AK8850 Datasheet, PDF (50/99 Pages) Asahi Kasei Microsystems – NTSC Digital Video Decoder

ASAHI KASEI
[AK8850]
( 2 ) BRIGHTNESS
Brightness adjustment is accomplished by adding an offset factor to the Luminance signal which is set by the
[ BRIGHTNESS CONTROL REGISTER ]. The adjustable range is +/- 200 ( 255 steps ). Arithmetic operations are
performed on the 10-bit data. When the result exceeds the specified range,it is clipped to 1023 ( upper limit ) or to 0
( lower limit ).
Brightness
Brightness Control Register :
* [ BRIGHTNESS CONTROL REGISTER ]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
BR7
BR6
BR5
BR4
BR3
BR2
BR1
BR0
Default Value
0
0
0
0
0
0
0
0
Increases the value of the Luminance signal. Arithmetic operations are done on the 10-bit data and adjustable range is
from – 128 to + 127 with 1 fraction per step. The adjustable value per step of the ITU-R BT.601 compatible output is
shown in the table below. The register is expressed in 2’s complement form and its default value is 0x00.
* Adjustable Value Per Each Step
Input Video Signal
286mV Sync without Setup
286mV Sync (with Setup)
300mV Sync (without Setup)
300mV Sync ( with Setup )
Add Value (rounding)
1 [BR7:BR0]*100/255
1 [BR7:BR0]*108/255
1 [BR7:BR0]*102/255
1 [BR7:BR0]*111/255
Note
NTSC Composite/YC /Betacam
NTSC Composite/YC /Betacam
MII / EBU-N10
MII
( 3 ) HUE CONTROL
HUE adjustment is made by rotating the Chroma signal by a predetermined angle which is set by the [ HUE CONTROL
REGISTER ]. HUE adjustment ranges from – 90 degrees to + 90 degrees ( 1/255 step ). HUE control is valid only when
either a Composite orY/C signals are input.
CR
C
CB
CB
HUE
Hue Control Register :
* [ HUE CONTROL REGISTER ]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
HUE7
HUE6
HUE5
HUE4
HUE3
HUE2
HUE1
HUE0
Default Value
0
0
0
0
0
0
0
0
Sets the rotation angle of HUE. Adjustable range is +/- 90 degrees with 0.7 degree HUE rotation per step. Default value is
the un-adjusted 0x00. The value is in 2’s complement format. The HUE control is valid only when the Composite or Y/C
signals are input ( it is disabled for Component input ).
NTSC(525 System)
Composite
Y/C
Component
Betacam
MII
This Register is functioned
This Register is disable
625 System
Component
This register is Disable
Rev.0
50
2003/01