UG-707
ADV8005 Hardware Reference Manual
7.4.18.
ED/HD Sharpness Filter and Adaptive Filter Controls
There are three filter modes available on the
encoder block: a sharpness filter mode and two adaptive filter modes.
7.4.18.1.
ED/HD Sharpness Filter Mode
To enhance or attenuate the Y signal in the frequency ranges shown in
, the ED/HD sharpness filter must be enabled (
set to
1) and the ED/HD adaptive filter must be disabled (
set to 0).
Figure 122: ED/HD Sharpness and Adaptive Filter Control Block
To enable the ED/HD sharpness filter, the following bit must be written to.
sharp_en
, Encoder Map,
Address 0xE431[7]
This bit is used to enable the ED/HD sharpness filter on the luma data. By default this is set to 0 which means the filter is disabled.
Function
sharp_en
Description
0 (default)
Disabled
1
Enabled
Likewise, the adaptive filter must be disabled by writing to the following bit.
adapt_en
, Encoder Map,
Address 0xE435[7]
This bit is used to enable the ED/HD adaptive filter.
Function
adapt_en
Description
0 (default)
Disabled
1
Enabled
To select one of the 256 individual responses, the corresponding gain values, ranging from –8 to +7 for each filter, must be programmed into
the ED/HD sharpness filter gain register. These are programmed using
and
kb[3:0]
, Encoder Map,
Address 0xE440[7:4]
This signal is used to configure the ED/HD sharpness filter gain, value B.
Function
kb[3:0]
Description
0000 (default)
Gain B 0
0001
Gain B +1
...
0111
Gain B +7
1000
Gain B -8
...
1110
Gain B -2
1111
Gain B -1
FREQUENCY (MHz)
FILTER A RESPONSE (Gain Ka)
M
AG
NI
T
UDE
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
FREQUENCY (MHz)
FILTER B RESPONSE (Gain Kb)
M
AG
NI
T
UDE
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
FREQUENCY (MHz)
M
AG
NI
T
UDE
RE
S
P
O
NS
E
(
L
in
ear S
cal
e)
1.0
1.1
1.2
1.3
1.4
1.5
1.6
10
12
INPUT
SIGNAL
STEP
FREQUENCY RESPONSE IN SHARPNESS
FILTER MODE WITH Ka = 3 AND Kb = 7
SHARPNESS AND ADAPTIVE FILTER CONTROL BLOCK
0
2
4
6
8
06398-
073
Rev. A | Page 266 of 317
