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Электронный компонент: CX22490

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d i g i t a l i n f o t a i n m e n t p r o d u c t s
lnteractive TV Decoders
C X 2 2 4 9 0 / 2 2 4 9 6
MPEG-2 A/V decoding, Dolby Digital decoding
Dedicated RISC-based transport
stream processor
High-performance 32-bit 175 MIPS integrated
CPU (ARM940T)
High-performance 2D graphics
rendering acceleration
Multiplane video/graphics compositing
and display engine
High-performance unified memory
controller architecture
Full suite of set top peripheral I/O
interface controllers
Distinguishing Features
Single-Chip Interactive TV Solutions
Conexant's interactive TV decoder products provide complete
system solutions for the core electronics of high-performance set top
boxes deployed in digital satellite, cable or terrestrial TV networks.
The CX22490 and CX22496 offer an advanced, embedded 32-bit RISC
CPU, an MPEG-2 audio/video decoder and 2D graphics performance.
This combination enables consumer electronics manufacturers to
build low-cost digital TV set top boxes to support a wide range of
advanced, interactive, consumer entertainment services.
The CX22490 and CX22491 combine an MP@ML MPEG-2 video
decoder, a digital audio decoder, a programmable MPEG-2/DVB/
ATSC/DSS transport stream demultiplexer, a high-speed 2D graphics
rendering engine, and an advanced display compositing engine with
a high-performance, embedded 32-bit 175 MIPS ARM940T RISC
processor and integrated peripheral I/O ports. These second-
generation interactive TV decoders share a common core feature
set. The CX22490 adds USB and IDE multiword DMA support to the
core features, while the CX22496 adds NDS CA hardware support.
CX22490/22496-based set top box system
lnteractive TV Decoders
C X 2 2 4 9 0 / 2 2 4 9 6
d i g i t a l i n f o t a i n m e n t p r o d u c t s
Fast CPU and Graphics
The CX22490/22496's powerful 32-bit RISC
processor and advanced video/graphics display
controller provide a platform ideally suited to
support Internet access and interactive multimedia
applications. The CPU core easily handles computa-
tionally intensive host signal processing tasks for
Internet applications, such as codecs for streaming
audio, Internet telephony, speech and video.
Additionally, the CX22490/22496 provides ample CPU
processing power to support implementation
of a complete, low-speed modem datapump and
controller in software.
Low-Cost ICs for Entry-Level Interactive TV
Conexant's interactive TV decoders feature all
the major subsystems required to implement the
core system and decoder electronics of a digital
interactive TV set top box. This includes an MPEG-2
A/V decoder (Dolby Digital audio is optional), a 32-bit
RISC CPU, a 2D graphics accelerator, a video/graphics
display compositing controller and a set of peripheral
I/O ports for set top box front and back panel
connectors. For a complete system hardware design,
you only need to add a TV encoder, tuner/demodulator,
modem codec, audio DAC, SDRAM and flash
memory ICs.
This high level of system-on-chip integration delivers
the low-cost system bill of materials sought after
by mainstream digital, multichannel TV operators. At
the same time, our ICs offer an advanced hardware
capability for entry-level interactive or enhanced TV.
Entry-level interactive TV lets viewers do more
than just watch programs. It upgrades the TV's
user navigation interface from a simple Electronic
Program Guide (EPG) to a more sophisticated
application for both digital TV programming and
enhanced information services. The services typically
offered include local news and weather, interactive
advertising and simple games.
An enhanced TV set top box requires more
memory than a basic box for TV viewing. Conexant's
interactive TV decoders feature an innovative, unified
memory architecture that reduces memory costs by
servicing all system requirements in a single, flexible,
external 4 MB SDRAM buffer. System hardware costs
are further minimized by implementing analog
modem return path functionality in software running
on the 175 MIPS embedded ARM940T CPU. This
embedded CPU offers ample resources to power
a 2,400-baud software modem datapump and
controller, in addition to servicing all interactive
TV system requirements.
Expandable to Advanced Interactive
Set Top Box Platform
Moving beyond the entry level, many operators are
offering a "walled garden" suite of truly interactive
online applications accessible through the TV. They
deliver services using both the digital broadcast
stream and an analog telco modem, typically V.34
or V.90. Interactive applications for this class of
platform include banking and shopping from home,
and possibly limited Internet access and e-mail
capabilities. Conexant's interactive TV decoders offer CPU and
graphics performance ideally suited for such mid-range interactive
TV set top boxes, in which a system can be implemented using
8 MB or 16 MB of SDRAM, depending on the functionality desired.
Conexant's powerful video/graphics display compositing engine
supports up to six independent image planes to enable the
rich visual interface required for simultaneous TV viewing and
application interaction. In addition, Conexant's 2D graphics
rendering engine can composite an unlimited number of graphics
planes with transparency into a single displayable OSD plane.
More advanced interactive systems on high-bandwidth cable
networks go even further. They offer full Internet access,
including Web browsing, e-mail and chat applications.
Conexant's architecture scales up to satisfy the requirements of
this computer-centric set top box model with a high-performance,
133 MHz, 32-bit SDRAM memory controller and a 160 MHz,
32-bit CPU providing 160 MIPS dedicated to OS and
application execution.
A high-performance 2D graphics rendering engine accelerates
8/16/32bpp graphics screen updates to support multiple
overlapping graphics screen surfaces. The display-compositing
engine enables picture-in-graphics, flicker filtering, alpha
blending and other effects. The CX22490 supports direct
attachment to an IDE hard disk drive for video pause and
Web-browser caching applications.
What is an Interactive TV Decoder?
An interactive TV decoder is a device that enables a
set top box connected to a digital TV network, to deliver
both digital TV programming and information services to a
TV set. The basic functions performed by an interactive TV
decoder include identifying and filtering specific programs
embedded in a compressed digital TV data stream, and
decompressing the video and audio data associated with
the selected program. This generates the TV program's
picture and sound. An interactive TV decoder can also
identify and filter information sent in the digital TV data
stream. Data pertaining to interactive applications is
processed by the interactive TV decoder's embedded CPU
under OS control, and generates a graphical user interface
that can be navigated using the set top box's remote
control unit.
The interactive TV decoder's graphics-controller function
allows both the TV picture and application user interface
graphics to be presented as a single image on the TV, using
a variety of video/graphics image scaling, filtering and
blending techniques. The interactive TV decoder must also
provide a return channel data communications mechanism
to allow the application to interact with the broadcast data
source. This is typically done via a telco or cable modem.
Finally, the interactive TV decoder should be able to
decrypt TV program and application content which has
been encrypted by the service provider to protect against
unauthorized access to services. Support for this kind
of conditional-access system is usually implemented via
smart card technology, combined with an embedded
decryption circuit.
f e a t u r e s a n d s p e c i f i c a t i o n s
CX22490/22496 block diagram
MPEG-2 MP@ML video decoder
supporting NTSC and PAL CCIR601
image resolution
MPEG-1/MPEG-2 audio decoder and
Dolby Digital (AC3)
MPEG-2/DVB/ATSC/DSS transport
stream demultiplexing
Integrated DVB common descrambler
NDS conditional access embedded
in the CX22496
160 MHz 175 MIPS 32-bit
ARM940T CPU
Advanced 2D graphics rendering for
bitblt, textblt, line draw and color
expansion acceleration
Unified memory architecture
supporting 32-bit, 133 MHz SDRAM
MPEG picture and still plane upscaling
and downscaling
Multiplane video/graphics image
compositing with color key or
256-level alpha blending
Video-picture-in-graphics and
video-picture-in-video-picture support
Flicker filtering, aspect ratio
conversion and hardware cursor
4/8/16/32-bit RGB/YCrCb graphics
PCM audio mix and playback
USB 1.1 OHCI host controller
(CX22490 only)
IDE multiword DMA support
(CX22490 only)
Serial, I
2
C and GPIO ports
Bi-directional IR controller and
dual smart card controllers
Full-Featured Development Platform
These ICs are packaged in a fully-engineered interactive
TV decoder development system that runs on third-party
interactive middleware/RTOS platforms and provides
complete set top box functionality. The initial platform
comes equipped with fully-integrated OpenTV, pSOS and
VxWorks runtime and driver software components. The
development platform set-top box hardware has a modular
design, allowing OEMs to configure the system with their
choice of tuner/demodulator, analog modem, TV encoder,
audio DAC and SDRAM buffer size.
www.conexant.com
General Information:
U.S. and Canada: (800) 854-8099
International: (949) 483-6996
Headquarters Newport Beach
4311 Jamboree Rd, P.O. Box C
Newport Beach, CA 92660-3095
Order# 100877B
01-0727
2001, Conexant Systems, Inc. All Rights Reserved.
Conexant and the Conexant logo are trademarks
of Conexant Systems, Inc. Other trademarks are
owned by their respective owners. Although Conexant
strives for accuracy in all its publications, this material
may contain errors or omissions and is subject to
change without notice.
THIS MATERIAL IS PROVIDED AS IS
AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NON-INFRINGEMENT.
Conexant shall not be
liable for any special, indirect, incidental or consequential
damages as a result of its use.
Product Features