adv7180 Analog Devices, Inc., adv7180 Datasheet - Page 65

• Manufacturer Part Number: adv7180
• Description: 10-bit, 4 X Oversampling Sdtv Video Decoder
• Manufacturer: Analog Devices, Inc.

Each data packet starts immediately after the EAV code of the
preceding line. Figure 47 and Table 82 show the overall
structure of the data packet.
Entries within the packet are as follows:
•
•
•
Table 82. Generic Data Output Packet
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Table 83. Data Byte Allocation
2×
1
1
0
0
Fixed preamble sequence of 0x00, 0xFF, and 0xFF.
Data identification word (DID). The value for the DID
marking a Gemstar or CCAP data packet is 0x140 (10-bit
value).
Secondary data identification word (SDID), which contains
information about the video line from which data was
retrieved, whether the Gemstar transmission was of 1× or
2× format, and whether it was retrieved from an even or
odd field.
Raw Information Bytes
Retrieved from the Video Line
4
4
2
2
D[9]
0
1
1
0
EP
EP
EP
EP
EP
EP
EP
EP
EP
EP
CS[8]
PREAMBLE FOR ANCILLARY DATA
D[8]
0
1
1
1
EP
EP
EP
EP
EP
EP
EP
EP
EP
EP
CS[8]
00
DATA IDENTIFICATION
FF
0
1
1
EF
0
0
0
0
0
0
0
0
0
CS[7]
D[7]
0
FF
DID
D[6]
0
1
1
1
2X
0
0
0
0
0
0
0
0
0
CS[6]
Figure 47. Gemstar and CCAP Embedded Data Packet (Generic)
SDID
SECONDARY DATA IDENTIFICATION
D[5]
0
1
1
0
0
CS[5]
COUNT
DATA
GDECAD
0
1
0
1
Rev. B | Page 65 of 112
D[4]
0
1
1
0
0
CS[4]
USER DATA (4 OR 8 WORDS)
word1[7:4]
word1[3:0]
word2[7:4]
word2[3:0]
word3[7:4]
word3[3:0]
word4[7:4]
word4[3:0]
line[3:0]
USER DATA
User Data-Words
(Including Padding)
8
4
4
4
•
•
•
•
Table 82 lists the values within a generic data packet that is
output by the ADV7180 in 8-bit format.
0
1
1
CS[3]
D[3]
0
DC[1]
Data count byte, giving the number of user data-words that
follow.
User data section.
Optional padding to ensure that the length of the user
data-word section of a packet is a multiple of 4 bytes
(requirement as set in ITU-R BT.1364).
Checksum byte.
D[2]
0
1
1
0
DC[0]
CS[2]
OPTIONAL PADDING
D[1]
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
BYTES
Padding Bytes
0
0
0
2
D[0]
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
CHECK
SUM
Description
Fixed preamble
Fixed preamble
Fixed preamble
DID
SDID
Data count (DC)
User data-words
User data-words
User data-words
User data-words
User data-words
User data-words
User data-words
User data-words
Checksum
ADV7180
DC[1:0]
10
01
01
01