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LSD20463

SmartHCF™ Mobile Modem

Conexant Systems 

SmartHCF Mobile Modem Designer’s Guide

In fax modem mode, the modem can operate in 2-wire, half-duplex, synchronous modes and can support Group 3 facsimile

send and receive speeds of 14400, 12000, 9600, 7200, 4800, and 2400 bps. Fax data transmission and reception performed

by the modem are controlled and monitored through the EIA/TIA-578 Class 1 or T.31 Class 1.0 command interface. Full

HDLC formatting, zero insertion/deletion, and CRC generation/checking are provided.

Synchronous Access Mode (SAM) - Video Conferencing

V.80 Synchronous Access Mode between the modem and the host/DTE is provided for host-controlled communication

protocols, e.g., H.324 video conferencing applications.

Voice-call-first (VCF) before switching to a videophone call is also supported.

TAM Mode

TAM Mode features include 8-bit µ-Law, A-Law, and linear coding at 8 kHz sample rate. Full-duplex voice supports

concurrent voice receive and transmit. Tone detection/generation, call discrimination, and concurrent DTMF detection are

also supported. This mode supports applications such as digital TAM, voice annotation, and recording from and playback to

the telephone line. ADPCM (4-bit IMA) coding is also supported to meet Microsoft WHQL logo requirements.

TAM Mode is supported by three submodes:

1. Online Voice Command Mode supports connection to the telephone line or, for S models, a

microphone/speaker/handset/headset.

2. Voice Receive Mode supports recording voice or audio data input from the telephone line or, for S models, a

microphone/handset/headset.

3. Voice Transmit Mode supports playback of voice or audio data to the telephone line or, for S models, a

speaker/handset/headset.

Voice/Speakerphone Mode (S Models)

The S models include additional telephone handset, external microphone, and external speaker interfaces which support

voice and full-duplex speakerphone (FDSP) operation.

Hands-free full-duplex telephone operation is supported in Speakerphone Mode under host control. Speakerphone Mode

features an advanced proprietary speakerphone algorithm which supports full-duplex voice conversation with acoustic, line,

and handset echo cancellation. Parameters are constantly adjusted to maintain stability with automatic fallback from full-

duplex to pseudo-duplex operation. The speakerphone algorithm allows position independent placement of microphone and

speaker. The host can separately control volume, muting, and AGC in microphone and speaker channels.

1.3.4 Reference Design

A MiniPCI Type IIIB data/fax/TAM reference design board is available to minimize application design time and costs.

The board is pretested to pass FCC Part 15, Part 68, and CTR 21 for immediate manufacturing.

A design package for the board is available in electronic form. The design package includes schematics, bill of materials

(BOM), vendor parts list (VPL), board layout files in Gerber format, and complete documentation.

The design can also be used for the basis of a custom design by the OEM to accelerate design completion for rapid market

entry.

1.4 HARDWARE DESCRIPTION

SmartDAA™ technology (patent pending) eliminates the need for a costly analog transformer, relays, and opto-isolators that

are typically used in discrete DAA implementations. The programmable SmartDAA architecture simplifies product

implementation in world-wide markets by eliminating the need for country-specific components.

1.4.1 Host Side Device (HSD)

The HSD, packaged in a 100-pin TQFP, includes a PCI/MiniPCI/CardBus Interface, a Modem Data Pump (MDP), and a

SmartDAA Interface.

The PCI/MiniPCI/CardBus interface connects directly to an embedded or external PCI/MiniPCI/CardBus interface eliminating

the need for additional external logic components.

The MDP performs telephone line signal modulation/demodulation in a hardware digital signal processor (DSP) which

reduces computational load on the host processor. Downloadable architecture allows updating of MDP executable code.

1-6

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