Embedded Dial-Up Modems
Controller-Based Modems
CSM92/34/32-SP Serial Modem with 4th
Generation SmartDAA and Speakerphone Support
Conexant’s portfolio includes a comprehensive suite of semiconductor
solutions for communications and consumer applications.
Controller-Based Modem with SmartDAA® 4 for
Embedded Applications
Conexant’s CX93021-2x Serial Modem device (CSM92/34/32-SP) is a full
controllered modem supporting V.92 data modulation, 14.4 kbps fax modem
operation, and remote Telephone Answering Machine (TAM) and speakerphone.
The modem also supports V.44/V.42bis/MNP 5 data compression for greater data
throughput and V.42 LAPM/MNP2-4 error correction protocol for increased data
integrity and reliability. The device set is ideal for embedded applications such
as Internet appliances, security systems, home/personal monitoring systems
and other applications that require robust dial-up connectivity and speakerphone
The device set offers the smallest footprint consisting of a CX93021-2x V.92
Modem device in a 36-pin Quad Flat-No Lead (QFN), a CX20548 SmartDAA®
4 Line Side Device (LSD) in a 16-pin QFN, and a CX20452 Voice Codec in a
24-pin QFN. The CX93021-2x modem device integrates a Microcontroller Unit
(MCU), a Digital Signal Processor (DSP), internal RAM, internal ROM, and a
SmartDAA System Side Device (SSD) making it independent of host processor
and operating system. The device set has a serial interface and codec interface
for connection to the optional CX20452 Codec for speakerphone applications. It
is also available without the CX20452 Codec for no speakerphone support.
The CX93021-2x modem MCU/DSP performs the command processing, host
interface functions and telephone line signal modulation/demodulation, which
reduces the computational load on the host processor. The modem operates by
executing masked code from internal ROM. The modem features internal RAM
memory that enhances the modem’s flexibility. The modem’s internal RAM can
be used to load new country profiles, override existing country profiles or add
customized firmware code. An optional external serial NVRAM is supported.
The optional external NVRAM adds the convenience of permanent storage, just
like internal RAM, NVRAM can be used to store new country profiles, override
existing ones or add customized firmware code.
Conexant’s SmartDAA 4 line side device builds on three generations of market
leading silicon DAA devices. It eliminates the need for costly analog transformers,
relays and opto-isolators typically used in discrete DAA implementation for
country-specific modem configurations. It’s system-powered, making it the most
reliable and best performing silicon DAA in the market. The SmartDAA 4 LSD
also adds enhanced telephony extension features to the modem’s operation
and other functions such as Call Waiting detection, and Caller ID decoding.
Incorporating Conexant’s proprietary Digital Isolation Barrier (DIB) design and
other innovative DAA features, the SmartDAA 4 architecture simplifies application
design and minimizes layout area. The result is a worldwide reduced system cost
solution using a single bill of materials.
Combined with the optional Codec, the CX93021-2x modem supports Full-duplex
Speakerphone (FDSP) operation using microphone and speaker, as well as other
voice/TAM applications using handset or headset. Speakerphone Mode features
Distinguishing Features
• Controller-based modem, no external memory required
• Optional Full Duplex Speakerphone with AEC
• Telephony/TAM support
• V.92, V.34, V.32bis data modulations
• V.17/V.29 Fax Class 1 and Fax Class 2
• SIA Protocol and Contact ID
• V.80 synchronous access mode, synchronous and asynchronous DTE interface
• V.44/V.42bis and MNP5 data compression
• V.42 and MNP2-4 error correction
• Call Waiting detection and Type II Caller ID decoding during data mode
• Type I Caller ID decoding
• 63 embedded and upgradeable country profiles
• Serial NVRAM interface for optional permanent country profile storage
• Embedded AT commands
• Worldwide pre-tested reference design
Part Number CX93021-2x
CSM92/34/32-SP Serial Modem with 4th Generation SmartDAA and Speakerphone Support Embedded Dial-Up Modems
Controller-Based Modems
Conexant’s advanced proprietary speakerphone algorithm, which
supports full-duplex voice conversation with acoustic, line and handset
echo cancellation to ensure clean and noise free voice quality.
(ADPCM) coding. This mode supports applications such as digital
telephone answering machine, voice annotation, and recording from
and playback to the telephone line.
In TAM mode, enhanced 2-bit or 4-bit per sample coding schemes at 8
kHz sample rate provide flexible format compatibility and allows efficient
digital storage of voice/audio. Also supported are 8-bit A-law, μ-law, and
linear coding and IMA 4-bit Adaptive Differential Pulse Code Modulation
Small, low-profile packages, reduced voltage operation, and low power
consumption make this device set an ideal solution for embedded
DAA Hardware
CX93021 Modem
36-Pin QFN
28.224 MHz
27.000 MHz
Crystal or Clock
Digital Isolation
Barrier (DIB)
SmartDAA 4
Line Side Device (LSD)
16-Pin QFN
Line Side
24-Pin QFN
CX93021-2x CSM92/34/32-SP Modem Simplified Interface
CX93021-2x Features
• Modulations and protocols
- ITU-T V.92: Quick Connect, Modem-on-Hold and PCM upstream
- V.90/V.34/V.32bis/V.32
- V.22bis/V.22/V.23/V.21
- V.23 reverse, V.23 half-duplex
- Bell 212A/Bell 103
- V.29 FastPOS and V.22 Fast Connect
- SIA Protocol and Contact ID for alarm equipment
- V.80 Synchronous Access Mode
- V.17/V.29 Fax Class 1/1.0 and Fax Class 2
• V.44/V.42bis/MNP5 data compression
• V.42/MNP2-4 Error correction
• Call waiting (CW) detection for selected countries
• Asynchronous Serial DTE interface
• Hardware and software flow control and speed buffering
• Embedded and upgradable 63 country profiles
• Optional serial NVRAM interface for country profile storage and code upgrades
• Full-duplex 8-bit/16-bit PCM voice pass-through mode
• 28.224 MHz or 27.000 MHz frequency XTAL or clock input
• Worldwide operation
- Complies to TBR21 and other country requirements
- Type I and Type II Caller ID (CID) decoding
- Type II Caller ID snooping
- Call progress, blacklisting
- Meets worldwide DC mask requirements
• Low power and voltage
- Single +3.3 V supply
- Low power consumption mode
- +3.3 V I/O level
• Compact, robust board design
- Reference design files provided for quick time-to-market
- Reference design tested for PTT and TBR 21 approvals
- Small, low-profile modem packages
- Reference design supports 6KV isolation
• Telephony/TAM
– V.253 commands
– 2-bit and 4-bit ADPCM, 4-bit IMA ADPCM, 8-bit and 16-bit linear PCM, and 8-bit μ-law and A-law PCM coding
– 8 kHz sample rate
– Concurrent DTMF, ring, and Caller ID detection
SmartDAA Features
• Extension pick-up detection
• Digital line protection
• Line reversal detection
• Remote hang-up detection
• Worldwide compliance
• CX20548 SmartDAA 4 LSD in a 16-pin QFN
• Worldwide support with a single design
Conexant Product Portfolio
Conexant’s comprehensive product portfolio includes solutions for imaging, audio, and video applications, and analog modems that enable costeffective Internet access. The company’s broadband access products include end-to-end solutions for xDSL networks, and PON solutions for fiber
optic applications.
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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.
General Information:
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International: 1+ (949) 483-3000
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Doc# PBR-202165