MSM7650 Ver la hoja de datos (PDF) - Oki Electric Industry

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componentes Descripción

Fabricante

MSM7650

NTSC/PAL Digital Encoder

Oki Electric Industry 

¡ Semiconductor

MSM7650

BLOCK FUNCTIONAL DESCRIPTION

Y Limitter

This block limits the contents outside the specified range as follows for input luminance signal

YD specified by the ITU-601 standard.

• Signals are limited to YD = 235 when YD_IN > 235

• Signals are limited to YD = 16 when YD_IN < 16

• In other cases, signals are fed as is to next processing

C Limitter

This block limits the contents outside the specified range as follows for input chrominance

signals specified by the ITU-601 standard.

The input chrominance signal is output as a 2’s complement format.

The processing procedure follows.

1) Format processing for input chrominance signals

• If MR [6] = 0, CD is in offset binary format. CD is converted to 2’s complement format and is

fed to next processing.

• If MR [6] = 1, CD is in 2’s complement format. CD is fed as is to next processing.

2) Clipping processing

• Signals are limited to CD = 112 when CD>112

• Signals are limited to CD = -112 when CD < -112

• In other cases, signals are fed to next processing

In addition, this block separates U and V components from the input chrominance signal CD into

which data of U and V components has been inserted using time sharing, and then passes signals

to the next process.

• Y Level Converter

Converts ITU-601 standard luminance signal level to DAC digital input level.

• U Level Converter

Converts ITU-601 standard chrominance signal level to DAC digital input level.

• V Level Converter

Converts ITU-601 standard chrominance signal level to DAC digital input level.

• YUV Color Generator

This block generates luminance and chrominance signals from over lay color signals OLR,

OLG and OLB. Control signals (CR [2:0] ) control the output content (overlay or color bar) and

output level (100%, 75%, 50%, 25%).

• Overlay Control

This block selects input image data or YUV Color Generator output signals.

It is determined by the level of the control signal (OLC, CR [2]), as shown below:

CR [2] = 1, OLC = ?: Selects color bar signal (YUV Color Generator output signal).

CR [2] = 0, OLC = 1: Selects overlay signal (YUV Color Generator output signal).

CR [2] = 0, OLC = 0: Selects input image data.

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