Texas Instruments TMS320DM648 manual BT.656 Frame Timing, Line Number, 525/60 Description

Models: TMS320DM648

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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 Table 4-2and 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.

Figure 4-11. Digital Vertical F and V Transitions

525 lines/60 Hz

625 lines/50 Hz

Line 4

Field 1 (F = 0)

Line 266

Field 2 (F = 1)

Line 3

Blanking

Optional blanking

Image: Field 1

Blanking

Optional blanking

Image: Field 2

H = 0 (SAV)

1(V = 1)

Line 1

 

 

10 (V = X)

 

 

20 (V = 0)

Field 1

 

 

 

 

(F = 0)

264

(V = 1)

Line

273

(V = X)

313

 

 

 

283

(V = 0)

Field 2

 

 

(F = 1)

525

(V = 0)

 

 

 

Line 625

 

 

 

Blanking

Image: Field 1

Blanking

Image: Field 2

Blanking

H = 0 (SAV)

1(V = 1)

23 (V = 0)

311 (V = 1)

336 (V = 0)

624 (V = 1)

625 (V = 1)

H = 1 (EAV)

Line Number

F

V

1-3

1

1

4-19

0

1

20-263

0

0

264-265

0

1

266-282

1

1

283-525

1

0

100Video Display Port

 

 

H = 1 (EAV)

 

 

 

 

H

H

 

 

 

H

H

(EAV)

(SAV)

Line Number

F

V

(EAV)

(SAV)

1

0

1-22

0

1

1

0

1

0

23-310

0

0

1

0

1

0

311-312

0

0

1

0

1

0

313-335

1

1

1

0

1

0

336-623

1

0

1

0

1

0

624-625

1

1

1

0

SPRUEM1 –May 2007

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Texas Instruments TMS320DM648 manual BT.656 Frame Timing, Line Number, 525/60 Description