WORD_1
FC0
Framing Code[23:16]
VBI_WORD_2
FC1
Framing Code[15:8]
VBI_WORD_3
FC2
Framing Code[7:0]
VBI_WORD_4
DB1
First data byte
…
…
…
VBI_WORD_N + 3
DBn
Last (n^th) data byte
VDP Framing Code
The length of the actual framing code depends on the VBI data
standard. For uniformity, the length of the framing code reported
in the ancillary data stream is always 24 bits. For standards with
a smaller framing code length, the extra LSB bits are set to 0.
The valid length of the framing code can be decoded from the
VBI_DATA_STD bits available in ID0 (UDW 1). The framing
code is always reported in the inverse-transmission order.
Table 77 shows the framing code and its valid length for VBI
data standards supported by VDP.
Example
For teletext (B-WST), the framing code byte is 11100100 (0xE4),
with bits shown in the order of transmission. VBI_WORD_1 =
0x27, VBI_WORD_2 = 0x00, and VBI_WORD_3 = 0x00
translated into UDWs in the ancillary data stream for nibble
mode are as follows:
UDW5[5:2] = 0010
UDW6[5:2] = 0111
UDW7[5:2] = 0000 (undefined bits set to 0)
UDW8[5:2] = 0000 (undefined bits set to 0)
UDW9[5:2] = 0000 (undefined bits set to 0)
UDW10[5:2] = 0000 (undefined bits set to 0)
For byte mode,
UDW5[9:2] = 0010_0111
UDW6[9:2] = 0000_0000 (undefined bits set to 0)
UDW7[9:2] = 0000_0000 (undefined bits set to 0)
Rev. J | Page 59 of 114