Ed/Hd Adaptive Filters - Analog Devices ADV8005 Hardware Reference Manual

ADV8005 Hardware Reference Manual
ka[3:0], Encoder Map, Address 0xE440[3:0]
This signal is used to configure the ED/HD sharpness filter gain, value A.
Function
ka[3:0]
0000 (default)
0001
0111
1000
1110
1111
7.4.18.2.

ED/HD Adaptive Filters

The ED/HD adaptive filter (Threshold A, Threshold B, and Threshold C) registers, the ED/HD adaptive filter (Gain 1, Gain 2, and Gain 3)
registers, and the ED/HD sharpness filter gain register are used in adaptive filter mode. To activate the adaptive filter control, the ED/HD
sharpness filter and the ED/HD adaptive filter must be enabled. Refer to the register tables above for enabling and disabling the sharpness and
adaptive filter.
The derivative of the incoming signal is compared to the three programmable threshold values; that is the ED/HD adaptive filter (Threshold A,
Threshold B, and Threshold C) registers. These registers (thold_a[7:0],
threshold range is 16 to 235, although any value in the range of 0 to 255 can be used.
thold_a[7:0], Encoder Map, Address 0xE45B[7:0]
This register is used to set the ED/HD adaptive filter threshold A.
thold_b[7:0], Encoder Map, Address 0xE45C[7:0]
This register is used to set the ED/HD adaptive filter threshold B.
thold_c[7:0], Encoder Map, Address 0xE45D[7:0]
This register is used to set the ED/HD adaptive filter threshold C.
The edges can then be attenuated with the settings in the ED/HD adaptive filter (Gain 1, Gain 2, and Gain 3) registers. Refer to the registers
fil_resp_aa[3:0], fil_resp_ab[3:0], fil_resp_bb[3:0],
fil_resp_ab[3:0], Encoder Map, Address 0xE458[7:4]
This signal is used to set the adaptive filter gain 1 for the ED/HD standard. This is value B.
Function
fil_resp_ab[3:0]
0000 (default)
0001
0111
1000
1110
1111
Description
Gain A 0
Gain A +1
...
Gain A +7
Gain A -8
...
Gain A -2
Gain A -1
fil_resp_ca[3:0]
Description
Gain B 0
Gain B +1
...
Gain B +7
Gain B -8
...
Gain B -2
Gain B -1
Rev. A | Page 267 of 317
thold_b[7:0] and thold_c[7:0]) are described below. The recommended
and fil_resp_cb[3:0] for details on setting the adaptive filter gains.
UG-707