ADV7181BCP Analog Devices Inc, ADV7181BCP Datasheet - Page 40

• 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
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 comes 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 is encoded by the
video encoder; therefore, the VBI lines are distorted.
Table 91. 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 therefore are not to be used
for active video. Additionally, the ITU also 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 ADV7181 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 92. 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 ADV7181 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 ADV7181. 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 93. 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 ADV7181 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 40 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 94. 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 can
be used to compensate for external filter group delay differences
in the luma vs. chroma path, and to allow a different number of
pipeline delays while processing the video down-stream. Review
this functionality together with the LTA[1:0] register.
The chroma can only be delayed/advanced 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 95. 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
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.
Description
No delay.
Luma 1 clk (37 ns) delayed.
Luma 2clk (74 ns) early.
Luma 1 clk (37 ns) early.