Overview
The ConexantSMXXD Modem is a full-featured, controller-based modem that integrates modem controller (MCU), modem data pump (MDP), 256 KB ROM, 32 KB RAM, and analog line interface codec functions into a single package.

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)
•  Support for many country-specific DAA configurations
−  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)
−  CX06833 Modem device in 144-pin TQFP
−  CX20442 VC in 32-pin TQFP
•  +3.3V operation with +5V tolerant digital inputs
•  Typical power use
−  CX06833: 191 mW (Normal Mode); 53 mW (Sleep Mode)
−  CX20442: 5 mW (Normal Mode)