AK8817_07 Datasheet, PDF (28/43 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Encoder

ASAHI KASEI
[AK8817/18]
(17) Video ID
The AK8817 supports to encode the Video ID ( EIAJ CPR-1204 ) which distinguishes the aspect ratio etc..
This is also used as CGMS ( Copy Generation Management System ).
Turning “ON/OFF” of this function is made by setting both VMOD-bit = 0 and VBID-bit = 1 of { Control 1 Register (0x00) }.
And data to be set is written into { VBID / WSS Data1 & 2 Registers ( 0x02,0x03 )}.
Video ID information is the highest order of priority information among VBI information
VBID Data Update timing .
VSYNC
u-P Data
Set C ontrol R egister
NEW DATA
DATA
OLD DATA
NEW DATA
VBID Code assignment
20 bit data is configured with WORD0 = 2 bit, WORD1 = 4 bit, WORD2 = 8 bit and CRC = 6 bit.
CRC is automatically calculated and added by the AK8817.
Default values of CRC polynomial expression X6 + X + 1 are all ones.
-data configuration
bit1
DATA
WORD0
2bit
VBID Waveform
WORD1
4bit
WORD2
8bit
Ref. bit1 bit2 bit3 ••• bit20
70IRE +/- 10IRE
CRC
6bit
bit20
2.235usec +/- 50nsec
11.2usec +/- 0.3usec
49.1usec +/- 0.44usec
1H
0IRE
+
−
10 IRE
5 IRE
Amplitude
Encode Line
525/60 System
70IRE
20/283
Rev.000E
28
2007 / 03