AK8856 Datasheet, PDF (24/105 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Decoder

ASAHI KASEI
[ AK8856 ]
Input Signal
The AK8856 is designed to decode the following video signals:
- NTSC
- PAL-B, -D, -G, -H, -I.
Those input signal types are set by Input Video Standard Register (R/W) [ Sub Address 0x00].
The input signal is converted into digital code as follows:
Clamp Block ---- Anti-aliasing Filter ---- PGA Block ---- ADC Block
Then the digitized signal is processed in digital block.
Settings of the Input Video Standard Register ( R/W ) [ Sub Address 0x00 ] is described here.
This register sets the input signal attributes.
Sub Address 0x00
bit 7
bit 6
Reserved
Reserved
0
0
bit 5
Reserved
0
bit 4
bit 3
AINSEL
VLF
Default Value
0
0
bit 2
VCEN
0
Default Value : 0x00
bit 1
bit 0
VSCF1
VSCF0
0
0
[VSCF1 : VSCF0]-bit
The input signal sub-carrier frequency is set by the [VSCF1 : VSCF0] bits.
[VSCF1:VSCF0]-bit
Sub-carrier frequency (MHz)
[00]
3.57954545
[01]
3.57561188
[10]
3.582054
[11]
4.43361875
Conditions
NTSC
PAL-B,D,G,H,I
[VCEN]-bit
The input signal Color Encoding system is set by the [VCEN]-bit.
[VCEN]-bit
Color Encoding system
0
NTSC
1
PAL
Conditions
[VLF]-bit
The number of lines per each Frame of the input signal is set by the [VLF] bit.
[VLF]-bit
Number of lines
Conditions
0
525 lines
1
625 lines
[AINSEL]-bit
The input signal is selected by the [AINSEL] bit.
[AINSEL]-bit
Input signal
0
AIN1 input is selected
1
AIN2 input is selected
Conditions
Rev-01
24
2007/03