AK8854VQ Datasheet, PDF (46/95 Pages) Asahi Kasei Microsystems – Multi-Format Digital Video Decoder

[AK8854VQ]
7.9 Auto Color Control_ACC
The ACC of the AK8854 measures the level of the input signal color burst, and adjusts the level to 286^a
or 300^b mV, as appropriate. The ACC is not applicable to SECAM, YPbPr and RGB input.
As in AGC, both ACC time constant and ACC freeze settings can be entered.
a _{NTSC-M,J, NTSC-4.43, PAL-M}
b _{PAL-B, D, G, H, I, N, PAL-Nc, PAL-60}
ACCT[1:0]-bits: Settings for ACC time constant
ACCT[1:0]-bits
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
Notes
[0]
Non-frozen
–
[1]
Frozen
–
Note. The burst-level setting at the time of freezing is maintained during the frozen state.
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.
7.10 Y/C separation
The adaptive two-dimensional Y/C separation of the AK8854 utilizes a correlation detector to select the
best-correlated direction from among vertical, horizontal, and diagonal samples, and selects the
optimum Y/C separation mode. For NTSC-4.43, PAL-60, and SECAM inputs, the Y/C separation is
one-dimensional only, regardless of the setting.
YCSEP[1:0]-bits: Settings for Y/C separation method
YCSEP[1:0]-bits
Y/C separation mode
Notes
[00]
Adaptive
Selects [01] or [10] setting, as appropriate
[01]
1-D
1D (BPF)
[10]
2-D
NTSC-M, J, PAL-M: 3 Line 2-D
PAL-B, D, G, H, I, N, Nc: 5 Line 2-D
[11]
Reserved
—
For NTSC-4.43, PAL-60, and SECAM inputs, Y/C separation is 1-D only, regardless of the setting.
7.11 C filter
The bandwidth of the C filter can be set via the register, as follows.
C358FIL[1:0]: Settings for C filter bandwidth, for input signal with 3.58 MHz subcarrier wave
C358FIL[1:0] -bits
Notes
Notes
[00]
Narrow
[01]
Medium
[10]
Wide
NTSC-M, J, PAL-M, PAL-Nc
[11]
Reserved
C443FIL[1:0]: Settings for C filter bandwidth, for input signal with 4.43 MHz subcarrier wave
C443FIL[1:0] -bits
Notes
Notes
[00]
Narrow
[01]
[10]
Medium
Wide
PAL-B, D, G, H, I, N, NTSC-4.43, PAL-60
[11]
Reserved
Note. No bandwidth selection is possible for SECAM input.
MS0973-E-01
46
2008/07