2.7.2
VBI Raw Data Output
The TVP5146 decoder can output raw A/D video data at twice the sampling rate for external VBI slicing. This is
transmitted as an ancillary data block, although a bit differently from the way the sliced VBI data is transmitted in the
FIFO format as described in Section 2.7.1. The samples are transmitted during the active portion of the line. VBI raw
data uses ITU-R BT.656 format having only luma data. The chroma samples are replaced by luma samples. The
TVP5146 decoder inserts a four-byte preamble 000h 3FFh 3FFh 180h before data start. There are no checksum
bytes and fill bytes in this mode.
Table 2−9. VBI Raw Data Output Format
BYTE
NO.
0
1
2
3
4
5
:
n−1
n
D9
(MSB)
0
1
1
0
D8
0
1
1
1
D7
0
1
1
1
D6
0
1
1
0
D5
0
1
1
0
1. Data
2. Data
:
n−1. Data
n. Data
2x pixel rate luma data
(i.e., NTSC 601: n = 1704)
D4
0
1
1
0
D3
0
1
1
0
D2
0
1
1
0
D1
0
1
1
0
D0
(LSB)
0
1
1
0
VBI raw data preamble
DESCRIPTION
2.8 Reset and Initialization
Reset is initiated at power up or any time terminal 34 (RESETB) is brought low. Table 2−10 describes the status of
the TVP5146 terminals during and immediately after reset.
Table 2−10. Reset Sequence
SIGNAL NAME
Y[9:0], C[9:0], DATACLK
RESETB, PWDN, SDA, SCL, FSS,
AVID, GLCO, HS, VS, FID
INTREQ
DURING RESET
Input
Input
Input
RESET COMPLETED
High-impedance
Input
Output
2.9 Adjusting External Syncs
The proper sequence to program the following external syncs is:
•
To set NTSC, PAL-M, NTSC 443, PAL60 (525-line modes):
−
−
•
Set the video standard to NTSC (register 02h)
Set HSYNC, VSYNC, VBLK, and AVID external syncs (registers 16h through 24h)
To set PAL, PAL-N, SECAM (625-line modes):
−
−
Set the video standard to PAL (register 02h)
Set HSYNC, VSYNC, VBLK, and AVID external syncs (registers 16h through 24h)
•
For autoswitch, set the video standard to autoswitch (register 02h)
2−22
TI [ TEXAS INSTRUMENTS ]
