RFX144V24-S23 and RFX96V24-S23 Modem Designer’s Guide
1070
1-1
1. INTRODUCTION
1.1 SUMMARY
The Rockwell RFX144V24-S23 and RFX96V24-S23 MONOFAX® facsimile modem family provides 14400 bps and 9600 bps
half-duplex capability with options supporting DigiTalk™ voice and ADPCM audio codecs, DigiTalk™ full-duplex
speakerphone, and V.23 full-duplex. The modem models are identified in Table 1-1.
These functions are supplied in a single VLSI device or two-device set (for speakerphone). The MDP (modem data pump) is
packaged in a 100-pin PQFP. The MDP contains an internal integrated analog codec (IIA) and is pin-compatible with the
RFX144V12/RFX96V12 and RFX144V12-S/RFX96V12-S MONOFAX modems. The XIA (external integrated analog codec),
provided with speakerphone models, is packaged in a 28-pin PLCC.
This device family enables cost-effective development of a common facsimile machine design with digital answering machine
and/or full-duplex speakerphone.
Facsimile Modem Features
The modem can operate at 14400 (RFX144 models), 12000 (RFX144 models), 9600, 7200, 4800, 2400, or 300 bps, and can
perform HDLC framing per T.30 at all rates. A programmable DTMF detector, three programmable tone detectors, and
Caller ID demodulator are provided.
DigiTalk™ Voice and ADPCM Audio Codecs (V24 Option)
The DigiTalk™ V24 voice coder/decoder (codec) compresses voice at an average rate of 2.9 kbps or at a fixed rate of 4.7
kbps with near toll quality playback. An average rate of 2.9 kbps provides 24 minutes of stored voice messages in 4 Mbits of
memory. This voice codec allows the host controller to efficiently store and playback digital incoming messages (ICMs) and
outgoing messages (OGMs).
The ADPCM audio codec compresses audio signals (e.g., music/voice) at 32 kbps or 24 kbps for highest fidelity coding and
reproduction.
Selectable error correction coding allows storage in audio grade RAMs (ARAMs). Echo cancellation techniques employed
during playback allow DTMF and tone detection during voice/audio codec operation to support user selectable features. The
coder can record messages from either the IIA or XIA. Dual/single tone transmission is available when the decoder is
disabled.
The DigiTalk™ Speakerphone (-S Option)
The DigiTalk™ speakerphone provides full-duplex hands-free voice conversation with both acoustic and line echo
cancellation.
The speakerphone algorithm constantly adjusts its parameters to deliver the best performance during real-time conditions,
allowing automatic fallback from full-duplex to pseudo-duplex. The host controller can easily set up the speaker mute,
microphone mute, automatic gain control (AGC) enable/disable, microphone level, speaker volume, tone transmit, and
handset functions.
V.23 Full-Duplex (-23 Option)
Both full-duplex transmit and receive (with asymmetric 1200/75 bps connection) and half-duplex (1200 bps) asynchronous
V.23 are supported, as well as both serial and parallel interfaces to the modem. The V.23 algorithm includes an optional,
programmable, receive compromise equalizer which is active in both V.23 and Caller ID (V.23 Receive only) modes.
Common applications for V.23 include France's Minitel and Japan's Lowest Cost Routing.
Содержание RFX144V24-S23
Страница 64: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 3 30 1070 This page is intentionally blank...
Страница 92: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 5 10 1070 This page is intentionally blank...
Страница 110: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 7 8 1070 This page is intentionally blank...
Страница 156: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 9 34 1070 This page intentionally left blank...
Страница 170: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 11 8 1070 This page is intentionally blank...
Страница 178: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 12 8 1070 This page is intentionally blank...
Страница 184: ...RFX144V24 S23 and RFX96V24 S23 Modem Designer s Guide 13 6 1070 This page intentionally left blank...
Страница 197: ......