AK8851 Datasheet, PDF (27/80 Pages) Asahi Kasei Microsystems – NTSC/PAL/SECAM Digital Video Decoder

ASAHI KASEI
[CKSCM1:CKSCM0]-bit:
This sets the level to activate the Color Killer function in SECAM mode.
[AK8851]
18. Black and White Mode
Black and White mode is to process all input signals as Y signal. In this mode, C signal output becomes 0x80 (REC.601
level). When the Black and White mode is selected, YC separation function is disabled.
When the discrete Y/C input signal is fed, only the Y signal is processed and C signal outputs the fixed 0x80 ( REC.601
level).
Black and White mode set is done by [B/W]-bits of [Input Video Standard Register](R/W)[Sub Address0x01].
Bit allocation of [Input Video Standard Register] is shown below.
Sub Address 0x01
bit 7
bit 6
bit 5
AUTODET
SETUP
B/W
0
0
0
bit 4
bit 3
VLF
VCEN1
Default Value
0
0
bit 2
VCEN0
0
Default Value : 0x00
bit 1
bit 0
VSCF1
VSCF0
0
0
[B/W]-bit:
* This sets the ON/OFF of Black and White mode.
B/W-bit
Status of B/W
Note
mode
0
OFF
Normal Decode
Y-Signal: Sampling data is output after converting to Rec.601 Level
1
ON
C-Signal: All the C-data is output as the value of 0x80.
(All data is output through Luminance data process)
19.UV Filter
The U/V signal bandwidth can be altered by switching the characteristics of the low pass filter positioned after
de-modulation of the C signal. Two filter types can be selected.
Frequency[MHz]
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
10
0
-10
-20
-30
-40
-50
-60
Switching the U/V low pass filters is done by [UVFILSEL1:UVFILSEL0]-bit of [Control 1 Register](R/W)[Sub Address 0x08].
Bit allocation of [Control 1 Register] is shown below.
Sub Address 0x08
bit 7
bit 6
CLKMODE1 CLKMODE0
bit 5
INTPOL1
0
0
0
bit 4
bit 3
INTPOL0 16BITOUT
Default Value
0
0
bit 2
UVFILSEL
0
Default Value : 0x00
bit 1
bit 0
YCSEP1
YCSEP0
0
0
*[UVFILSEL]-bit:
This selects the bandwidth of the UV filters.
[UVFILSEL]-bit
0
1
Please refer to the frequency response characteristics.
Note
Wide
Narrow
MS0244-E-03
27
Confidential
2005 / 07