Texas Instruments TVP5147M1PFP - Manual (Page 33)

Functional Description
25 SLES140A—March 2007 TVP5147M1PFP
2.7.1 VBI FIFO and Ancillary Data in Video Stream
Sliced VBI data can be output as ancillary data in the video stream in ITU-R BT.656 mode. VBI data is output
on the Y[9:2] terminals during the horizontal blanking period. Table 2−7 shows the header format and
sequence of the ancillary data inserted into the video stream. This format is also used to store any VBI data
into the FIFO. The size of the FIFO is 512 bytes. Therefore, the FIFO can store up to 11 lines of teletext data
with the NTSC NABTS standard.
Table 2−7. Ancillary Data Format and Sequence
BYTE
NO.
D7
(MSB)
D6 D5 D4 D3 D2 D1 D0
(LSB)
DESCRIPTION
0 0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1 1 Ancillary data preamble
2 1 1 1 1 1 1 1 1
Ancillary data preamble
3 NEP EP 0 1 0 DID2 DID1 DID0 Data ID (DID)
4 NEP EP F5 F4 F3 F2 F1 F0 Secondary data ID (SDID)
5 NEP EP N5 N4 N3 N2 N1 N0 Number of 32-bit data (NN)
6 Video line # [7:0] Internal data ID0 (IDID0)
7 0 0 0 Data
error Match
#1
Match
#2
Video line # [9:8] Internal data ID1 (IDID1)
8 1. Data Data byte 1st word
9 2. Data Data byte
1 word
10 3. Data Data byte
11 4. Data Data byte
: : : :
m. Data Data byte Nth word
CS[7:0] Check sum
N word
4N+7 0 0 0 0 0 0 0 0 Fill byte
NOTE: The number of bytes (m) varies depending on the VBI data service.
EP: Even parity for D0−D5, NEP: Negated even parity
DID: 91h: Sliced data of VBI lines of first field
53h: Sliced data of line 24 to end of first field
55h: Sliced data of VBI lines of second field
97h: Sliced data of line 24 to end of second field
SDID: This field holds the data format taken from the line mode register bits [2:0] of the corresponding line.
NN: Number of Dwords beginning with byte 8 through 4N+7. Note this value is the number of Dwords
where each Dword is 4 bytes.
IDID0: Transaction video line number [7:0]
IDID1: Bit 0/1 = Transaction video line number [9:8]
Bit 2 = Match 2 flag
Bit 3 = Match 1 flag
Bit 4 = 1 if an error was detected in the EDC block. 0 if no error was detected.
CS: Sum of D0−D7 of first data through last data byte.
Fill byte: Fill bytes make a multiple of 4 bytes from byte 0 to last fill byte. For teletext modes, byte 8 is the sync
pattern byte. Byte 9 is the first data byte.