ADV7183AKST Analog Devices Inc, ADV7183AKST Datasheet - Page 41

• Manufacturer Part Number: ADV7183AKST
• Description: IC VIDEO DECODER NTSC 80-LQFP
• Manufacturer: Analog Devices Inc
• Type: Video Decoderr

Specifications of ADV7183AKST

• Applications: Projectors, Recorders, Security
• Voltage - Supply, Analog: 3.15 V ~ 3.45 V
• Voltage - Supply, Digital: 1.65 V ~ 2 V
• Mounting Type: Surface Mount
• Package / Case: 80-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

BL_C_VBI Blank Chroma During VBI,
Address 0x04 [2]
Setting BL_C_VBI high, the Cr and Cb values of all VBI lines
get blanked. This is done so any data that may come during VBI
is not decoded as color and output through Cr and Cb. As a
result, it should be possible to send VBI lines into the decoder,
then output them through an encoder again, undistorted.
Without this blanking, any wrongly decoded color gets encoded
by the video encoder; therefore, the VBI lines are distorted.
Table 92. BL_C_VBI Function
BL_C_VBI
0
1 (default)
RANGE Range Selection, Address 0x04 [0]
AV codes (as per ITU-R BT-656, formerly known as CCIR-656)
consist of a fixed header made up of 0xFF and 0x00 values.
These two values are reserved and are not to be used for active
video. Additionally, the ITU specifies that the nominal range for
video should be restricted to values between 16 and 235 for
luma and 16 to 240 for chroma.
The RANGE bit allows the user to limit the range of values
output by the ADV7183A to the recommended value range. In
any case, it is ensured that the reserved values of 255d (0xFF)
and 00d (0x00) are not presented on the output pins unless they
are part of an AV code header.
Table 93. RANGE Function
RANGE
0
1 (default)
AUTO_PDC_EN Automatic Programmed Delay Control,
Address 0x27 [6]
Enabling the AUTO_PDC_EN function activates a function
within the ADV7183A that automatically programs the
LTA[1:0] and CTA[2:0] to have the chroma and luma data
match delays for all modes of operation. If set, manual registers
LTA[1:0] and CTA[2:0] are not used by the ADV7183A. If the
automatic mode is disabled (via setting the AUTO_PDC_EN bit
to 0), the values programmed into LTA[1:0] and CTA[2:0]
registers take effect.
Table 94. AUTO_PDC_EN Function
AUTO_PDC_EN
0
1 (default)
Description
Decode and output color during VBI.
Blank Cr and Cb values during VBI (no color, 0x80).
Description
16 ≤ Y ≤ 235
1 ≤ Y ≤ 254
Description
Use LTA[1:0] and CTA[2:0] values for delaying
luma and chroma samples. Refer to the
LTA[1:0] Luma Timing Adjust, Address 0x27
[1:0] and CTA[2:0] Chroma Timing Adjust,
Address 0x27 [5:3] sections.
The ADV7183A automatically determines the
LTA and CTA values to have luma and chroma
aligned at the output.
16 ≤ C/P ≤ 240
1 ≤ C/P ≤ 254
Rev. B | Page 41 of 104
LTA[1:0] Luma Timing Adjust, Address 0x27 [1:0]
The Luma Timing Adjust register allows the user to specify a
timing difference between chroma and luma samples.
There is a certain functionality overlap with the CTA[2:0]
register.
For manual programming, use the following defaults:
•
•
•
Table 95. LTA Function
LTA[1:0]
00 (default)
01
10
11
CTA[2:0] Chroma Timing Adjust, Address 0x27 [5:3]
The Chroma Timing Adjust register allows the user to specify a
timing difference between chroma and luma samples. This may
be used to compensate for external filter group delay differences
in the luma vs. chroma path, and to allow for a different
number of pipeline delays while processing the video down-
strReview this functionality together with the LTA[1:0] register.
The chroma can be delayed/advanced only in chroma pixel
steps. One chroma pixel step is equal to two luma pixels. The
programmable delay occurs after demodulation, where one can
no longer delay by luma pixel steps.
For manual programming use the following defaults:
•
•
•
Table 96. CTA Function
CTA[2:0]
000
001
010
011 (default)
100
101
110
111
CVBS input LTA[1:0] = 00.
YC input LTA[1:0] = 01.
YPrPb input LTA[1:0] = 01.
CVBS input CTA[2:0] = 011.
YC input CTA[2:0] = 101.
YPrPb input CTA[2:0] = 110.
Description
No delay.
Luma 1 clk (37 ns) delayed.
Luma 2 clk (74 ns) early.
Luma 1 clk (37 ns) early.
Description
Not used.
Chroma + 2 chroma pixel (early).
Chroma + 1 chroma pixel (early).
No delay.
Chroma – 1 chroma pixel (late).
Chroma – 2 chroma pixel (late).
Chroma – 3 chroma pixel (late).
Not used.
ADV7183A