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BT.656 Video Display Mode
SAV and EAV codes are identified by a 3-byte preamble of FFh, 00h, and 00h. This combination must be
avoided in the video data output by the video port to prevent accidental generation of an invalid sync
code. The video display module provides programmable maximum and minimum value clipping on the
video data to prevent this possibility.
The typical values for H, V, and F on different lines are shown in
F and V are only allowed to change at EAV sequences. The EAV and SAV sequences must occupy the
first four words and the last four words of the digital horizontal-blanking interval, respectively. The EAV
code is inserted when FPCOUNT = HBLNKSTART. The SAV code is inserted when FPCOUNT =
HBLNKSTOP.
Line Number
625/50
624-625
1-22
23-310
311-312
313-335
336-623
525 lines/60 Hz
Line 4
Field 1
(F = 0)
Line 266
Field 2
(F = 1)
Line 3
H = 0 (SAV)
H = 1 (EAV)
Line Number
1-3
4-19
20-263
264-265
266-282
283-525
100
Video Display Port
Table 4-2. BT.656 Frame Timing
525/60
F
1-3
1
4-19
0
20-263
0
264-265
0
266-282
1
283-525
1
Figure 4-11. Digital Vertical F and V Transitions
1(V = 1)
Blanking
10 (V = X)
Optional blanking
20 (V = 0)
Image: Field 1
264 (V = 1)
Blanking
273 (V = X)
Optional blanking
283 (V = 0)
Image: Field 2
525 (V = 0)
H
F
V
(EAV) (SAV)
1
1
1
0
1
1
0
0
1
0
1
1
1
1
1
1
0
1
Table 4-2
V
Description
1
Vertical blanking for field 1, EAV/SAV code still indicates field 2.
1
Vertical blanking for field 1. Change EAV/SAV code to field 1.
0
Active video, field 1.
1
Vertical blanking for field 2, EAV/SAV code still indicates field 1.
1
Vertical blanking for field 2. Change EAV/SAV code to field 2.
0
Active video, field 2.
625 lines/50 Hz
Line 1
Blanking
Image: Field 1
Field 1
(F = 0)
Line
Blanking
313
Image: Field 2
Field 2
(F = 1)
Blanking
Line 625
H = 0 (SAV)
H = 1 (EAV)
H
Line Number
0
1-22
0
23-310
0
311-312
0
313-335
0
336-623
0
624-625
www.ti.com
and
Figure
4-11.
1(V = 1)
23 (V = 0)
311 (V = 1)
336 (V = 0)
624 (V = 1)
625 (V = 1)
H
F
V
(EAV) (SAV)
0
1
1
0
0
1
0
0
1
1
1
1
1
0
1
1
1
1
SPRUEM1 – May 2007
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H
0
0
0
0
0
0
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