HMP8117_07 Datasheet, PDF (19/45 Pages) Intersil Corporation – NTSC/PAL Video Decoder

HMP8117
CLOCK
RUN-IN
Bit 0
DATA PACKET
MSB
NOTES:
31. The MSB is bit number: 271 for system C, 279 for system B 525-line and 343 for system B 625-line.
32. The clock run-in is 16 bits wide for both systems and is not included in the BT.656 ancillary data stream.
33. The bit rate is 5.727272 Mbits/s for system B and C on 525/60 systems and 6.9375 and 5.734375 Mbits/second respectively for 625/50 systems.
34. Teletext VBI Video Signal
FIGURE 16. TELETEXT VBI VIDEO SIGNAL
TABLE 8. OUTPUTTING THE SLICED TELETEXT DATA AS BT.656 ANCILLARY DATA
PIXEL INPUT
P15
P14
P13
P12
P11
P10
P9
P8
Preamble
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Data ID
P14
ep
1
1
0
1
0
0
Data Block Number
P14
ep
0
0
0
0
0
1
Data Word Count
P14
ep
0
1
0
1
1
0
Teletext Data
P14
ep
0 = 525-line
0 = system B
bit 343 bit 342 bit 341 bit 340
(B, 625-line = 43 bytes)
1 = 625-line
1 = system C
(B, 525-line = 35 bytes)
(C = 34 bytes)
P14
ep
0
0
bit 339 bit 338 bit 337 bit 336
:
P14
ep
0
0
bit 7
bit 6
bit 5
bit 4
P14
ep
0
0
bit 3
bit 2
bit 1
bit 0
Reserved
P14
ep
0
0
0
0
0
0
P14
ep
0
0
0
0
0
0
CRC
P14
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
NOTES:
35. ep = even parity for P8-P13.
36. CRC = Sum of P8-P14 of Data ID through last user data word. Preset to all zeros, carry is ignored.
37. For 525-line system B, bits 280-343 are “0”.
38. For system C, bits 272-343 are “0”.
“RAW” VBI DATA CAPTURE
“Raw” data capture of VBI data during blanked scan lines
may be optionally implemented. In this instance, the active
line time of blanked scan lines are sampled at the CLK2 rate,
and output onto the pixel outputs. This permits software
decoding of the VBI data to be done.
The line mask registers specify on which scan lines to
generate “raw” VBI data. If the RAW VBI All bit is enabled, all
the video lines are treated as raw VBI data, excluding the
equalization and serration lines.
The start and end timing of capturing “raw” VBI data on a
scan line is determined by the Start and End Raw VBI
Registers. This allows the proper capture of “raw” VBI data
regardless of the BLANK# output timing for active video.
The blanking level is subtracted from the “raw” VBI data
samples, and the result is output onto the pixel outputs.
Note both “sliced” and “raw” VBI data may be available on
the same line.
During NTSC operation, the first possible line of VBI data is
lines 10 and 272, and the last possible lines are the last
blanked scan lines. Lines 1-9 and 264-271 are always
blanked.
19
FN4643.3
April 19, 2007