ml87v2105 Oki Semiconductor, ml87v2105 Datasheet - Page 37

• Manufacturer Part Number: ml87v2105
• Description: Video Signal Noise Reduction Ic With A Built-in 5.6 Mbit Frame Memory
• Manufacturer: Oki Semiconductor

OKI Semiconductor
Detection of the basic noise status signal (YBDTO, CBDTO) involves comparing the average noise value
(YBAVRO[6:0], CBAVRO[6:0]) and the noise status comparison value (YAVR1[5:0] (SUB:53h-bit[5:0]),
CAVR1[5:0] (SUB:54h-bit[5:0])) of the blanking period. The noise status is switched when the new status has
continued for four frames or more.
The detection of the noise status signal has the hysteresis characteristic shown in Figure F1-3-6(4). You can
select the characteristic with YAH1(SUB:53h-bit[7]) and CAH1 (SUB:54h-bit[7]).
Detection of Basic Noise Status Signals
Table F1-3-7 (8) Noise Status Reduction Direction Detection Hysteresis Settings
Table F1-3-7 (7) Color Difference Blanking Period Noise Status Detection
YBDTO=1,CBDTO=1
YBDTO=0,CBDTO=0
Table F1-3-7 (6) Luminance Blanking Period Noise Status Detection
Figure F1-3-7 (4) Basic Noise Status Judgment Transition Diagram
transition
transition
CBDTO
YBDTO
Basic noise status judgment
Before
Before
0
0
1
1
0
0
1
1
Set with YAH1, CAH1
CBAVRO[6:0] > CAVR1[5:0] x (hysteresis
YBAVRO[6:0] > YAVR1[5:0] x (hysteresis
CBAVRO[6:0]
YBAVRO[6:0]
0
YAH1
CAH1
0
1
CBAVRO[6:0] > CAVR1[5:0]
YBAVRO[6:0] > YAVR1[5:0]
CBAVRO[6:0]
YBAVRO[6:0]
YAVR1[6:0]
CAVR1[6:0]
coefficient)
coefficient)
coefficient)
coefficient)
Noise reduction direction
Noise reduction direction judging threshold value
Condition
Condition
YAVR1[5:0] x (hysteresis
CAVR1[5:0] x (hysteresis
switching coefficient
Noise increase direction judging threshold value
YAVR1[5:0]
CAVR1[5:0]
3/4
7/8
Basic average noise value
CBAVRO[6:0]
YBAVRO[6:0]
transition
transition
YBDTO
CBDTO
After
After
0
1
0
1
0
1
0
1
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