Introduction
Overview
The Conexant® SmartV.XX Modem is a full-featured, worldwide, controller-based modem that integrates modem controller (MCU), modem data pump (MDP), 256 KB ROM, 32 KB RAM, and SmartDAA system side device (SSD) functions onto a single die.
The modem operates by executing firmware from internal ROM and RAM. Optional customized firmware is supported with optional external flash ROM memory. Additionally, added/modified country profiles are supported by internal SRAM patch (maximum of one profile) or serial EEPROM. Downloadable architecture supports downloading of customized MCU firmware from the host/DTE to the SmartV.XX modem.

Features
General Modem Features
• Data modem
   − Quick connect, Modem-on-Hold, and PCM upstream functions (V.92 models)
   − ITU-T V.92/V.90 (V.92 models), V.34 (V.92 and V.34 models), V.32bis, V.32, V.29, FastPOS (V.29), V.22 bis, V.22, V.22 Fast Connect, V.23, V.21, Bell 212A, and Bell 103
   − V.250 and V.251 commands
• Data compression and error correction
   − V.44 data compression
   − V.42 bis and MNP 5 data compression
   − V.42 LAPM and MNP 2-4 error correction
• Fax modem send and receive rates up to 14.4 kbps
   − V.17, V.29, V.27 ter, and V.21 channel 2
   − EIA/TIA 578 Class 1 and T.31 Class 1.0
• V.80 synchronous access mode supports host-controlled communication protocols with H.324 interface support
• Interfaces to optional external ROM/flash ROM, RAM, and/or optional serial EEPROM
• Data/Fax/Voice call discrimination
• Hardware-based modem controller
• Hardware-based digital signal processor (DSP)
• Worldwide operation
   − Complies to TBR21 and other country requirements
   − On-hook and/or off-hook Caller ID detection for selected countries
   − Call progress, blacklisting
   − Internal ROM includes default values for 29 countries
   − Additional and modified country profile can be stored in internal SRAM
• Caller waiting detection
• Caller ID detect
   − On-hook Caller ID detection
   − Off-hook Call Waiting Caller ID detection during data mode in V.92, V.90, V.34, V.32bis, and V.32
• Distinctive ring detect
• Modem customization available through patch code that can be stored in optional serial EEPROM or internal SRAM
• Telephony/TAM
   − V.253 commands
   − 2-bit and 4-bit Conexant ADPCM, 8-bit linear PCM, and 4-bit IMA coding
   − 8 kHz sample rate
   − Concurrent DTMF, ring, and Caller ID detection
• Full-duplex speakerphone (FDSP) mode using optional CX20442 Voice Codec (S models)
   − Microphone and speaker interface
   − Telephone handset or headset interface
   − Acoustic and line echo cancellation
   − Microphone gain and muting
   − Speaker volume control and muting
• Built-in host/DTE interface
   − Parallel 16550A UART-compatible interface up to 230.4 kbps
   − Serial ITU-T V.24 (EIA/TIA-232-E) logical interface up to 115.2 kbps
• Downloadable architecture
• Direct mode (serial DTE interface)
• Flow control and speed buffering
• Automatic format/speed sensing
• Serial async/sync data; parallel async data
• Thin packages support low profile designs (1.6 mm max. height)
   − CX81801 Modem device in 128-pin TQFP
   − CX20493 LSD in 28-pin QFN
   − CX20442 VC in 32-pin TQFP
• +3.3V operation with +5V tolerant digital inputs
• Typical power use
   − CX81801 and CX20493: 209 mW (Normal Mode); 59 mW (Sleep Mode)
   − CX20442: 5 mW (Normal Mode)

SmartDAA Features
• System side powered DAA operates under poor line current supply conditions
• Modem Wake-on-Ring
• Ring detection
• Line current loss detection
• Pulse dialing
• Line-in-use detection during on-hook operation
• Remote hang-up detection for efficient call termination
• Extension pickup detection
• Digital PBX line protection
• Meets worldwide DC Voltage/Current (VI) masks requirements

Applications
• Set top boxes
• Gaming devices
• Point of sale terminals
• Remote monitoring and data collections systems
• Handheld computers
• Other embedded systems