Conexant RC336D User manual

Doc. No. 1154, Rev. 3
January 22, 1999
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RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
ii Conexant 1154
Information provided by Conexant Systems, Inc. is believed to be accurate and reliable. However, no responsibility is assumed by Conexant
for its use, nor any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent rights of Conexant other than for circuitry embodied in Conexant products. Conexant reserves the right to change
circuitry at any time without notice. This document is subject to change without notice.
K56flex is a trademark of Conexant Systems, Inc. and Lucent Technologies.
Conexant, “What's Next in Communications Technologies”, MNP 10EC, and ConfigurACE are trademarks of Conexant Systems, Inc.
Product names or services listed in this publication are for identification purposes only, and may be trademarks or registered trademarks of
their respective companies. All other marks mentioned herein are the property of their respective owners.
©1999, Conexant Systems, Inc.
Printed in U.S.A.
All Rights Reserved.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant iii
Table of Contents
1. INTRODUCTION................................................................................................................................................. 1-1
1.1 SUMMARY............................................................................................................................................... 1-1
1.2 FEATURES.............................................................................................................................................. 1-3
1.3 TECHNICAL OVERVIEW......................................................................................................................... 1-4
1.3.1 General Description ................................................................................................................... 1-4
Data/Fax Modes..................................................................................................................1-4
Synchronous Access Mode (SAM)..................................................................................... 1-4
World Class Operation........................................................................................................ 1-4
Voice/TAM Mode ................................................................................................................ 1-6
Telephony Extension Operation.......................................................................................... 1-6
Speakerphone Mode (SP and SVD Models)....................................................................... 1-6
AudioSpan Mode (SP and SVD Models)............................................................................ 1-6
DSVD Mode using RCDSVD SCP Device (SVD Models)................................................... 1-6
Host-Based DSVD.............................................................................................................. 1-7
Sleep Mode......................................................................................................................... 1-7
1.3.2 Devices...................................................................................................................................... 1-7
Modem Data Pump (MDP).................................................................................................. 1-7
Microcontroller (MCU)......................................................................................................... 1-7
RCDSVD Speech Codec Processor (SCP) (Optional)........................................................ 1-7
Plug and Play (PnP) ISA Bus Interface Device (PNP Models) ........................................... 1-8
1.3.3 MCU Firmware........................................................................................................................... 1-8
1.3.4 Supported Interfaces.................................................................................................................. 1-8
Serial DTE Interface and Indicator Outputs........................................................................ 1-8
Parallel Host Bus Interface ................................................................................................. 1-8
NVRAM (Serial EEPROM) Interface................................................................................... 1-8
External Bus Interface......................................................................................................... 1-9
Telephone Line/Telephone Interface.................................................................................. 1-9
Speakerphone Interface (SP and SVD Models) ................................................................. 1-9
RCDSVD SCP Interface (SVD Models).............................................................................. 1-9
1.3.5 Commands............................................................................................................................... 1-13
1.3.6 ConfigurACE II for Windows Utility Program............................................................................ 1-13
2. TECHNICAL SPECIFICATIONS ........................................................................................................................ 2-1
2.1 SERIAL DTE INTERFACE OPERATION................................................................................................. 2-1
2.1.1 Automatic Speed/Format Sensing .............................................................................................2-1
2.2 PARALLEL HOST BUS INTERFACE OPERATION................................................................................. 2-1
2.3 ESTABLISHING DATA MODEM CONNECTIONS................................................................................... 2-1
Telephone Number Directory.............................................................................................. 2-1
Dialing................................................................................................................................. 2-1
Modem Handshaking Protocol............................................................................................ 2-1
Call Progress Tone Detection............................................................................................. 2-2
Answer Tone Detection....................................................................................................... 2-2
Ring Detection .................................................................................................................... 2-2
Billing Protection................................................................................................................. 2-2
Connection Speeds............................................................................................................. 2-2
Automode............................................................................................................................ 2-2
2.4 DATA MODE............................................................................................................................................ 2-3
Speed Buffering (Normal Mode)......................................................................................... 2-3
Flow Control........................................................................................................................ 2-3
Escape Sequence Detection............................................................................................... 2-3
BREAK Detection................................................................................................................ 2-3
Telephone Line Monitoring ................................................................................................. 2-3
Send SPACE on Disconnect (V.22 bis and Below) ............................................................ 2-3
Fall Forward/Fallback (V.34/V.32 bis/V.32) ........................................................................ 2-3
Retrain ................................................................................................................................ 2-3

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
iv Conexant 1154
Programmable Inactivity Timer........................................................................................... 2-3
DTE Signal Monitoring (Serial DTE Interface Only)............................................................ 2-4
2.5 ERROR CORRECTION AND DATA COMPRESSION............................................................................. 2-4
V.42 Error Correction.......................................................................................................... 2-4
MNP 2-4 Error Correction................................................................................................... 2-4
V.42 bis Data Compression................................................................................................ 2-4
MNP 5 Data Compression.................................................................................................. 2-4
2.6 MNP 10 DATA THROUGHPUT ENHANCEMENT................................................................................... 2-4
2.7 MNP 10EC™ ENHANCED CELLULAR CONNECTION .......................................................................... 2-4
2.8 FAX CLASS 1 AND FAX CLASS 2 OPERATION .................................................................................... 2-5
2.9 VOICE/AUDIO MODE.............................................................................................................................. 2-5
2.9.1 Online Voice Command Mode................................................................................................... 2-5
2.9.2 Voice Receive Mode.................................................................................................................. 2-5
2.9.3 Voice Transmit Mode................................................................................................................. 2-5
2.9.4 Audio Mode................................................................................................................................ 2-5
2.9.5 Tone Detectors .......................................................................................................................... 2-5
2.9.6 Speakerphone Modes................................................................................................................ 2-5
2.9.7 Sound Card Support Modes....................................................................................................... 2-6
2.10 SIMULTANEOUS AUDIO/VOICE AND DATA (AUDIOSPAN) ................................................................. 2-6
2.10.1 AudioSpan Mode Selection........................................................................................................ 2-6
2.10.2 AudioSpan Audio Interface ........................................................................................................ 2-6
2.10.3 Audio Quality Considerations..................................................................................................... 2-6
2.11 ON-BOARD DSVD MODE........................................................................................................................ 2-6
2.11.1 DSVD Handset Mode................................................................................................................. 2-6
2.11.2 DSVD Headset Mode................................................................................................................. 2-6
2.11.3 DSVD Half-Duplex Speakerphone (HDSP) Mode...................................................................... 2-6
2.12 HOST-BASED DSVD MODE.................................................................................................................... 2-7
2.13 FULL-DUPLEX SPEAKERPHONE (FDSP) MODE.................................................................................. 2-7
2.14 CALLER ID............................................................................................................................................... 2-7
2.15 WORLD CLASS COUNTRY SUPPORT .................................................................................................. 2-7
2.15.1 Dialing........................................................................................................................................ 2-7
2.15.2 Carrier Transmit Level................................................................................................................ 2-7
2.15.3 Calling Tone............................................................................................................................... 2-7
2.15.4 Call Progress Tone Detection.................................................................................................... 2-7
2.15.5 Answer Tone Detection.............................................................................................................. 2-8
2.15.6 Blacklist Parameters .................................................................................................................. 2-8
2.15.7 Relay Control ............................................................................................................................. 2-8
2.16 DIAGNOSTICS......................................................................................................................................... 2-8
2.16.1 Commanded Tests..................................................................................................................... 2-8
2.16.2 Power On Reset Tests............................................................................................................... 2-8
2.17 LOW POWER SLEEP MODE................................................................................................................... 2-8
3. HARDWARE INTERFACE ................................................................................................................................. 3-1
3.1 HARDWARE SIGNALS............................................................................................................................ 3-1
3.2 INTERFACE TIMING AND WAVEFORMS............................................................................................. 3-23
3.2.1 External Memory Bus Timing................................................................................................... 3-23
3.2.2 Parallel Host Bus Timing.......................................................................................................... 3-25
3.2.3 Serial DTE Interface................................................................................................................. 3-27
4. PARALLEL HOST INTERFACE......................................................................................................................... 4-1
4.1 OVERVIEW.............................................................................................................................................. 4-1
4.2 REGISTER SIGNAL DEFINITIONS ......................................................................................................... 4-3
4.2.1 IER - Interrupt Enable Register (Addr = 1, DLAB = 0) ............................................................... 4-3
4.2.2 FCR - FIFO Control Register (Addr = 2, Write Only).................................................................. 4-4
4.2.3 IIR - Interrupt Identifier Register (Addr = 2)................................................................................ 4-5
4.2.4 LCR - Line Control Register (Addr = 3)...................................................................................... 4-6
4.2.5 MCR - Modem Control Register (Addr = 4)................................................................................ 4-7
4.2.6 LSR - Line Status Register (Addr = 5) ....................................................................................... 4-8
4.2.7 MSR - Modem Status Register (Addr = 6) ................................................................................. 4-9
4.2.8 RBR - RX Buffer (Receiver Buffer Register) (Addr = 0, DLAB = 0)............................................ 4-9

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant v
4.2.9 THR - TX Buffer (Transmitter Holding Register) (Addr = 0, DLAB = 0)...................................... 4-9
4.2.10 Divisor Registers (Addr = 0 and 1, DLAB = 1) ........................................................................... 4-9
4.2.11 SCR - Scratch Register (Addr = 7)............................................................................................. 4-9
4.3 RECEIVER FIFO INTERRUPT OPERATION......................................................................................... 4-10
4.3.1 Receiver Data Available Interrupt............................................................................................ 4-10
4.3.2 Receiver Character Timeout Interrupts.................................................................................... 4-10
4.4 TRANSMITTER FIFO INTERRUPT OPERATION ................................................................................. 4-10
4.4.1 Transmitter Empty Interrupt ..................................................................................................... 4-10
5. DESIGN CONSIDERATIONS............................................................................................................................. 5-1
5.1 PC BOARD LAYOUT GUIDELINES......................................................................................................... 5-1
5.1.1 General Principles...................................................................................................................... 5-1
5.1.2 Component Placement............................................................................................................... 5-1
5.1.3 Signal Routing............................................................................................................................ 5-2
5.1.4 Board Power Traces .................................................................................................................. 5-3
5.1.5 MCU Power................................................................................................................................ 5-3
5.1.6 MDP Power and Ground............................................................................................................ 5-3
5.1.7 Ground Planes........................................................................................................................... 5-3
5.1.8 Crystal Circuit............................................................................................................................. 5-4
5.1.9 Standalone Modem Design with EIA/TIA-232 Interface............................................................. 5-4
5.1.10 VC and VREF Circuit ................................................................................................................. 5-4
5.1.11 Telephone and Local Handset Interface.................................................................................... 5-5
5.1.12 Optional Configurations ............................................................................................................. 5-5
5.1.13 MDP Specific.............................................................................................................................. 5-5
5.2 DAA TRANSFORMER CONSIDERATION............................................................................................... 5-5
5.3 CRYSTAL/OSCILLATOR SPECIFICATIONS .......................................................................................... 5-7
5.4 SCHEMATICS........................................................................................................................................ 5-11
6. PACKAGE DIMENSIONS................................................................................................................................... 6-1

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
vi Conexant 1154
List of Figures
Figure 1-1. Block Diagram - Serial DTE Interface.................................................................................................................... 1-5
Figure 1-2. Block Diagram - Parallel Host Interface................................................................................................................. 1-5
Figure 1-3. 1-Relay Data/Fax/TAM DAA Interface (U.S.)....................................................................................................... 1-10
Figure 1-4. 2-Relay Data/Fax/TAM/V.61/Speakerphone DAA Interface (U.S.)...................................................................... 1-11
Figure 3-1. Hardware Interface Signals - Serial DTE Interface................................................................................................ 3-2
Figure 3-2. Hardware Interface Signals - Parallel Host Interface............................................................................................. 3-3
Figure 3-3. MCU Pin Signals - Serial DTE Interface - 80-Pin PQFP........................................................................................ 3-4
Figure 3-4. MCU Pin Signals - Parallel Host Interface - 80-Pin PQFP..................................................................................... 3-4
Figure 3-5. MDP Pin Signals - 100-Pin PQFP.......................................................................................................................... 3-7
Figure 3-6. RCDSVD SCP Pin Signals- 100-Pin PQFP ........................................................................................................... 3-9
Figure 3-7. Waveforms - External Memory Bus ..................................................................................................................... 3-24
Figure 3-8. Waveforms - Parallel Host Bus............................................................................................................................ 3-26
Figure 3-9. Waveforms - Serial DTE Interface ....................................................................................................................... 3-27
Figure 5-1. Interface Schematic - MCU with Serial DTE Interface - 80-Pin PQFP................................................................. 5-12
Figure 5-2. Interface Schematic - MCU with Parallel Host Interface - 80-Pin PQFP.............................................................. 5-13
Figure 5-3. Interface Schematic - MDP - 100-Pin PQFP........................................................................................................ 5-14
Figure 5-4. Interface Schematic - RCDSVD SCP - 100-Pin PQFP ........................................................................................ 5-15
Figure 6-1. Package Dimensions - 80-Pin PQFP..................................................................................................................... 6-1
Figure 6-2. Package Dimensions - 100-Pin PQFP................................................................................................................... 6-2

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant vii
List of Tables
Table 1-1. Modem Models and Functions................................................................................................................................ 1-2
Table 1-2. Modem Memory Options......................................................................................................................................... 1-9
Table 1-3. +VLS Command Options....................................................................................................................................... 1-12
Table 2-1. +MS Command Automode Connectivity ................................................................................................................. 2-2
Table 3-1. MCU Pin Signals - Serial DTE Interface - 80-Pin PQFP ......................................................................................... 3-5
Table 3-2. MCU Pin Signals- Parallel Host Interface - 80-Pin PQFP....................................................................................... 3-6
Table 3-3. MDP Pin Signals - 100-Pin PQFP........................................................................................................................... 3-8
Table 3-4. RCDSVD SCP Pin Signals - 100-Pin PQFP.......................................................................................................... 3-10
Table 3-5. MCU Pin Signal Definitions................................................................................................................................... 3-11
Table 3-6. MDP Pin Signal Definitions ................................................................................................................................... 3-14
Table 3-7. RCDSVD SCP Pin Signal Definitions.................................................................................................................... 3-17
Table 3-8. MCU Digital Electrical Characteristics................................................................................................................... 3-19
Table 3-9. MDP Digital Electrical Characteristics................................................................................................................... 3-20
Table 3-10. Analog Electrical Characteristics......................................................................................................................... 3-21
Table 3-11. Current and Power Requirements....................................................................................................................... 3-22
Table 3-12. Absolute Maximum Ratings................................................................................................................................. 3-22
Table 3-13. Timing - External Memory Bus............................................................................................................................ 3-23
Table 3-14. Timing - Parallel Host Bus................................................................................................................................... 3-25
Table 4-1. Parallel Interface Registers..................................................................................................................................... 4-2
Table 4-2. Interrupt Sources and Reset Control....................................................................................................................... 4-5
Table 4-3. Programmable Baud Rates................................................................................................................................... 4-10
Table 5-4. MCU, MDP and SCP Pin Noise Characteristics...................................................................................................... 5-6
Table 5-5. Crystal Specifications - Surface Mount ................................................................................................................... 5-7
Table 5-6. Crystal Specifications - Through Hole..................................................................................................................... 5-8
Table 5-7. Clock Oscillator Specifications - Surface Mount...................................................................................................... 5-9
Table 5-8. Clock Oscillator Specifications - Through Hole..................................................................................................... 5-10

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
viii Conexant 1154
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RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-1
1. INTRODUCTION
1.1 SUMMARY
The ConexantRC56D, RC336D, and RC144D Modem Device Set families support data/fax, voice/TAM/telephony
extensions, V.80 synchronous access mode, host-DSVD, and optional speakerphone, AudioSpan, and on-board DSVD
functions depending upon model (Table 1-1).
The modem supports the following primary data modulations: ITU-T V.90/K56flex(RC56), V.34 (RC56 and RC336) and
V.32bis. Otherwise, the modems are identical within like models, e.g., SP models operate the same. Unless otherwise noted,
descriptions in this document apply to all modem families and models.
The modem is designed to operate with dial-up telephone lines in the U.S. and world-wide.
Low profile, small PQFP packages make this device set ideal for desktop applications using parallel host or serial DTE
interface.
The device set consists of an 8-bit microcontroller (MCU) in an 80-pin PQFP, a modem data pump (MDP) in a 100-pin PQFP,
and an optional Plug and Play (PnP) ISA Bus Interface Device in 80-pin PQFP. The SVD model is the same as the SP model
with the addition of an RCDSVD Speech Codec Processor (SCP) in a 100-pin PQFP to support DSVD.
Downloadable architecture supports downloading of modem firmware from the host/DTE to the MCU and, transparently to the
host/DTE, the downloading of MDP code modules from the MCU.
The modem operates by executing firmware from installed 1Mbit (128k x 8) RAM and 2Mbit (256k x 8) ROM/flash ROM. The
RC336 and RC144 can alternatively use 32k x 8 RAM and 1Mbit or 2Mbit ROM/flash ROM.
In V.90/K56flex mode (RC56), the modem can receive data at speeds up to 56 kbps from a digitally connected V.90- or
K56flex-compatible central site modem. Taking advantage of the PSTN which is primarily digital except for the client modem
to central office local loop, V.90/K56flex modems are ideal for applications such as remote access to an Internet Service
Provider (ISP), on-line service, or corporate site. The modem can send data at speeds up to V.34 rates.
In V.34 data mode (RC56 and RC336), the modem operates at line speeds up to 33.6 kbps. Error correction (V.42/MNP 2-4)
and data compression (V.42 bis/MNP 5) maximize data transfer integrity and boost average data throughput up to
230.4 kbps. Non-error-correcting mode is also supported.
In V.32 bis mode, the modem operates at line speeds up to 14.4 kbps.
The modem supports fax Group 3 send and receive rates up to 33.6 kbps and T.30 protocol.
In voice/TAM mode, enhanced 2-bit or 4-bit per sample ADPCM coding and decoding at 7200 Hz sample rate allows efficient
digital storage of voice/audio. This mode supports applications such as digital telephone answering machine (TAM), voice
annotation, and recording from and playback to the telephone line. Other voice/TAM functions using handset or headset are
supported by SP and SVD models. Extension pickup /remote hangup detection and line-in-use detection telephony
extensions are also supported.
SP and SVD models support position independent, full-duplex speakerphone (FDSP) operation using microphone and
speaker, as well as other voice/TAM applications using handset or headset.
SP and SVD models also support AudioSpan (analog simultaneous audio/voice and data) operation with a data rate of 4.8
kbps with audio.
SVD models, using the optional RCDSVD SCP device (see RCDSVD SCP Designer’s Guide, Order No. 1087), support
hardware-based (on-board) V.70 DSVD (digital simultaneous voice and data) with speech coding per ITU-T interoperable
G.729 and G.729 Annex A with interoperable G.729 Annex B.
Host-based DSVD is supported in all models, however, the host PC must supply full-duplex sound support, typically to a
microphone/speaker, such as provided by Conexant WaveArtist devices or a sound card.
A common PC board design can support data/fax, V.80, voice/TAM/telephony extensions, speakerphone, AudioSpan, and
host- or on-board DSVD operation depending on the installed modem and optional PnP and RCDSVD devices.
Accelerator kits and reference designs are available to minimize application design time and costs. PC-based
“ConfigurACE™ II for Windows” software allows MCU firmware to be customized.
This designer's guide describes the modem system capabilities and hardware interfaces. Supporting AT commands and S
Registers are identified in firmware release notes and defined in the AT Command Reference Manual (Order No. 1131 or
1199 depending on installed firmware).

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-2 Conexant 1154
Table 1-1. Modem Models and Functions
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RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-3
1.2 FEATURES
•Downloadable MCU firmware from the host/DTE and downloadable MDP code modules from the MCU
•Data modem
−ITU-T V.90 and K56flex (RC56 models)
−V.34 (33.6 kbps) (RC56 and RC336 models)
−V.32 bis, V.32, V.22 bis, V.22, V.23, and V.21
−Bell 212A and 103
−V.42 LAPM, MNP 2-4, and MNP 10 error correction
−V.42 bis and MNP 5 data compression
−MNP 10EC™ enhanced cellular performance
•Fax modem send and receive rates up to 33.6 kbps
−V.34 fax, V.17, V.29, V.27 ter, and V.21 channel 2
•V.80 synchronous access mode supports host-based communication protocols
•World-class operation
−Call progress
−Blacklisting
−Multiple country support
•Voice/TAM/telephony extensions mode
•Handset support (SP and SVD models)
•Full-duplex speakerphone (FDSP) mode (SP and SVD models)
−Acoustic and line echo cancellation
−Microphone gain and muting
−Speaker volume control and muting
•AudioSpan simultaneous audio/voice and data (SP and SVD models)
−ITU-T V.61 modulation (4.8 kbps data with audio)
−Handset, headset, or microphone/speaker
•ITU-T V.70 DSVD using the RCDSVD SCP (SVD models)
−ITU-T interoperable G.729 and G.729 Annex A with interoperable G.729 Annex B
−Voice/silence detection and handset echo cancellation
−Robust DSVD timing recovery
−Handset, headset, or half-duplex speakerphone
•Host-based DSVD support with V.70 software drivers for Windows 95
•Communication software compatible AT command sets
•NVRAM directory and stored profiles
•Flash memory support
•Internal phase-locked loop (PLL)
•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)
•Supports Conexant PnP ISA Bus Interface Device
•Supports Serial PnP interface per Plug and Play External COM Device Specification, Rev 1.00
•Flow control and speed buffering
•Automatic format/speed sensing
•Serial sync/async data; parallel async data
•Caller ID and distinctive ring detect
•Packages:
−MCU: 80-pin PQFP
−MDP: 100-Pin PQFP
−PNP: 80-Pin PQFP
−RCDSVD SCP: 100-pin PQFP
•+5V operation
•Sleep Mode

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-4 Conexant 1154
1.3 TECHNICAL OVERVIEW
1.3.1 General Description
The modem device set, consisting of separate microcontroller (MCU), modem data pump (MDP), optional Plug and Play
(PnP) ISA Bus Interface Device, and optional RCDSVD Speech Codec Processor (SCP) devices, provides the processing
core for a complete modem design.
For data/fax/V.80/voice/TAM/speakerphone/host-DSVD/AudioSpan operation, only the microcontroller (MCU) and modem
data pump (MDP) devices are needed. The OEM adds an MCU crystal, discrete components, and a telephone
line/telephone/voice/TAM/telephony extension interface circuit to complete the modem system. Optional on-board DSVD
operation is supported with addition of the RCDSVD Speech Codec Processor (SCP) device to an SP model (included in SVD
models). Table 1-1 shows the supported functions by product family.
Dialing, call progress, V.80, telephone line interface, voice/TAM, speakerphone, AudioSpan, and DSVD functions are
supported and controlled through the AT command set.
Connection to the host/DTE is supported by serial DTE interface (Figure 1-1) or parallel host interface (Figure 1-2) depending
on installed modem firmware.
Data/Fax Modes
In V.90/K56flex data modem mode (RC56), the modem can receive data from a digital source using a V.90- or K56flex-
compatible central site modem at line speeds up to 56 kbps. Asymmetrical data transmission supports sending data at
speeds up to V.34 rates. This mode can fallback to full-duplex V.34 mode.
In V.34 data modem mode, the modem can operate in 2-wire, full-duplex, asynchronous modes at line rates up to 33.6 kbps.
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 33.6 kbps
to 300 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 mode, the modem can operate in 2-wire, half-duplex, synchronous mode and can support Group 3 facsimile
send and receive speeds of 33600, 31200, 28800, 26400, 24000, 21600, 19200, 16800, 14400, 12000, 9600, 7200, 4800,
and 2400 bps. 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 at speeds up to 33.6 kbps with automatic rate adaption. Fax data transmission
and reception performed by the modem are controlled and monitored through the EIA/TIA-578 Fax Class 1, T.31 Fax Class
1.0, or Fax Class 2 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.
Synchronous Access Mode (SAM)
V.80 synchronous access mode between the modem and the host/DTE is provided for host-based communication protocols,
e.g., H.324 video conferencing applications.
Voice-call-first (VCF) before switching to a videophone call is also supported.
V.80 SAM is controlled by the +ES (Enable/Disable Synchronous Access Mode), +ESA (Configure Synchronous Access
Submode), and + ITF (Select Transmit Flow Control Thresholds) AT commands.
World Class Operation
W-class functions support modem operation in multiple countries. Additional capabilities are provided in addition to the data
modem functions in areas such as for dialing, carrier transmit level, calling tone, call progress tone detection, answer tone
detection, blacklisting, relay control. Country dependent parameters are programmable by ConfigurACE II for Windows.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-5
1154F1-1 BD-Ser
TELEPHONE
LINE/
TELEPHONE
HANDSET/
TELEPHONY
EXTENSIONS/
AUDIO
INTERFACE
CIRCUIT
TELEPHONE
LINE
TEL HANDSET
MICROPHONE
HEADPHONE/
SPEAKER
SERIAL
DTE/
INDICATOR
INTERFACE
256 x 8
SERIAL
NVRAM
(OPTIONAL)
MODEM DEVICE SET
MICRO
CONTROLLER
UNIT
(MCU)
[80-PIN PQFP]
MODEM
DATA PUMP
(MDP)
[100-PIN PQFP]
RCDSVD
SPEECH
CODEC
PROCESSOR
(SCP)
[R6715-14,
100-PIN PQFP]
(OPTIONAL)
ROM/FLASH ROM
2M (256K x 8)
[RC56/RC336/RC144]
or 1M (128K x 8)
[RC336/RC144]
RAM
1M (128K x 8)
[RC56/RC336/RC144]
or 32K x 8
[RC336/RC144]
Figure 1-1. Block Diagram - Serial DTE Interface
1154F1-2 BD-Par
TELEPHONE
LINE/
TELEPHONE
HANDSET/
TELEPHONE
EXTENSIONS/
AUDIO
INTERFACE
CIRCUIT
TELEPHONE
LINE
TEL HANDSET
MICROPHONE
HEADPHONE/
SPEAKER
MODEM DEVICE SET
MICRO
CONTROLLER
UNIT
(MCU)
[80-PIN PQFP]
MODEM
DATA PUMP
(MDP)
[100-PIN PQFP]
PARALLEL
HOST
BUS
INTERFACE
RCDSVD
SPEECH
CODEC
PROCESSOR
(SCP)
[R6715-14,
100-PIN PQFP]
(OPTIONAL)
256 x 8
SERIAL
NVRAM
(OPTIONAL)
PnP
INTERFACE
DEVICE
[11596-21:
80-PIN PQFP]
(OPTIONAL)
ROM/FLASH ROM
2M (256K x 8)
[RC56/RC336/RC144]
or 1M (128K x 8)
[RC336/RC144]
RAM
1M (128K x 8)
[RC56/RC336/RC144]
or 32K x 8
[RC336/RC144]
Figure 1-2. Block Diagram - Parallel Host Interface

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-6 Conexant 1154
Voice/TAM Mode
Voice/TAM Mode features include enhanced ADPCM compression/decompression, tone detection/generation and call
discrimination, concurrent DTMF detection, and 8-bit monophonic audio data encoding.
Voice/TAM Mode is supported by three submodes:
1. Online Voice Command Mode supports connection to the telephone line or, for SP and SVD models, a handset.
2. Voice Receive Mode supports recording voice or audio data input at the RIN pin, typically from the telephone line or, for
SP and SVD models, a microphone/handset.
3. Voice Transmit Mode supports playback of voice or audio data to the TXA1/TXA2 output, typically to the telephone line
or, for SP and SVD models, a speaker/handset.
Telephony Extension Operation
Extension pickup/remote hangup detection and line-in-use detection are supported.
Speakerphone Mode (SP and SVD Models)
The speakerphone mode features an advanced proprietary speakerphone algorithm which supports full-duplex voice
conversation with both acoustic and line 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 speakerphone mode provides hands-free full-duplex telephone operation under host control. The host can separately
control volume, muting, and AGC in microphone and speaker channels.
AudioSpan Mode (SP and SVD Models)
AudioSpan provides full-duplex analog simultaneous audio/voice and data over a telephone line at a data rate of 4800 bps
with audio 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 a microphone and speaker.
Handset echo cancellation is provided.
DSVD Mode using RCDSVD SCP Device (SVD Models)
On-board DSVD operation requires installation of the optional RCDSVD SCP (R6715-14).
DSVD provides full-duplex digital simultaneous voice and data over a single telephone line. DSVD uses codecs in the
RCDSVD SCP to code (compress) analog speech signal on the RCDSVD LINEIN pin or MICIN pin for passing to the modem
controller in digitized form, and to decode (decompress) coded speech received from the modem controller for routing to the
RCDSVD LINEOUT pin or SPKP/SPKN pins in analog form.
DSVD operates in accordance with ITU-T interoperable G.729 and G.729 Annex A with interoperable G.729 Annex B. Voice
activity detection supports speech coding at average bit rate significantly lower than 8.0 kbps.
DSVD decoder timing recovery algorithm compensates for clock skew, asynchronous host-to-decoder data transfer delay,
intervening variable length data block transmission delay, and loss of encoded speech data.
The voice interface can be in the form of a headset, handset or a microphone and speaker (half-duplex speakerphone).
Handset echo cancellation supports handset use through a hybrid.
In Handset Mode, the RCDSVD SCP interfaces to the telephone interface circuit using the Line Input (LINEIN) and Line Out
(LINEOUT) lines. In Headset or Speakerphone Mode, the RCDSVD SCP interfaces to the audio interface circuit using the
Microphone Input (MICIN) and Speaker out (SPKR) lines.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-7
Host-Based DSVD
All modem models support host-based ITU-T V.70 DSVD. The RCDSVD SCP (R6715) is not required. V.70 software drivers
for Windows 95 are provided which support a speech/audio bit rate of significantly less than 8.0 kbps by implementing
interoperable G.729 and G.729 Annex A with interoperable G.729 Annex B. The minimum PC performance recommended for
host-based DSVD is 150 MHz Pentium or equivalent. The V.70 software drivers require about 10% of the MIPS available in a
Pentium 150 MHz class PC. The host PC must supply full-duplex sound support, typically to a microphone/speaker, such as
provided by Conexant WaveArtist devices or a sound card. The modem is configured for host-based V.70 via AT commands,
and, when using a TAPI-compliant communication application, the V.70 software drivers will automatically run upon a
successful V.70 connection.
Sleep Mode
Sleep Mode is supported in the modem device set and the RCDSVD SCP device.
1.3.2 Devices
Modem Data Pump (MDP)
The data/fax/voice/optional speakerphone modem data pump (MDP) is a Conexant R6764 packaged in a 100-pin PQFP. The
input clock frequency is 28.224 MHz and can be supplied by the MCU. An internal phase locked loop (PLL) circuit supports
56.448 MHz internal operation. The operating voltage is +3.3V, which can be supplied by the MCU, with +5V tolerant inputs.
The MDP supports +5V analog signal interface.
In V.90/K56flex data modem mode (RC56), the MDP can receive data from a digital source using a V.90- or K56flex-
compatible central site modem at line speeds up to 56 kbps. Asymmetrical data transmission supports sending data at
speeds up to V.34 rates.
In V.34 data modem mode, the MDP can operate in 2-wire, full-duplex, synchronous/asynchronous modes at line rates up to
33.6 kbps. Using V.34 modulation to optimize modem configuration for line conditions, the MDP can connect at the highest
data rate that the channel can support from 33.6 kbps to 300 bps with automatic fallback. Automode operation in V.34 is
provided in accordance with PN3320 and in V.32 bis in accordance with PN2330.
In fax modem mode, the MDP supports Group 3 facsimile send and receive speeds of speeds of 33600, 31200, 28800,
26400, 24000, 21600, 19200, 16800, 14400, 12000, 9600, 7200, 4800, and 2400 bps.
ADPCM voice processing is supported.
Downloading of MDP code from the MCU is supported.
Microcontroller (MCU)
The MCU is a Conexant 8-bit microcomputer with pins to support host/ DTE, MDP, voice/audio/speakerphone, and optional
RCDSVD SCP interface operation. The operating voltage is +5V. The MCU provides a +3.3V output to power the MDP.
The MCU connects to the host via a V.24 (EIA/TIA-232-E) serial interface or a parallel microcomputer bus depending on
installed MCU firmware.
The MCU performs the command processing and host interface functions. The crystal frequency is 28.224 MHz. The MCU
outputs a 28.224 MHz clock to the MDP eliminating need for a separate MDP crystal circuit.
The MCU connects to the MDP via dedicated lines and the external bus. The external bus also connects to OEM-supplied
RAM and ROM/flash ROM, and to the optional RCDSVD SCP.
The MCU connects to an optional 256-byte serial EEPROM over a dedicated serial interface.
The MCU is packaged in an 80-pin PQFP.
RCDSVD Speech Codec Processor (SCP) (Optional)
The RCDSVD SCP (R6715-14), required for on-board DSVD operation, is packaged in a 100-pin PQFP. The 56.448 MHz
crystal frequency is supplied by the MDP XCLK output.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-8 Conexant 1154
Plug and Play (PnP) ISA Bus Interface Device (PNP Models)
The Conexant Plug and Play (PnP) ISA Bus Interface Device (11596-21) is an 80-pin PQFP VLSI device that supports
automatic configuration of an Industry Standard Architecture (ISA) modem card operating on a personal computer (PC) with
PnP capability. The PnP Device supports host performance of the following functions when interfacing with the PnP ISA card:
•Isolate the ISA card
•Read the card's resource data
•Identify the card and configure its resources
The PnP Device meets the requirements stated in the Plug and Play ISA Specification Version 1.0a.
See Plug and Play (PnP) ISA Bus Interface Device Data Sheet (Order No. MD144) for additional information.
1.3.3 MCU Firmware
MCU firmware performs processing of general modem control, command sets, data modem, error correction and data
compression (ECC), fax class 1, fax class 2, DSVD, AudioSpan, voice/audio/TAM/speakerphone, W-class, V.80, and serial
DTE/parallel host interface functions according to modem models.
Configurations of the modem firmware are provided to support parallel host bus or serial DTE interface operation.
The modem firmware is provided in object code form for the OEM to program into external ROM/flash ROM. The modem
firmware may also be provided in source code form under a source code addendum license agreement.
1.3.4 Supported Interfaces
The major hardware signal interfaces of the modem device set are identified in Figure 1-1 (serial DTE interface) and Figure 1-
2 (parallel host bus interface).
Serial DTE Interface and Indicator Outputs
A V.24/EIA/TIA-232-E logic-compatible serial DTE interface is selected by the Parallel/Serial Interface (PARIF) input low. One
serial transmit data input line (~TXD), one serial receive data output line (~RXD), three synchronous clocks (~XTCLK,
~RXCLK, and ~TXCLK), four control input lines (~DTR, ~RTS, ~RDL, and ~AL), and six status output lines (~CTS, ~DSR,
~RLSD, ~TM, ~RI, and ~DRSOUT) are supported.
Three dedicated indicator output lines (~DTRIND, ~TMIND, and ~AAIND) are also provided.
Parallel Host Bus Interface
A 16550A UART-compatible parallel host bus interface is selected by Parallel/Serial Interface (PARIF) input high. The
interface signals are: eight bidirectional data lines (HD0-HD7), three address input lines (HA0-HA2), three control input lines
(~HCS, ~HRD, and ~HWT), one status output line (HINT), and a reset input line (-RESET).
NVRAM (Serial EEPROM) Interface
A 2-line serial interface to non-volatile RAM (NVRAM, i.e., serial EEPROM) is supported. The interface signals are a
bidirectional data line (NVMDATA) and a clock output line (NVMCLK). Data stored in NVRAM can take precedence over the
factory default settings. A 256-byte NVRAM can store up to two user-selectable configurations and up to four 32-digit dial
strings.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-9
External Bus Interface
The non-multiplexed external bus supports eight bidirectional data lines (D0-D7) and 18 address output lines (A0-A17). Read
enable output (~READ), write enable output (~WRITE), and four chip select output (~ROMSEL, ~RAMSEL, ~DPSEL, and
~SCPSEL) lines are also supported.
The external bus connects to OEM-supplied 1Mbit (128k x 8) or 2Mbit (256k x 8) external ROM/flash ROM, 1Mbit (128k x 8)
or 32k x 8 external SRAM, the MDP, and the optional RCDSVD SCP depending upon modem model. The modem memory
options are shown in Table 1-2.
Table 1-2. Modem Memory Options
External Memory Required (Bytes)
Modem Model ROM:
90 ns, 256k ROM: 45 ns, 128k or 256k ROM: 70 ns, 128k or 256k
RAM:
15 ns, 128k RAM: 45 ns, 32k RAM: 70 ns, 32k
RC56D X — —
RC336D X X —
RC144D X X X
Telephone Line/Telephone Interface
For U.S. operation, the modem can operate with 1-relay data/fax/TAM DAA interface (Figure 1-3) or a 2-relay
data/fax/TAM/V.61/Speakerphone DAA interface (Figure 1-4).
Voice mode signal routing commands are summarized in Table 1-3.
MCU. Relay control outputs to the line interface are supported:
•~RLY1: Off-hook (~OH)
•~RLY2: Voice (~VOICE), if needed. Pulse (~PULSE) relay function can be enabled by ConfigurACE II.
•~RLY3: Mute (~MUTE), if needed, can be enabled by ConfigurACE II.
•~RLY4: Caller ID (~CALLID) if needed. The DAAs shown in Figure 1-3 and Figure 1-4 support the Caller ID function without
use of a separate relay.
Ring signal (RINGD) and loop current sense (LCS) inputs are supported.
MDP. A single-ended receive analog input (RIN) and a differential transmit analog output (TXA1/TXA2) are supported. A
digitized speaker output (SPKMD) is provided for call progress monitoring.
Speakerphone Interface (SP and SVD Models)
Microphone input (MICV) and a speaker output (SPKM) lines connect to handset, headset, or a microphone and speaker to
support functions such as AudioSpan headset and speakerphone modes, FDSP, telephone emulation, microphone voice
record, speaker voice playback, and call progress monitor. The speaker output (SPKM) carries the normal speakerphone
audio or reflects the received analog signals in the modem.
An input from the telephone microphone (TELIN) and an output to the telephone speaker (TELOUT) are supported in
AudioSpan modes. These lines connect voice record/playback and AudioSpan audio to the local handset.
RCDSVD SCP Interface (SVD Models)
The Line In (LINEIN) and Line Out (LINEOUT) lines connect DSVD audio to the local telephone handset.
Microphone input (MICIN) and speaker output (SPKP) lines connect to the microphone and speaker to support DSVD
headset and speakerphone modes.

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-10 Conexant 1154
MODEM
DEVICE SET
1154F1-3 AIF 2R-US
TELEPHONE LINE/TELEPHONE HANDSET/
TELEPHONY EXTENSIONS INTERFACE CIRCUIT
HEADPHONE
MICROPHONE
RINGD
~OH
VC
BIAS
AMP/
SOUNDUCER
(OPTIONAL)
AUDIO/HEADPHONE
INTERFACE CIRCUIT
SSI &
BRDGE OH RELAY
HYBRD
&
XFRMR TEL LINE
TEL HANDSET
SURG
PROT
MICV*
SPK
TXA1
RIN
TXA2 RNG
DET
* SP OR SVD MODELS.
** NON-(SP OR SVD) MODELS.
EXTENSION
PICKUP/
REMOTE
HANG-UP
~EXTOH
MICM**
Figure 1-3. 1-Relay Data/Fax/TAM DAA Interface (U.S.)

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1154 Conexant 1-11
MODEM
DEVICE SET
(SP/SVD MODELS)
1154F1-4 AIF 2R-US
TELEPHONE LINE/TELEPHONE HANDSET/
TELEPHONY EXTENSIONS INTERFACE CIRCUIT
HEADPHONE
MICROPHONE
LCS
RINGD
~VOICE
~OH
VC
BIAS
AMP/
SOUNDUCER
(OPTIONAL)
AUDIO/HEADPHONE
INTERFACE CIRCUIT
SSI &
BRDGE OH RELAY
HYBRD
&
XFRMR
TEL LINE
TEL HANDSET
VOICE
RELAY LCS
CUR
SRC
RNG
DET
SURG
PROT
MICV
SPK
HANDSET
HYBRID
TELOUT
TELIN
TXA1
RIN
TXA2
EXTENSION
PICKUP/
REMOTE
HANG-UP
~EXTOH
Figure 1-4. 2-Relay Data/Fax/TAM/V.61/Speakerphone DAA Interface (U.S.)

RC56D, RC336D, and RC144D Modem Device Sets Designer’s Guide
1-12 Conexant 1154
Table 1-3. +VLS Command Options
Label Primitives Description +VTX +VRX +VSP=1
0 None DCE on-hook. Local phone connected to the line.
1 T DCE off-hook. DCE connected to the line. Local phone provided with power to
detect hook condition. XX
2 L DCE on-hook. Local phone connected to the DCE. XX
3 LT DCE off-hook. Local phone connected to the line. DCE connected to the line. XX
4 S Internal Speaker connected to the DCE. DCE on-hook. Local phone connected to
the line. X
5 ST Internal Speaker connected to the line. DCE off-hook. DCE connected to the line.
Local phone provided with power to detect hook condition. XX
6 M Internal Microphone connected to the DCE. DCE on-hook. Local phone
connected to the line. X
7 MST Internal Microphone and Internal Speaker connected to the line. DCE off-hook.
DCE connected to the line. Local phone provided with power to detect hook
condition.
X
8 S1 External Speaker connected to the DCE. DCE on-hook. Local phone connected
to the line. X
9 S1T External Speaker connected to the line. DCE off-hook. DCE connected to the
line. Local phone provided with power to detect hook condition. XX
10 MS1T Internal microphone and External Speaker connected to the line. DCE off-hook.
DCE connected to the line. Local phone provided with power to detect hook
condition.
X
11 M1 External Microphone connected to the DCE. DCE on-hook. Local phone
connected to the line. X
12 M1ST External Microphone and Internal Speaker connected to the line. DCE off-hook.
DCE connected to the line. Local phone provided with power to detect hook
condition.
X
13 M1S1T External Microphone and External Speaker connected to the line. DCE off-hook.
DCE connected to the line. Local phone provided with power to detect hook
condition.
X
14 H External Microphone and Speaker combination (handset or headset) connected
to the DCE. DCE on-hook. Local phone connected to the line. XX
15 HT External Microphone and Speaker combination (handset or headset) connected
to the line. DCE off-hook. DCE connected to the line. Local phone provided with
power to detect hook condition.
XX
16 MS Internal Microphone and Internal Speaker connected to DCE.
17 MS1 Internal Microphone and External Speaker connected to DCE.
18 M1S External Microphone and Internal Speaker connected to DCE.
19 M1S1 External Microphone and External Speaker connected to DCE.
30 Mute Speakerphone Microphone. X
31 Unmute Speakerphone Microphone. X
32 Mute Speakerphone Speaker. X
33 Unmute Speakerphone Speaker. X
Primitives (Column 2):
L Local Phone.
T Telephone Line.
M Internal Microphone.
M1 External Microphone.
S Internal Speaker.
S1 External Speaker.
H External Microphone and Speaker combination (handset or headset).
Notes:
1. Internal Microphone (M) corresponds to MICM. External Microphone (M1) corresponds to MICV.
2. Internal Speaker (S) and External Speaker (S1) are treated the same by the modem.