AK8811_12 Datasheet, PDF (30/36 Pages) Asahi Kasei Microsystems – NTSC/PAL Digital Video Encoder

ASAHI KASEI
[AK8811/12]
DAC Mode Register (W only default 00H)
Sub Add bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
05H ^{Reserved Reserved Reserved Reserved Reserved} OUTCP OUTC
bit 0
OUTY
Symbol
OUTCP
OUTC
OUTY
Value
0
1
0
1
0
1
Description
Composite video signal or U signal output : OFF
Composite video singal or U signal output : ON
Chroma signal or V signal output : OFF
Chroma signal or V signal output : ON
Y signal output : OFF
Y signal output : ON
default
default
default
• Video output of AK8811/12 (DAC) can be forced “OFF” independently.
The output of DAC that is forced “OFF” is Hi-impedance. When three DACs are
forced “OFF”, then the internal VREF is also forced “OFF”. In this case, it takes
several miliseconds before the internal VREF reaches the proper voltage after any
DAC becomes “ON”.
SubC Freq. Register (W only default 00H)
Sub Add bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
06H SUBF7 SUBF6 SUBF5 SUBF4 SUBF3 SUBF2 SUBF1 SUBF0
Symbol
SUBF7-SUBF0
Value
Description
Adjustment of frequency between
+127 and –128 step of 0.8Hz
default 0
• AK8811/12 generates the necessary sub-carrier frequency from a system clock by DFS
(Digital Frequency Synthesizer)
• Frequency of default is adjustable by specifying this bit. This bit adjusts the default
frequency.
SubC Phase Register (W only default 00H)
Sub Add bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
07H SUBP7 SUBP6 SUBP5 SUBP4 SUBP3 SUBP2 SUBP1 SUBP0
Symbol
Value
description
SUBP7 – SUBP0
Step: (360° /256°)
• Sub- carrier phase is adjustable by (360° /256) step.
default 0
Rev.1.1
30
2000/01