AK8813 Datasheet, PDF (21/51 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Encoder

ASAHIKASEI
[AK8813/14]
♦ Closed Caption and Extended Data
AK8813/14 supports both Closed Captioning and Extended Data. They are controlled “ON” or ”OFF”
respectively by [ Video Process 2 Register(02H) ]. Each data consists of 2 continuous bytes
register( Closed Caption R (16H,17H) ), and it is recognized as the data is renewed when the second
byte(17H register) is written in the register. After the data is renewed, AK8813/14 encodes Closed
Captioning and Extended Data at the designated line. If the data isn’t renewed, AK8813/14 outputs
“ASCII-NULL” code. The data is supposed as Odd Parity and 7 bit US-ASCII code. Host should provide a
parity bit.
*In PAL encoding mode, AK8813/14 outputs them at the same timing and same pattern as NTSC.
*The line where Closed Captioning data is encoded is as follows.
Closed Caption
525/60 System (SMPTE)
21 Line default
625/50 System (CCIR)
22 Line default
Extended Data
284 Line default
335 Line default
50 +/- 2 IRE
10.5 +/- 0.25usec
12.91 usec
240+/- 48nsec
240+/- 48nsec
Two 7-bit + PARITY ASCII
Characters Data
D0-D6
D0-D6
40IRE
10.003 +/- 0.25usec
27.382 usec
61 usec
33.764 usec
Fig. 4 Closed Captioning Wave form
Rev.00
- 22 -
2004/Oct