AK8825 Datasheet, PDF (50/162 Pages) Asahi Kasei Microsystems – HD/SD Multi Format Video Encoder with 3ch DAC

Over-sampling filter with aperture-effect compensation for Luminance (525P/625P)
[AK8825]
AK8825 equips the aperture-effect compensation filter for Luminance Signal.
This filter can be set with HDAFT[1:0]-bit of HD Block Miscellaneous Control Register [Sub Address 0x0A].
Compensation degree can be set with this register-bit. “Mode 0” is less compensation and “Mode 3” is more compensation.
HD Block Miscellaneous Control Register
Sub Address 0x0A
bit 7
bit 6
bit 5
Reserved
Reserved STD770_2C
0
0
0
bit 4
bit 3
HDCEA805B CCWSSSUE
Default Value
0
0
bit 2
Reserved
0
default Value 0x00
bit 1
bit 0
HDAFLT1
HDAFLT0
0
0
HDAFLT[1:0]-bit
00
01
10
11
Filter mode
MODE0
MODE1
MODE2
MODE3
less
more
Note
x2 Over-sampling Filter for Y-data
10
0
3
0 2 4 6 8 10 12 14 16 18 20 22 24 26
2
-10
1
-20
0
-30
-1 ⁰
-2
-40
-3
-50
-4
-60
-5
Frequency[MHz]
Fig. 43 x2 Over-sampling filter for 525p/625p
x4 Over-sampling Filter for Cb/Cr
10
0
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
-10
-20
-30
-40
-50
-60
Frequency[MHz]
Fig. 44 x4 Over-sampling filter for 525p/625p
Aperteu Filter
5
10
MODE3
MODE2
MODE1
MODE0
Frequency[MHz]
Fig. 42 Aperture Filter
Rev-E-00
50
2008/03