ADV7184_15 Datasheet, PDF (4/112 Pages) Analog Devices – Multiformat SDTV Video Decoder with Fast Switch Overlay Support

ADV7184
INTRODUCTION
The ADV7184 is a high quality, single chip, multiformat video
decoder that automatically detects and converts PAL, NTSC,
and SECAM standards in the form of composite, S-video, and
component video into a digital ITU-R BT.656 format.
The advanced, highly flexible digital output interface enables
performance video decoding and conversion in line-locked, clock-
based systems. This makes the device ideally suited for a broad
range of applications with diverse analog video characteristics,
including tape-based sources, broadcast sources, security and
surveillance cameras, and professional systems.
ANALOG FRONT END
The ADV7184 analog front end includes four 10-bit ADCs that
digitize the analog video signal before applying it to the standard
definition processor (SDP). The analog front end uses differential
channels for each ADC to ensure high performance in mixed-
signal applications.
The front end also includes a 12-channel input mux that enables
multiple video signals to be applied to the ADV7184. Current and
voltage clamps are positioned in front of each ADC to ensure
that the video signal remains within the range of the converter.
Fine clamping of the video signals is performed downstream
by digital fine clamping within the ADV7184. The ADCs are
configured to run in 4× oversampling mode.
The ADV7184 has optional antialiasing filters on each of
the four input channels. The filters are designed for standard
definition (SD) video with approximately 6 MHz bandwidth.
SCART and overlay functionality are enabled by the ability of
the ADV7184 to process CVBS and standard definition RGB
signals simultaneously. Signal mixing is controlled by the fast
blank (FB) pin.
STANDARD DEFINITION PROCESSOR (SDP)
The ADV7184 is capable of decoding a large selection of baseband
video signals in composite, S-video, and component formats. The
video standards that are supported include PAL B/D/I/G/H,
PAL 60, PAL M, PAL N, PAL Nc, NTSC M/J, NTSC 4.43, and
SECAM B/D/G/K/L. The ADV7184 can automatically detect
the video standard and process it accordingly.
The ADV7184 has a 5-line, superadaptive, 2D comb filter that
provides superior chrominance and luminance separation when
decoding a composite video signal. This highly adaptive filter
automatically adjusts its processing mode according to the video
standard and signal quality without requiring user intervention.
Video user controls such as brightness, contrast, saturation, and
hue are also available within the ADV7184.
The ADV7184 implements the patented ADLLT algorithm to
track varying video line lengths from sources such as a VCR.
ADLLT enables the ADV7184 to track and decode poor quality
video sources such as VCRs and noisy sources from tuner outputs,
VCD players, and camcorders. The ADV7184 contains a CTI
processor that sharpens the edge rate of chroma transitions,
resulting in sharper vertical transitions.
The ADV7184 can process a variety of VBI data services, such
as closed captioning (CC), wide-screen signaling (WSS), copy
generation management system (CGMS), Gemstar® 1×/2×,
extended data service (XDS), and teletext. The ADV7184 is
fully Macrovision certified; detection circuitry enables Type I,
Type II, and Type III protection levels to be identified and
reported to the user. The decoder is also fully robust to all
Macrovision signal inputs.
FUNCTIONAL BLOCK DIAGRAM
AIN1 TO ¹²
AIN12
ANTI-
10
CLAMP ALIAS A/D
FILTER
DATA
PREPROCESSOR
ANTI-
INPUT CLAMP ALIAS
MUX
FILTER
ANTI-
CLAMP ALIAS
FILTER
10
A/D
10
A/D
10
DECIMATION AND 10
DOWNSAMPLING 10
FILTERS
10
ANTI-
10
CLAMP ALIAS A/D
FILTER
SYNC PROCESSING AND
CLOCK GENERATION
SYNC AND
CLK CONTROL
FB
ADV7184
SCLK
SDA
ALSB
SERIAL INTERFACE
CONTROL AND VBI DATA
CONTROL
AND DATA
CVBS/Y
F_SC
RECOVERY
CVBS
C
Cr
CHROMA
DEMOD
Cb
R
G COLOR SPACE
B CONVERSION
STANDARD DEFINITION PROCESSOR
LUMA
FILTER
LUMA
RESAMPLE
LUMA
2D COMB
Y
(5H MAX)
SYNC
EXTRACT
CHROMA
FILTER
RESAMPLE
CONTROL
CHROMA
RESAMPLE
CHROMA ^Cr
2D COMB _Cb
(4H MAX)
Y
Cr
Cb
16
FAST
BLANK
OVERLAY
CONTROL
AND
AV CODE
INSERTION
VBI DATA RECOVERY
MACROVISION
DETECTION
GLOBAL CONTROL
STANDARD
AUTODETECTION
SYNTHESIZED
LLC CONTROL
FREE-RUN
OUTPUT CONTROL
8 _PIXEL
DATA
8 _{P15 TO P8}
P7 TO P0
HS
VS
FIELD
LLC1
LLC2
SFL
INT
Figure 1.
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