ADV7181BCP Analog Devices Inc, ADV7181BCP Datasheet - Page 34

• Manufacturer Part Number: ADV7181BCP
• Description: IC VIDEO DECODER NTSC 64-LFCSP
• Manufacturer: Analog Devices Inc
• Type: Video Decoderr

Specifications of ADV7181BCP

• Applications: Recorders, Set-Top Boxes
• Voltage - Supply, Analog: 3.15 V ~ 3.45 V
• Voltage - Supply, Digital: 1.65 V ~ 2 V
• Mounting Type: Surface Mount
• Package / Case: 64-LFCSP
• Adc/dac Resolution: 9b
• Screening Level: Industrial
• Package Type: LFCSP EP
• Pin Count: 64
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: EVAL-ADV7181BEB - BOARD EVALUATION FOR ADV7181
• Lead Free Status / RoHS Status: Compliant, Contains lead / RoHS non-compliant

ADV7181
CG[11:0] Chroma Gain, Address 0x2D [3:0];
Address 0x2E [7:0] CMG[11:0] Chroma Manual Gain,
Address 0x2D [3:0]; Address 0x2E [7:0]
Chroma gain [11:0] is a dual-function register:
•
•
•
Table 71. CG/CMG Function
CG[11:0]/CMG[11:0]
CMG[11:0]
CG[11:0]
Example
Freezing the automatic gain loop and reading back the
CG[11:0] register results in a value of 0x47A.
1.
2.
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 is one
of the following values:
o
o
Convert the read back value to decimal:
0x47A = 1146d
Apply Equation 2 to convert the readback value:
1146/1024 = 1.12
Chroma
Chroma manual gain value (CAGC[1:0] set to chroma
manual gain mode).
Chroma automatic gain value (CAGC[1:0] set to any
of the automatic modes).
_
Gain
=
(
Read/Write
Write
Read
0
<
CG
1024
≤
4095
)
Description
Manual gain for chroma
path.
Currently active gain.
=
0
...
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CKE Color Kill Enable, 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 modu-
lated chroma part. For component input (YPrPb), there is no
color kill.
Table 72. CKE Function
CKE
0
1 (default)
CKILLTHR[2:0] Color Kill Threshold, 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 ADV7181 may not work satisfactorily for poor input video
signals.
Table 73. CKILLTHR Function
CKILLTHR[2:0]
000
001
010
011
100 (default)
101
110
111
Description
Color kill disabled.
Color kill enabled.
Kill at < 9.5%
SECAM
No color kill
Kill at < 5%
Kill at < 7%
Kill at < 8%
Kill at < 15%
Kill at < 32%
Reserved for ADI internal use only. Do not
select.
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%