Datasheet

TVP5158, TVP5157, TVP5156

SLES243G –JULY 2009–REVISED APRIL 2013

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Figure 3-9. Peaking Filter Response, NTSC/PAL ITU-R BT.601 Sampling

3.3 AVID Cropping

AVID or active video cropping provides a means to decrease the amount of video data output. This is

accomplished by horizontally blanking a number of AVID pulses and by vertically blanking a number of

lines per frame. Horizontal cropping can be enabled/disabled using bit-6 of address B1h. When line

cropping is enabled, active video is reduced from 720 to 704 pixels for unscaled video and from 360 to

352 pixels for down-scaled video.

When line cropping is enabled, the TVP5158 crops an equal amount from both the start and end of active

video. Register 8Ch can be used to delay both the start and end of active video. It allows selecting which

704 pixels out of 720 are actually being used for active video when line cropping is enabled.

3.4 Embedded Syncs

Standards with embedded syncs insert SAV and EAV codes into the data stream at the beginning and end

of horizontal blanking. These codes contain the V and F bits which also define vertical timing. F and V

change on EAV. Table 3-1 gives the format of the SAV and EAV codes.

H equals 1 always indicates EAV. H equals 0 always indicates SAV. The alignment of V and F to the line

and field counter varies depending on the standard. Please refer to ITU-R BT.656 for more information on

embedded syncs.

The P bits are protection bits:

P3 = V xor H

P2 = F xor H

P1 = F xor V

P0 = F xor V xor H

Table 3-1. EAV and SAV Sequence

8-BIT DATA

D7 (MSB) D6 D5 D4 D3 D2 D1 D0

Preamble 1 1 1 1 1 1 1 1

Preamble 0 0 0 0 0 0 0 0

Status word 1 F V H P3 P2 P1 P0

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