ADV7180
SYNC PROCESSING
Table 64. NTSC
The ADV7180 has two additional sync processing blocks that
postprocess the raw synchronization information extracted
from the digitized input video. If desired, the blocks can be
disabled via the following two I2C bits.
Feature
Standard
Teletext System B and D
Teletext System C/NABTS
Vertical Interval Time Codes (VITC )
ITU-R BT.653
ITU-R BT.653/EIA-516
–
Copy Generation Management
System (CGMS)
EIA-J CPR-1204/IEC 61880
ENHSPLL, Enable Hsync Processor, Address 0x01 [6]
The HSYNC processor is designed to filter incoming hsyncs
that have been corrupted by noise, providing improved per-
formance for video signals with stable time bases but poor SNR.
Gemstar
Closed Captioning (CCAP)
–
EIA-608
Setting ENHSPLL to 0 disables the hsync processor.
The VBI data standard that the VDP decodes on a particular
line of incoming video has been set by default as described in
Table 65. This can be overridden manually and any VBI data
can be decoded on any line. The details of manual
programming are described in Table 66.
Setting ENHSPLL to 1 (default) enables the hsync processor.
ENVSPROC, Enable Vsync Processor, Address 0x01 [3]
This block provides extra filtering of the detected vsyncs to
improve vertical lock.
VDP Default Configuration
Setting ENVSPROC to 0 disables the vsync processor.
Setting ENVSPROC to 1(default) enables the vsync processor.
VBI DATA DECODE
The VDP can decode different VBI data standards on a line-to-
line basis. The various standards supported by default on
different lines of VBI are explained in Table 65.
VDP Manual Configuration
There are two VBI data slicers on the ADV7180. The first is
called the VBI data processor (VDP), and the second is called
VBI System 2.
MAN_LINE_PGM, Enable Manual Line Programming of
VBI Standards, Address 0x64 [7], User Sub Map
The user can configure the VDP to decode different standards on
a line-to-line basis through manual line programming. For this,
the user has to set the MAN_LINE_PGM bit. The user needs to
write into all the line programming registers VBI_DATA_Px_Ny
(see Register 0x64 to Register 0x77 in Table 104).
The VDP can slice both low bandwidth standards and high
bandwidth standards such as teletext. VBI System 2 can slice
low data rate VBI standards only.
The VDP is capable of slicing multiple VBI data standards on
SD video. It decodes the VBI data on the incoming CVBS and
Y/C or YUV data. The decoded results are available as ancillary
data in output 656 data stream. For low data rate VBI standards
like CC/WSS/CGMS, users can read the decoded data bytes
from I2C registers.
0 (default)—The VDP decodes default standards on lines, as
shown in Table 65.
1—VBI standards to be decoded are manually programmed.
VBI_DATA_Px_Ny [3:0], VBI Standard to be Decoded on
Line X for PAL, Line Y for NTSC, Addresses 0x64 to 0x77,
User Sub Map
The VBI data standards that can be decoded by the VDP are
listed in Table 63 and Table 64.
Table 63. PAL
Feature
These are related 4-bit clusters in Register 0x64 to Register 0x77
of the User Sub Map. These 4-bit, line programming registers,
named VBI_DATA_Px_Ny, identify the VBI data standard that
would be decoded on Line X in PAL or on Line Y in NTSC
mode. The different types of VBI standards decoded by
Standard
Teletext System A, C, or D
Teletext System B/WST
Video Programming System (VPS)
Vertical Interval Time Codes ( VITC)
Wide Screen Signaling (WSS)
ITU-R BT.653
ITU-R BT.653
ETSI EN 300 231 V 1.3.1
–
ITU-R BT.1119-1/
ETSI EN.300294
VBI_DATA_Px_Ny are shown in Table 66. Note that the X or Y
value depends on whether the ADV7180 is in PAL or NTSC mode.
Closed Captioning (CCAP)
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