msm7664 Oki Semiconductor, msm7664 Datasheet - Page 19

• Manufacturer Part Number: msm7664
• Description: Ntsc/pal Digital Video Decoder
• Manufacturer: Oki Semiconductor

¡ Semiconductor
If an S-video signal is input, these Y/C separation circuits are bypassed.
The functions of this block only operate when lines are valid as image information. During the
V blanking interval, CVBS signals are not processed.
2. Luminance Block
The luminance block removes synchronous signals from signals containing luminance components
after Y/C separation. The signals are compensated and then output as luminance signals. Two
modes of gain control functions can be selected for the luminance signal output level: AGC (Auto
Gain Control) and MGC (Manual Gain Control).
In the AGC mode, luminance level amplification is determined by comparing the SYNC depth
with a reference value. The default is 40IRE and can be changed by the register setting. The input
has a sync tip clamp.
In the MGC mode, the signal amplification and black level can be changed by register settings.
This block can select the follwing operating modes.
1) Selection of luminance level limiter usage (related register LUMC[7])
2) Selection of prefilter and sharp filter usage (related register LUMC[6])
3) Selection of aperture bandpass filter coefficient (related register LUMC[5:4])
4) Coring range selection (related register LUMC[3:2])
5) Aperture weighting coefficient selection (related register LUMC[1:0])
6) Selection of pixel position compensating circuit usage (related register MRC[6])
When a limiter is used, the luminance level is limited to 16 to 235.
These filters are used to enhance the edges of luminance component signals.
Two filters operate in pairs. For their characteristics, refer to Filter Characteristics described
later.
Both coring and aperture compensation processes perform contour compensation.
Do not use*
Use
Do not use*
Use
Middle range*
High range
Off*
0*
0.25
0.75
1.50
Use*
Do not use
4LBS
5LBS
7LBS
PEDL7664-01
MSM7664
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