MSM7662 View Datasheet(PDF) - Oki Electric Industry

Part Name

Description

Manufacturer

MSM7662

NTSC/PAL Digital Video Decoder

Oki Electric Industry 

¡ Semiconductor

PEDL7662-02

MSM7662

Decoder Unit

1. Prologue Block

The prologue block inputs data and performs Y/C separation.

Data can be input at either the pixel frequency (ITU-RBT.601: 13.5 MHz) or at twice the pixel

frequency (ITU-RBT.601: 27 MHz). If input at twice the pixel frequency, data is processed after

passing through a decimator circuit to convert it to the pixel frequency. The decimator circuit

may be bypassed by changing the register setting, regardless of whether data is input at the

normal pixel frequency or at twice the pixel frequency.

If a composite signal (CVBS) is input, the default setting performs Y/C separation using a 2-

dimensional adaptive comb filter.

The following operating modes can be selected via the I2C-bus. Default settings are indicated by

an asterisk (*). The default state is selected at reset.

1) Video input mode selection (related register MRC[7])

NTSC/PAL auto-select* (only for ITU-RBT.601)

Dependent upon operating mode selected

When ITU-RBT.601 is selected, the video input mode is automatically set depending upon

the number of lines per field.

2) Operating mode selection (related register MRA[3:1])

NTSC ITU-RBT.601

13.5 MHz*

NTSC Square Pixel

12.272727 MHz

NTSC 4fsc

14.31818 MHz

PAL ITU-RBT.601

13.5 MHz

PAL Square Pixel

14.75 MHz

Even if input at twice the pixel frequency, the internal processing is performed at the pixel

frequency.

3) Decimator circuit pass/bypass selection (related register MRC[4])

Pass through decimator circuit*

Bypass decimator circuit

Compatible only when input at twice the pixel frequency.

4) Y/C separation mode selection (related register MRB[1:0])

Use adaptive comb filter*

Use non-adaptive comb filter

Do not use comb filter (use trap filter)

The adaptive comb filter for a NTSC signal makes the correlation between up to 3 consecutive

lines, and Y/C separation is performed by the 3-line or 2-line comb filter according to the format

of correlation.

The adaptive comb filter for a PAL signal makes the correlation between only 2 lines and

performs Y/C separation by switching between the 2-line comb filter and trap filter.

The non-adaptive comb filter performs Y/C separation by removing the luminance component

based on the average of preceding and following lines (when there is correlation between 3 lines).

(the average of 2 lines in the case of a PAL signal)

When a comb filter is not used, Y/C separation is performed by a trap filter.

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