AK8857VQ Datasheet, PDF (63/105 Pages) Asahi Kasei Microsystems – Dual Channel Digital Video Decoder

[AK8857VQ]
Color killer
In CVBS or S-video input, the chroma signal quality of the input signal is determined by comparison of
its color burst level against the threshold setting in the color killer control register. If the level is below
the threshold, the color killer is activated, resulting in processing of the input as a monochrome signal
and thus with CbCr data fixed at 0x80. Depending on the register setting, the color killer may also be
activated by failure of the color decode PLL lock.
○COLKILL-bit: Settings for color killer ON and OFF
COLKILL-bit
[0]
[1]
Enable
Disable
Notes
○CKLVL[3:0]-bit: For threshold setting; default setting [1000] = −23dB.
○CKSCM[1:0]-bit: Used for threshold setting with SECAM input
CKSCM [1:0]
[00]
{CKLVL [3:0]}
[01]
{0, CKLVL [3:1]}
[10]
{0,0, CKLVL [3:2]}
[11]
Reserved
Notes
1bit shift to right
2bit shift to right
○CKILSEL: Settings for color killer activation
CKILSEL-bit
Condition for activation
[0]
Burst level below threshold setting in CKLVL[3:0]-bits
Burst level below threshold setting in CKLVL[3:0]-bits, or
[1]
Failure of color decode PLL lock
Notes
*
* PLL lock for color decode is not activate during SECAM signal is decode. The color killer ON/OFF
status also depends on No-signal and Burst-level judgement and will not effect by CKILSEL setting.
MS1189-E-01
-63-
2010/12