INTRODUCTION
Overview
The ConexantSmartSCMV.90/K56flex Modem Device Set with SmartDAA technology supports analog data up to 56kbps, analog fax to 14.4 kbps, telephone answering machine (TAM)/telephony extensions, voice/speakerphone (optional), GSM, analog cellular (optional), and parallel/serial host interface operation depending on model. Table 1-1 lists the available models.

FEATUREs
General Modem Features
•Data modem
− ITU-T V.90/K56flex (/56 models)/V.34 (/56 and /33 models), V.32bis, V.32, V.22 bis, V.22, V.23, and V.21;
Bell 212A and Bell 103
− V.42 LAPM and MNP 2-4 error correction
− V.42 bis and MNP 5 data compression
− MNP 10EC™ enhanced cellular performance
− V.250 and V.251 commands
• V.22 bis fast connect
• Analog cellular direct connect using optional CX20437 Voice Codec (S models)
• GSM cellular direct connect (parallel interface only)
• 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, and EIA/TIA 578 Class 2 commands
•V.80 synchronous access mode supports host-controlled communication protocols with H.324 interface support
•Interfaces to optional external ROM/flash ROM and/or to optional external serial EEPROM and RAM for  customized modem firmware
•Downloadable Architecture
− Downloadable MCU firmware from the host/DTE to optional external flash ROM
− Downloadable MDP code modules from the MCU transparent to the host
•Data/Fax/Voice call discrimination
• Hardware-based modem controller
• Hardware-based digital signal processor (DSP)
•Worldwide operation
− Complies to TBR21 and other country requirements
− Caller ID detection
− Call progress, blacklisting
− Internal ROM includes default values for 29 countries
• Caller ID and distinctive ring detect
•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 CX20437 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 with speeds up to 230.4 kbps
− Parallel 16550A UART-compatible interface
− Serial ITU-T V.24 (EIA/TIA-232-E) logical interface
•Direct mode (serial DTE interface)
•Flow control and speed buffering
•Automatic format/speed sensing
•Serial async data; parallel async data
• Thin packages support low profile designs (1.6 mm max. height)
− CX88168 SCM: 128-pin TQFP
− CX20463 LSD: 32-pin TQFP
− CX20437 VC: 32-pin TQFP
• +3.3V operation with +5V tolerant digital inputs
•Typical power use
  SCM and LSD: 470 mW (Normal Mode); 140 mW (Sleep Mode) VC: 5 mW (Normal Mode)