VDP313XY Ver la hoja de datos (PDF) - Micronas

Número de pieza

componentes Descripción

Fabricante

VDP313XY

Video Processor Family

Micronas 

ADVANCE INFORMATION

VDP 313xY

2.4.7. Automatic standard recognition

The burst-frequency measurement is also used for

automatic standard recognition (together with the sta-

tus of horizontal and vertical locking) thus allowing a

completely independent search of the line and color

standard of the input signal. The following standards

can be distinguished:

– PAL B,G,H,I

– NTSC M

– SECAM

– NTSC 44

– PAL M

– PAL N

– PAL 60

For a preselection of allowed standards, the recogni-

tion can be enabled/disabled via I2C bus for each stan-

dard separately.

If at least one standard is enabled, the VDP 313xY

checks regularly the horizontal and vertical locking of

the input signal and the state of the color killer. If an

error exists for several adjacent fields a new standard

search is started. Depending on the measured line

number and burst frequency the current standard is

selected.

For error handling the recognition algorithm delivers

the following status information:

– search active (busy)

– search terminated, but failed

– found standard is disabled

– vertical standard invalid

– no color found

– standard switched

2.4.8. PAL Compensation/1-H Comb Filter

The color decoder uses one fully integrated delay line.

Only active video is stored.

The delay line application depends on the color stan-

dard:

– NTSC: 1-H comb filter or color compensation

– PAL: color compensation

– SECAM: crossover-switch

In the NTSC compensated mode, Fig. 2–5 c), the color

signal is averaged for two adjacent lines. Thus,

cross-color distortion and chrominance noise is

reduced. In the NTSC combfilter mode, Fig. 2–5 d), the

delay line is in the composite signal path, thus allowing

reduction of cross-color components, as well as

cross-luminance. The loss of vertical resolution in the

luminance channel is compensated by adding the ver-

tical detail signal with removed color information. If the

2-H adaptive comb filter is used, then the 1-H NTSC

comb filter should not be used.

CVBS

8

Notch

filter

Chroma

Process.

a) conventional

Y

Luma

8

chroma

CRCB

8

Chroma

Process.

b) S-VHS

Y

CRCB

CVBS

Notch

Y

8

filter

CVBS

8

Chroma

Process.

1H

Delay

c) compensated

1H

Delay

Notch

filter

CRCB

Y

Chroma

Process.

d) comb filter

Fig. 2–5: NTSC color decoding options

CRCB

Micronas

11

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