ADV7194KST(Rev0) View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
ADV7194KST Datasheet PDF : 69 Pages
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ADV7194
DNR17
DNR16
DNR15
DNR14
DNR13
DNR12
DNR11
DNR10
BLOCK SIZE
CONTROL
DNR17
0 8 PIXELS
1 16 PIXELS
BORDER AREA
DNR16
0 2 PIXELS
1 4 PIXELS
DNR THRESHOLD
DNR DNR DNR DNR DNR DNR
15 14 13 12 11 10
0 0 0 0 00 0
0 0 0 0 01 1
• • • ••• •
• • • ••• •
• • • ••• •
1 1 1 1 1 0 62
1 1 1 1 1 1 63
Figure 86. DNR Register 1
DNR2 BIT DESCRIPTION
DNR Input Select (DNR20–DNR22)
Three bits are assigned to select the filter which is applied to the
incoming Y data. The signal which lies in the passband of the
selected filter is the signal which will be DNR processed. Figure 87
shows the filter responses selectable with this control.
DNR Mode Control (DNR23)
This bit controls the DNR mode selected. A Logic 0 selects
DNR mode, a Logic 1 selects DNR Sharpness mode.
DNR works on the principle of defining low amplitude, high-
frequency signals as probable noise and subtracting this noise
from the original signal.
In DNR mode, it is possible to subtract a fraction of the signal
which lies below the set threshold, assumed to be noise, from
the original signal. The threshold is set in DNR Register 1.
When DNR Sharpness mode is enabled it is possible to add a
fraction of the signal which lies above the set threshold to the
original signal, since this data is assumed to be valid data and
not noise. The overall effect being that the signal will be boosted
(similar to using Extended SSAF Filter).
1
FILTER D
0.8
Y DATA
INPUT
DNR
MODE
GAIN CONTROL
BLOCK SIZE CONTROL
BORDER AREA
BLOCK OFFSET
GAIN
CORING GAIN DATA
CORING GAIN BORDER
NOISE SIGNAL PATH
FILTER BLOCK
FILTER OUTPUT
< THRESHOLD ?
MAIN SIGNAL PATH
FILTER OUTPUT
> THRESHOLD
Y DATA
INPUT
DNR
SHARPNESS
MODE
GAIN CONTROL
BLOCK SIZE CONTROL
BORDER AREA
BLOCK OFFSET
GAIN
CORING GAIN DATA
CORING GAIN BORDER
NOISE SIGNAL PATH
FILTER BLOCK
FILTER OUTPUT
> THRESHOLD ?
MAIN SIGNAL PATH
FILTER OUTPUT
< THRESHOLD
SUBTRACT
SIGNAL IN
THRESHOLD
RANGE
FROM
ORIGINAL
SIGNAL
DNR
OUT
ADD
SIGNAL
ABOVE
THRESHOLD
RANGE
TO
ORIGINAL
SIGNAL
DNR
OUT
0.6 FILTER C
0.4
FILTER B
0.2
FILTER A
0
0
1
2
3
4
5
6
FREQUENCY – MHz
Figure 87. Filter Response of Filters Selectable
Figure 88. Block Diagram for DNR Mode and DNR Sharp-
ness Mode
Block Offset (DNR24–DNR27)
Four bits are assigned to this control which allows a shift of the
data block of 15 pixels maximum. Consider the coring gain
positions fixed. The block offset shifts the data in steps of one
pixel such that the border coring gain factors can be applied at the
same position regardless of variations in input timing of the data.
APPLY DATA APPLY BORDER
CORING GAIN CORING GAIN
OXXXXXXO OXXXXXXO
OFFSET CAUSED BY
O X X X X X X O O X X X X X X O VARIATIONS IN INPUT
TIMING
DNR27-DNR24
= 01HEX
OXXXXXXO
OXXXXXXO
Figure 89.
–42–
REV. 0
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