SmartHSF Mobile Modem Data Sheet
The Conexant SmartHSF Host-Processed (SoftK56) V.90/K56flex Modem Device Family with SmartDAA technology
supports analog data up to 56 kbps, analog fax to 14.4 kbps, telephone answering machine (TAM), and PCI Bus/Mini PCI
host interface operation. In addition, the device set optionally supports cellular phone interface (PDC high speed/PDC packet
data, PHS data, CDMA/CDMA Packet data, GSM data) or voice/speakerphone. These modem devices meet the size and
power requirements of the mobile environment. Table 1-1 lists the available models.
The modem operates with PSTN telephone lines in the U.S./Japan/Canada and, optionally, worldwide. Optional cellular
interface supports Japanese PDC (Personal Digital Cellular) and PHS (Personal Handyphone System) phones, GSM (Global
System for Mobile Communications) phones, and cdmaOne (IS-95A/IS-95B) phones. Modem and cellular data protocol
software is provided.
Conexant's SmartDAA technology (patent pending) eliminates the need for a costly line transformer, relays, and opto-
isolators typically used in discrete DAA (Data Access Arrangement) implementations. The SmartDAA architecture also
simplifies product implementation by eliminating the need for country-specific board configurations enabling worldwide
homologation of a single modem board design.
The SmartDAA system-powered DAA operates reliably without drawing power from the line, unlike line-powered DAAs which
operate poorly when line current is insufficient due to long lines or poor line conditions. Enhanced features, such as
monitoring of local extension status without going off-hook, are also supported.
Incorporating Conexant’s proprietary Digital Isolation Barrier (DIB) design (patent pending) and other innovative DAA
features, such as Digital PBX line protection and reporting, the SmartDAA architecture simplifies application design,
minimizes layout area, and reduces component cost.
For over a decade, Conexant has assisted customers with DAA technology and homologation. This expertise and system
level approach has been leveraged in this product.
The SmartHSF device set, consisting of a CX11250 Host Side Device (HSD) in a 100-pin TQFP and a CX20463 SmartDAA
Line Side Device (LSD) in a 32-pin TQFP, supports data/fax/TAM operation with host software-based digital signal processing
and cell phone/DAA/telephone line interface functions.
The optional CX20437 Voice Codec (VC), in a 32-pin TQFP, supports voice/full-duplex speakerphone (FDSP) operation with
interfaces to a microphone, speaker, and telephone handset/headset. Because some cellular interface signals and CX20437
VC interface signals share the same CX11250 HSD pins, speakerphone configuration does not support the cellular interface.
The major hardware signal interfaces are identified in Figure 1-1.
In V.90/K56flex data mode, the modem can receive data at speeds up to 56 kbps from a digitally connected V.90 or K56flex-
compatible central site modem. In this mode, the modem can transmit data at speeds up to V.34 rates.
In V.34 data mode, the modem operates at line speeds up to 33.6 kbps. When applicable, error correction (V.42/MNP 2-4)
and data compression (V.42 bis/MNP 5) maximize data transfer integrity and boost average data throughput. Non-error-
correcting mode is also supported.
Fax Group 3 send and receive rates are supported up to 14.4 kbps with T.30 protocol.
V.80 synchronous access mode supports host-controlled communication protocols, e. g., H.324 video conferencing.
Audio recording and playback over the telephone line interface using A-Law, µ-Law, or linear coding at 8 kHz sample rate
supports applications such as remote digital telephone answering machine (TAM).
This designer's guide describes the modem hardware capabilities and identifies the supporting commands. Commands and
parameters are defined in the Commands Reference Manual (Doc. No. 100498, formerly identified as Doc. No. 1118).