AK4710 Datasheet, PDF (18/31 Pages) Asahi Kasei Microsystems – Low Power Single SCART Driver

[AK4710]
■ Video Output Control (05H: D6-D0,)
Each video output can be set to Hi-Z individually via the control registers.
TVV: TVVOUT output control
TVR: TVRCOUT output control
TVG: TVGOUT output control
TVB: TVBOUT output control
RCAV: RCAVOUT output control
TVFB: TVFB output control
0: Hi-Z. (default)
1: Active.
■ Clamp and DC-restore Circuit Control (06H: D7-D3)
Each CVBS and Y input has a sync tip clamp circuit. The DC-restore circuit has two clamp voltages; 0.20V(typ) and
1.44V(typ) to support both RGB and YPbPr signal. They correspond to 0.10V(typ) and 0.72V(typ) at the SCART
connector when matched by 75Ω resistors. CLAMP1 and CLAMPB bits select the input circuit for both the ENCRC pin
(Encoder Red/Chroma) and the ENCB pin (Encoder Blue), and CLAMP2 bit selects the input circuit for the ENCG pin.
VCLP1-0 bits select the sync source of DC- restore circuit.
CLAMPB
0
0
1
1
CLAMP1
0
1
0
1
ENCRC Input Circuit
ENCB Input Circuit
DC restore clamp active
(0.20V at sync timing/output pin)
Biased
(1.44V at sync timing/output pin)
DC restore clamp active
(0.20V at sync timing/output pin)
DC restore clamp active
(0.20V at sync timing output pin)
DC restore clamp active
DC restore clamp active
(1.44V at sync timing/output pin) (1.44V at sync timing/output pin)
(reserved)
(reserved)
Table 8. DC-restore Control for Encoder Input
note
for RGB
for Y/C
for Y/Pb/Pr
(default)
CLAMP2
0
1
ENCG Input Circuit
DC restore clamp active
(0.20V at sync timing/output pin)
Sync tip clamp active
(0.20V at sync timing/output pin)
note
for RGB
for Y/Pb/Pr
(default)
Note: When the VTV1-0 bits = “01” (source for TV = Encoder CVBS /RGB), TVG bit = “1” (TVG = active) and
VCLP1-0 bits = “11” (DC restore source = ENCG), the sync tip is selected even if the CLAMP2 bit = “0”.
Table 9. DC-restore Control for Encoder Green/Y Input
VCLP1-0: DC restore source control
VCLP1 VCLP0
Sync Source of DC Restore
0
0
ENCV
0
1
1
0
ENCY
(Reserved)
1
1
ENCG
Table 10. DC-restore Source Control
(default)
Rev. 0.3
- 18 -
2011/07