Set-Top Box Solutions
Cable
CX24430/1/2/3 Distinguishing Features
Cable modem compliant with
DOCSIS
/ EuroDOCSISTM1.0/1.1,
DVS 178, DVS 167 and DVB
MPEG-2 Digital TV broadcast
decoder system
Worldwide NTSC/PAL/SECAM
TV encoder
Dual CPU architecture delivering
500+ aggregate MIPS
Dual tuner PVR support
High-performance, IP packet bridging
to Ethernet, USB and internal CPU
Advanced 2D graphics rendering
OpenCableTM compliant
QPSK out-of-band receiver
and a QPSK/16-QAM upstream
burst modulator
Conexant`s highly integrated, single IC,
MPEG-2/DVB-compliant, decoder/transceiver
solution for digital cable television receivers
Conexant's broadband communications portfolio includes a
comprehensive suite of semiconductor solutions that enable the
digital home and information network. Adding to this impressive line
up are the CX24430/1 and CX24432/3 Interactive Cable TV Decoder
ICs. These highly-integrated products combine a high-speed broadband
cable modem and an interactive TV broadcast service decoder onto a
single chip. It is a breakthrough in IC integration that will allow set-top
box manufacturers to offer advanced, fully-interactive broadband home
gateways or other set-top appliances for the price of an entry-level
product that only receives TV broadcasts. The CX24431/3 versions
support NDS Videoguard
conditional access technology.
The CX24430/2 ICs combine the industry's highest performance
DOCSIS
cable modem with the company's third generation interactive
TV decoder technology. This new platform optimizes performance by
partitioning cable modem tasks between a dedicated 32-bit ARM940T
processor and programmable software MAC. At the same time, digital
TV broadcast service decoding and set-top box interactive applications
are hosted by a second, dedicated high performance 275MIPS main
system processor. The cable modem section of the device also allows
for narrowband interactivity based on DAVIC 1.2 and 1.5 as well as the
DVS 178 and DVS 167 specifications.
Part Number CX24430/1/2/3
Description Interactive Cable TV Decoder IC
Interactive Cable TV Decoder IC
CX24430/1/2/3
Set-Top Box Solutions
Cable
The CX24430/1 and CX24432/3 cable modem sub-systems include
a complete upstream/downstream physical layer, and an Ethernet
MAC in addition to the cable modem MAC and host processor.
The set-top box decoder functionality includes an MPEG-2 video
decoder, digital audio decoder, three multi-standard transport
streamdemultiplexers, an advanced 2D graphics processor,
TV encoder, multi-plane compositing engine, a 256 QAM
demodulator/FEC block and a high performance 32-bit ARM920
RISC processor with integrated peripheral I/O ports. This makes
for an architecture that delivers a rich, high quality navigation/
user interface for advanced electronic program guides and other
interactive TV applications.
The dual CPU system architecture provides 500+ aggregate MIPS
for hosting the operating system, interactive middleware, DOCSIS
stack and interactive TV applications, while delivering industry-
leading cable modem packet performance. The CX24430/1 and
CX24432/3 ICs fully support Data Over Cable Service Interface
Specification (DOCSIS
) and EuroDOCSIS
TM
version 1.1 standards.
The CX24430 and CX24431 set-top box sub-systems also enable
advanced Personal Video Recorder (PVR) functionality. Users are able
to record two different programs simultaneously with DES copy
protection while playing back a third. The CX24430 and CX24431
incorporate a built-in high-speed hard disk drive controller interface
for fast data transfers in PVR applications like pause, instant replay,
fast forward and rewind.
Analog video support is provided by four high quality CVBS/
S-video/RGB output signals for all worldwide NTSC/PAL/SECAM
broadcast standards. The IC also provides an input port for
digitized analog signals based on the CCIR 656 format to support
analog TV display and compositing with program guide graphics.
The CX24430/1 and CX24432/3 ICs integrate dual, high
performance SDRAM memory controllers. A 32-bit 143MHz
memory controller supports all of the set-top box back-end
requirements in a unified memory architecture. This back-end
SDRAM memory system is used to support the requirements
of the main system CPU, MPEG-2 Audio Video (A/V) decoder,
transport demultiplexer, graphics, frame buffer and the still plane
picture buffers. A second, dedicated 16-bit 143MHz SDRAM
controller services the needs of the cable modem system, including
the code store for the RTOS executing on the cable modem
CPU as well as packet buffers for bridging to Ethernet and USB.
CX24430/1 IC Block Diagram
Display
Compositing
MPEG Scale
Still Plane
Scale
Video/OSD
Blend
Flicker Filter
TV Encoder
GPIO/I
2
C/
Serial/IR
Smart
Cards
ARM920T
250MHz
Main
System
CPU
ARM920T
Cable
Modem
Host CPU
DOCSIS
DBV
DAVIC
MAC
MPEG
MP@ML
Video
Decoder
MPEG/
Dolby
Audio
Decoder
16-bit
MC
SDR
SRAM
USB
Host
and
Device
10/100
Ethernet
MAC
GXA
2D
Accel-
erator
SDRAM
32-bit
MC
SDR
SDRAM
PHY
PCI/
ISA
Bus
ATA
66
FLASH
16-256 QAM
Demod
Annex A, B, C
FEC
TS I/O Switch
NTSC
Decoder
QAM
Demod
IB
Tuner
IB
Tuner
OOB
Tuner
OOB
Rx
OOB
Tx
Baseband
TS I/O
ADC
QPSK
Demod
FEC
ADC
Triple Demux
DES/CRC
QAM
Demod
FEC
ADC
QPSK/
16 QAM
Burst
Mod
DAC
Fully integrated set-top box middleware and Real Time Operating
System (RTOS) support includes hardware abstraction layer
solutions for Liberate, OpenTV, Nucleus+, pSOS and VxWorks.
The CX24430/1 and CX24432/3 IC solutions are also complemented
by Conexant's DOCSIS communications protocol stack which is
available for license by set-top box manufacturers.
A complete set of low-level software drivers and the associated
API are also available to support the OpenCable Advanced Host
requirements, including the legacy OOB mode (DVS 167 or DVS
178 signalling with a POD module) and the DSG mode (OOB
signaling through an embedded DOCSIS cable modem). These
drivers and API also support the OOB signaling through an
embedded DAVIC cable modem.
Conexant's system-level approach with the CX24430/1 reduces
cost and time-to-market for OEM set-top box vendors as well as
allowing them an opportunity to offer their customers a complete
interactive set-top box design for the same price as a broadcast
service-only product.
Table 2. CX24430/1/2/3 Part/Dash Number Matrix
n=functional/performance configuration; X=die revision
1X 2X 3X 4X 5X 6X 7X 8X 1X 2X 3X 4X 5X 6X 7X 8X
NDS ICAM
Macrovision 7x
Dolby Digital
250MHz ARM920
200MHz ARM920
CX24430/2-nX
CX24431/3-nX
Part
Number
TS
Demuxes
Ultra DMA
66MHz
Controller
IDE HDD
Interface
(ATAPI Port)
Copy
Protection &
DES Ciphering
Dual Tuner
PVR Support
CX24430/1
3
Yes
Yes
Yes
Yes
CX24432/3
2
No
No
No
No
Table 1. CX24430/1 and CX24432/3 Feature Differences
2003, Conexant Systems, Inc. All Rights Reserved. Conexant and the Conexant
logo are registered trademarks of Conexant Systems, Inc. All 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.
Set-Top Box Solutions
Cable
03-0855
CX24430/1/2/3 Features
MPEG-2 MP@ML Video Decoder
MPEG-1, MPEG-2 Audio Decoder
Dolby Digital Decoder
32-bit ARM920T Main System CPU
TV Encoder
Multi-standard, Multi-stream Transport Demultiplexing
Multi-Plane Video/Graphics Display Controller
Advanced 2D Graphics Accelerator
PCM Audio I/O
OpenCable POD Interface
Peripheral I/O Interfaces
32-bit ARM940T Cable Modem Host CPU
Cable Modem MAC
Ethernet MAC
Cable Modem Downstream PHY
Cable Modem Upstream PHY
DVS 178 Downstream PHY
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# 101991B
Audio
DACs
Composite
S-Video
RGB
"F"
S/PDIF
LR
1394
USB
1394 Link
and PHY
Ethernet
PHY
x32
STB
SDRAM
Peripheral I/O
x16
Cable Modem
SDRAM
FLASH
EEPROM
Broadcast
Tuner
Data
Tuner
CX24430/1
Hard disk
interface
CX24430/1 System Diagram
PDF 
ZIP