Texas Instruments TMS320C64x DSP - Manual (Page 155)

BT.656 Video Display Mode
Video Display Port 4-10 SPRU629
Figure 4–10. 625/50 BT.656 Horizontal Blanking Timing
One Line
861 862 863 0 1 2 718 719 720 721 722 723 720 721 722 723 FPCOUNT
Active Video Blanking
VCLKOUT
Next Line
4 4 280 1440
VDOUT[9–0]
80.0 80.0 10.0 FF
.C
00.0 00.0 Cb
0
Y 2
Cb 359
Y 718 Cr 359 Y 719
Y 0 Cr 0 Y 1
Cb 1 XY
.0
10.0 80.0 10.0 FF
.C
00.0 00.0 XY
.0
80.0 80.0 10.0 FF
.C
00.0 00.0 XY
.0
10.0
SAV EAV Blanking Data EAV
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 Table 4–2 and
Figure 4–11.
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.
Table 4–2. BT.656 Frame Timing
Line Number
625/50 525/60 F V Description
624–625 1–3 1 1 Vertical blanking for field 1, EAV/SAV code still indicates field 2.
1–22 4–19 0 1 Vertical blanking for field 1. Change EAV/SAV code to field 1.
23–310 20–263 0 0 Active video, field 1.
311–312 264–265 0 1 Vertical blanking for field 2, EAV/SAV code still indicates field 1.
313–335 266–282 1 1 Vertical blanking for field 2. Change EAV/SAV code to field 2.
336–623 283–525 1 0 Active video, field 2.