Hayes Microcomputer Products RCV56HCF Technical Overview, General Description, Operating Modes

RCV56HCF PCI/CardBus Modem Designer’s Guide

1.3 TECHNICAL OVERVIEW

1.3.1 General Description

The RCV56HCF Device Set provides the processing core for a complete system design featuring data/fax modem, DSVD, AudioSpan, speakerphone, voice/audio, and VoiceView depending on specific model (Table 1-1). Note: RCV56HCF Device Set refers to the family of single device modem models listed in Table 1-1.

The modem is the full-featured, self-contained data modem/fax modem/DSVD/voice/audio/speakerphone solution. Dialing, call progress, telephone line interface, AudioSpan, DSVD, speakerphone, voice/audio, and VoiceView functions are supported and controlled through the command set.

The modem hardware connects to the host PC via a PCI bus interface. The OEM adds a crystal circuit, telephone line interface, telephone interface (optional), audio interface (optional), and ISDN interface (optional) to complete the system.

1.3.2 Operating Modes

Data/Fax Modes

In K56flexä mode, the modem can receive data from a digital source using a K56flexä -compatible central site modem (e. g., Rockwell RC56CSM) over the digital telephone network portion of the PSTN at line speeds up to 56 kbps. Asymmetrical data transmission supports sending data at V.34 rates. This mode can fall back to full-duplex V.34 mode, and to slower rates as supported by line conditions.

In V.34 data modem mode, the modem can also operate in 2-wire, full-duplex, asynchronous modes at line rates up to

33600 bps. Data modem modes perform complete handshake and data rate negotiations. Using V.34 modulation to optimize modem configuration for line conditions, the modem can connect at the highest data rate that the channel can support from 33600 bps to 2400 bps with automatic fallback. Automode operation in V.34 is provided in accordance with PN3320 and in V.32 bis in accordance with PN2330. All tone and pattern detection functions required by the applicable ITU or Bell standard are supported.

In fax modem modes, the modem fully supports Group 3 facsimile send and receive speeds of 28800, 14400, 12000, 9600, 7200, 4800, or 2400 bps. Fax modes support Group 3 fax requirements. Fax data transmission and reception performed by the modem are controlled and monitored through the fax EIA-578 Class 1 command interface. Full HDLC formatting, zero insertion/deletion, and CRC generation/checking are provided.

Both transmit and receive fax data are buffered within the modem. Data transfer to and from the DTE is flow controlled by XON/XOFF and RTS/CTS.

AudioSpan Modes

AudioSpan provides full-duplex analog simultaneous audio/voice and data over a single telephone line at a data rate with audio of 4800 bps using V.61 modulation. AudioSpan can send any type of audio waveform, including music. Data can be sent with or without error correction. The audio/voice interface can be in the form of a headset, handset, or microphone and speaker (half-duplex speakerphone). Handset echo cancellation is provided.

Host-Controlled DSVD Mode (ISDN and SP Models)

ISDN and SP models support host-controlled DSVD. A microphone and a speaker are required.

ITU-T interoperable G.729 and G.729 Annex A with interoperable G.729 Annex B Operation. Voice activity detection

supports speech coding at an average bit rate significantly lower than 8.0 kbps.

SIG DigiTalk. Speech coding is performed at 8.5 kbps.

Voice/Audio Mode (V Models)

Voice/Audio Mode features include 8-bit linear and 8-bit m-Law coding/decoding, tone detection/generation and call discrimination, concurrent DTMF detection, and 8-bit monophonic audio data encoding at 11.025 kHz or 8000 Hz.

Voice/Audio Mode is supported by three submodes:

1.Online Voice Command Mode supports connection to the telephone line or a voice/audio I/O device (e.g., microphone, speaker, or handset).

2.Voice Receive Mode supports recording voice or audio data input at the MIC_M pin, typically from a microphone/handset or the telephone line.

3.Voice Transmit Mode supports playback of voice or audio data to the TXA1_L1/TXA2_L1 output, typically to a speaker/handset or to the telephone line.

1129 ROCKWELL PROPRIETARY INFORMATION 1-7