[AK4706]
CIO
VCRC
State of VCRC pin
0
0
1
1
0
1
0
1
Hi-Z (default)
Active
Connected to GND
Connected to GND
Table 17 Red/Chroma Bi-directional Control
■ RGB Video Gain Control (06H: D1-D0)
VVOL1-0 bits set the RGB video gain.
VVOL1 VVOL0
Gain
Output level (Typ. @Input=0.7Vpp)
0
0
1
1
0
1
0
1
+6dB
1.4Vpp (default)
1.6Vpp
+7.2dB
+8.2dB
+9.1dB
1.8Vpp
2.0Vpp
Table 18. RGB video gain control
■ Clamp and DC-restore circuit control (06H: D7-D2, 0AH: D3)
Each CVBS and Y input has the sync tip clamp circuit. The DC-restore circuit has two clamp voltages 0.7V(typ) and
2.2V(typ) to support both RGB and YPbPr signal. They correspond to 0.35V(typ) and 1.1V(typ) at the SCART connector
when matched by 75ohm resistors. The CLAMP1, CLAMP0 and CLAMPB bits select the input circuit for ENCRC pin
(Encoder Red/Chroma), ENCB pin (Encoder Blue), VCRRC pin (VCR Red/Chroma) and VCRB pin (VCR Blue)
respectively. VCLP1-0 bits select the sync source of DC- restore circuit.
CLAMPB
CLAMP0
VCRRC Input Circuit
VCRB Input Circuit
VCRG Input Circuit
note
0
0
1
1
0
1
0
1
DC restore (0.7V)
Biased
DC restore (2.2V)
(reserved)
DC restore (0.7V)
DC restore (0.7V)
DC restore (2.2V)
(reserved)
DC restore (0.7V)
DC restore (0.7V)
Sync Tip Clamp (0.7V)
(reserved)
for RGB
for Y/C
for YPbPr
(default)
Table 19. DC-restore control for VCR Input
CLAMPB
CLAMP1
ENCRC Input Circuit
ENCB Input Circuit
note
0
0
1
1
0
1
0
1
DC restore (0.7V)
Biased
DC restore (2.2V)
(reserved)
DC restore (0.7V)
DC restore (0.7V)
DC restore (2.2V)
(reserved)
for RGB
for Y/C
for YPbPr
(default)
Table 20. DC-restore control for Encoder Input
CLAMP2
ENCG Input Circuit
DC restore (0.7V)
note
0
1
for RGB
for YPbPr
(default)
Sync tip clamp (0.7V)
Note: When the VTV2-0 bits = “001”, TVG bit = “1” and VCLP2-0 bits = “011”, Sync tip is selected even if the
CLAMP2 bit = “0”.
Table 21. DC-restore control for Encoder Green/Y Input
MS0507-E-01
2010/09
- 31 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
