AK8850 Datasheet, PDF (60/99 Pages) Asahi Kasei Microsystems – NTSC Digital Video Decoder

ASAHI KASEI
[AK8850]
Video Aspect Related Registers :
* [ REQUEST VBI INFO REGISTER ]
bit 7
bit 6
bit 5
Reserved Reserved Reserved
0
0
0
bit 4
bit 3
WSSRQ VBIDRQ
Default Value
0
0
bit 2
EXTRQ
0
bit 1
CCRQ
0
bit 0
ASPECTRQ
0
* [ STATUS 2 REGISTER ]
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
APS1
APS0
Reserved
WSS
VBID
EXT
CC
ASPECT
A decoding request of the Video Aspect signal, superimposed on the input signal is done by writing “1” to the
ASPECTRQ-bit of the [ REQUEST VBI INFO REGISTER ]. The AK8850 is put into a wait state for data decoding. A
decode complete signal is sent back to the [ STATUS 2 REGISTER ]. The decoded data is written into the [ WSS 2 &
ASPECT DATA REGISTER ].
* [ WSS 2 & ASPECT DATA REGISTER ]
bit 7
bit 6
bit 5
ASPECT Reserved
G4-13
bit 4
G4-12
bit 3
G4-11
bit 2
G3-10
bit 1
G3-9
bit 0
G3-8
Aspect-bit =0 : Normal signal
Aspect-bit =1 : Wide signal
A Video Aspect decode request signal should be made only when NTSC Composite or Y/C signals are input. If a
decoding request is made with the 525 Component input, decoding is actually done as in the Composite signal input case.
In this case no Video Aspect signal exists in the signal and resulting data is meaningless.
If a decoding request is made with the 625 Component input, it is ignored and the request bit is kept at “1” ).
7-4-14 DIGITAL PIXEL INTERPOLATOR
A digital Pixel Interpolator is equipped in order to align Pixels in the Vertical direction. ON / OFF / AUTO modes of the
interpolator is selectable by the [ CONTROL 1 REGISTER ] setting. If the Auto mode is selected, the ON / OFF state of
the interpolator is automatically set by the clock mode used as follows.
Line-locked mode : OFF
Frame-locked mode : ON
External clock mode : ON
Pixel Interpolator Related Registers :
* [ CONTROL 1 REGISTER ]
bit 7
bit 6
bit 5
FRCSYNC Reserved INTPOL1
1
0
0
bit 4
bit 3
INTPOL0 AGCC1
Default Value
0
0
bit 2
AGCC0
0
bit 1
AGCT1
0
bit 0
AGCT0
0
* INTOL1 : INTOL0-bit set
INTPOL1:INTPOL0
00
Auto
01
ON
10
OFF
11
Reserved
Pixel Interpolator
In Auto mode, ON / OFF states of the interpolator are selected by the clock mode used. The interpolator mode selection is
not affected by the types of input signals ( same for 525 line and 625 line systems ).
Rev.0
60
2003/01