Broadband Modems
Cable Modems

CX24943 Distinguishing Features

· High level of integration
· Dual software programmable

network processing engines

· 225 MHz system processor
· Less than 500mW typical

power dissipation

· Support for DOCSIS

1.0/1.1,

EuroDOCSIS 1.0/1.1, DVB and
Proprietary Standards

· Direct IF sampling at 44 and 36 MHz
· Integrated A/Ds and D/As
· Embedded IEEE 802.3 MAC with MII
· 12Mb USB 1.1 communications

transceiver

· Support for home networking

standards and VoIP

Conexant's next generation cable modem solution
offers a higher level of integration, increased
performance, and lower power dissipation

Conexant's broadband communications portfolio includes a comprehensive
suite of semiconductor solutions that enable the digital home and information
network. The InfoSurge

family of products, supporting broadband cable

modem applications, presents the industry with yet another example of
Conexant's ability to exceed the needs of a growing market segment. The
CX24943, Conexant's next generation single-chip cable modem IC, reduces
the cost of consumer premise equipment (CPE) by providing a highly
integrated, robust and flexible solution.

The CX24943 leads the industry in cost-effectiveness through its high

level of integration, advanced process technology, extremely small package

and low power consumption. It offers a dual software programmable
network processing engine architecture, allowing for real-time-critical
packet management processing for superior performance. The software
programmability of this architecture accommodates application specific
requirements, worldwide standards, and manufacturers' unique value added
features, for maximum flexibility. The CX24943 is software compatible with
its predecessor, the CN9414.

A multitude of interfaces are integrated into the chip, including an
embedded IEEE 802.3 Media Access Controller (MAC) with a Media

Independent Interface (MII), a USB 1.1 communications transceiver, and
a host interface. The CX24943 supports internal and external PC cable
modems, home networking gateway products, IP (Internet Protocol)
telephony products, and digital set-top boxes.

Part Number CX24943

Description Single-Chip Cable Modem IC

Single-Chip Cable Modem IC

With Dual Software Programmable

Network Processing Engines

CX24943

Broadband Modems
Cable Modems

Highly Integrated

The CX24943 single-chip cable modem IC integrates both

downstream and upstream physical layer (PHY) technologies
as well as dual software programmable network processing
engines with on-chip memory for cable MAC and application layer
processing. The CX24943 provides a cost-effective, single-chip,
digital cable communications solution. The IC supports a number
of interfaces including: an IEEE 802.3 10/100 Ethernet MAC with
MII for access to home networking standards such as HPNA 2.0
and HomePlug; a USB 1.1 transceiver; and a host interface to
accommodate IP telephony (VoIP), IEEE 802.11a and IEEE 802.11b
wireless networking standards.

The CX24943 was developed using leading-edge process and

packaging technologies. This helps drive down the size of the
monolithic IC, package and power, while allowing clock rates to
increase more than 40% from the previous generation of this
product. The CX24943 dissipates less than 500mW of power,
setting a new standard for the industry.

The CX24943, through its high level of integration, enables

manufacturers to achieve cost targets unparalleled in the industry.

The additional components required to develop a complete cable

modem are minimal as shown in the CX24943-based Cable
Modem block diagram.

Increased Performance

The CX24943 utilizes the proven architecture of its predecessor,

the CN9414, and boosts performance by increasing the system
processor speed to 225 MHz. The CX24943 single-chip cable
modem IC block diagram shows the major functional blocks of
the monolithic IC.

Conexant's sixth-generation physical-layer downstream receiver

includes a 10-bit A/D that accepts a direct IF signal (at 44 or
36 MHz) and a 16/256 QAM demodulator with Annex A and B
forward error correction. The CX24943 also contains an 11-bit
D/A converter, which can accommodate 65 MHz of upstream
bandwidth for EuroDOCSIS and DVB applications, and a

QPSK/16 QAM burst upstream modulator. Conexant's proven
PHY technology exceeds all DOCSIS

/EuroDOCSIS 1.0/1.1

requirements for low BERs in noise-filled environments.

The CX24943 is the fastest solution in the industry with

integrated dual software programmable network processing

engines on board. Its unique packet management, unified
memory architecture, and advanced system buses, maximize

performance by allowing segmentation of real-time-critical
DOCSIS/EuroDOCSIS 1.0/1.1 functions from non real-time-critical
application processes. The CX24943's processor performance
and unique architecture enables DOCSIS/EuroDOCSIS 1.0/1.1 and

other software applications, including: firewall for added security;

routing for home networking; or VoIP for low-cost IP telephony.

CX24943-Based Cable Modem Block Diagram

10/100

Ethernet

PHY

SDRAM

Interface

CX24943

Host

Interface

GPIO

MII

USB

Conexant

HPNA 2.0

PHY

Conexant

HomePlug

PHY

Conexant

Voice DSP

RJ-45

RJ-11

Antenna

Powerline

Type B

Socket

2 MB

Flash

8 MB

SDRAM

LED Indicators

Power

Supply

1.3v

3.3v

5.0v

802.11a/b

MAC/PHY

ADC

DAC

Control

Tuner

Cable

High Flexibility

Cable modem manufacturers have to devote a significant
amount of resources to bring new certifiable solutions to market.

The unique architecture of the CX24943 provides a number of

advantages for cable modem manufacturers and cable operators
alike. The software programmability of the dual network processing
engine allows manufacturers to customize the CX24943 for
application specific requirements, both at the cable MAC and
software applications layer. This feature allows one base platform
to support numerous products, including IP telephony, home
networking and set-top boxes as shown in the CX24943-based
Cable Modem block diagram. In addition, the architectural similarities

between the CX24943 and its predecessor, the CN9414, allows

for maximum reuse of certified code.

The CX24943 provides the ability to adapt to a multitude of standards

by downloading different software into the embedded dual network
processing engine, including DOCSIS/EuroDOCSIS 1.0/1.1, DVB

and proprietary standards. Finally, cable operators can download
complex feature enhancements above and beyond simple code
upgrades to field-deployed solutions, minimizing
truck rolls and equipment obsolescence.

Complete Solution

To reduce the resources and development time required to bring

CX24943-based cable modem solutions to market, Conexant
provides complete certifiable DOCSlS/EuroDOCSIS 1.0/1.1 cable
modem reference designs which incorporate all of the hardware
and software needed for DOCSIS certification.

The cable modem reference designs include Conexant software

that is compliant to DOCSIS/EuroDOCSIS 1.0/1.1 and include the
USB drivers that meet Microsoft's Windows Hardware Quality Lab
(WHQL) requirements. Additional software enhancements that are
above and beyond standards-based requirements are also included
in this complete software offering.

CX24943 Single-Chip

Cable Modem IC Block Diagram

Peripheral

I/O

Memory

DMA

Interrupt

Controllers

Applications

Network

Processor

USB

Host

Interface

Cable PHY

Downstream

Cable PHY

Upstream

S-CDMA

A-TDMA

Cable MAC

Network

Processor

MII

© 2002, 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.

Broadband Modems
Cable Modems

02-0703

CX24943 Features

Cable PHY Downstream

· 10-bit A/D
· Direct IF sampling at 44 and 36 MHz
· 16/256 QAM Demodulator
· Programmable equalization
· Annex A and B FEC

Cable PHY Upstream

· 11-bit D/A
· QPSK/16 QAM burst modulator
· Programmable pre-equalization

DMA Interrupt Controller

· 16 asynchronous channels
· Memory to memory moves: aligned/unaligned
· Source/destination mode for simple data transfer
· Circular/linked buffer support for inbound/outbound data

Peripheral I/O

· 32 GPIO
· JTAG boundary scan
· UART

Cable MAC Network Processor

· Software Programmable
- DOCSIS 1.0/1.1 compliant
- EuroDOCSIS 1.0/1.1 compliant
- DVB compliant
- Fixed wireless compliant
- Proprietary standards

Application Network Processor

· ARM940T microcontroller
· Up to 225 MHz operation
· 4KB instruction and 4KB data cache
· Embedded ICE and debug extensions
· PID, SID, DA/SA, MAC, IP and LLC filtering
· Four 56-bit DES/CRC engines
· HCS 16- and 32-bit CRC single-cycle engines

MII

· IEEE 802.3 MAC layer
· Networking technologies
- 10/100 Ethernet
- Conexant HPNA 2.0
- Conexant HomePlug 1.0

Host Interface

· Master mode
- 16-bit data
- 8-chip selects
· Supports Flash, IP telephony, IEEE 802.11a or IEEE 802.11b
· 16/32-bit Slave mode (external host and test)

USB 1.1

· Integrated 12 Mb transceiver
· Communications peripheral device

Memory

· Internal 8K x 32 SRAM
· External SDRAM Interface
- 16-bit interface
- Supports both 4MB and 8MB technologies

Phase-Locked Loops (4)

· TDM clock and frame sync generator
· Transmit clock generator
· Supplied 25MHz Ethernet reference clock
· Internal USB clock

Miscellaneous Functions

· Watchdog timer
· Four additional timers
· Interrupt controller

Package and Power

· 228 PBGA
· All I/O at 3.3V
· Power supply: 3.3V and 1.2V
· <500 mW (typical)

Reference Designs

· DOCSIS 1.0/1.01
· EuroDOCSIS 1.0/1.1
· PCI

Product Applications

(DOCSIS/EuroDOCSIS /1.0/1.1, DVB, Proprietary)

· Cable Modems with Ethernet
· Cable Modems with USB
· Cable Modems with IP Telephony
· PCI Cable Modem Card Internal (CMCI)
· Cable Modem with Home Networking
· PCMCIA Cable Modem
· Digital Set-Top Box with Cable Modem

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# 101645B

Part Number CX24943