ADV7181B
Rev. B | Page 54 of 100
NTSC CCAP Data
Half-byte output mode is selected by setting CDECAD = 0; the
full-byte mode is enabled by CDECAD = 1. See the GDECAD
Gemstar Decode Ancillary Data Format,
Address 0x4C[0] section. The data packet formats are shown in
Table 69 and Table 70.
NTSC closed caption data is sliced on Line 21d on even and
odd fields. The corresponding enable bit has to be set high.
See the GDECEL[15:0] Gemstar Decoding Even Lines,
Address 0x48[7:0]; Address 0x49[7:0] and the GDECOL[15:0]
Gemstar Decoding Odd Lines, Address 0x4A[7:0]; Address
0x4B[7:0] sections.
PAL CCAP Data
Half-byte output mode is selected by setting CDECAD = 0;
full-byte output mode is selected by setting CDECAD = 1.
See the GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C[0] section. Table 71 and Table 72 list the bytes
of the data packet.
PAL closed caption data is sliced from Lines 22 and 335. The
corresponding enable bits have to be set.
See the GDECEL[15:0] Gemstar Decoding Even Lines,
Address 0x48[7:0]; Address 0x49[7:0] and the GDECOL[15:0]
Gemstar Decoding Odd Lines, Address 0x4A[7:0]; Address
0x4B[7:0] sections.
Table 70. NTSC CCAP Data, Full-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 0 0 0 0 0 Fixed
preamble
1 1 1 1 1 1 1 1 1 1 1 Fixed
preamble
2 1 1 1 1 1 1 1 1 1 1 Fixed
preamble
3 0 1 0 1 0 0 0 0 0 0 DID
4 !EP EP EF
0 1 0 1 1
0 0 SDID
5 !EP EP
0 0 0 0
0 1
0 0 Data
count
6 CCAP
Word1[7:0]
0
0
User
data-words
7 CCAP
Word2[7:0]
0
0
User
data-words
8 1 0 0 0 0 0 0 0 0 0 UDW
padding
0x200
9 1 0 0 0 0 0 0 0 0 0 UDW
padding
0x200
10 !CS[8] CS[8] CS[7] CS[6] CS[5] CS[4] CS[3] CS[2] CS[1] CS[0] Checksum
Table 71. 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 0 0 0 0 0 Fixed
preamble
1 1 1 1 1 1 1 1 1 1 1 Fixed
preamble
2 1 1 1 1 1 1 1 1 1 1 Fixed
preamble
3 0 1 0 1 0 0 0 0 0 0 DID
4 !EP EP EF
0 1 0 1 0
0 0 SDID
5 !EP EP
0 0 0 0
0 1
0 0 Data
count
6 !EP EP
0 0
CCAP
Word1[7:4]
0 0 User
data-words
7 !EP EP
0 0
CCAP
Word1[3:0]
0 0 User
data-words
8 !EP EP
0 0
CCAP
Word2[7:4]
0 0 User
data-words
9 !EP EP
0 0
CCAP
Word2[3:0]
0 0 User
data-words
10
!CS[8] CS[8] CS[7] CS[6] CS[5] CS[4] CS[3] CS[2] CS[1] CS[0] Checksum
