1.0 Functional Description
CX25870/871
1.3 Device Description
Flicker-Free Video Encoder with Ultrascale Technology
1.3 Device Description
1.3.1 Overview
The CX25870/871 is a video encoder designed for TV output of interlaced and
noninterlaced graphics data. Common applications requiring flicker-filtered TV
output include:
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desktop/portable PCs with TV Out
high definition TVs
DVD players and set top boxes
graphic cards with TV Out
game consoles
set-top boxes
It incorporates normal and adaptive filtering technology for flicker removal
and flexible amounts of overscan compensation for high-quality display of
noninterlaced images on an interlaced TV. The CX25870/871 accomplishes this
by minimizing the flicker and controlling the amount of overscan so that the
entire image is viewable.
The CX25870/871 consists of a Color Space Converter/Flicker Filter engine
followed by a digital video encoder. The Color Space Converter/Flicker Filter
contains:
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A timing converter
Various horizontal video processing functions
Flicker filter and vertical scaler for overscan compensation
The output of this engine feeds into a FIFO for synchronization with the
digital video encoder.
The CX25870/871 provides Composite, S-Video, or 3-signal analog RGB or
YPBPR HDTV output. While the encoder is in HDTV output mode, the device
will automatically insert trilevel synchronization pulses (when necessary) and
vertical synchronizing “broad pulses.” The CX25870/871 is compliant with
EIA770-3, SMPTE 274M/293M/296M and supports ATSC HDTV resolutions
including 480p, 720p, and 1080i.
1.3.2 Serial Interface
The device includes a 2-wire read and write serial interface for programming the
registers in the device. The interface is designed to operate with 3.3 V levels. To
ensure that valid serial data is received and transmitted, make sure the VDD_SI
pin is connected to a stable 3.3 V supply. Review Chapter 2.2, Chapter 2.3 and
Chapter 2.4 for more details of the encoder’s serial interface.
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Conexant
100381B
CONEXANT [ CONEXANT SYSTEMS, INC ]
