Datasheet

29
SLES084C − August 2007 TVP5146
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 somewhat 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 2−8. VBI Raw Data Output Format
BYTE
NO.
D9
(MSB)
D8 D7 D6 D5 D4 D3 D2 D1 D0
(LSB)
DESCRIPTION
0 0 0 0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1 1 1 1
VBI raw data preamble
2 1 1 1 1 1 1 1 1 1 1
VBI raw data preamble
3 0 1 1 0 0 0 0 0 0 0
4 1. Data
5 2. Data
2 iltl dt
: :
2× pixel rate luma data
(i e NTSC 601: n = 1707)
n–1 n–5. Data
(i
.e.,
NTSC
601
: n =
1707)
n n–4. Data
2.8 Reset and Initialization
Reset is initiated at power up or any time terminal 34 (RESETB) is brought low. Table 2−9
describes the status of the TVP5146 terminals during and immediately after reset.
Table 2−9. Reset Sequence
SIGNAL NAME DURING RESET RESET COMPLETED
Y[9:0], C[9:0], DATACLK Input High-impedance
RESETB, PWDN, SDA, SCL, FSS,
AVID, GLCO, HS, VS, FID
Input Input
INTREQ Input Output
DATACLK Output High-impedance
TI recommends the following power-up sequence.
3 ms (min)
RESETB
(Terminal 34)
1 ms (min)
Invalid I
2
C Cycle Valid
Normal Operation
100 ms
SDA
(Terminal 29)
Power (1.8 V)
Power (3.3 V)
Reset
NOTE: All times shown are minimum values. Maximum time between 1.8 V and 3.3 V should be no longer than 1 second.
Figure 2−26. Reset Timing