EVAL-ADV7183BEB View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'EVAL-ADV7183BEB' PDF : 104 Pages View PDF
ADV7183A
AV CODE INSERTION AND CONTROLS
This section describes the I2C based controls that affect
• Insertion of AV codes into the data stream
• Data blanking during the vertical blank interval (VBI)
• The range of data values permitted in the output data
stream
• The relative delay of luma vs. chroma signals
Some of the decoded VBI data is inserted during the horizontal
blanking interval. See the Gemstar Data Recovery section for
more information.
BT656-4 ITU Standard BT-R.656-4 Enable, Address 0x04 [7]
The ITU has changed the position for toggling of the V bit
within the SAV EAV codes for NTSC between revisions 3 and 4.
The BT656-4 standard bit allows the user to select an output
mode that is compliant with either the previous or the new
standard. For further information, review the standard at
http://www.itu.int.
The standard change affects NTSC only and has no bearing on
PAL.
Table 89. BT656-4 Function
BT656-4 Description
0 (default) BT656-3 Spec: V bit goes low at EAV of Lines 10
and 273.
1
BT656-4 Spec: V bit goes low at EAV of Lines 20
and 283.
SD_DUP_AV Duplicate AV codes, Address 0x03 [0]
Depending on the output interface width, it may be necessary to
duplicate the AV codes from the luma path into the chroma path.
In an 8-bit-wide output interface (Cb/Y/Cr/Y interleaved data),
the AV codes are defined as FF/00/00/AV, with AV being the
transmitted word that contains information about H/V/F.
In this output interface mode, the following assignment takes
place: Cb = FF, Y = 00, Cr = 00, and Y = AV.
In a 16-bit output interface where Y and Cr/Cb are delivered via
separate data buses, the AV code is over the whole 16 bits. The
SD_DUP_AV bit allows the user to double up the AV codes, so
the full sequence can be found on the Y bus as well as
(= duplicated) the Cr/Cb bus. See Figure 19.
Table 90. SD_DUP_AV Function
SD_DUP_AV Description
0 (default)
AV codes in single fashion (to suit 8-bit
interleaved data output).
1
AV codes duplicated (for 16-bit interfaces).
VBI_EN Vertical Blanking Interval Data Enable,
Address 0x03 [7]
The VBI enable bit allows data such as intercast and closed
caption data to be passed through the luma channel of the
decoder with only a minimal amount of filtering. All data for
Lines 1 to 21 is passed through and available at the output port.
The ADV7183A does not blank the luma data, and automati-
cally switches all filters along the luma data path into their
widest bandwidth. For active video, the filter settings for YSH
and YPK are restored.
Refer to the BL_C_VBI Blank Chroma During VBI section for
information on the chroma path.
Table 91. VBI_EN Function
VBI_EN
Description
0 (default)
All video lines are filtered/scaled.
1
Only active video region is filtered/scaled.
Y DATA BUS
Cr/Cb DATA BUS
SD_DUP_AV = 1
16-BIT INTERFACE
FF
00
00
AV
FF
00
00
AV
AV CODE SECTION
16-BIT INTERFACE
Y
00
AV
Y
Cb
FF
00
Cb
AV CODE SECTION
Figure 19. AV Code Duplication Control
SD_DUP_AV = 0
8-BIT INTERFACE
Cb/Y/Cr/Y
INTERLEAVED
FF 00 00 AV Cb
AV CODE SECTION
Rev. B | Page 40 of 104
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