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ADV7183A
Table 72. Betacam Levels
Name
Y Range
Pb and Pr Range
Sync Depth
Rev. A | Page 35 of 104
Betacam (mV)
0 to 714 (incl. 7.5% pedestal)
–467 to +467
286
Betacam Variant (mV)
0 to 714
–505 to +505
286
SMPTE (mV)
0 to 700
–350 to +350
300
MII (mV)
0 to 700 (incl. 7.5% pedestal)
–324 to +324
300
CG[11:0] Chroma Gain (SDP), Address 0x2D, [3:0];
Address 0x2E, [7:0] CMG[11:0] Chroma Manual Gain (SDP),
Address 0x2D, [3:0]; Address 0x2E, [7:0]
Chroma gain [11:0] is a dual function
register:
If written to, a desired manual chroma gain can be
programmed. This gain becomes active if the CAGC[1:0]
mode is switched to manual fixed gain.
Refer to Equation 2 for calculating a desired gain.
If read back, this register returns the current gain value.
Depending on the setting in the CAGC[1:0] bits, this will
be one of the following values:
o
Chroma manual gain value (CAGC[1:0] set to chroma
manual gain mode).
o
Chroma automatic gain value (CAGC[1:0] set to any
of the automatic modes).
Table 73. CG/CMG Function
CG[11:0]/CMG[11:0]
Read/Write
CMG[11:0]
Write
Description
Manual gain for chroma
path.
Currently active gain.
CG[11:0]
Read
(
)
4
...
0
1024
4095
0
_
=
≤
<
=
CG
Gain
Chroma
Equation 2. SDP Chroma Gain Formula
Example
Freezing the automatic gain loop and reading back the
CG[11:0] register results in a value of
Convert the read back value to decimal:
0x47A = 1146
d
Apply Equation 2 to convert the readback value:
1146/1024 = 1.12
CKE Color Kill Enable (SDP), Address 0x2B, [6]
The Color Kill Enable bit allows the optional color kill function
to be switched on or off.
For QAM based video standards (PAL and NTSC) as well as FM
based systems (SECAM), the threshold for the color kill
decision is selectable via the CKILLTHR[2:0] bits.
If color kill is enabled, and if the color carrier of the incoming
video signal is less than the threshold for 128 consecutive video
lines, color processing is switched off (black and white output).
To switch the color processing back on, another 128 consecutive
lines with a color burst greater than the threshold are required.
The color kill option only works for input signals with a
modulated chroma part. For component input (YPrPb), there is
no color kill.
Table 74. CKE Function
CKE
Description
0
Color kill disabled.
1*
Color kill enabled.
*Default value.
CKILLTHR[2:0] Color Kill Threshold (SDP),
Address 0x3D, [6:4]
The CKILLTHR[2:0] bits allow the user to select a threshold for
the color kill function. The threshold only applies to QAM
based (NTSC and PAL) or FM modulated (SECAM) video
standards.
To enable the color kill function, the CKE bit must be set. For
settings 000, 001, 010, and 011, chroma demodulation inside the
ADV7183A may not work satisfactorily for poor input video
signals.
Table 75. CKILLTHR Function
CKILLTHR[2:0]
SECAM
000
No color kill
001
Kill at < 5%
010
Kill at < 7%
011
Kill at < 8%
100*
Kill at < 9.5%
101
Kill at < 15%
110
Kill at < 32%
111
Reserved for ADI internal use only. Do not
select.
*Default value.
Description
NTSC, PAL
Kill at < 0.5%
Kill at < 1.5%
Kill at < 2.5%
Kill at < 4.0%
Kill at < 8.5%
Kill at < 16.0%
Kill at < 32.0%