AK8857VQ Datasheet, PDF (56/105 Pages) Asahi Kasei Microsystems – Dual Channel Digital Video Decoder

[AK8857VQ]
○AGCTL-bit : Settings for selection of quick or slow transition between peak and sync AGC
AGCTL-bit
AGC transition
Notes
[0]
Quick
[1]
Slow
Auto Color Control (ACC)
The ACC of the AK8854 measures the level of the input signal color burst, and adjusts the level to 286
or 300 mV, as appropriate. The ACC is not applicable to SECAM input.
As in AGC, both ACC time constant and ACC freeze settings can be entered.
NTSC-M,J , NTSC-4.43 , PAL-M…………………………..286mV
PAL-B,D,G,H,I,N , PAL-Nc , PAL-60…………. 300mV
○ACCT[1:0]-bit : Settings for ACC time constant
ACCT[1:0]-bit
Time constant
[00]
Disable
[01]
Fast
[10]
Middle
[11]
Slow
Notes
ACC OFF
T= 2Fields
T= 8Fields
T= 30Fields
○ACCFRZ-bit : Settings for freezing ACC function
ACCFRZ-bit
ACC status
[0]
Non-frozen
[1]
Frozen
Notes
The ACC and Color saturation functions operate independently. If ACC is enabled, the color
saturation adjustment is applied to the signal that has been adjusted to the appropriate level by the
ACC.
No-signal output
If no input signal is found (as shown by the control bit NOSIG-bit), the output signal is black-level, blue
level (blueback), or input-state (sandstorm), depending on the register setting.
○NSIGMD-bit : Settings for output signals for no input signal
NSIGMD [1:0]-bit
Output
[00]
Black-level
[01]
Blue-level (blueback)
[10]
Input-state (sandstorm)
[11]
Reserved
Notes
MS1189-E-01
-56-
2010/12