
ASAHI KASEI 
AKM CONFIDENTIAL
[AK4703] 
Rev. 0.1 
2004/03 
- 16 - 
3.
Video Block 
Video Switch Control 
The AK4703 has switches for TV, VCR and RF modulator. Each switch can be controlled via registers independently. 
When AUTO bit = “1” or STBY bit = “1”, these switches setting is ignored and set to fixed configuration (loop-through 
mode). Please refer the auto setup mode and standby mode.
(04H: D2-D0)
Source of 
TVVOUT pin
Shutdown 
000 
(Hi-Z) 
Encoder CVBS /RGB 
001 
ENCV pin 
Encoder Y/C 1 
010 
ENCV pin 
Encoder Y/C 2 
011 
ENCY pin 
VCR (default) 
100 
VCRVIN pin 
TV CVBS 
101 
TVVIN pin 
(Reserved) 
110 
- 
(Reserved) 
111 
- 
Table 6. TV video output (Please refer notes) 
(04H: D5-D3)
Mode 
VTV2-0 bit 
Source of 
TVRC pin 
(Hi-Z) 
ENCRC pin 
ENCRC pin 
ENCC pin 
VCRRC pin 
(Hi-Z) 
- 
- 
Source of 
TVG pin 
(Hi-Z) 
ENCG pin 
Hi-Z 
Hi-Z 
VCRG pin 
(Hi-Z) 
- 
- 
Source of 
TVB pin 
(Hi-Z) 
ENCB pin 
(Hi-Z) 
(Hi-Z) 
VCRB pin 
(Hi-Z) 
- 
- 
Mode 
VVCR2-0 bit
Source of  
VCRVOUT pin
(Hi-Z) 
ENCV pin 
ENCY pin 
TVVIN pin 
VCRVIN pin 
- 
- 
- 
Source of  
VCRC pin 
(Hi-Z) 
ENCRC pin 
ENCC pin 
(Hi-Z) 
VCRRC pin 
- 
- 
- 
Shutdown 
000 
001 
010 
011 
100 
101 
110 
111 
Encoder CVBS or Y/C 1
Encoder CVBS or Y/C 2
TV CVBS (default) 
VCR 
(Reserved) 
(Reserved) 
(Reserved) 
Table 7. VCR video output (Please refer notes) 
(04H: D7-D6)
Mode 
VRF1-0 bit
00 
Source of RFV pin 
ENCV pin 
ENCG pin  
(Note 2) 
VCRVIN pin 
(Hi-Z) 
Encoder CVBS1 
Encoder CVBS2 
01 
VCR (Default) 
Shutdown 
10 
11 
Table 8. RF video output 
Note 1. When input the video signal via ENCRC pin or VCRRC pin, set CLAMP1-0 bits respectively. 
  Note 2. When VTV2-0 bit = “001”, TVG bit = “1” and VRF1-0 bit = “01”, RFV pin output is same as TVG pin 
output (Encoder G).