Datasheet RC224ATL, RC224ATLV Datasheet (Conexant)

RC224ATL/224ATLV

EmbeddedModem Family

The new Conexant RC224ATL utilizes a new integrated data pump/controller to allow
the device to directly connect to host processors that are 3.3 V I/O capable. The codec
used in the new part is the same as the codec used in the existing RC224ATL. The
new device is form, fit, and function compatible with the existing device. This means
there are no hardware and software differences between the existing and the new part,
with one exception. The 3.3 V I/O capable part incorporates 3.3 V compatible digital
I/O buffers, hence requiring 3.3 V digital supply instead of 5 V digital supply.

In addition, unlike the current version of RC224ATL, the new part provides both

data and fax capabilities.

Data modes, controlled by an industry standard 2400 AT command set, can

transmit and receive up to 2400 bps.

Fax modes, controlled by a built-in EIA-578 Class 1 command interface, provide

Group 3 transmit and receive functions.

Functional Block Diagram

V.24

EIA-232-D

Interface

Modem

Data Pump

Modem

Controller

Crystal

Telephone

Line

Interface

Modem

LED

Indictors

Optional
NVRAM

Optional
Speaker

Distinguishing Features

• Data modes
– CCITT V.22 bis (2400 bps), V.22

(1200 bps)

– Bell 212A (1200 bps) and 103

(300 bps)

– Enhanced AT commands

• Group 3 fax modes
– V.29 (9600/7200 bps) transmit
– V.27 ter (4800/2400 bps)

transmit and receive

– V.21 Channel 2 (300 bps)

transmit and receive

• EIA-578 Service Class 1 commands

• V.42/MNP2-4 and V.42 bis/MNP 5
can be supported through host
software without additional hardware

• Data/fax discriminator and auto
answering

• Communications software
compatible

• Integrated call progress and dialing

• No external microcomputer or
memory required

• Parallel or serial asynchronous DTE
interface

• A/A1 relay control

• NVRAM interface allows storage of
two user configurations and four
36-digit dial strings

• Automatic adaptive/fixed
compromise equalization

• Programmable sleep mode and
wake-up

• Full-duplex data mode test
capabilities: Analog loop, local digital
loop, and remote digital loop

• Half-duplex fax mode test capabilities

• Automatic format/speed sensing

• Low power consumption (typical)
– Operating: 100 mW
– Sleep—Idle: 25 mW
– Sleep—Stop: 5 mW

• Single +5 V power supply or Dual
+ 3.3 VDD and + 5 VAA power
supplies

• Package options:
– 68-pin plastic leaded chip carrier

(PLCC)

– 100-pin plastic quad flat pack

(PQFP)

Data Sheet D224ATLVDSC

March 25, 1999

Ordering Information

Marketing

Number

Manufacturing

Number

DSP Die

Number

I/O & VCC VAA/Codec Package

RC224ATL R6781-11 L2501 5V 5V 68 PLCC

RC224ATL R6781-12 L2501 5V 5V 100 PQFP

RC224ATL R6781-13 L2503 5V 5V 68 PLCC

RC224ATL R6781-14 L2503 5V 5V 100 PQFP

RC224ATLV R6781-21 L2531 3V 5V 68 PLCC

RC224ATLV R6781-22 L2531 3V 5V 100 PQFP

Replacement Matrix

Marketing

Number

RC224ATL R6781-11 68 PLCC RC224ATL/V (R6641-14), RC224ATL (R6641-15),

RC224ATL R6781-12 100 PQFP RC224ATL/V (R6641-18), RC224ATL (R6641-19),

Manufacturing

Number

Package Replaces

RC224ATL/VN (R6641-16), RC224ATLN (R6641-17),
RC224ATL/VE (R6641-24), RC224ATLE (R6641-25)

RC224ATL/VN (R6641-20), RC224ATLN (R6641-21),
RC224ATL/VE (R6641-26), RC224ATLE (R6641-27)

RC224ATL R6781-13 68 PLCC RC224ATL/VN (R6641-36), RC224ATL/V

(R6641-37), RC224ATLN (R6641-38), RC224ATL
(R6641-39)

RC224ATL R6781-14 100 PQFP RC224ATL/VN (R6641-40), RC224ATATL/V

(R6641-41), RC224ATL (R6641-43)

RC224ATLV R6781-21 68 PLCC N/A: New 3.3 V Digital I/O

RC224ATLV R6781-22 100 PQFP N/A: New 3.3 V Digital I/O

Information provided by C onexant Systems, Inc. (Conexant) 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 circuitr y embodied in Conexant
products. Conexant reserves the right to change circuitry at any time without notice. This document is subject to change without
notice.

Conexant and “What’s Next in Communications Technologies” are tr ademarks 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 mark s mentioned herein are the property of their respective holders.

© 1999 Conexant Systems, Inc.
Print e d in U.S.A.
All Rights Reserved

Reader Response:

suggestions via e-mail to Conexant Reader [e-mail]. Sorry, we can't answer your technical
questions at this address. Please contact your local Conexant sales office or local field applications engineer if you
have technical questions.

To improv e th e qu ali t y o f our p ublications, we welco me your feedback. Pleas e se nd c om me nts or

D224ATLVDSC Conexant

Table of Contents

List of Figures

List of Tables

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

1.0 Functional Description

1.1 Overview

1.2 Technical Specifications

1.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.2 Configurations and Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.3 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.4 Data/Fax Auto Answering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.5 Data Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.6 Equalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.7 Scrambler/Descrambler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.8 Transmit Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.9 Transmit Tones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.10 Receive Level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.11 Receiver Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.12 Low Power Sleep Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2.3.1 Data Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2.3.2 Fax Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1-1
1-2
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-4
1-4
1-4
1-4
1-5

2.0 Hardware Interface

2.1 Hardware Interface

2.1.1 Parallel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.1.2 Serial/Indicator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.1.3 Speaker Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.1.4 Line Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2 Additional Information

D224ATLVDSC Conexant

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2-6
2-12
2-12
2-12

iii

Table of Contents

RC224ATL/224ATLV

3.0 Pin Descriptions

4.0 AT Commands

5.0 S Registers

6.0 Operation

6.1 Data Modes

6.1.1 Data Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1.2 Data Modem Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1.3 Call Origination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1.4 Call Answering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1.5 Call Termination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2 Fax Modes

6.2.1 Fax Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.2 Fax Mode Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.3 Fax Origination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.4 Fax Answering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.5 Fax Data Transmission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.6 Fax Data Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.7 Fax Control Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.8 Fax Control Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.9 Fax I/O Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

EmbeddedModem Family

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6-1

6-1

6-2

6-2

6-2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

6-3

6-3

6-3

6-3

6-4

6-4

6-4

6-5

6-5

6.3 Fax Enhanced Flow Control

6.3.1 Parallel/Serial Interface Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.3.2 Fax V.42 Buffer Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.3.3 DTE Flow Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.4 Data/Fax Auto Answering

6.5 Call Progress

6.5.1 Call Progress Algorithms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.5.2 Ring Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

7.0 Electrical/Mechanical Specifications

7.1 Interfacing the RC224ATLV

7.2 Environmental Requirements

7.3 Interface Timing and Waveforms

Appendix A: RC224ATF Modem Designs

A.1 68-Pin PLCC Design for Serial Interface

A.2 68-Pin PLCC Design for Parallel Interface

Appendix B: Acronyms/Abbreviations

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

6-7

6-7

6-8

6-12
6-13

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6

iv

Conexant

D224ATLVDSC

RC224ATL/224ATLV

List of Figures

EmbeddedModem Family

List of Figures

Figure 2-1. RC224ATLV Signals—Parallel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Figure 2-2. RC224ATLV Signals—Serial Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Figure 3-1. 68-Pin PLCC Package—Serial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Figure 3-2. 68-Pin PLCC Package—Parallel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

Figure 3-3. 100-Pin PQFP Package—Serial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

Figure 3-4. 100-Pin PQFP Package—Parallel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

Figure 3-5. NVRAM Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20

Figure 7-1. Timing Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

Figure 7-2. 68-Pin PLCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Figure 7-3. 100-Pin PQFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9

Figure A-1. Serial Interface Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

Figure A-2. Serial Interface Design DAA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

Figure A-3. Parallel Interface Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7

Figure A-4. Parallel Interface Design DAA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8

D224ATLVDSC Conexant v

List of Figures

RC224ATL/224ATLV

EmbeddedModem Family

vi Conexant D224ATLVDSC

RC224ATL/224ATLV

List of Tables

EmbeddedModem Family

List of Tables

Table 1-1. Configurations and Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Table 1-2. Data Rates vs. Connection Modem Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1- 3

Table 1-3. Dial Digits/Tone Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Table 1-4. Current and Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

Table 2-1. Parallel Interface Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Table 2-2. Programmable Baud Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Table 3-1. RC224ATL/224ATLV 68-Pin PLCC Pin Assignments—Serial Mode . . . . . . . . . . . . . . . . . . . 3-5

Table 3-2. RC224ATLV 68-Pin PLCC Pin Assignments—Parallel Mode. . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Table 3-3. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Serial . . . . . . . . . . . . . . . . . . . . . . . 3-7

Table 3-4. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Parallel . . . . . . . . . . . . . . . . . . . . . 3-11

Table 3-5. Hardware Interface Signal Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15

Table 4-1. Result Codes and Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Table 4-2. AT Command Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Table 4-3. Fax Command Set Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Table 5-1. S Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Table 5-2. S Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Table 6-1. Data Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Table 6-2. Terminal Called by a 1200 bps Data Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

Table 6-3. Terminal Called by a Fax Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-11

Table 6-4. Tone Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Table 6-5. Fax Class 1 Calling Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Table 6-6. Fax Class 1 Answering Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-15

Table 7-1. Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

Table 7-2. Timing–Host Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Table 7-3. Current and Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

Table 7-4. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Table 7-5. Digital Interface Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

Table 7-6. Analog Interface Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

Table 7-7. 68-Pin PLCC Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

Table 7-8. 100-Pin PQFP Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10

Table A-1. Serial Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4

Table A-2. Parallel Billing Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-9

D224ATLVDSC Conexant vii

List of Tables

RC224ATL/224ATLV

EmbeddedModem Family

viii Conexant D224ATLVDSC

1

1.0 Functional Description

1.1 Overview

The Conexant RC224ATLV is a combination V.22 bis data and Group 3 fax
CMOS modem in a single VLSI package and is identical to the RC224ATLV. The
RC224ATLV integrated data/fax modem is available in either a 68-pin plastic
leaded chip carrier (PLCC) or a 100-pin plastic quad flat pack (PQFP).

Full error correction (V.42 LAPM, MNP2-4) and data compression (V.42 bis,
MNP 5) capabilities can be supported in the RC224ATLV using the host
communication software.

The modem has a selectable parallel or serial interface to the host data
terminal equipment (DTE). When parallel mode is selected, a 16C450-compatible
interface allows direct connection to a notebook, laptop, or PC-compatible bus
without an external universal asynchronous receive/transmit (UART). When
serial mode is selected, a CCITT V.24 logic-compatible interface with transistor to
transistor logic (TTL) levels is supplied along with indicator outputs.

1.2 Technical Specifications

1.2.1 General

The RC224ATLV modem is a full-featured, self-contained data/fax solution. No
external microcontroller for data or fax control functions is required. Dialing, call
progress, and telephone line interface functions are fully supported and controlled
through the AT command set.

Data modes perform complete handshake and data rate negotiations. All tone
and pattern detection required by the applicable CCITT or Bell standard are
supported.

Fax modes support Group 3 fax requirements. Fax data and fax control (V.21
300 bps), performed by the modem, are controlled and monitored through the fax
EIA-578 Class 1 command interface. Full HDLC formatting, flag
insertion/deletion, and CRC generation/checking is provided.

Both transmit and receive fax data is buffered within the modem. Fax data
transfer to and from the DTE is flow controlled by X-on/X-off.

D224ATLVDSC Conexant 1-1

1.0 Functional Description

RC224ATL/224ATLV

1.2 Technical Specifications

1.2.2 Configurations and Rates

The supported modem configurations and signaling rates are listed in Ta bl e 1-1 .
In data modes with serial interface selected, DTE rate offsets of + 1%, – 2.5% are
accommodated by adding/deleting stop bits as required. In fax modes, the DTE
rate is 19,200 bps.

Table 1-1. Configurations and Rates

Configuration Modulation

Data Mode

V.22 bis
V. 2 2
Bell 212A
Bell 103

Fax Mode

V. 2 9

V.2 7 te r

V.2 1

QAM
DPSK
DPSK
FSK

QAM
QAM
DPSK
DPSK
FSK

Transmitter Carrier

Frequency (Hz)

Answer
2400
2400
2400
2225 M
2025 S

Receive
N/A
N/A
1800
1800
1650 M
1850 S

0.01%

±

Originate
1200
1200
1200
1270 M
1070 S

Transmit
1700
1700
1800
1800
1650 M
1850 S

Data Rate

(bps)

2400
1200
1200

300

9600
7200
4800
2400

300

Baud

(Symbols/Sec.)

600
600
600
300

2400
2400
1600
1200

300

EmbeddedModem Family

Bits Per

Symbol

4
2
2
1

4
3
3
2
1

Constellation

Points

16

4
4
1

16

8
8
4
1

Legend:

QAM Quadrature Amplitude Modulation
DPSK Differential Phase Shift Keying
FSK Frequency Shift Keying
M Mark condition
S Space Condition
N/A Not Applicable

1-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

1.0 Functional Description

EmbeddedModem Family

1.2.3 Operation

1.2.3.1 Data Modes

1.2.3.2 Fax Modes

1.2 Technical Specifications

Modem operation is controlled by AT commands, fax service class 1 commands,
and supporting S registers.

Data rate selection is determined by the speed of the originating and answering
modems, as defined in Ta ble 1 -2 .

Table 1-2. Data Rates vs. Connection Modem Rate

Originate Modem Rate

(bps)

300 300 300 300

1200 300 1200 1200

2400 300 1200 2400

Fax modes are negotiated as defined in T.30 and are implemented by AT+F
commands. The AT+FCLASS=1 command causes entry into the fax mode from
the data mode. Most other fax class 1 commands, which start with the AT+F
prefix, are valid only in the fax mode. All data commands are valid in the fax
mode except A/, On, &Tn, and the escape sequence (+++). The AT+FCLASS=0
command terminates the fax mode and causes entry into the data mode.

Connect Speed Based on Answer Modem Rate (bps)

300 1200 2400

1.2.4 Data/Fax Auto Answering

The modem can automatically determine if the incoming call is from a data or fax
modem, make the appropriate connection, and inform the DTE of the connection
type.

1.2.5 Data Modulation

The data modulation conforms to V.29, V.27 ter, V.22 bis, V.22, V.21, Bell 212A,
or Bell 103, depending on the selected configuration. Transmitter and receiver
spectrum shaping is provided in accordance with the applicable standard.

1.2.6 Equalization

Automatic adaptive equalization and fixed compromised equalization are
provided to compensate for line distortions and to minimize the effects of
intersymbol interference.

1.2.7 Scrambler/Descrambler

The modem incorporates a self-synchronizing scrambler/descrambler, which
satisfies the applicable CCITT or Bell requirements.

D224ATLVDSC Conexant 1-3

1.0 Functional Description

RC224ATL/224ATLV

1.2 Technical Specifications

1.2.8 Transmit Level

1.2.9 Transmit Tones

Answer Tone

Guard Tone

Calling Tone

1.2.10 Receive Level

EmbeddedModem Family

The transmit level is – 10 dBm ± 1 dB (at TIP and RING) and can be obtained
using the circuits shown in Appendix A. Carrier and dual tone multi-frequency
(DTMF) transmit levels can be further attenuated using AT%Ln + AT%Dn
commands, respectively. If a higher transmit level is required, an external op amp
can be added.

An answer tone of 2100 Hz (V.22 bis, V.22, or T.30) or 2225 Hz (Bell 212A or

103) is generated.

An 1800 Hz guard tone can be generated in all data modes.

An 1100 Hz (0.5 seconds on, 3 seconds off) calling tone (T.30) is generated in the
originate fax mode.

The receiver satisf ies performance requirements for a received signal from
– 9 dBm to – 43 dBm. The carrier detect is ON at – 43 dBm and OFF at – 48 dBm
with a minimum of 2 dB hysteresis.

1.2.11 Receiver Tracking

The modem can accommodate carrier frequency offset up to ± 7 Hz, and a
transmit timing error of
212A).

DTMF Dialing

Ring Detection

Standard DTMF tones (digits 0-9, A, B, C, D, *, and #) or pulses (digits 0-9) can
be generated. Refer to Table 1- 3.

RING signal is detected from valid high to low transitions on the RING input line
at frequencies of 15.3 Hz to 63 Hz. A RING is valid if the RING ON time is
greater than 0.125 seconds and is followed by a RING OFF time greater than 0.5
seconds.

Table 1-3. Dial Digits/Tone Pairs (1 of 2)

±

0.01% (V.22 bis or V.27 ter) or ± 0.02% (V.22 or Bell

Dial Digit

0 941 1336

1 697 1209

2 697 1336

3 697 1477

4 770 1209

Tone 1

Frequency (Hz)

Tone 2

Frequency (Hz)

5 770 1336

1-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

1.0 Functional Description

EmbeddedModem Family

Table 1-3. Dial Digits/Tone Pairs (2 of 2)

1.2.12 Low Power Sleep Mode

1.2 Technical Specifications

Dial Digit

6 770 1477

7 852 1209

8 852 1336

9 852 1477

* 941 1209

# 941 1477

A 697 1633

B 770 1633

C 852 1633

D 941 1633

Tone 1

Frequency (Hz)

Tone 2

Frequency (Hz)

To conserve power, the RC224ATLV has two selectable sleep (power-down)
modes – Idle and Stop. If enabled by the IDLEN0 and IDLN1 inputs, the selective
sleep mode is entered whenever the modem is active. The sleep mode indicator
output, SLEEP

, is provided to allow external circuits to be powered down when

the modem is in Idle or Stop mode.

The Idle mode allows reduced power consumption with automatic recovery
without additional circuitry. If Idle mode is selected, the modem exits Idle mode
and returns to full operation whenever a ring signal occurs, the DTE writes to the
modem (parallel interface), or WAKEUP

input, normally tied to DTR or TXD, is

asserted (serial interface).

The Stop mode further reduces power consumption, as defined in Tabl e 1 -4 .

Table 1-4. Current and Power Requirements

Current (ID) Power (PD)

Mode

Operating 21 mA 22 mA 100 mW 110 mW

Idle

Sleep

–

Sleep–Stop

NOTE(S):

1. Test conditions: VDD = 5.0 VDC for typical values; VDD = 5.25 VDC for maximum values.

2. Test conditions: VDD = 3.3 V

Typical

Current @ 25°C

5 mA 6 mA 25 mW 30 mW

1 mA 1 mA 5 mW 5 mW

for typical values; VDD = 3.6 VDC for maximum values.

DC

Maximum Current

@ 0°C

Typical

Power @ 25°C

Maximum

Power @ 0°C

D224ATLVDSC Conexant 1-5

1.0 Functional Description

RC224ATL/224ATLV

1.2 Technical Specifications

Entry

Wake-up—Parallel

Interface Configuration

Wake-up—Serial

Interface Configuration

EmbeddedModem Family

The modem will enter the low-power sleep mode when no line connection exists
and no host activity occurs for the period of time specified in the S24 register. All
EmbeddedModem circuits are turned off except the internal Microcontroller Unit
(MCU) clock circuitry in order to consume lower power but are able to
immediately wake up and resume normal operation.

Wake-up occurs when a ring signal occurs, or the host write to the modem.

Wake-up occurs when a ring signal occurs, or the DTE sends a character to the
modem.

1-6 Conexant D224ATLVDSC

2

2.0 Hardware Interface

Figure 2-1 and Figure 2-2 illustrate the RC224ATLV hardware interface signals

for the parallel and serial interfaces, respectively.

The RC224ATLV hardware interface signals are described in

Table 3-5,

See Table 7-2,
timing parameters and Figure 7-1,
interface waveforms.

Hardware Interface Signal Definitions

Timing–Host Bus Interface

Timing Waveform

for a list of the host bus interface

.

for an illustration of the

D224ATLVDSC Conexant 2-1

2.0 Hardware Interface

RC224ATL/224ATLV

Figure 2-1. RC224ATLV Signals—Parallel Interface

XTLI

Crystal

Host

Computer

Parallel BUS

XTLO

HDIS

HCS

HRD

HWT

HINT

HA0

HA1

HA2

HD0

HD1

HD2

HD3

HD4

HD5

HD6

HD7

RC224ATL

RC224ATLV

MODEM

TXAI

TXA2

RXA

RFILO

AGCIN

SPKR

SLEEP

IDLEN0

IDLEN1

A/A1

RING

TLKRELAY

OHRELAY

EmbeddedModem Family

Telephone

Line

Interface

Optional
Speaker

Amplifier

Sleep Mode

Interface

NVRCS

RESET

NVRSK

NVRDIO

Optional
NVRAM

2-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

2.0 Hardware Interface

EmbeddedModem Family

Figure 2-2. RC224ATLV Signals—Serial Interface

XTLI

Crystal

LED

Indicators

V. 24

EIA-232-D

Interface

XTLO

AAE

MR

DCDL

DTRL

RXD

CI/HS

DCD

DSR

RI

CTS

TXD

DTR

RC224ATL

RC224ATLV

MODEM

TXAI

TXA2

RXA

RFILO

AGCIN

SPKR

SLEEP

WAKEUP

IDLEN0

IDLEN1

A/A1

RING

TLKRELAY

OHRELAY

Telephone

Line

Interface

Optional
Speaker

Amplifier

Sleep Mode

Interface

+5 V

RESET

SEREN

NVRCS

NVRSK

NVRDIO

Optional

NVRAM

D224ATLVDSC Conexant 2-3

2.0 Hardware Interface

RC224ATL/224ATLV

The parallel interface registers are identified in Ta ble 2- 1.

Table 2-1. Parallel Interface Registers (1 of 2)

Register

Number

7 Scratch

6Modem

5Line Status

4Modem

Register

Name

Register
(SCR)

Status
Register
(MSR)

Register
(LSR)

Control
Register
(MCR)

7 6 5 4 3 2 1 0

Data
Carrier
Detect
(DCD)

Ring
Indicator
(RI)

0 Transmitter

Empty
(TEMT)

0 0 0 Local

Data Set
Ready
(DSR)

Transmitter
Holding
Register
(THRE)

Bit Number

Scratch Register

Clear to
Send (CTS)

Break
Interrupt
(BI)

Loopback

EmbeddedModem Family

Delta Data
Carrier
Detect
(DDCD)

Framing
Error (FE)

Out 2 Out 1 Request to

Trailing
Edge of
Ring
Indicator
(TERI)

Parity Error
(PE)

Delta Data
Set Ready
(DDSR)

Overrun
Error (OE)

Send (RTS)

Delta Clear
to Send
(DCTS)

Data Ready
(DR)

Data
Terminal
Ready
(DTR)

3Line

Control
Register
(LCR)

2 Interrupt

Identify
Register
(IIR) (Read
Only)

1

Interrupt

DLAB = 0

DLAB = 0

DLAB = 0

0

0

Enable
Register
(IER)

Transmitter
Holding
Register
(THR)

Receiver
Buffer
Register
(RBR)

Divisor
Latch
Access Bit
(DLAB)

Set Break
(SB)

0 0 0 0 0 Pending

0000Enable

Stick Parity
(SP)

Even Parity
Select
(EPS)

Transmitter Holding Register (Write Only)

Receiver Buffer Register (Read Only)

Parity
Enable
(PEN)

Modem
Status
Interrupt
(EDSSI)

Number of
Stop Bits
(STB)

Interrupt ID
Bit 1
(PL1)

Enable
Receiver
Line Status
Interrupt
(ELSI)

Word
Length
Select Bit 1
(WLS1)

Pending
Interrupt ID
Bit 0
(PL0)

Enable
Transmitter
Holding
Register
Empty
Interrupt
(ETBEI)

Word
Length
Select Bit 0
(WLS0)

0 if
Interrupt
Pending
(IP)

Enable
Received
Data
Available
Interrupt
(ERBFI)

2-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

2.0 Hardware Interface

EmbeddedModem Family

Table 2-1. Parallel Interface Registers (2 of 2)

Register

Number

1

DLAB = 1

0

DLAB = 1

Register

Name

Divisor
Latch MSB
Register
(DLM)

Divisor
Latch LSB
Register
(DLL)

7 6 5 4 3 2 1 0

Bit Number

Divisor Latch (MS)

Divisor Latch (LS)

D224ATLVDSC Conexant 2-5

2.0 Hardware Interface

RC224ATL/224ATLV

2.1 Hardware Interface

EmbeddedModem Family

2.1 Hardware Interface

2.1.1 Parallel Interface

A 16450 UART-compatible parallel interface is provided.

Host Bus Interface

Interrupt Enable Register

(Addr=1, DLAB=0)

7 6 5 4 3 2 1 0

0 0 0 0 EDSSI ELSI ETBEI ERBFI

Eight data lines, three address lines, and four control lines are supported.

The Interrupt Enable Register (IER) enables four types of interrupts that can
separately assert the HINT output. A selected interrupt can be enabled by setting
the corresponding enable bit to a logic 1, or disabled by resetting the
corresponding enable bit to a logic 0. All interrupt sources are disabled by setting
bits 0–3 to a logic 0. Disabling all interrupts inhibits the Interrupt Identifier
Register (IIR) and inhibits assertion of the HINT output. All other system
functions operate normally, including the setting of the Line Status Register
(LSR) and the Modem Status Register (MSR).

Bits 4-7:

EDSSI Enable Modem Status Interrupt.

ELSI Enable Receiver Line Status Interrupt.

ETBEI Enable Transmitter Holding Register Empty Interrupt.

ERBFI Enable Received Data Available Interrupt.

Not used (always logic 0).

When this bit is a logic 1,
it enables assertion of the HINT output whenever bit 0, 1, 2, or
3 in the Modem Status Register (MSR) is a logic 1. When this
bit is a logic 0, it disables assertion of HINT due to setting of
any of these four MSR bits.

When this bit is a
logic 1, it enables assertion of the HINT output when any
receiver status bit in the Line Status Register (LSR); i.e., bits
1, 2, 3, or 4, changes state. When this bit is a logic 0, it
disables assertion of HINT due to change of the receiver LSR
bits.

When this bit is a logic 1, it enables assertion of the HINT
output when the Transmitter Holding Register Empty (THRE)
bit in the Line Status Register (LSR5) is set to a logic 1. When
this bit is a logic 0, it disables assertion of HINT due to LSR5.

When this bit is
a logic 1, it enables assertion of the HINT output when
received data is available in the Receiver Buffer; i. e., the Data
Ready bit in the Line Status Register (LSR0) is a logic 1.
When this bit is a logic 0, it disables assertion of HINT due to
the LSR0.

2-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

2.0 Hardware Interface

EmbeddedModem Family

Interrupt Identifier

Register (Addr = 2)

The Interrupt Identifier Register (IIR) identifies the existence and type of
prioritized pending interrupts. Four priority levels are set to assist interrupt

2.1 Hardware Interface

processing in the host.

When addressed during chip-select time, the IIR freezes the highest priority
interrupt pending and acknowledges no other interrupts until the particular
interrupt is serviced by the host.

7 6 5 4 3 2 1 0

00000PL1PL0IP

Bits 3-7:

PL0-1 Highest Priority Pending Interrupt.

Not used (always 0).

These two bits identify

the highest priority pending interrupt.

Priority

2 1 Level Pending Interrupt

1 1 (highest) Receiver Line Status
1 0 2 Receiver Buffer Full
0 1 3 Transmitter Holding Register

Empty

0 0 4 Modem Status

IP Interrupt Pending

pending. When this bit is a logic 1, no interrupt is pending.
This bit can be used in a hardwired prioritized or polled
environment to indicate whether an interrupt is pending. If an
interrupt is pending, the IIR contents can be used as a pointer
to the appropriate interrupt service routine in the host.

. When this bit is a logic 0, an interrupt is

D224ATLVDSC Conexant 2-7

2.0 Hardware Interface

RC224ATL/224ATLV

2.1 Hardware Interface

Line Control Register

(Addr = 3)

7 6 5 4 3 2 1 0

DLAB SB SP EPS PEN STB WLS1 WLS0

The Line Control Register (LCR) specifies the format of the asynchronous data
communications exchange.

DLAB Divisor Latch Access Bit

. This bit must be set to a logic 1 to

EmbeddedModem Family

access the Divisor latches of the baud generator during a read
or write operation. It must be reset to a logic 0 to access the
Receiver Buffer, the Transmitter Holding Register, or the
Interrupt Enable Register.

SB Set Break

. When this bit is set to a logic 1, the transmit data is
forced to the space (logic 0) state. The break is disabled by
setting this bit to a logic 0. The Set Break bit acts only on the
transmit data and has no effect on the serial in logic.

SP Stick Parity

. When stick parity is selected (LCR5 = 1), parity
is enabled (LCR3 = 1), and even parity is selected (LCR4 = 1),
the parity bit is transmitted and checked by the receiver as a
logic 0. When stick parity is selected (LCR5 = 1), parity is
enabled (LCR3 = 1), and odd parity is selected (LCR4 = 0),
the parity bit is transmitted and checked by the receiver as a
logic 1.

EPS Even Parity Select

. When parity is enabled (LCR3 = 1), and
Stick Parity (LCR5) is a logic 0, the number of logic 1s
transmitted or checked in the data word bits and parity bit is
either even (LCR4 = 1) or odd (LCR4 = 0).

PEN Parity Enable

. When bit 3 is a logic 1, a parity bit is
generated in the serial out (transmit) data stream and checked
in the serial in (receive) data stream. The parity bit is located
between the last data bit and the first stop bit.

STB Number of Stop Bits

bits in each serial out character. If bit 2 is a logic 0, one stop
bit is generated regardless of word length. If bit 2 is a logic 1
when either a 5-, 6-, 7-, or 8-bit word length is selected, two
stop bits are generated. The serial in logic checks the f irst stop
bit only regardless of the number of stop bits selected.

WLS0 and WLS1 Word Length Select

bits in each serial in or serial out character. The encoding of
bits 0 and 1 is:

Bit 1 Bit 0 Word Length

0 0 5 Bits
0 1 6 Bits
1 0 7 Bits
1 1 8 Bits

. This bit specifies the number of stop

. These two bits specify the number of

2-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

2.0 Hardware Interface

EmbeddedModem Family

Modem Control Register

(Addr = 4)

7 6 5 4 3 2 1 0

0 0 0 LL OUT2 OUT1 RTS DTR

The Modem Control Register (MCR) controls the interface with the modem or
data set.

Bit 5-7:

LL Local Loopback

Not used (always 0).

. When this bit is set to a logic 1, the

2.1 Hardware Interface

diagnostic mode is selected and the following occurs:

1.

Data written to the Transmit Holding Register will be
looped back to the Receiver Buffer Register.

2.

The four modem control bits (CTS, DSR, RI, and DCD)
are internally connected to the four modem control
outputs (RTS, DTR, OUT1, and OUT2), respectively.

OUT2 Output 2

. When this bit is a logic 1, HINT is enabled. When

this bit is a logic 0, HINT is in the high impedance state.

OUT1 Output 1

. This bit is used in local loopback (see MCR4).

RTS Request to Send

. This bit controls the Request to Send (RTS)
function. When this bit is a logic 1, RTS is on. When this bit is
a logic 0, RTS is off.

DTR Data Terminal Ready

Ready (DTR) function. When this bit is a logic 1, DTR is on.
When this bit is a logic 0, DTR is off.

. This bit controls the Data Terminal

D224ATLVDSC Conexant 2-9

2.0 Hardware Interface

RC224ATL/224ATLV

2.1 Hardware Interface

Line Status Register

(Addr = 5)

7 6 5 4 3 2 1 0

0TEMTTHREBI FE PE OE DR

The LSR, an 8-bit register, provides status information to the host concerning data
transfer.

Bit 7:

This bit is set to logic 0.

TEMT Transmitter Empty

. This bit is set to a logic 1 whenever the

EmbeddedModem Family

Transmitter Holding Register (THR) and the Transmitter Shift
Register (TSR) are both empty. It is reset to a logic 0 whenever
either the THR or TSR contains a data character.

THRE Transmitter Holding Register Empty

. This bit indicates that
the modem is ready to accept a new character for
transmission. In addition, this bit causes the modem to issue
an interrupt to the host when the Transmit Holding Register
Empty Interrupt Enable bit (IIR1) is set to logic 1. The THRE
bit is set to a logic 1 when a character is transferred from the
Transmitter Holding Register into the Transmitter Shift
Register. The bit is reset to logic 0 concurrently with the
loading of the Transmitter Holding Register by the host.

BI Break Interrupt

received data input is a space (logic 0) for longer than two full
word lengths plus 3 bits. The 81 indicator is reset whenever
the host reads the LSR.

FE Framing Error

did not have a valid stop bit. Bit 3 is set to a logic 1 whenever
the stop bit following the last data bit or parity bit is detected
as a zero bit. The FE bit is reset to a logic 0 whenever the host
reads the LSR.

PE Parity Error

. This bit indicates that the received data
character does not have the correct even or odd parity, as
selected by the Even Panty Select bit (LCR4) and the Stick
Parity bit (LCR5). The PE bit is set to a logic 1 upon detection
of parity error and is reset to a logic 0 whenever the host reads
the LSR.

OE Overrun Error

Buffer Register was not read by the host before the next
character was transferred into the Receiver Buffer Register,
thereby destroying the previous character. The OE bit is reset
whenever the host reads the LSR.

DR Data Ready

. This bit is set to a logic 1 whenever a complete
incoming character has been received and transferred into the
Receiver Buffer Register. Bit 0 is reset to a logic 0 when the
host reads the Receiver Buffer Register.

. This bit is set to a logic 1 whenever the

. This bit indicates that the received character

. This bit indicates that data in the Receiver

2-10 Conexant D224ATLVDSC

RC224ATL/224ATLV

2.0 Hardware Interface

EmbeddedModem Family

Modem Status Register

(Addr = 6)

The Modem Status Register (MSR) reports the modem’s current state and change
information. Bits 4-7 supply current state, and bits 0-3 supply change

2.1 Hardware Interface

information. The change bits are set to a logic 1 whenever a control input from the
modem changes state from the last MSR read by the host. Bits 0-3 are reset to
logic 0 when the host reads the MSR or upon reset.

Whenever Bits 0,1, 2, or 3 are set to a logic 1, a Modem Status Interrupt is

generated.

7 6 5 4 3 2 1 0

DCD RI DSR CTS DDCD TERI DDSR DCTS

DCD Data Carrier Detect

. This bit indicates the logic state of the
DCD output. If Loopback is selected (MCR4 = 1), this bit
reflects the state of OUT2 in the MCR (MCR3).

RI Ring Indicator

. This bit indicates the logic state of the RI
output. If Loopback is selected (MCR4 = 1), this bit reflects
the state of OUT1 in the MCR (MCR2).

DSR Data Set Ready

. This bit indicates the logic state of the DSR
output. If Loopback is selected (MCR4 = 1), this bit reflects
the state of DTR in the MCR (MCR0).

Receiver Buffer Register

(Addr=0, DLAB=0)

Transmitter Holding

Register (Addr=0,

DLAB=0)

CTS Clear to Send

. This bit indicates the logic state of the CTS
output. If Loopback is selected (MCR4 = 1), this bit reflects
the state of RTS in the MCR (MCR1).

DDCD Delta Data Carrier Detect

. This bit is set to a logic 1 when
the DCD bit has changed since the MSR was last read by the
host.

TERI Trailing Edge of Ring Indicator

. This bit is set to a logic 1
when the RI bit changes from a 1 to a 0 state since the MSR
was last read by the host.

DDSR Delta Data Set Ready

. This bit is set to a logic I when the
DSR bit has changed state since the MSR was last read by the
host.

DCTS Delta Clear to Send

. This bit is set to a logic 1 when the CTS

bit has changed state since the MSR was last read by the host.

The Receiver Buffer Register (RBR) is a read-only register at location 0 (with
DLAB = 0). Bit 0 is the least significant bit of the data, and is the first bit
received.

The Transmitter Holding Register (THR) is a write-only register at address 0
when DLAB = 0. Bit 0 is the least significant bit and the first bit sent.

D224ATLVDSC Conexant 2-11

2.0 Hardware Interface

RC224ATL/224ATLV

2.2 Additional Information

Divisor Registers

(Addr=0 and 1, DLAB=1)

Scratch Register (SCR)

(Addr = 7)

EmbeddedModem Family

The Divisor Latch LS Byte and Divisor Latch MS Byte are two read-write
registers at locations 0 and 1 when DLAB = 1, respectively.

The baud rate is selected by loading each divisor latch with the appropriate
hex value. Ta bl e 2 -2 lists the programmable values corresponding to the desired
baud rate.

Table 2-2. Programmable Baud Rates

Divisor Latch (Hex)

MS LS

01
00
00
00

80
C0
60
30

Divisor

(Decimal)

384
192

96
48

Baud Rate

300

600
1200
2400

The Scratchpad Register is a read-write register at location 7. This register is not
used by the DSP and can be used by the host for temporary storage.

2.1.2 Serial/Indicator Interface

A DTE serial interface and indicator outputs are supported.

• Serial Interface: An 8-line V.24/EIA-232-D or TTL logic serial interface to
the DTE is supported.

• LED Indicator Interface: Four direct connect LED indicator outputs are
supported.

2.1.3 Speaker Interface

A speaker output, controlled by AT or V.25 bis commands, is provided for an
optional OEM-supplied speaker circuit.

2.1.4 Line Interface

The EmbeddedModem connects to the line interface circuitry by means of a
receive analog input, two transmit analog outputs, and a ring signal input.

The EmbeddedModem provides three relay control outputs to the line
interface. These outputs may be used to control relays such as off-hook, A/A1
and talk/data.

,

2.2 Additional Information

Additional information is provided in the RC224ATLV
(Order No. 821).

2-12 Conexant D224ATLVDSC

Modem Designer’s Guide

3.0 Pin Descriptions

The RC224ATLV 68-pin PLCC serial and parallel pinouts are displayed in

Figure 3-1 and Figure 3-2, respectively. The 100-pin PQFP serial and parallel

pinout diagrams are displayed in Figure 3-3 and Figure 3-4, respectively.

Figure 3-5 displays NVRAM timing.

RC224ATLV 68-pin PLCC serial and parallel pin assignments are displayed in

Ta bl e 3 - 1 and Ta ble 3- 2, respectively. The 100-pin serial and parallel pin

assignments are displayed in Ta bl e 3 -3 and Table 3-4 , respectively.

Figure 3-1. 68-Pin PLCC Package—Serial

AAE

NC

RXD
VCC

NC

NC
TXD
DTR

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

DTRL

RESET
NVRSK

IDLEN1

RAGCO

RADCI
TSTBO
RSTBO
RRSTO

A/A1

NVRDIO

NVRCS

WAKEUP

SEREN

NC

RING

IDLEN0

9 8 7 6 5 4 3 2 1

3

DCDL

RI
68

MR

67

NMI
66

CI/HS
65

DCD

CTS

64

63

DSR
62

DGND2

61

60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44

DGND1
XTLO
XTLI
TEST

φ

2
SLEEP
SPKR
VAA
MODEI
TSTBI
TRSTI
TDACI
RADCO
RRSTI
NC
RSTBI
NC

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

TRSTO

NC

TXA1

TXA2

TDACO

MODEO

RXA

RFILO

AGCIN

VC

NC

NC

AGND

TLKRELAY

RAGCI

SLEEPI

OHRELAY

D224ATLVDSC Conexant 3-1

3.0 Pin Descriptions

RC224ATL/224ATLV

Figure 3-2. 68-Pin PLCC Package

HA1
HA0

IDLEN0

NVRSK
RESET

VCC
HINT
HDIS

NC

NVRDIO

NC

IDLEN1

RAGCO

RADCI
TSTBO
RSTBO

RRSTO

Parallel

—

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

A/A1

9

HA2

NVRCS

8 7 6

HCS

HWT

5 4 3

HRD

EmbeddedModem Family

RING

HD7

HD6

HD5

HD4

NMI

HD3

HD2

HD1

HD0

DGND2

1

2

68

67

66

65

64

63

62

61

60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44

DGND1
XTLO
XTLI
TEST

φ

2
SLEEP
SPKR
VAA
MODEI
TSTBI
TRSTI
TDACI
RADCO
RRSTI
NC
RSTBI
NC

27

TRSTO

28

MODEO

29

TDACO

30

NC

31

TXA2

32

TXA1

33

RXA

34

RFILO

35

36

37

VC

NC

AGCIN

38

TLKRELAY

39

AGND

40

OHRELAY

41

NC

42

SLEEPI

43

RAGCI

3-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Figure 3-3. 100-Pin PQFP Package

DTR

RADCI

NC
NC
NC

SLEEP

NC

DGND

VAA

SPKR

NC

AGND

TXA2
TXA1

NC

RXA

NC

RFILO

AGCIN

VC

AGND

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

IDLEN1
RAGCO

TSTBO

RSTBO
RRSTO
TRSTO

MODEO

TDACO

MODEI

Serial

—

NCNCNC

DGNDNCNC

99989796959493929190898887868584838281

100

TXDNCNC

NVRSKNCVCC

VCC

RESET

RXDNCDTRL

AAENCDGND

80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51

DGND

)

(A/A1
NVRDIO
NVRCS
WAKEUP
SEREN
NC
NC
RING
IDLENO
DCDL
RI
MR
NC
DGND
NMI
CI/HS
DCD
CTS
DSR
NC
NC
DGND
DGND
NC
XTLO
XTLI
TEST

2

φ

NC

31323334353637383940414243444546474849

NC

NCNCNCNCNC

AGND

TLKRELAY

NC

AGND

RSTBI

TDACI

RRSTI

RAGCI

OHRELAY

SLEEPI

RADCO

TRSTI

50

NC

TSTBI

D224ATLVDSC Conexant 3-3

3.0 Pin Descriptions

RC224ATL/224ATLV

Figure 3-4. 100-Pin PQFP Package

NC

RADCI

NC
NC
NC

SLEEP

NC

DGND

VAA

SPKR

NC

AGND

TXA2
TXA1

NC

RXA

NC

RFILO

AGCIN

VC

AGND

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

IDLEN1
RAGCO

TSTBO

RSTBO
RRSTO
TRSTO

MODEO

TDACO

MODEI

Parallel

—

NCNCNC

DGNDNCNC

99989796959493929190898887868584838281

100

NVRDIONCHDIS

HINTNCVCC

VCC

RESET

NVRSK

IDLENO

HA0

HA1NCDGND

80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51

EmbeddedModem Family

DGND

)

(A/A1
HA2
NVRCS
HCS
HWT
HRD
NC
RING
HD7
HD6
HD5
HD4
NC
DGND
NMI
HD3
HD2
HD1
HD0
NC
NC
DGND
DGND
NC
XTLO
XTLI
TEST

2

φ

NC

31323334353637383940414243444546474849

NC

NCNCNCNCNC

AGND

TLKRELAY

NC

AGND

RSTBI

TDACI

RRSTI

RAGCI

OHRELAY

SLEEPI

RADCO

50

NC

TSTBI

TRSTI

3-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-1. RC224ATL/224ATLV 68-Pin PLCC Pin Assignments

Pin

Number

1DCDL D0 35 AGCIN —

2 IDLEN0 DI 36 VC —

3 RING

4 NC — 38 TLKRELAY

5 SEREN DI 39 AGND —

6WAKEUP

7 NVRCS DO 41 NC —

8 NVRDIO DI 42 SLEEPI

9A/A1

10 AAE

11 DTRL DO 45 RSTBI MI TO RSTBO

12 NC — 46 NC —

Signal Label I/O Type

DI 37 NC —

DI 40 OHRELAY OD

DO 43 RAGCI MI TO RAGCO

DO 44 NC —

Serial Mode

—

Pin

Number

Signal Label I/O Type

OD

DI

13 RXD

14 RESET DI 48 RADCO RADCO

15 VCC — 49 TDACI MI TO TADCO

16 NVRSK DO 50 TRSTI MI TO TRSTO

17 NC — 51 TSTBI MI TO TSTBO

18 NC — 52 MODEI MI TO MODEO

19 TXD

20 DTR DI 54 SPKR O(DF)

21 IDLEN1 DI 55 SLEEP

22 RAGCO MI TO RAGCI 56 φ2DO

23 RADCI MI TO RADCO 57 TEST

24 TSTBO MI TO TSTBI 58 XTLI IE

25 RSTBO MI TO RSTBI 59 XTLO OE

26 RRSTO MI TO RRSTI 60 DGND1 —

27 TRSTO MI TO TRSTI 61 DGND2 —

28 MODEO MI TO MODEI 62 DSR

29 TDACO MI TO TDACI 63 CTS DO

30 NC — 64 DCD

DO 47 RRSTI MI TO RRSTO

DI 53 VAA —

DO

DI 4.7K TO VCC

DO

DO

31 TXA2 O (DD) 65 CI

32 TXA1 O(DD) 66 NMI

33 RXA I(DA) 67 MR DO

34 RFILO — 68 RI

/HS DO

DI

DO

D224ATLVDSC Conexant 3-5

3.0 Pin Descriptions

RC224ATL/224ATLV

Table 3-2. RC224ATLV 68-Pin PLCC Pin Assignments

Pin

Number

1 HD6 DIO 35 AGCIN —

2 HD7 DIO 36 VC —

3 RING

4 HRD

5HWT DI 39 AGND —

6HCS

7 NVRCS DO 41 NC —

8 HA2 DI 42 SLEEPI

9A/A1

10 HA1 DI 44 NC —

11 HA0 DI 45 RSTBI MI TO RSTBO

12 IDLEN0 — 46 NC —

Signal Label I/O Type

DI 37 NC —

DI 38 TLKRELAY OD

DI 40 OHRELAY OD

DO 43 RAGCI MI TO RAGCO

Parallel Mode

—

Pin

Number

Signal Label I/O Type

EmbeddedModem Family

DI

13 NVRSK DO 47 RRSTI MI TO RRSTO

14 RESET

15 VCC — 49 TDACI MI TO TADCO

16 HINT DO 50 TRSTI MI TO TRSTO

17 HDIS DO 51 TSTBI MI TO TSTBO

18 NC — 52 MODEI MI TO MODEO

19 NVRDIO DIO 53 VAA —

20 NC — 54 SPKR O(DF)

21 IDLEN1 DI 55 SLEEP

22 RAGCO MI TO RAGCI 56 φ2OA

23 RADCI MI TO RADCO 57 TEST

24 TSTBO MI TO TSTBI 58 XTLI IE

25 RSTBO MI TO RSTBI 59 XTLO OE

26 RRSTO MI TO RRSTI 60 DGND1 —

27 TRSTO MI TO TRSTI 61 DGND2 —

28 MODEO MI TO MODEI 62 HD0 DIO

29 TDACO MI TO TDACI 63 HD1 DIO

30 NC — 64 HD2 DIO

DI 48 RADCO RADCO

OA

4.7k TO VCC

31 TXA2 O (DD) 65 HD3 DIO

32 TXA1 O(DD) 66 NMI

33 RXA I(DA) 67 HD4 DIO

34 RFILO — 68 HD5 DIO

DI

3-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-3. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments

Pin Number Signal Label I/O Type

1DTR DI

2IDLEN1 DI

3RAGCO

MI

(2)

4 RADCI MI to RADCO

5 TSTBO MI to TSTBI

6

NC

(3)

7NC —

8NC —

9 RSTBO MI to RSTBI

10 RRSTO MI to RRSTI

11 TRSTO MI to TRSTI

12 MODEO MI to MODEI

13 TDACO MI to TDACI

Serial (1 of 4)

—

to RAGCI

(1)

—

14 SLEEP

15

NC

16 DGND

DO

DGND

—

(4)

17 MODEI MI to MODEO

18 VAA —

19 SPKR O(DF)

20 NC —

21 AGND AGND

22 TXA2 O(DD)

23 TXA1 O(DD)

24 NC —

25 RXA I(DA)

26 NC —

27 RFILO —

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

D224ATLVDSC Conexant 3-7

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-3. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Serial (2 of 4)

Pin Number Signal Label I/O Type

(1)

28 AGCIN —

29 VC —

30 AGND AGND

31 NC —

32 NC —

33 NC —

34 NC —

35 NC —

36 TLKRELAY OD

37 AGND AGND

38 OHRELAY OD

39 NC —

40 NC —

41 SLEEPI DI

42 RAGCI MI to RAGCO

43 AGND AGND

44 RSTBI MI to RSTBO

45 RRSTI MI to RRSTO

46 RADCO MI to RADCI

47 TDACI MI to TDACO

48 TRSTI MI to TRSTO

49 TSTBI MI to TSTBO

50 NC —

51 NC —

52 φ2DO

53 TEST

(5)

54 XTLI IE

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

3-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-3. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Serial (3 of 4)

Pin Number Signal Label I/O Type

(1)

55 XTLO OE

56 NC —

57 DGND DGND

58 DGND DGND

59 NC —

60 NC —

61 DSR DO

62 CTS DO

63 DCD DO

64 CI/HS DO

65 NMI

(6)

66 DGND DGND

67 NC —

68 MR DO

69 RI DO

70 DCDL DO

71 IDLENO DI

72 RING DI

73 NC —

74 NC —

75 SEREN DI

76 WAKEUP DI

77 NVRCS DO

78 NVRDIO DIO

79 (A/A1) DO

80 DGND DGND

81 DGND DGND

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

D224ATLVDSC Conexant 3-9

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-3. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Serial (4 of 4)

Pin Number Signal Label I/O Type

(1)

82 NC —

83 AAE DO

84 DTRL DO

85 NC —

86 RXD DO

87 RESET IC

88 VCC

89 VCC

(6)

(6)

90 NC —

91 NVRSK DO

92 NC —

93 NC —

94 TXD DI

95 NC —

96 NC —

97 DGND DGND

98 NC —

99 NC —

100 NC —

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

3-10 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-4. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Parallel (1 of 4)

Pin Number Signal Label I/O Type

(1)

1NC —

2IDLEN1 DI

3RAGCO

MI

(2)

to RAGCI

4 RADCI MI to RADCO

5 TSTBO MI to TSTBI

6

NC

(3)

—

7NC —

8NC —

9 RSTBO MI to RSTBI

10 RRSTO MI to RRSTI

11 TRSTO MI to TRSTI

12 MODEO MI to MODEI

13 TDACO MI to TDACI

14 SLEEP

15

NC

16 DGND

DO

DGND

—

(4)

17 MODEI MI to MODEO

18 VAA —

19 SPKR O(DF)

20 NC —

21 AGND AGND

22 TXA2 O(DD)

23 TXA1 O(DD)

24 NC —

25 RXA I(DA)

26 NC —

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection.
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

D224ATLVDSC Conexant 3-11

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-4. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Parallel (2 of 4)

Pin Number Signal Label I/O Type

(1)

27 RFILO —

28 AGCIN —

29 VC —

30 AGND AGND

31 NC —

32 NC —

33 NC —

34 NC —

35 NC —

36 TLKRELAY DO

37 AGND AGND

38 OHRELAY DO

39 NC —

40 NC —

41 SLEEPI DI

42 RAGCI MI to RAGCO

43 AGND AGND

44 RSTBI MI to RSTBO

45 RRSTI MI to RRSTO

46 RADCO MI to RADCI

47 TDACI MI to TDACO

48 TRSTI MI to TRSTO

49 TSTBI MI to TSTBO

50 NC —

51 NC —

52 φ2DI

53 TEST

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection.
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

(5)

3-12 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-4. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Parallel (3 of 4)

Pin Number Signal Label I/O Type

(1)

54 XTLI IE

55 XTLO OE

56 NC —

57 DGND DGND

58 DGND DGND

59 NC —

60 NC —

61 HD0 DIO

62 HD1 DIO

63 HD2 DIO

64 HD3 DIO

65 NMI

(6)

66 DGND DGND

67 NC —

68 HD4 DIO

69 HD5 DIO

70 HD6 DIO

71 HD7 DIO

72 RING DI

73 NC —

74 HRD DI

75 HWT DI

76 HCS DI

77 NVRCS DO

78 HA2 DI

79 (A/A1) DO

80 DGND DGND

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection.
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

D224ATLVDSC Conexant 3-13

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-4. RC224ATL/224ATLV 100-Pin PQFP Pin Assignments—Parallel (4 of 4)

Pin Number Signal Label I/O Type

(1)

81 DGND DGND

82 NC —

83 HA1 DI

84 HA0 DI

85 IDLENO DI

86 NVRSK DO

87 RESET IC

88 VCC

89 VCC

(6)

(6)

90 NC —

91 HINT DO

92 HDIS DO

93 NC —

94 NVRDIO DIO

95 NC —

96 NC —

97 DGND DGND

98 NC —

99 NC —

100 NC —

NOTE(S):

(1)

(2)
(3)

(4)
(5)
(6)

I/O Types are described in Figure 7-5, Digital Interface Characteristics and

Figure 7-6, Analog Interface Characteristics.

MI = Modem Interconnection.
NC = No external connection (may have internal connection, leave pin disconnected
(open)).
AGND is analog ground and DGND is digital ground.

Connect to VCC through 4.7 kΩ.

Connect ATL to + 5 VCC, ATLV to + 3 VCC.

3-14 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-5. Hardware Interface Signal Definitions (1 of 5)

Label I/O Type Signal Name/Description

System Signals

XTLI
XTLO

RESET IC Reset. The active low RESET input resets the internal modem logic. Upon RESET

SEREN DI Serial Interface Enable. When the SEREN input is low, serial interface is selected upon reset.

VCC
VAA

IE
OE

PWR

Crystal/Clock In and Crystal Out.

circuit consisting of a 16.000312 MHz crystal and two capacitors. Alternatively, XTLI may be
driven with a buffered clock, in which case XTLO should be left open.

transitioning from high to low, modem operation returns to the state controlled by factory
default values and stored values in NVRAM. During modem power-on, RESET
low for at least 5 ms after +5 VD and +5 VA operating voltage (see TSVD and +5 VA below) is
attained for the modem top stabilize.

When the serial interface is selected, RESET
to cause the modem to reset upon power turn on. When the parallel interface is selected,
RESET should be connected to the hose bus reset line.

In this case, the serial interface signals should be connected to the V.24 (EIA-232-D) interface
and LED indicators.

Digital Supply.
Analog Supply. +5 V ±5% is required.

+5 V/3.3V ATLV ±5% is required.

The modem must be connected to an external crystal

must be held

can be connected to an external RC network

DGND
AGND

IDLEN0
IDLEN1

SLEEP DO

SLEEPI

GND Digital and Analog Grounds.

DI
DI

DI

Sleep Mode Signals

Idle Enable 0 and Idle Enable 1. Encoded inputs enable or disable the sleep modes as

follows:

IDLEN1 IDLEN0 Mode

L L Idle mode disabled

L H Idle mode enabled

H L Stop mode disabled

H H Stop mode enabled

If Idle option is enabled, the modem will enter idle mode after 5 seconds of inactivity
(WAKEUP
activity (RXD for parallel mode and low on WAKEUP
RING.

inverted). The modem will enter stop mode after 5 seconds of inactivity (and if WAKEUP
high for the serial interface). Only a 4 ms or longer pulse on the RING pin can wake up the
modem from stop mode.

Sleep Mode.

SLEEP
used to control power to other devices.

Sleep Mode.

mode.

must also be high for the serial interface). The modem will wakeup upon DTE

for serial mode) or the presence of

If Stop option is selected, the RING input becomes RING (i.e., the RING signal must be

is

SLEEP output high indicates the modem is operating in its normal mode.

low indicates that the modem is in the sleep mode. The SLEEP output can also be

SLEEP input low causes the Integrated Analog (IA) to enter low-power sleep

D224ATLVDSC Conexant 3-15

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-5. Hardware Interface Signal Definitions (2 of 5)

Label I/O Type Signal Name/Description

WAKEUP DI Wake Up. For serial interfaces only, WAKEUP input low removes the modem from the sleep

mode (if in the sleep mode), or prevents the modem from entering the sleep mode (if not in
the sleep mode). WAKEUP
modem inactivity. WAKEUP

high allows the modem to enter sleep mode after 5 seconds of

is typically connected to DTR or TXD.

NVRAM Interface

NVRCS DO NVRAM Chip Select. NVRCS output high enables the NVRAM.

NVRSK DO NVRAM Shift Clock. The NVRSK output is used to shift data to or from the NVRAM.

NVRDIO DIO NVRAM Data In/NVRAM Data Out. NVRDIO is a bidirectional signal that carries both the

serial input data from the NVRAM and the serial output data to the NVRAM. Depending on the
specific NVRAM used, a resistor may be required between the NVRAM DO output pin and the
modem NVRDIO bidirectional line. (Refer to Figure 3-5 and the NVRAM data sheet.)

Speaker Interface

SPKR O(DF)

Speaker Analog Output.

The SPKR output is turned on or off by the Speaker Control Option (Mn command), and the
gain is controlled by the Speaker Volume Option (Ln command). When the speaker is turned
off, the SPKR output is clamped to the voltage at the VC pin. The SPKR output can drive a

load as low as 300 Ω. Typically, the SPKR output is an input to an external LM386 audio

power amplifier.

The SPKR output reflects the output of the receive analog signal.

Asynchronous Serial Interface (Serial Interface Only; SEREN = Low)

RXD DO Received Data. The modem presents received serial data to the RXD output pin.

TXD DI Transmitted Data. The modem obtains serial data to be transmitted from the TXD pin.

DTR DI Data Terminal Ready. DTR input ON (low) indicates that the DTE is ready to operate. DTR

input OFF (high) indicates that the DTE is not ready to operate.

CTS

DSR

DCD DO Data Carrier Detected. The DCD output is controlled by the AT&C command.

CI/HS DO Calling Indicator/High Speed Indicator. CI/HS output ON (low) indicates modem connection

RI

DO Clear to Send. In data modes, the CTS output is ON; in fax modes, CTS is optionally used for

flow control.

DO Data Set Ready. The DSR output is controlled by the AT&Sn command.

at 2400 bps.

DO Ring Indicator. RI output ON (low) indicates the presence of an ON segment of a ring signal

on the telephone line. (The ring signal cycle is typically 2 seconds ON, 4 seconds OFF.) The
OFF (high) condition of the RI
(between rings) and at all other times when ringing is not being received.

output is maintained during the OFF segment of the ring cycle

Serial Indicator Interface (Serial Interface Only; SEREN = Low)

AAE DO Auto Answer Enable. AAE output ON (low) indicates that modem auto answer mode has

been enabled with the S0 = command. AAE

output also indicates the status of the RI output.

The AAE

high indicates auto answer has been disabled.

MR DO

Modem Ready.

on and a test mode is not selected. In a test mode, the MR
in process.

MR output ON (low) indicates that the modem is ready; i.e., modem power is

output pulses to indicate a test is

3-16 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-5. Hardware Interface Signal Definitions (3 of 5)

Label I/O Type Signal Name/Description

DCDL DO DCD Indicator. The DCDL output is controlled by the AT&C command.

DTRL DO DTR Indicator. The DTRL output is controlled by the AT&D command.

Parallel Host Interface (Parallel Interface Only)

When the HWT input signal is connected to the host bus write line, the parallel interface is
selected upon reset. (See Section 7.3, Interface Timing and Waveforms for waveform and
timing information.)

The parallel interface emulates a 16C450 UART; (See Table 2-1, Parallel Interface

Registers). Parallel interface operation is equivalent to 16C450 operation with CS0 and CS1

inputs high and DISTR, DOSTR, and ADS
16C450 signals are shown below. 16C450 signals that are not required for RC224ATLV host
computer operation are not shown.

16C450 Signal RC224ATLV Signal

A0 - A2 HA0 - HA2

D0 - D7 HD0 - HD7

MR RESET

HCS

CS2

DISTR HWT

DOSTR HRD

INTRPT HINT

DDIS HDIS

OUT2 None (Implemented internally in RC224ATLV)

inputs low. The corresponding RC224ATLV and

(Active low)

HA0-HA2

HD0-HD7

DI

DIO

Host Bus Address Lines 0-2. During a host read or write operation, signals HA0–HA2 select
an internal register. The state of the divisor latch access bit (DLAB) affects the selection of
certain registers.
Host Bus Data Lines 0-7. HD0-HD7 are comprised of eight tri-state I/O lines providing
bidirectional communication between the host and the modem. Data, control words, and
status information are transferred through HD0-HD7.

DLAB HA2 HA1 HA0 Register

0 0 0 0 Receive Buffer Register (Read),

Transmitter Holding Register (Write)
0 0 0 1 Interrupt Enable Register
X 0 1 0 Interrupt Identification Register (Read Only)
X 0 1 1 Line Control Register
X 1 0 0 Modem Control Register
X 1 0 1 Line Status Register (Read Only)
X 1 1 1 Scratch Register
1 0 0 0 Divisor Latch Register (Least Significant Byte)
1 0 0 1 Divisor Latch Register (Most Significant Byte)

HCS

HRD

HWT DI Host Bus Write. HWT is an active low write control input. When the modem is selected with

DI

DI Host Bus Read. HRD is an active low read control input. When the modem is selected with

Host Bus Chip Select

parallel bus.

HCS

, HRD low allows status or data words to be read from an addressed register.

, HWT low allows data or control words to be written to an addressed register.

HCS

. HCS input low enables reading from or writing to the modem using the

D224ATLVDSC Conexant 3-17

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Table 3-5. Hardware Interface Signal Definitions (4 of 5)

Label I/O Type Signal Name/Description

HDIS DO Host Bus Driver Disable. HDIS output is low when the host is reading data from the modem

and HCS are low). HDIS is also used to disable the external

HINT DO

over the host data bus (both HRD
transceiver drivers whenever data is not being read from the modem.

Host Bus Interrupt.

is enabled by the OUT2 bit set to a 1 in the Modem Control Register.

HINT output is 16C450-compatible output indicating interrupt status and

Telephone Line Interface

TXA1
TXA2

RXA I(DA)

VC OA

TLKRELAY

O(DF) Transmit Analog 1 and 2. The TXA1 and TXA2 outputs are differential outputs. A 600 Ω

telephone coupling transformer may be driven directly without the need for external discrete
buffer amplifiers.

Both TXA1 and TXA2 outputs are turned off when the transmitter is disabled or during

local analog loopback.

Receive Analog.

Centerpoint Voltage.

voltage. The TXA1 and TXA2 outputs are biased at VC.

DO Talk/Data Relay Driver. TLKRELAY is an open drain output which can directly drive a relay

with greater than 360 Ω coil resistance and has “must operate” voltage of no greater than 4.0

VDC. A heavier load, such as an electro-mechanical relay, requires the use of an external
transistor. An external diode should be provided across the relay coil.

The TLKRELAY

TLKRELAY

In a typical application, TLKRELAY

disconnects the handset from the telephone line.

RXA is a single-ended receive data input from the telephone line interface.

A +2.5 VDC centerpoint voltage derived from an internal reference

output is clamped off during power-on reset or the sleep mode. The

output is activated and deactivated at the same time as the OHRELAY output.

ON opens the normally closed Talk/Data relay and

OHRELAY

RING

A/A1 DO

DO Off-Hook Relay Driver. OHRELAY is an open drain output which can directly drive a relay with

DI

greater than 360 Ω coil resistance and has “must operate” voltage of no greater than 4.0

VDC. A heavier load, such as an electro-mechanical relay, requires the use of an external
transistor. An external diode should be provided across the relay coil.

The OHRELAY
application, OHRELAY
to the telephone line (off-hook).

Ring Detector

to 63 Hz ringing signal is present.

The signal (a 4N35 optoisolator compatible output) into the RING input should not
respond to a voltage less than 40 V

respect to ground.

A low-going edge on the RING

Key Telephone Hold Indicator.

when used on multi-line key telephones.

output is clamped off during power-on reset or the sleep mode. In a typical

ON closes the normally open Off-Hook relay and connects the modem

. RING is a TTL-compatible input used to indicate to the modem that a 15.3 Hz

, 15 Hz to 68 Hz, appearing across TIP and RING with

RMS

input also removes the modem from the sleep mode.

A/A1 output low indicates that the telephone line is in use

3-18 Conexant D224ATLVDSC

RC224ATL/224ATLV

3.0 Pin Descriptions

EmbeddedModem Family

Table 3-5. Hardware Interface Signal Definitions (5 of 5)

Label I/O Type Signal Name/Description

Modem Interconnect

RFILO MI Receive Filter Output. RFILO is the output of the internal receive anti-aliasing filter which

must be connected to AGCIN through a 0.1 µF, 20%, DC decoupling capacitor. The 1000 pF
capacitor to ground provides noise immunity at low noise levels.

AGCIN MI Receive AGC Gain Amplifier Input. See RFILO.

MODEO (DSP),
MODEI (IA)

TDACO (DSP),
TDACI (IA)

TSTBO (DSP),
TSTBI (IA)

TRSTO (DSP),
TRSTI (IA)

RADCI (DSP),
RADCO (IA)

MI Mode Control. Direct modem interconnect line.

MI Transmitter DAC Signal. Serial digital DAC signal. Direct modem interconnect line.

MI

MI Transmitter Reset. 9.6 kHz, 8228.57 Hz, or 7.2 kHz digital transmitter timing reference.

MI Receiver ADC Signal. Serial digital ADC signal. Direct modem interconnect line.

Transmitter Strobe.

line.

Direct modem interconnect line.

576 kHz digital transmitter timing reference. Direct modem interconnect

RAGCO (DSP),
RAGCI (IA)

RRSTO (DPS),
RRSTI (IA)

RSTBO (DSP),
RSTBI (IA)

MI Receiver AGC Signal. Serial digital AGC signal. Direct modem interconnect line.

MI Receiver Reset. 9.6 kHz, 8228.57 Hz, or 7.2 kHz digital receiver timing reference. Direct

modem interconnect line.

MI Receiver Strobe. 576 kHz digital receiver timing reference. Direct modem interconnect line.

D224ATLVDSC Conexant 3-19

3.0 Pin Descriptions

RC224ATL/224ATLV

EmbeddedModem Family

Figure 3-5. NVRAM Timing

(1)

4µS

NVRSK

t

S

DIH

0.4µS

0.4

t

DIS

t

µ

S

DIH

0.4

µ

NVRDI

t

0.2

CSS

µ

t

DIS

0.4

µ

S

S

t

CSH

0.0µS

NVRCS

t

PDO

2

µ

S

t

PDO

2µS

NVRDO

NOTE(S):
(1) This is the minimum NVRSK period.

3-20 Conexant D224ATLVDSC

4

4.0 AT Commands

Each command line must start with the AT pref ix and be terminated with a
carriage return (CR). Several commands may be included on one command line.
A command line may contain up to 40 characters, excluding the AT prefix and the
terminating CR. A separator is not required between data commands. A
semicolon (;) separator is required between fax commands.

AT commands are composed of 10-bit ASCII encoded asynchronous
characters. The character format in data mode is 8 data bits with no parity, or 7
data bits with even, odd, or no (two stop bits) parity, at a data rate of 19,200, 2400,
1200, or 300 bps. The character format in fax mode is 8 data bits with no parity at
19,200 bps.

Table 4- 1 lists result codes and messages. Tabl e 4- 2 summarizes the AT

command set. Tabl e 4 -3 summarizes the fax command set.

Table 4-1. Result Codes and Messages

Digital Code Word Code Meaning

0 OK Command line executed without errors

1 CONNECT Connection at 300 bps

2 RING Ringing signal detected

3 NO CARRIER Carrier lost or never present

4 ERROR Invalid command, checksum, error in

command line, or command line exceeds 40
characters

5 CONNECT 1200 Connection at 1200 bps

6 NO DIALTONE No dial tone detected

7 BUSY Busy signal detected

8 NO ANSWER No silence detected when dialing a system not

providing a dial tone

10 CONNECT 2400 Connection at 2400 bps

+F4 +FCERROR Fax carrier error

13 DATA Connected as data modem during auto answer

15 FAX Connected as fax modem during auto answer

D224ATLVDSC Conexant 4-1

4.0 AT Commands

RC224ATL/224ATLV

EmbeddedModem Family

Table 4-2. AT Command Set Summary (1 of 5)

Command Function Default Parameters/Description

A/ Re-execute command — —

A Answer a call — —

AT Command line prefix

Parameters: none

Bn Select CCITT or Bell Mode

Parameters: n = 0,1

Cn Carrier control

Parameters: n = 0,1

D

——

Dn Dial modifier — —

— Attention Code. Precedes the command line except for +++

(escape) and A/ (repeat) commands.

n = 1

n = 1 —

Selects CCITT operation at 300 or 1200 bps during Call

n = 0

Establishment and a subsequent connection.

n = 1 Selects BELL operation at 300 or 1200 bps during Call

Establishment and a subsequent connection.

Dial Command. D causes the modem to dial the number which
follows the D in the command line. Valid dial characteristics are 0
to 9, A to D, #, and *. Other valid dial modifier characters are “,”
P, R, S=n, T, W, “;”, @, and !.

En Command echo

Parameters: n = 0,1

Fn On-line character echo option

Parameters: n = 0,1

Hn Disconnect (hang-up)

Parameters: n = 0,1

In Identification

Parameters: n = 0,1,2,3

Ln Speaker volume

Parameters: n = 0,1,2,3

Mn Speaker control

Parameters: n = 0,1,2,3

n = 1

n = 1 n = 0 Returns ERROR result code.

n = 0 n = 0 Modem on-hook (relay open).

n = 0 n = 0 Reports product identification code.

n = 2 n = 0 Low volume.

n = 1

Disables command echo.

n = 0
n = 1 Enables command echo.

Returns OK result code.

n = 1

n = 1 Modem off-hook (relay closed).

n = 1 Calculates the ROM checksum.
n = 2 Calculates the ROM checksum and compares it with the

prestored checksum. Reports "OK" if the calculated
checksum equals the prestored checksum or if the
prestored checksum value is FFh; otherwise reports
“ERROR”.

n = 3 Reports the firmware version and ROM part number.

n = 1 Low volume.

Medium volume.

n = 2

High volume.

n = 3

Speaker is always off.

n = 0

Speaker is on during Call Establishment, but off when

n = 1

receiving carrier.

n = 2 Speaker is always on.
n = 3 Speaker is on after dialing, until carrier is detected.

On Go on-line

Parameters: n = 0,1

P Force pulse dialing — —

Qn Quiet Result codes control n = 0 n = 0 Enables result codes to the DTE.

— n = 0 On-line state.

n = 1 On-line state with equalizer retrain.

Disables result codes to the DTE.

n = 1

4-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

4.0 AT Commands

EmbeddedModem Family

Table 4-2. AT Command Set Summary (2 of 5)

Command Function Default Parameters/Description

Sn Select S register as default

Range: n = 0-27

Sn = Parameters: none

Range: n = 0-27 (register
no.)

x=0-255 (value)

Sn? Parameters: none

Range: n = 0-27

T Force DTMF dialing — —

Vn Report codes form n = 1

Xn Extended result codes n = 4 n = 0 Basic set of result codes 0-4 are enabled. The modem

— n Establishes S-Register n as the last register accessed.

Sets S-Register n to the value v.

n = v
n? Reports the value of S-Register n.

— Writes to an S Register. Sr=x sets register “n” to the value “x”.

Configuration registers are provided to retain modem
configuration parameters. The contents of these registers can be
modified with this command.

— Reads an S register. Sn? causes the contents stored in register

“n” to be returned.

Result code is sent as a digit.

n = 0
n = 1 Result code is sent as ASCII text.

blind dials and sends the appropriate connect result code
once a satisfactory connection is established. Dial tone
and busy are not recognized.

n = 1 Result codes 0-5 and 10 are enabled. The modem blind

dials and sends the appropriate connect result code once
a satisfactory connection is established. Dial tone and
busy are not recognized.

n = 2 Result codes 0-6 and 10 are enabled; dial tone detected.

The modem waits for a dial tone before dialing, then
sends the appropriate result code once a satisfactory
connection is established. The busy result code is sent if
a busy signal is detected.

Result codes 0-5, 7 and 10 are enabled; busy signal

n = 3

detected; dial tone not detected. The modem blind dials
and sends the appropriate connect result code once a
satisfactory connection is established. The busy result
code is sent if a busy signal is detected.

Result codes 0-7 and 10 are enabled; busy signal and

n = 4

dial tone detected. The modem waits for a dial tone
before dialing, then sends the appropriate result code
once a satisfactory connection is established. The NO
DIALTONE result code is sent if the dial tone is not
detected within 5 seconds. The BUSY result code is sent
if a busy signal is detected.

Yn Long space disconnect n = 0 n = 0 Disables long space disconnect.

Enables long space disconnect.

n = 1

Zn Soft reset and restore profile n = 0

&Cn RLSD (DCD) option n = 0

Soft reset. Restores stored profile 0.

n = 0

Soft reset. Restores stored profile 1.

n = 1

RLSD remains ON at all times.

n = 0
n = 1 RLSD follows the state of the carrier.

D224ATLVDSC Conexant 4-3

4.0 AT Commands

RC224ATL/224ATLV

EmbeddedModem Family

Table 4-2. AT Command Set Summary (3 of 5)

Command Function Default Parameters/Description

&Dn DTR option n = 0 n = 0 Modem ignores DTR.

Modem assumes command state when ON-to-OFF

n = 1

transition is detected on DTR.

Modem hangs up, assumes command state and disables

n = 2

auto-answer upon detecting ON-toOFF transition on
DTR.

n = 3 Modem assumes software reset state upon detecting

ON-to-OFF transition on DTR.

&F Recall (restore) factory profile —

&Gn Select guard tone n = 0 n = 0 No guard tone.

&Jn Telephone jack control n = 0 n = 0 Suitable for RJ11, RJ41S. or RJ45S type phone jack.

S Registers:

S7=30, S8=2, S9=5, S10=14, S11=95, S12=50, S18=0, S25=5,
S26=1

Commands: B1, C1, E1, F1, L2, M1, P, Q0, V1, Y0, X4, &C0, &D0,
&G0, &J0, &M0/&G0, &P0, &R0, &S0, &T4, &X0

n = 1
n = 2 1800 Hz guard tone.

n = 1

S0=1, S1=0, S2=43. S3=13, S4=10, S5=8, S6=0,

550 Hz guard tone.

Suitable for RJ12 or RJ13 type phone jack; the A lead is

connected to A1 lead while the modem is off-hook.

&L0 Dial-up line operation n = 0 n = 0 Requests dial-up operation.

&Mn Asynchronous mode n = 0 n = 0 Asynchronous operation.

n = 1 Reserved

Reserved

n = 2
n = 3 Reserved

&Pn Pulse dial make/break ratio n = 0 n = 0 Selects 39%–61% make/break ratio at 10 pps.

(USA/Canada)

n = 1 Selects 33%–67% make/break ratio at 10 pps. (UK/HK)

&Q0 Asynchronous mode n = 0 Idle State On-line State

n = 0 Normal Asynchronous
n = 1 Reserved Reserved
n = 2 Reserved Reserved

Reserved Reserved

n = 3

&Sn DSR override n = 0

DSR will remain ON at all times.

n = 0

DSR will become active after answer tone has been

n = 1

detected and inactive after the carrier has been lost. DSR
is OFF when the modem is in test mode or idle state.

4-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

4.0 AT Commands

EmbeddedModem Family

Table 4-2. AT Command Set Summary (4 of 5)

Command Function Default Parameters/Description

&Tn Test and diagnostic n = 4 n = 0 Terminates test in progress.

Initiates local analog loopback.

n = 1
n = 2 Returns ERROR.

Initiates local digital loopback.

n = 3

Enables digital loopback acknowledgment from remote

n = 4

modem for RDL.

n = 5 Disables digital loopback acknowledgment from remote

modem for RDL.

n = 6 Initiates remote digital loopback.
n = 7 Initiates remote digital loopback with self test.

Initiates local analog loopback with self test.

n = 8

&V Display current configurations — Example:

AT&V
ACTIVE PROFILE:
B0 E1 L1 M1 QO T V1 Y0 &C0 &D0 &G2 &J0 &L0 &P0 &Q0 &R0
&S0 &X0 &Y0
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002
S07:030 S08:002 S09:006
S10:014 S12:050 S14:AAH S16:00H S18:000 S21:00H S22:76H
S23:17H S25:005 S26:001 S27:40H
STORED PROFILE 0:
B1 E1 L2 QO V1 X4 Y0 &C0 &D0 &G0 &J0 &L0 &P0 &Q0 &R0
&S0 &X0
S00:000 S14:AAH S18:000 S21:00H S22:76H S23:17H S25:005
S26:001 S27:40H
STORED PROFILE 1:
B1 E1 L2 QO V1 X4 Y0 &C0 &D0 &G0 &J0 &L0 &P0 &Q0 &R0
&S0 &X0
S00:000 S14:AAH S18:000 S21:00H S22:76H S23:17H S25:005
S26:001 S27:40H
TELEPHONE NUMBERS:
&Z0= 5551212
&Z1=
&Z2=
&Z3=

(1)

(1)

(1)

&Wn Store current configuration n = 0

&X0 Asynchronous data

transmission

&Yn Select default profile —

&Zn = x Store dial string to location n — &Zn = x n = 0 to 3 and x = dial string. (up to 36 characters)

n = 0

Commands:

&Jn, &Ln, &Pn, &Qn, &Rn, &Sn &Xn &Yn

Registers: S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S12,
S14, S16, S18, S21, S22, S23, S25, S26, S27

n = 0
n = 1

n = 0
n = 1
n = 2

n = 0
n = 1

Bn, En, Ln, Mn, P or T, Qn, Vn, Yn, &Cn &Dn, &Gn,

Stores active profile in location 0.
Stores active profile in location 1.

Reserved
Reserved
Reserved

The modem will use profile 0 on powerup.
The modem will use profile 1 on powerup.

D224ATLVDSC Conexant 4-5

4.0 AT Commands

RC224ATL/224ATLV

EmbeddedModem Family

Table 4-2. AT Command Set Summary (5 of 5)

Command Function Default Parameters/Description

%Dn DTMF Level Attenuation — —

%J Load Secondary Defaults — —

%Ln Transmit Level Attenuation — —

Dial

Function

Modifier

P Pulse Dial

Parameters: none

R Originate Call in Answer Mode

Parameters: none

S=n Dial Stored Number

Parameters:
n = 0, 1, 2, 3

S<CR>
S=<CR>
S=n<CR> where n = 0-3

——

——

——

T Tone Dial

Parameters: none

W Wait for Dial Tone

Parameters: none

; Return to Idle State

Parameters: none

@ Wait for Quiet Answer

Command
Parameters: none

!Flash Hook

Parameters: none

, (comma) Pause

Parameters: none

0-9, A, B, C,
D, #, *

NOTE(S):

(1)

Not available for 300 bps.

Dial Digits/Characters
Parameters: none

——

——

——

——

——

——

——

4-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

4.0 AT Commands

EmbeddedModem Family

Table 4-3. Fax Command Set Summary (1 of 2)

Fax Command Function Default Parameters/Description

+FCLASS=n Service class n = 0 Select Service Class. +FCLASS=n command sets the active service

class.
+FCLASS=0 Returns to data mode
+FCLASS=1 Fax Class 1
+FCLASS=2 Fax Class 2 (Not supported)
+FCLASS=3 Fax Class 3 (Not supported)

+F<command>? Report Active Configuration — Report Active Configuration. +F<command>? interrogates the

modem to determine the active configuration.
The responses are:
+FAA? 0 if auto answer is disabled; 1 if auto answer is

enabled
+FCLASS 0 if in data mode; 1 if in fax class 1
+FF? 0 if flow control off; 1 if flow control on

+F<command>=? Report Operating

Capabilities

— Report Operating Capabilities. +F<commands>=? can be used to

determine the operating capabilities of the modem.
The responses are:
+FAA=? 0, 1
+FCLASS=? 0, 1
+FTM=? 24, 48, 72, 96
+FTM=? 24, 48
+FTH=? 3
+FTH=? 3
+FF=? 0,1

+FAA=n Data/Fax Auto Answer n = 0 Data/Fax Auto Answer. +FAA command configures the modem to

automatically detect whether an incoming call is from a data
modem or a fax modem. This command is valid in both data and
fax modes.

Disable data/fax auto answer mode (default).

n = 0
n = 1 Enable data/fax auto answer mode. The modem

determines calling type and issues DATA result code (13) if
caller is a data modem, or issues FAX result code (15) in
the caller is a fax modem.

+FF Enhanced Flow Control n = 0 Enhanced Flow Control. +FF=n command enables an enhanced

flow control mode for data transfer between the DTE and DCE.

Disables enhanced flow control interface. In this mode,

n = 0

data transfer is compatible with the EIA-578 standard.

Enables enhanced flow control.

n = 1

+FTS=n Stop Transmission and Wait n = 0

+FRS=n Receive Silence n = 0 Receive Silence. +FRS=n causes the modem to report back to the

Stop Transmission and Wait.

terminate a transmission. After temination the modem waits for n
10–ms intervals before responding with the OK result code. An
ERROR response code results if this command is issued while the
modem is on-hook.

DTE with an OK result code after n 10-millisecond intervals of
silence have been detected on the line. This command is aborted if
any command character is received. The modem discards the
aborting character and issues an OK result code. An ERROR
response code results if this command is issued while the modem
is on-hook.

+FTS=n causes the modem to

D224ATLVDSC Conexant 4-7

4.0 AT Commands

RC224ATL/224ATLV

EmbeddedModem Family

Table 4-3. Fax Command Set Summary (2 of 2)

Fax Command Function Default Parameters/Description

+FTM=n Transmit Data n = 48 Transmit Data. +FTM=n causes the modem to transmit data using

the modulation defined below. An ERROR response code results if
this command is issued while the modem is on-hook.
+FTM=24 V.27 ter 2400 bps
+FTM=48 V.27 ter 4800 bps
+FTM=72 V.29 7200 bps
+FTM=96 V.29 9600 bps

+FRM=n Receive Data n = 48 Receive Data. +FRM=n causes the modem to enter the receiver

mode using the modulation defined below. An ERROR response
code results if this command is issued while the modem is
on-hook.
+FRM=24 V.27 ter 2400 bps
+FRM=48 V.27 ter 4800 bps

(1)

(1)

)
)

+FTH=n Transmit Data with HDLC

Framing

+FRM=72 V.29 7200 bps (Not supported
+FRM=96 V.29 9600 bps (Not supported

n = 3 Transmit Data with HDLC Framing. +FTH=n causes the modem to

transmit data framed in HDLC protocol using the modulation
defined below. An ERROR response code results if this command
is issued while the modem is on-hook.
+FTH=3 V.21 Channel 2300 bps

+FRH=n Receive Data with HDLC

Framing

n = 0

Receive Data with HDLC Framing.

+FRH=n causes the modem to
receive frames in HDLC protocol using the modulation defined
below. An ERROR response code results if the command is issued
while the modem is on-hook.
+FRH=3 V.21 Channel 2300 bps

+FRTn Receive Test Data n = 48 Receive Test Data. +FRTn causes the modem to go off-hook and

begin demodulating received data at the specified rate.

n Configuration/Data Rate

n = 24

V.27 ter 2400 bps

n = 48 V.27 ter 4800 bps

+FTTn = m Transmit Test Data n = 96

m = 0

Transmit Test Data. +FTTn = m causes the modem to transmit a
continuous test pattern at the specified rate. The transmission will
terminate by a DTE abort (i.e., any character recognized at the DTE
interface).

n Configuration/Data Rate
n = 24
n = 48

V.27 ter 2400 bps
V.27 ter 4800 bps

n = 72 V.29 7200 bps
n = 96 V.29 9600 bps

m Test Pattern
m = 0
m = 1
m = 2

ASCII data (20h - 7Fh sequential)
All zeros
All ones

m = 3 Alternate 10
m = 4

Sliding 0 (01111)

m = 5 Sliding 1 (00001)

NOTE(S):

(1)

Modem will respond with ERROR result code.

4-8 Conexant D224ATLVDSC

5

5.0 S Registers

The S register commands are summarized in Ta bl e 5- 1. The range of possible
values and the factory default value for each S register are also shown. The
factory default values are used whenever the &F command is received or a parity
error is detected in the NVRAM upon modem power turn-on.

The user-defined S registered default values are used at modem power turn-on
or when a modem reset is received. If the NVRAM is not available or contains a
parity error, the factory default S register values are used.

The S registers are described in Tabl e 5- 2.

Reading an S Register

The command Sn? reads the current value of an S register, where “n” is the
decimal number of the register.

Example: To read the current value in register S0 (Ring to Answer On) and S7
(Wait Time for Data Carrier), perform the following:

Enter: AT S0? S7? (Value in register S0? Value in register S7?)

A typical response to the might be:

Result: 001 (modem will answer on first ring)

Result: 030 (modem will wait 30 seconds for a carrier)

Result: OK (command completed)

D224ATLVDSC Conexant 5-1

5.0 S Registers

RC224ATL/224ATLV

Table 5-1. S Register Summary

Register Range Units Default Description

S0

(1)

0–255 Rings 00 Rings to Auto-Answer

S1 0–255 Rings 00 Ring Counter

S2 0–127 ASCII 43 Escape Character

S3 0–127 ASCII 13 Carriage Return Character

S4 0–127 ASCII 10 Line Feed Character

S5 0–32, 127 ASCII 08 Backspace Character

S6 2–255 Seconds 02 Maximum time to Wait for Dial Tone

S7 1–255 Seconds 30 Wait for Carrier

S8 0–255 Seconds 02 Pause Time for Comma

S9 1–255 1/10 seconds 06 Carrier Detect Response Time

S10 1–255 1/10 seconds 14 Carrier Loss Disconnect Time

S11 50–255 ms 95 DTMF Dialing Speed

EmbeddedModem Family

S12 0–255 1/50 seconds 50 Escape Prompt Delay

S14

(1)

Bit Mapped None AA hex General Bit Mapped Options

S16 Bit Mapped None 00 Test Mode Bit Mapped Options (&T)

S17 0–250 4 ms increments 00 Fax Mode Null Byte Timer

S18

(1)

0–255 Seconds 00 Test Timer

S19 0–1 None 00 Conexant Protocol Interface Speed

S20 0–127 Seconds 00 Fax Mode Inactivity Timer

S21

S22

S23

(1)

(1)

(1)

Bit Mapped None 00 General Bit Mapped Options

Bit Mapped None 76 hex General Bit Mapped Options

Bit Mapped None 07 General Bit Mapped Options

S24 0–255 Seconds 00 Sleep Inactivity Timer

S25

S26

S27

S28

(1)

(1)

(1)

(1)

0–255 0.1 or 1 seconds 05 Delay to DTR Off

0–255 0.01 seconds 1 RTS-to-CTS Delay

Bit Mapped None 40 hex General Bit Mapped Options

Bit Mapped None 00 General Bit-Mapped Options

NOTE(S):

(1)

Register value may be stored in one of two user profiles with the AT&W command.

5-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

5.0 S Registers

EmbeddedModem Family

Table 5-2. S Register Description (1 of 8)

Register Default Range Units Description

S0 00 0–255 Rings

Ring to Answer On. Assigning S0 a value from 1 to 255 places the
modem in auto-answer mode. The modem will auto answer after
the specified number of rings has occurred.

Setting S0 to 0 disables auto-answer.

S1 00 0–255 Rings

Ring Count. S1 is incremented each time a ring is detected. It will
be cleared if no ring occurs within 8 seconds after the last ring.

S2 43 0–127 ASCII

Escape Code Character. S2 holds the ASCII value used for the
escape code. The + character responds to the factory default value.
Values greater than 127 disable the escape code operation. To
enter the command mode when the escape code is disabled, a loss
of carrier must occur or DTR must be set to a 0 (dependent on &D
command).

127 ASCII Carriage Return Character. S3 holds the ASCII value for the

S3 13 0

–

carriage return; 13 is the standard value. The character in S3 is
both the command line terminator and the result code terminator.

S4 10 0

127 ASCII

–

Line Feed Character.

S4 holds the ASCII value for the line feed.
The line feed character is output after the carriage return only
when English word result codes have been selected (V1). If a line
feed character is not desired, it may be changed to a null, but it
cannot be totally disabled.

S5 08 0

32, 127 ASCII

–

Backspace Character.

S5 holds the ASCII value for the backspace
character. This character is both the backspace key and the
character echoed to move the cursor back one position. Normally
a value of 8 is used. The backspace character must not be set to a
value corresponding to a printable ASCII character (i.e., between
33 and 126) or to a value greater than 127. A backspace is used as
follows:

The keystroke is echoed back to the terminal and the cursor moved
back over the last character entered. The last character in the com­mand buffer is deleted.

S6 02 2–255 Seconds Wait for Dial Tone. S6 specifies the wait time before dialing. The

delay allows time for the dial tone to occur on the telephone line.
The minimum time is 2 seconds. Values greater than 2 seconds
may be necessary if trouble is encountered getting dial tones.

S7 30 1

255 Seconds Wait for Carrier After Dial. S7 specifies the delay time that the

–

modem waits for the carrier signal from the remote modem before
hanging up. Typically, a delay time of 30 seconds is enough, but it
can be extended to 255 seconds. If the carrier is not detected
within the specified time period, the modem hangs up and sends
the NO CARRIER result code. If carrier is detected, the modem
returns the CONNECT result code and goes on-line.

D224ATLVDSC Conexant 5-3

5.0 S Registers

RC224ATL/224ATLV

Table 5-2. S Register Description (2 of 8)

Register Default Range Units Description

S8 02 0

255 Seconds Pause Time for the Comma Dial Modifiers. S8 sets the pause

–

time for the comma dial modifier. The comma is used during
dialing when it is necessary to dial through a PBX and wait for a
second dial tone. A 2-second delay is usually enough. S8 can be
changed or multiple commas can be used to lengthen the delay.

S9 06 1

S10 14 1

255 1/10

–

seconds

255 1/10

–

seconds

Carrier Detect Response Time. S9 sets the carrier detect
response time.

Lost Carrier to Hang Up Delay. S10 sets the delay time between
loss of carrier and hang-up. The modem will not hang-up due to
loss of carrier if the value of S10 is 255.

255 ms DTMF Dialing Speed. S11 sets the duration and inter-digit delay

S11 95 50

–

of the touch-tones.

S12 50 0

255 1/50

–

Escape Code Guard Time.

S12 sets the escape code guard time.

seconds

S13

———

Reserved

EmbeddedModem Family

S14 AAh Bit Mapped None General Bit Mapped Options. S14 is the modem option register

with the following bit functions.

Bit 0 Reserved
Bit 1 Command Echo (See E command)
0 E0–No echo

1E1

Echo (factory default)

—

Bit 2 Results Code (See Q command)

0Q0
1Q1

Enabled (factory default)

—

Disabled

—

Bit 3 Verbose Command (See V command)

0V0
1V1

Digits

—

Words (factory default)

—

Bit 4 Reserved

(1)

Bit 5

Dial Method (See T and P commands)
0T
1P

Tone dial

—

Pulse dial (factory default)

—

Bit 6 Reserved
Bit 7 Originate/Answer (See A, D, and R commands, and

register S0)
0Answer
1 Originate (factory default)

S15

———

Reserved

5-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

5.0 S Registers

EmbeddedModem Family

Table 5-2. S Register Description (3 of 8)

Register Default Range Units Description

S16 00

S17 00 0-250 4 ms

—

None Modem Test Option. Controls the diagnostic modes as follows:

Bit 0 Local Analog Loopback L3 (See &T1 command)

0 Disabled (factory default)

Enabled

—

Enabled

—

Enabled

—

Increments

1&T1

Bit 1 Reserved
Bit 2 Local Digital Loopback (See &T3 command)

0 Disabled (factory default)
1&T3

Bit 3 Remote Digital Loopback L2 (See &T6 command)

0 Disabled (factory default)
1&T6

Fax Mode Null Byte Timer. The value of S17 determines the
length of time null bytes are sent by the modem if the last byte
sent during DTE underrun in Fax Mode is not a null byte.

S17≤250 corresponds to a timer value of 0–1 second (i.e.,

0

≤

the timer value is the value of S17 times 4 ms).

S18 00 0-255 Seconds Tes t Ti m er. Sets the length of time the modem conducts a test

before returning to the command mode. If this register is zero, the
test will not automatically terminate; the test must be terminated
from the command mode by issuing an AT&T0 or ATH command.

S19

S20 0 1-127 Seconds Fax Mode Inactivity Timer. S20 can be used to cause the modem

———

Not Supported

to automatically place the telephone on-hook or reset itself if
inactivity (of variable duration) is detected while in Fax Mode.

D224ATLVDSC Conexant 5-5

5.0 S Registers

RC224ATL/224ATLV

Table 5-2. S Register Description (4 of 8)

Register Default Range Units Description

S21 00 Bit Mapped

—

Bit Mapped Options. S21 is the modem register with the following
bit functions:

Bit 0 Telco Jack (See &J Command)

11/RJ-45S (factory default)

0&J0
1&J1

—

RJ-12/RJ-13

—

Bit 1 Reserved
Bit 2 Ready to Send (RTS)/Clear to Send (CTS). (See &R

Command)
0&R0
1&R1

CTS tracks RTS (not supported)

—

RTS is ignored (factory default)

—

Bit 3, 4 Data Terminal Ready (DTR) (See &D Command)

43

00 &D0
01 &D1

Modem ignores DTR (factory default)

—

Modem goes to command state if

—

ON-to-OFF transition on DTR

1 0 &D2–Modem “hangs up” if ON-to-OFF

transition on DTR

11 &D3

Modem goes to initialization state if

—

ON-to-OFF transition on DTR

Bit 5 Data Carrier Detect (DCD) (See &C Command)

0&C0
1&C1

DCD is always on (factory default)

—

An ON condition on DCD indicates the

—

presence of a valid data carrier

Bit 6 Data Set Ready (DSR) (See &S Command)

0&S0
1&S1

DSR is always on

—

DSR is turned on at the start of

—

handshaking

Bit 7 Long Space Disconnect (See Y Command)

0&Y0
1&Y1

Disabled (factory default)

—

Enabled

—

EmbeddedModem Family

5-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

5.0 S Registers

EmbeddedModem Family

Table 5-2. S Register Description (5 of 8)

Register Default Range Units Description

S22 76h Bit Mapped

—

Bit Mapped Options. S22 is the modem register with the following
bit functions:

Bit 0, 1 Speaker Volume (See L Command)

10

Speaker volume low

00 L0
01 L1
10 L2
11 L3

—

Speaker volume low

—

Speaker volume medium (factory default)

—

Speaker volume high

—

Bit 2, 3 Speaker Control (See M Command)

32

00 M0
01 M1

Speaker disabled

—

Speaker on until carrier detected (factory

—

default)
10 M2
11 M3

Speaker always on

—

Speaker on until carrier detected but off

—

during dialing

Bit 4, 5, 6Result Code Options (See X Command)

654

000 X0

Selects appropriate connect result code,

—

goes off-hook when the dial command is

received, waits the number of nds given by

register S6, and “blind dials” (does not look

for dial tone).
0 0 1 Reserved
0 1 0 Reserved
0 1 1 Reserved
100 X1

Selects appropriate connect result code,

—

goes off-hook, waits the number of seconds

specified by register S6 and blind dials

without waiting for dial tone. Busy is not

detected.
101 X2

Selects appropriate connect result code,

—

goes off-hook, and dials when dial tone is

detected. Busy is not detected.
110 X3

Selects appropriate connect result code,

—

goes off-hook, waits the number of seconds

specified in register S6, blind dials, detects

busy signal and sends BUSY result code.
111 X4

Selects appropriate connect result code,

—

goes off-hook and dials when dial tone is

detected, detects busy signal and sends BUSY

result code. All result codes are enabled

(factory default).

Bit 7 Make/Break Ratio (See &P Command)

0&P0

39/61 United States/Canada (factory

—

default)
1&P1

33/67 UK/Hong Kong

—

D224ATLVDSC Conexant 5-7

5.0 S Registers

RC224ATL/224ATLV

Table 5-2. S Register Description (6 of 8)

Register Default Range Units Description

S23 07 Bit Mapped

—

Bit Mapped Options.

Bit 0 Obey request from remote modem for a Remote Digital

Loopback (See &T4 and &T5 Commands)
0 &T5 selected
1 &T4 selected

Bit 1, 2 Communications Rate

21

0 0 300 bps
0 1 Reserved
1 0 1200 bps
1 1 2400 bps (factory default)

Bit 3 Reserved
Bit 4, 5 Parity Option

54

0 0 Even parity (factory default)
0 1 Space parity
10 Odd parity
1 1 Mark/None parity

Bit 6, 7 Guard Tones (See &G Command)

76

00 &G0
0 1 Reserved
10 &G2
1 1 Reserved

Guard tone disabled (factory default)

—

1800 Hz guard tone

—

EmbeddedModem Family

RDL disabled

—

RDL enabled (factory default)

—

S24 00 0-255 Seconds Sleep Mode Inactivity Timer. S24 is used to set the amount of

time the modem may be inactive before it will enter sleep mode.

S24 ≤ 4, and Sleep Mode is inhibited when

≤

If &Q1 is selected, S25 is the delay in

S25 05 0-255 0.01 or 1

Seconds

S26 01 0-255 0.01

Seconds

The range of S24 is 0
S24 = 255. (Also see Sleep Mode Signals in Tab l e 3 -5 .)

Detect DTR Change.

seconds after a connection has been made, but before the modem
examines the DTR lead.

If in the on-line or on-line command state, changes in DTR that last
less than the time specified by S25, in 0.01 sec increments, are
ignored by the modem.

RTS to CTS Delay Intervals. Reserved

5-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

5.0 S Registers

EmbeddedModem Family

Table 5-2. S Register Description (7 of 8)

Register Default Range Units Description

S27 40h Bit Mapped

—

Bit Mapped Options.

Bit 3, 1, 0Communications Mode Option (See &D Command)

310

0 0 0 &Q0 selected

default)
0 0 1 &Q1 selected
0 1 0 &Q2 selected
0 1 1 &Q3 selected
1 0 0 Reserved
1 0 1 Reserved
1 1 0 Reserved
1 1 1 Reserved

Bit 2 Dial Up/Leased Line Option

0 Dial Up (factory default)
1 Leased Line (not supported)

Bit 4, 5 Synchronous Transmit Clock Source Selection (See &X

Command)

54

00 &X0
01 &X1
10 &X2

Internal Clock (factory default)

—

External DTE Clock (not supported)

—

Receive Clock (not supported)

—

1 1 Reserved

Bit 6 Communications Standard Option (See B Command)

0B0
1B1

CCITT V.22 bis/V.22

—

Bell 212A (factory default)

—

Bit 7 Data/Fax Discrimination (i.e., AT+FAA Status)

0 Data/Fax auto answer mode disabled

(AT+FAA = 0)
1 Data/Fax auto answer mode enabled

(AT+FAA = 1)

Asynchronous (factory

—

Synchronous (not supported)

—

Synchronous (not supported)

—

Synchronous (not supported)

—

D224ATLVDSC Conexant 5-9

5.0 S Registers

RC224ATL/224ATLV

Table 5-2. S Register Description (8 of 8)

Register Default Range Units Description

S28 00 Bit Mapped

—

Bit Mapped Options.

Bit 2, 1, 0Transmit Level Attenuation (See %Ln Command)

2 1 0 Description

0 0 0 0 dB attenuation
0 0 1 2 dB attenuation
0 1 0 4 dB attenuation
0 1 1 6 dB attenuation
1 0 0 8 dB attenuation
1 0 1 10 dB attenuation
1 1 0 12 dB attenuation
1 1 1 14 dB attenuation

Bit 5, 4, 3DTMF Transmit Level Attenuation (See %Dn Command)

5 4 3 Description

0 0 0 0 dB attenuation
0 0 1 2 dB attenuation
0 1 0 4 dB attenuation
0 1 1 6 dB attenuation
1 0 0 8 dB attenuation
1 0 1 10 dB attenuation
1 1 0 12 dB attenuation
1 1 1 14 dB attenuation

Bit 6 Dialing Pulses per Second

010 pps
120 pps

Bit 7 Secondary Defaults (See %J Command)

0 &F defaults
1 %J defaults

EmbeddedModem Family

NOTE(S):

(1)

Bit 5 is set or reset if the dial command string contains a P (pulse dial) or T (tone dial), respectively. If a subsequent dial
command string is used with a P or T, the modem uses the option specified by this bit.

5-10 Conexant D224ATLVDSC

6.0 Operation

Modem operation supports data modem processing, fax modem processing and
common call progress processing.

The AT+FCLASS command allows the operator to select either data or fax

operation.

AT+FCLASS=0 Data mode
AT+FCLASS=1 Fax mode Class 1

6.1 Data Modes

6.1.1 Data Mode Selection

Data mode operation is defined by the AT commands and S register settings
described in Chapter 4 and Chapter 5. Data rate selection is determined by the
speed of the originating and answering modems as listed in Ta bl e 6- 1.

6

Table 6-1. Data Rate Selection

Answer Mode

300 300 1200 1200

1200 300 1200 1200

2400 300 1200 2400

6.1.2 Data Modem Processing

Data modem processing is explicitly defined in CCITT V.22 bis, CCITT V.22,
Bell 212A, and Bell 103 documentation. All modulation, waveform spectrum,
and data processing functions conform to the appropriate specif ications with the
following exceptions:

1.

CTS is ON all the time and does not go OFF during handshake.

2.

DSR is always ON in parallel mode operation.

3.

The rate change request option is not supported for V.22 bis.

4.

V.22 operation supports only Alternative B, mode ii (1200 bps
asynchronous, 10 bit characters)

Originate Mode

300 1200 2400

D224ATLVDSC Conexant 6-1

6.0 Operation

RC224ATL/224ATLV

6.1 Data Modes

6.1.3 Call Origination

6.1.4 Call Answering

6.1.5 Call Termination

EmbeddedModem Family

Automatic and manual origination of calls is supported. Automatic call
origination is supported by the ATDS command. The modem automatically enters
the data handshaking mode upon completion of the dial function.

Automatic and manual answering of calls is supported. Incoming ring signals are
detected by the modem and indicated by the RING result code. Answering can be
performed by the DTE acknowledging the RING result code and issuing the ATA
command or by having the modem automatically go off-hook after N rings are
detected. The number of rings, N, is determined by the setting of the S0 register.
Upon going off-hook, the DCE will transmit 2100 Hz (or 2225 Hz for Bell
modes) for a duration of not less than 2.6 seconds and not more than 4.0 seconds.

A call is terminated by the DTE sending the ATH command to the modem.

6-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

6.2 Fax Modes

6.2.1 Fax Mode Selection

Fax modes and rates are determined by the AT+F commands and are defined in

Chapter 4.0,

6.2.2 Fax Mode Processing

Fax modem processing is explicitly defined in CCITT V.29, CCITT V.27 ter, and
CCITT V.21 recommendations. All modulation, waveform spectrum, and data
processing functions conform to the appropriate specifications with the following
exceptions:

1.

2.

3.

4.

5.

6.

6.2 Fax Modes

AT Commands

V.29 receive functions are not supported.
V.29 4800 bps is not supported; V.27 ter 4800 bps is used instead.
V.29 half-duplex continuous carrier mode only is supported.
V.29 channel multiplexer option is not supported.
V.27 ter 75-baud backward channel option is not supported.
V.27 ter short train mode is not supported.

.

6.2.3 Fax Origination

6.2.4 Fax Answering

Automatic origination of fax call is supported by the ATDS command. Upon
completion of the dial function, a calling tone at 1100 Hz (± 38 Hz) with an ON
duration of 0.5 seconds (± 75 ms) and OFF duration of 3 seconds (± 450 ms) is
transmitted.

Answering of fax calls is identical to answering of data calls, with the exception
that the DCE enters the fax handshaking mode instead of the data handshaking
mode after going off-hook.

D224ATLVDSC Conexant 6-3

6.0 Operation

RC224ATL/224ATLV

6.2 Fax Modes

6.2.5 Fax Data Transmission

Fax data transmission is initiated by the +FTM command. Upon recognition of
the command, the modem initiates the selected modulation mode and issues the
CONNECT result code. The proper training sequence for the selected mode is
transmitted, followed by constant 1 bits, until data is received from the DTE. DTE
data is buffered and processed prior to being transmitted. The transmission is
terminated when the transmit buffer becomes empty and the last transmitted
character was not a NUL character. The modem then turns off the carrier and
issues the OK result code. If the last character was a NUL character (00), the
modem continues to transmit NUL characters until more data is received by the
DTE or until 5 seconds have elapsed. After 5 seconds, the modem turns off the
carrier and issues the ERROR result code.

6.2.6 Fax Data Reception

Fax data reception is initiated by the +FRM command. Upon recognition of the
command, the modem initiates the selected demodulation mode and looks for the
proper carrier. When the selected carrier is detected, the modem issues the
CONNECT result code +FCERROR. If a signal other than the selected carrier is
detected, the modem returns to the command state. Demodulated data is stored in
an output buffer for additional I/O processing and eventual output to the DTE.
Detection of loss of carrier will cause the modem to issue the NO CARRIER
result code and will cause the modem to return to the command state. Any
character other than flow control characters issued while the receiver is outputting
data will cause the receiver to abort and return to the command state.

EmbeddedModem Family

6.2.7 Fax Control Transmission

Fax control transmission is initiated by the +FTH command or after answering a
call. The modem initiates the selected modulation mode, issues the CONNECT
result code, transmits one second of flags, then transmits data sent by the DTE.
DTE data is buffered and processed prior to transmission.

Processed I/O data is grouped into frames and encoded with a CRC generator.
The generator polynomial is X
sequence (FCS) is appended to the end of the frame. The end of the frame is
indicated by an empty I/O buffer. Transmission frames begin and end with a flag
sequence (7Eh). The ending flag may serve as the beginning flag for the next
frame. To prevent data from looking like flags, a 0 is inserted into the data stream
after five consecutive 1s are detected.

16

+ X12 + X5 + 1. The CRC parity or frame check

6-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

Each frame is checked to see if the current frame is the last frame of the
transmission. If the final frame bit (5th received bit of the second byte of the
frame) is 1, indicating that the current frame is the final frame, the modem
completes the frame transmission, issues the OK result code, and returns to the
command state. If the final frame bit is a 0, the modem issues the CONNECT
result code and continues to transmit flags until one of the following actions is
taken by the DTE:

1.

2.

3.

6.2.8 Fax Control Reception

Fax control reception is initiated by the +FRH command or after dialing. Upon
recognition of the command, the modem initiates the selected demodulation mode
and looks for the proper carrier. When the selected carrier is detected, the modem
issues the CONNECT result code. If a signal other than the selected carrier is
detected, the modem issues an +FCERROR result code and returns to the
command state.

The modem removes the flags, removes transmitter inserted 0 bits (a 0
following f ive consecutive 1s), performs the CRC error checking, and stores the
data in the internal I/O buffer for further processing and eventual passing to the
DTE.

The modem indicates the end of a frame by issuing the <DLE> <ETX>
characters and an OK result code if the frame was received correctly, or by issuing
an ERROR result code if one or more errors were detected in the frame. The first
frame received is stripped of flags (CONNECT result code indicates that a valid
flag has been received) and output to the DTE. Subsequent frames are buffered
and output to the DTE when additional +FRH commands are received.

Any characters other than flow control that are received while demodulating
data and prior to issuance of the status result code will result in the receive
process being aborted, an OK result code being issued, and the modem returning
to the command state. After the status result code is issued, the modem continues
to demodulate data. Additional +FRH commands specifying the same modulation
rate will result in the issuance of a CONNECT result code, output of the next data
frame, and continuation of normal demodulation. Any other commands will result
in the receive process being aborted, buffered data being discarded, and the
command being implemented.

Detection of loss of carrier will result in the modem issuing the NO
CARRIER result code and returning to the command state.

6.2 Fax Modes

If additional data is sent by the DTE, the modem transmits another frame.
If the transmission is terminated by the <DLE> <ETX> string, the modem
turns off the carrier and issues the OK result code.
If no data is sent by the DTE within 5 seconds of receiving the CONNECT
message, the modem turns off the carrier and issues the ERROR result
code.

6.2.9 Fax I/O Processing

The fax I/O interface supports asynchronous serial and parallel interfaces. The
interface rate is 19.2 kbps. Start and stop elements are removed from the
incoming serial data stream and are added to the outgoing serial data (receive).

D224ATLVDSC Conexant 6-5

6.0 Operation

RC224ATL/224ATLV

6.2 Fax Modes

EmbeddedModem Family

Both transmit and receive data are buffered. Flow control using X-on/X-off
(DC1/DC3) is provided.

Unique control character strings are identified, filtered, or reinserted into the
I/O data stream. These control characters and their resultant action are shown
below.

DTE to Modem Transmit Data Stream

<DLE> <data> Delete <DLE> <data> characters.
<DLE> <ETX>

<DLE> <DLE> Replace with single <DLE> character.

Modem to DTE Receive Data Stream

<DLE> Insert extra <DLE> ahead of <DLE>

Recognize as a string terminator and take
appropriate action.

The modem also identifies the end of a frame by inserting <DLE> <ETX>
into the data stream after the FCS bytes.

6-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

6.3 Fax Enhanced Flow Control

The fax Class 1 standard provides for bidirectional X-on/X-off flow control.
However, in multitasking “windowing” environments, the DTE communication
package can be suspended long enough to miss a 19,200 bps serial asynchronous
character sent by the DCE (520.83 µs). X-on/X-off flow control will not solve this
problem because the DTE software does not always know when it is going to be
suspended. To solve this problem, a new enhanced flow control mechanism is
provided. This mechanism is enabled/disabled by issuing an AT+FF=1/0
command.

6.3.1 Parallel/Serial Interface Selection

For parallel host interface operation, the enhanced flow control takes advantage of
the fact that the DCE hardware knows if the DTE has read the last character. The
DCE will not send a new character until the DTE reads the previous one. The
modem fax receiver has an internal 223-byte buffer. Therefore, the DTE can stop
reading characters for 371 ms (4800 bps receive) before any data is lost.

For serial interface operation, the enhanced flow control mechanism utilizes
the fact that the Fax Class 1 serial interface is only required to operate half
duplex. The scheme involves sending characters to the DTE and waiting for the
DTE to send an acknowledgment (if the DTE reads the character OK) or a request
for re-transmission (if the DTE misses a character and detects an overrun). The
required DTE operation using the enhanced flow control mechanism is defined
below.

6.3 Fax Enhanced Flow Control

6.3.2 Fax V.42 Buffer Sizes

Fax V.42 buffer sizes are shown below.

Buffer Type Size in Bytes

Fax V.27/V.29 Tx 255 (9600:212 ms)

Fax V.21 (HDLC) Tx 255 (300:6.8 sec)

RPI (HDLC) Tx 238 (2400:793 ms)

Fax V.27 Rx 223 (4800:371 ms)

Fax V.21 (HDLC) Rx 255 (300:6.8 sec)

D224ATLVDSC Conexant 6-7

6.0 Operation

RC224ATL/224ATLV

6.4 Data/Fax Auto Answering

6.3.3 DTE Flow Control Operation

Normal operation:

Overrun Operation:

DTE does not miss character. The DTE reads the serial character sent by the
DCE. The DTE checks serial hardware overrun status and determines that an
overrun did not occur. The DTE can therefore use the character. The DTE must
send the following acknowledgment character back to the DTE.

11111110 (FEh)

DTE misses character. The DTE returns after being suspended and reads the
serial character sent by the DCE. The DTE checks serial hardware overrun status
and determines that an overrun occurred. The DTE does not use the received
character. The DTE then sends the following re-transmission request character
back to the DCE.

11110000 (F0h)

6.4 Data/Fax Auto Answering

EmbeddedModem Family

Data/fax auto answering, when used with appropriate DTE host software, will
automatically recognize whether an incoming call is a data or fax modem. This
mechanism can be used with an integrated data/fax communication package or
with separate data/fax communication packages operating together in a
foreground/background configuration.

The auto answering mechanism is structured such that the DTE is initially
operating in the fax mode. The DTE enables auto answering using the
AT+FAA=1 command (saved in NVRAM under S27). This command should be
issued while AT+FCLASS=1. The DTE will then change its communication rate
from 19,200 bps (fax class 1 rate) to the rate expected in data mode (2400, 1200,
or 300 bps).

The DCE will attempt to establish a connection with the incoming call as a
data modem. If the incoming call is a fax, the DCE will switch to the fax mode
and establish the connection. To minimize incompatibilities with various fax and
data modems, the 59 register is used to define the length of time that the DCE has
to establish a data connection.

S9 (Range: 0–255; Default: 06) defines the time (in seconds) after going off-hook
that the DCE waits for the entire data mode handshaking process to complete
before switching to fax mode.

When a call is received (DCE sends RING result code), the DTE can initiate
the answer manually by sending an ATA command. Alternatively, the DTE can
allow the DCE to answer automatically by setting S0=non-zero value. After the
DCE goes off-hook, it will automatically determine the caller type (data or fax),

6-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

6.4 Data/Fax Auto Answering

establish the appropriate connection, and inform the DTE of the caller type with
the following result codes:

Numeric Verbose Description

13 (0Dh) DATA

15 (0Fh) FAX

DCE sends this result code only during auto answering or
when DCE has connected as a data modem.

DCE sends this result code only during auto answer
mode when DCE has connected as a fax modem.

It is assumed initially for auto answer operation that the DTE is running the
fax communication package.

It is impractical to force the fax package to use the same options selected by
the data package. Therefore, some method must be provided to allow the DTE fax
package to restore the DCEs registers after the DCE has connected as a data
modem. The DCE accommodates this by automatically entering the on-line
command mode after connecting. After the DTE receives the DATA result code, it
can then send any necessary AT commands to the DCE. The DCE will wait in the
on-line command mode and delay sending the “data” connect message until the
DTE sends an ATO command. After sending the ATO command, the DTE then
transfers control to the data communication package.

For DTEs running separate data and fax packages in a foreground/background
configuration, a method is provided to allow the fax package to regain control
after the data connection has terminated during auto answer mode without
requiring changes to existing data packages. The RC224ATLV accommodates
this through the use of the data carrier detect (DCD) indicator. Initially, in auto
answer mode DCD will be off. When connected in data mode, the DCE will turn
DCD on. When the data connection is terminated, the DCE will turn DCD off
again. The fax package, running in the background, can poll DCD (160450
modem status register bit 7) to ascertain the data connection status. The DTE
must send AT&C1 to cause DCD to operate in this manner.

During auto answer mode, when the caller is a fax machine, the DCE will
behave as a normal fax DCE (as defined by +FCLASS=1) with the following
exceptions:

1.

The transmission of the fax 2100 Hz answer tone will be delayed by the
time needed to determine that the caller is a fax machine (S9 seconds).

2.

The DCE sends FAX message at the data mode DTE rate (as defined by
the previous AT command autobaud rate) and automatically sets
+FCLASS=1 after detecting that the caller is a fax.

3.

After the answer tone is sent and the DCE enters the V.21 transmit mode,
the CONNECT result code will be sent at 19,200.

During auto answer mode, if the DCE determines that the caller is not a data
modem nor a fax machine, then DCE will send the NO CARRIER result code, go
on-hook and remain in data mode.

Table 6- 2 describes a procedure to configure a terminal being called by a 1200

bps data modem. Tab le 6 -3 describes a procedure to configure a terminal being
called by a fax machine with or without calling tone.

D224ATLVDSC Conexant 6-9

6.0 Operation

RC224ATL/224ATLV

6.4 Data/Fax Auto Answering

Table 6-2. Terminal Called by a 1200 bps Data Modem

DTE Command DCE Response Comments

——

Assume DCE in fax mode (FCLASS = 1), DTE running fax
communication package, and DCD is off.

AT&C1 OK

ATS 9=n OK

AT+ FAA=1 OK

——

DTE commands DCD to follow data carrier.

DTE defines the data mode connection time.

DTE enables data/fax auto answer mode.

DTE sets the communication rate to the data modem rate (e.g., 2400
bps) prior to an incoming call.

— RING

ATA —

——

Terminal is being called.

DTE commands DCE to go off-hook and start auto answer.

DCE determines caller as data modem and establishes connection
with caller.

——

DCE turns on DCD to indicate data connection is established.

EmbeddedModem Family

——

—DATA

AT commands OK

ATO CONNECT 1200

——

——

——

— “Callers data”

——

— NO CARRIER

——

DCE then waits in on-line command mode.

DCE indicates data modem connection is established.

DTE optionally sends any commands to DCE to restore conditions
required by data modem communications package.

DTE instructs DCE to switch from on-line command to data state.

DTE then transfers control to data modem package.

Fax package remains in background polling DCD to check connection
status.

DCE response will then be read by data modem communication rate
to 1200 bps.

DTE sends/receives data.

Caller hangs up. DTE detects carrier loss and turns off DCD.

DCE indicates connection with caller has terminated.

DTE fax communications software, running in background, sees DCD
turn off, and regains control from data modem package.

6-10 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

Table 6-3. Terminal Called by a Fax Machine

DTE Command DCE Response Comments

——

Assume DCE in fax mode (FCLASS = 1), DTE is running fax
communication package, and DCD is off.

AT&C1 OK

ATS 9=n OK

AT+ FAA=1 OK

——

DTE commands DCD to follow data carrier.

DTE defines the data mode connection time.

DTE enables data/fax auto answer mode.

DTE sets the communication rate to the data modem rate (e.g., 2400
bps) prior to an incoming call.

— RING

ATA —

——

Terminal is being called.

DTE commands DCE to go off-hook and start auto answer.

DCE starts data modem handshaking. If receive data signal is not
detected within S9 seconds from going off-hook, DCE switches to fax
mode and automatically sets FCLASS=1.

—FAX

DCE switches to fax mode handshaking and sends “FAX” message at
the data modem rate (e.g., 2400 bps).

6.4 Data/Fax Auto Answering

——

DCE sends 3 seconds of 2100 Hz answer tone, enters V.21 transmit
mode, and sends HDLC flags.

— CONNECT

DCE ends CONNECT response at the fax rate (i.e., 19,200 bps).

D224ATLVDSC Conexant 6-11

6.0 Operation

RC224ATL/224ATLV

6.5 Call Progress

6.5 Call Progress

6.5.1 Call Progress Algorithms

Data call progress algorithms measure the power and/or relative power of the
highband and lowband channels and determine signal presence and cadence
correlations. Highband channel signals include 2100 and 2225 Hz signalling
tones. Lowband channel signals include dial tones, busy tones, ringback tones and
voice ranging in frequency from 120 to 620 Hz.

Characteristics of the tones detected by the RC224ATLV are listed in

Table 6- 4.

Table 6-4. Tone Characteristics

Dial Tone Continuous 350 + 440

EmbeddedModem Family

Tone Cadence Frequency (Hz)

Old Dial Tone Continuous 600+120/133

Busy 0.5 sec ON

0.5 sec OFF

Old Busy 0.5 sec ON

0.5 sec OFF

Precision Reorder 0.3 sec ON

0.2 sec OFF

Old Reorder (local) 0.25 sec ON

0.25 sec OFF

Old Reorder (toll) 0.2 sec ON

0.3 sec OFF

Ringback 0.8-1.2 sec ON

2.7-3.3 OFF

Old Ringback 2 sec ON

4 sec OFF

Double Ringback 0.8 sec ON

0.3 sec OFF

0.8 sec ON
4 sec OFF

480 + 620
480 + 620

600 + 120
600 + 120

480 + 620
480 + 620

600 + 120
600 + 120

600 + 120
600 + 120

440 + 480
440 + 480

420 + 40
420 + 40

440 + 480
440 + 480
440 + 480
440 + 480

Fax answer tone detection requirements include 2100 and 1100 Hz. The call
progress detection requirements are identical to the lowband data signals
identified above.

6-12 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

6.5.2 Ring Detection

6.5 Call Progress

Ring detection is based on a digital input to the modem. External circuitry not
part of the modem is required to convert the analog 40 to 150 V

ring signal to

RMS

a digital single-bit data stream representation. Valid ring frequencies of 15.3 to 68
Hz are detected. Detection is achieved by counting valid high to low ring signal
transitions. Valid transitions consist of a high state of 2 to 34 ms followed by a low
state of 2 to 42 ms. Ring signals that have transition counts less than the nominal
value are discarded.

In addition to valid high to low transitions, ring detection depends on the
cadence of the ring ON time (valid transitions occurring) and ring OFF time (no
valid transitions). Ring OFF times must be greater than 0.5 seconds. Ring ON
times must be greater than 125 ms at 20 Hz (100 ms at 68 Hz).

Ring detection is integrated over 8 seconds. All counters and timers are reset
at 8 second intervals. The modem will answer the ring after N valid ON/OFF ring
cycles. N is programmable via the S0 register. Upon detecting N rings, the
modem verifies that the current ring state has been in the OFF state for 0.5
seconds before seizing the line.

Table 6- 5 lists the Fax Class 1 calling sequence; Ta bl e 6 -6 lists the answering

sequence.

Table 6-5. Fax Class 1 Calling Sequence (1 of 2)

DTE Commands

(Host)

(1) AT+FCLASS=1 (2) OK — Set to Class 1

(3) ATDT6163 (4) Dials

— — (8) Send NSF frame —

— (9) <NSF>, OK — —

(10) AT+FRH=3 (11) CONNECT — —

— — (12) Send CSI frame —

— (13) <CIS>, OK — —

(14) AT+FRH=3 (15) CONNECT — —

— — (16) Send DIS frame Last frame bit = 1

— (17) <DIS>, OK (18) Drop carrier —

(19) AT+FTH=3 (20) Send HDLC flags (21) Receive flags —

— (21) CONNECT — —

(22) <TSI> (23) Send TSI frame (24) Receive TSI Last frame bit = 0

DCE Responses

(Modem)

(6) CONNECT

Remote Fax Notes

PHASE A

(5) Answers
(7) Send HDLC flags

PHASE B

+FRH=3 implied by Dialing

— (25) CONNECT — —

(26) <DCS> (27) Send DCS frame (28) Received DCS Last frame bit = 1

— (29) Detect last frame bit — —

D224ATLVDSC Conexant 6-13

6.0 Operation

RC224ATL/224ATLV

6.5 Call Progress

EmbeddedModem Family

Table 6-5. Fax Class 1 Calling Sequence (2 of 2)

DTE Commands

(Host)

— (30) OK, drop carrier — —

(31) AT+FTS=8 (32) OK, wait 80 ms — —

(33) AT+FTM=96 (34) Send F.29 — —

— (35) CONNECT — —

(36) <TCF> (37) Send TCF data (38) Receive and check —

—(39) OK — —

(40) AT+FRH=3 (41) CONNECT — —

— — (42) Send CFR frame Last frame bit = 1

— (43) <CFR>, OK (44) Drop carrier —

—(45) OK — —

(46) AT+FRM=06 (47) Send V.29 — —

— (48) CONNECT — —

DCE Responses

(Modem)

Remote Fax Notes

PHASE C

(49) Page data (50) Send page data (51) Receive data —

—(52) OK — —

(53) AT+FTH=3 (54) Send HDLC flags (55) Receive flags —

— (56) CONNECT — —

PHASE D

(57) <EOP> (58) Send EOP frame (59) Receive EOP Last frame bit = 1

— (60) OK, drop carrier — —

(61) AT+FRH=3 (62) CONNECT — —

— — (63) Send MCF frame Last frame bit = 1

— (64) <MCF>,OK — —

(65) AT+FTH=3 (66) Send HDLC flags (67) Receive flags —

— (68) CONNECT — —

(69) <DCN> (70) Send DCN frame (71) Receive DCN Last frame bit = 1

— (72) OK, drop carrier — —

PHASE E

(73) ATH0 (74) OK, hang up (75) Hang up —

6-14 Conexant D224ATLVDSC

RC224ATL/224ATLV

6.0 Operation

EmbeddedModem Family

Table 6-6. Fax Class 1 Answering Sequence (1 of 2)

DTE Commands

(Host)

(1) AT+FCLASS=1 (2) OK — Set to Class 1

(2b) AT+FRM=? 24,48 — —

—OK — —

— — (3) FAX machine dials —

— (4) RING — —

(5) ATA (6) Modem answers — —

— (7) Send HDLC flags (8) Receive flags +FTH=3 implied by answering

— (9) CONNECT — —

(10) <NSF> (11) Send NSF frame (12) Receive NSF Last frame bit = 0

DCE Responses

(Modem)

Remote Fax Notes

PHASE A

PHASE B

6.5 Call Progress

— (13) CONNECT — —

(14) <CSI> (15) Send CSI frame (16) Receive CSI Last frame bit = 0

— (17) CONNECT — —

(18) <DSI> (19) Send DSI frame (20) Receive DSI Last frame bit = 1

— (21) OK, drop carrier — —

(22) AT + FRH=3 (23) CONNECT — —

— — (24) Send TSI frame Last frame bit = 0

— (25) <TSI>,OK — —

(26) AT+FRH=3 (27) CONNECT — —

— — (28) Send DCS frame Last frame bit = 1

— (29) <DCS>,OK (30) Drop carrier —

(31) AT+FTH=3 — — —

— — (32) Send V.27 (4800) —

— (33) CONNECT (34) Send TCF frame —

— (35) <TCF> (36) Drop carrier —

— (37) NO CARRIER — —

(38) AT+FRM=48 (39) CONNECT — —

(40) <CFR> (41) Send CFR frame (42) Receive CFR Last frame bit = 1

— (43) OK, drop carrier — —

D224ATLVDSC Conexant 6-15

6.0 Operation

RC224ATL/224ATLV

6.5 Call Progress

EmbeddedModem Family

Table 6-6. Fax Class 1 Answering Sequence (2 of 2)

DTE Commands

(Host)

(44) AT+FRM-48 — — —

— — (45) Send page data —

— (46) <page data> (47) Drop carrier —

— (48) NO CARRIER — —

(49) AT+FRH=3 (50) CONNECT — —

— — (51) Send EOP frame Last frame bit = 1

— (52) <EOP>, OK — —

(53) AT+FTH=3 (54) CONNECT — —

(55) <MCF> (56) Send MCF frame (57) Receive MCF Last frame bit = 1

DCE Responses

(Modem)

Remote Fax Notes

PHASE C

PHASE D

— (58) OK, drop carrier — —

(59) AT+FRH=3 (60) CONNECT — —

— — (61) Send DCN frame Last frame bit = 1

— (62) <DCN>, OK — —

PHASE E

(73) ATH0 (74) OK, hang up (75) Hang up —

6-16 Conexant D224ATLVDSC

7

7.0 Electrical/Mechanical Specifications

7.1 Interfacing the RC224ATLV

The RC224ATLV is not 5.0 V I/O logic tolerant. It is recommended that a series
resistor of 150 Ω be added to current limit the digital inputs to the RC224ATLV
when interfacing to + 5.0 V logic output lines. The digital outputs of the
RC224ATLV should not go to resistor pullups that are connected to the + 5 V
power supply. These precautions will help prevent the modem chip from going
into latchup due to raising any input or output pin level more than + 0.3 V above
the + 3.3 V power rail of the RC224ATLV.

7.2 Environmental Requirements

The environmental specifications are listed in Tabl e 7- 1.

Table 7-1. Environmental Specifications

Parameter Specification

Operating Temperature 0 °C to + 70 °C (32 °F to 158 °F)

Storage Temperature – 55 °C to + 125 °C (– 67 °F to + 257 °F)

Relative Humidity Up to 90 % noncondensing, or a wet bulb temperature up

to 35 °C, whichever is less.

D224ATLVDSC Conexant 7-1

7.0 Electrical/Mechanical Specifications

RC224ATL/224ATLV

7.3 Interface Timing and Waveforms

EmbeddedModem Family

7.3 Interface Timing and Waveforms

Table 7 -2 lists the host bus interface timing parameters. Figure 7-1 illustrates the

interface waveforms. Ta bl e 7- 3 lists the current and power requirements, and

Table 7- 4 lists absolute maximum ratings.

Table 7-2. Timing–Host Bus Interface

Symbol Parameter Min Max Units

t

AS

t

AH

t

CS

t

CH

t

RD

Address Setup 25 — ns

Address Hold 0 — ns

Chip Select Setup 10 — ns

Chip Select Hold 0 — ns

Read Strobe Width 100 — ns

t

t

DRH

t

t

t

DWH

t

t

t

t

DD

WT

DS

DF

DIS

DIH

INH

Delay HRD to Data — 75 ns

HRD to Data Hold 10 — ns

Write Strobe Width 75 — ns

Write Data Setup 30 — ns

Write Data Hold 10 — ns

HRD to Driver Off — 30 ns

HDIS Enable — 40 ns

HDIS Hold 40 — ns

Interrupt Hold — 100 ns

7-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

7.0 Electrical/Mechanical Specifications

EmbeddedModem Family

Figure 7-1. Timing Waveform

HA0-HA2

HCS

HRD

HWT

HD0-HD7

HDIS

7.3 Interface Timing and Waveforms

t

AS

t

CS

t

RD

t

DD

t

DIS

t

AH

t

CH

t

DF

t

DRH

t

DIH

HA0-HA2

HCS

HRD

HWT

HD0-HD7

HDIS

t

AS

t

CS

a. Host Read

t

WT

t

AH

t

CH

t

DS

t

DWH

b. Host Write

D224ATLVDSC Conexant 7-3

7.0 Electrical/Mechanical Specifications

RC224ATL/224ATLV

7.3 Interface Timing and Waveforms

EmbeddedModem Family

Table 7-3. Current and Power Requirements

Current (ID) Power (PD)

Mode

Typical

Current @ 25°C

Maximum Current

@ 0°C

Typical

Power @ 25°C

Maximum

Power @ 0°C

Operating 20 mA 22 mA 100 mW 110 mW

Sleep - Idle 5 mA 6 mA 25 mW 30 mW

Sleep - Stop 1 mA 1 mA 5 mW 5 mW

NOTE(S):

1. Test conditions: VDD = 5.0 VDC for typical values; VDD = 5.25 VDC for maximum values.

2. Test conditions: VDD = 3.3 V

for typical values; VDD = 3.6 VDC for maximum values.

DC

Table 7-4. Absolute Maximum Ratings

Parameter Symbol Limits Units

Supply Voltage V

DD

– 0.5 to + 7.0 V

Input Voltage V

Analog Inputs V

Voltage Applied to Outputs in High Z State V

DC Input Clamp Current I

DC Output Clamp Current I

Static Discharge Voltage (@ 25°C) V

Latch-Up Current (@ 25°C) I

Operating Temperature Range T

Storage Temperature Range T

NOTE(S):

Stresses above those listed may cause permanent damage to the device. This is a stress rating only, and functional

IN

IN

HZ

IK

OK

ESD

TRIG

A

STG

– 0.5 to VCC + 0.5 V

– 0.3 to + 5 VAA + 0.3 V

– 0.5 to + 5 VDD + 0.5 V

20 mA

20 mA

3000 V

200 mA

– 0 to + 70 C

– 40 to + 80 C

operation at these or any other conditions above those listed in the operational section of this specification is not implied.
Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

7-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

7.0 Electrical/Mechanical Specifications

EmbeddedModem Family

Table 7- 5 lists digital interface characteristics, and Ta bl e 7 - 6 lists analog interface

characteristics.

Table 7-5. Digital Interface Characteristics

Parameter Symbol Min. Typ. Max Units Test Conditions

Input High Voltage

Typ e IA
Type DIO
Typ e IH

Input Low Voltage

Type IA, IC, and DO

Input Low Voltage

Typ e IF

Input Leakage Current

IA and IC

Output High Voltage

Typ e OA
Typ e OD
Typ e OG
Typ e OH

V

IH

V

IL

V

IL

I

IN

V

OH

7.3 Interface Timing and Waveforms

V

2.0

2.4
– 30

—
—
—

V
V
30

CC

CC

V

– 0.3 — 0.8

V

38 — —

µAdc V

——10

V

2.4
—
—
5

—
—
—
8

—
V

V
—

CC

CC

DC

DC

RMS

DC

(2)

= 0 to V

IN

I

LOAD

I

LOAD

(1)

—

—

CC

= -100 µA
= 0 mA

Output Low Voltage

Typ e OA
Typ e OB
Typ e OD
Typ e OG
Typ e OH

Three-State (off) Current I

NOTE(S):

(1)

RC224ATL Test Conditions: VCC = 5 V 5%, TA = 0°C to 70°C (unless otherwise stated).
RC224ATLV Test Conditions: V
Output loads: 50 pF + one TTL.

(2)

AC V

voltage between Tip and Ring, using the on-board modular DAA.

RMS

V

OL

TS

= 3.3 V 5%, TA = 0°C to 70°C (unless otherwise stated).

CC

—
—
—

0.5
– 8

—
—

0.75
—
– 5

——25µAdcV

0.4

0.4
—
—
—

V

DC

I

= 1.6 mA

LOAD

I

= 0.8 mA

LOAD

I

= 15 mA

LOAD

I

= 8 mA

LOAD

= 0.8 V to 4.5 V

IN

D224ATLVDSC Conexant 7-5

7.0 Electrical/Mechanical Specifications

RC224ATL/224ATLV

7.3 Interface Timing and Waveforms

EmbeddedModem Family

Table 7-6. Analog Interface Characteristics

Name Type Characteristic Value

RXA I (DA) Input impedance >50 k Ω

— — Voltage range 2.5 ± 1.6 V

TXA1, TXA2 O (DD) Minimum load 300 Ω

— — Maximum capacitive load 0.01 µF

— — Output impedance 10 Ω

— — Output voltage 2.5 ± 1.6 V

— — DC offset

SPKR O (DF) Minimum load 300 Ω

— — Maximum capacitive load 0.01 µF

— — Output impedance 10 Ω

— — Output voltage 2.5 ± 1.6 V

— — DC offset

<200 mV

<20 mV

(1)

(1)

NOTE(S):

(1)

With Reference to VC (2.5 V nominal).

Figure 7-2 shows the mechanical drawing of the 68-pin PLCC. Ta bl e 7 -7 lists its

dimensions.

Figure 7-3 shows the mechanical drawing of the 100-pin PQFP. Tabl e 7 -8 lists

its dimensions.

7-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

7.0 Electrical/Mechanical Specifications

EmbeddedModem Family

Figure 7-2. 68-Pin PLCC

INDEX

CORNER

DD1

D2

TOP VIEW TOP VIEW

A

CHAM.

h x 45 DEG.

3 PLCS

e

BOTTOM VIEW

7.3 Interface Timing and Waveforms

D
D1

D2

α

CHAM.
J x 45 DEG.

A

b

TYP. FOR EACH AXIS

(EXCEPT FOR BEVELED EDGE)

SECTION A-A

SEATING
PLANE

D
D1
D3

R1

A

A1

A2

R

D224ATLVDSC Conexant 7-7

7.0 Electrical/Mechanical Specifications

RC224ATL/224ATLV

7.3 Interface Timing and Waveforms

EmbeddedModem Family

Table 7-7. 68-Pin PLCC Dimensions

Millimeters Inches

Dim

Min Max Min Max

A 4.14 4.39 0.163 0.173

A1 1.37 1.47 0.054 0.058

A2 2.31 2.46 0.091 0.097

b 0.457 TYP 0.018 TYP

D 25.02 25.27 0.985 0.995

D1 24.00 24.26 0.945 0.955

D2 20.19 20.45 0.795 0.805

D3 23.24 23.5 0.915 0.925

e 1.27 BSC 0.050 BSC

h 0.254 TYP 0.010 TYP

J 1.15 TYP 0.045 TYP

α 45° TYP 45° TYP

R 0.89 TYP 0.035 TYP

R1 0.254 TYP 0.010 TYP

NOTE(S):

Reference: PD68J/GP00-D164

7-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

7.0 Electrical/Mechanical Specifications

EmbeddedModem Family

Figure 7-3. 100-Pin PQFP

CHAM.

H x 45 DEG.

(4x)

D

D1

PIN 1

REF

A

A1

7.3 Interface Timing and Waveforms

D

D1

ba

TOP VIEW SIDE VIEW

R1

J

See

Detail A

E1

R2

A2

DETAIL A

K2

K3

K1

D224ATLVDSC Conexant 7-9

7.0 Electrical/Mechanical Specifications

RC224ATL/224ATLV

7.3 Interface Timing and Waveforms

EmbeddedModem Family

Table 7-8. 100-Pin PQFP Dimensions

Millimeters Inches

Dim

Min Max Min Max

A 1.95 2.05 0.077 0.081

A1 0.95 1.05 0.037 0.041

A2 0.15 0.25 0.006 0.010

D 22.96 23.44 0.904 0.923

D1 19.89 20.09 0.783 0.791

E 16.94 17.45 0.667 0.687

E1 13.89 14.10 0.547 0.555

K1 0.70 0.90 0.028 0.035

K2 0.40 — 0.016 —

K3 1.60 REF 0.083 REF

R1 0.13 — 0.005 —

R2 0.15 0.25 0.008 0.010

a 0.60 0.70 0.024 0.028

b 0.26 0.36 0.010 0.014

H — 0.25 — 0.010

J 0.13 0.17 0.005 0.007

NOTE(S):

Reference: GP00-D234

7-10 Conexant D224ATLVDSC

A

Appendix A: RC224ATF Modem Designs

This appendix describes two modem design examples. The schematics and parts
lists are provided for designs incorporating the RC224ATF packaged in a 68-pin
PLCC and implemented with either a parallel or serial interface.

A.1 68-Pin PLCC Design for Serial Interface

Figure A-1 and Figure A-2 provide the schematic of a RC224ATF 68-pin PLCC

serial interface board design. Ta ble A -1 lists the bill of materials for this design.

D224ATLVDSC Conexant A-1

Appendix A: RC224ATF Modem Designs

RC224ATL/224ATLV

A.1 68-Pin PLCC Design for Serial Interface

Figure A-1. Serial Interface Design

C21

.1

C15

.1

C14

.1

DECOUPLING CAPS

VCC

C12

.1

OH*

RXA

TO DAA

TXA1

LS1

C16

5

U6

LM386

1

6

+

7

2

F

INTERFACE

C19

.1

TXA2

RING*

2200

C5

-

3

pF

161201

220

4

C10

16V

C11

C131016V

8

.1

.1

C18

1000 pF

EmbeddedModem Family

C6

22

10V

VCC

2

8

1

NC

NC

VCC

CS

DI

SK

U2

DO GND

5

4

HY93C46J

6 7

3

VCCVCC

C7

R12

100

5%

56 pF

L1

47

VCC

Y1

2

C91210%

C22

.1

3

16.000312MHZ
1

5%

C17

56 pF

VCC

532949285227502647254524514823224338403332313639353455425439816

20V

VAA

U7

VCC

15665958101563046444137571411

D6
2K

R13

TDACI

TDACO

MODEO

NMI*

XTLO

XTLI

D7

2K

R14

MODEI

AAE*

R15

TRSTI

RSTBI

RRSTI

TRSTO

RSTBO

RRSTO

DCDL*

PH2NCNCNCNCNCTEST*

R17

4.7K

R16

C8

330K

D8

D9

2K

R18 2K

TSTBI

TSTBO

D10

2K

R19

RADCI

RAGCI

RADCO

RAGCO

TLKRLY*

RESET*

DTRL*

MR*

IDLENO

DTR*

67220

216196863136564624121718560

.1

D11

D12

2K

2K

R20

R21

RXA

TXA1

TXA2

OHRLY*

IDLEN1

WAKEUP*

TXD*

RI*

D13

2K

R22

VC

A/A1*

RING*

CTS*

RXD*

CI*/HS

RFILO

AGCIN

SLEEP*

SLEEPI*

DCD*

DSR*NCNCNCNC

DTR*

RI*

TXD*

TO V.24

SPKR

CTS*

RXD*

EIA-232-C

INTERFACE

AGND

NVRSK

NVRDIO

SEREN*

DGND1

CI*

DCD*

TRANSCEIVERS

7

NVRCS

DGND2

61

DSR*

R4

R6781-11

2.2K

A-2 Conexant D224ATLVDSC

RC224ATL/224ATLV

Appendix A: RC224ATF Modem Designs

EmbeddedModem Family

Figure A-2. Serial Interface Design DAA

J4

TELCO4/6

12345

R10

A.1 68-Pin PLCC Design for Serial Interface

J3

TELCO4/6

687

TOP

0

RV1

V150LA2

R11

R1

0

18

1W

C3

.47

10%

250V

12345

R2

7.5K

1W

C2

687

C1

.001

.001

10%

1KV

D1

TOP

10%

1KV

1N970B

D2

1N970B

K1

D3

1N4148

14

1

3

2

LINE

C20

.1

3

C4

.01

R9

D4

TTC143

1.5K

1N749A

RELAY

VCC

R6

536

1%

D5

R3

1N749A

U1

100K

4N35

6

4

5

2

VCC

T1

OH*

RXA

TXA1

TXA2

RING*

D224ATLVDSC Conexant A-3

Appendix A: RC224ATF Modem Designs

RC224ATL/224ATLV

A.1 68-Pin PLCC Design for Serial Interface

Table A-1. Serial Bill of Materials (1 of 2)

Item Quantity Reference Part

12C2,C1 0.001

2 1 C3 0.47

31C4 .01

4 1 C5 2200 pF

51C6 22

6 2 C7,C17 56 pF

7 9 C8,C10,C11,C12,C14,C15,C19,

81C9 12

91C13 10

10 1 C16 220

EmbeddedModem Family

0.1

C20,C21

11 1 C18 1000 pF

12 2 D1,D2 1N970B

13 1 D3 1N4148

14 2 D5,D4 1N749A

15 8 D6,D7,D8,D9,D10,D11,D12,D13

16 2 J4,J3 TELCO4/6

17 1 K1 RELAY

18 1 LS1 161201

19 1 L1 47

20 1 RV1 V150LA2

21 1 R1 18

22 1 R2 7.5 k

23 1 R3 100 k

24 1 R4 2.2 k

25 1 R6 536

26 1 R9 1.5 k

27 2 R11,R10 0

28 1 R12 100

29 8 R13,R14,R15,R18,R19,R20,R21,

R22

2 k

A-4 Conexant D224ATLVDSC

RC224ATL/224ATLV

Appendix A: RC224ATF Modem Designs

EmbeddedModem Family

A.1 68-Pin PLCC Design for Serial Interface

Table A-1. Serial Bill of Materials (2 of 2)

Item Quantity Reference Part

30 1 R16 330 k

31 1 R17 4.7 k

32 1 T1 TTC143

33 1 U1 4N35

34 1 U2 HY93C46J

35 1 U6 LM386

36 1 U7 R6781-11

37 1 Y1 16.000312 MHz

D224ATLVDSC Conexant A-5

Appendix A: RC224ATF Modem Designs

RC224ATL/224ATLV

A.2 68-Pin PLCC Design for Parallel Interface

A.2 68-Pin PLCC Design for Parallel Interface

Figure A-3 and Figure A-4 provide the schematic of a RC224ATF 68-pin PLCC

parallel interface board design. Ta bl e A - 2 lists the bill of materials for this design.

EmbeddedModem Family

A-6 Conexant D224ATLVDSC

RC224ATL/224ATLV

Appendix A: RC224ATF Modem Designs

EmbeddedModem Family

Figure A-3. Parallel Interface Design

C21

.1

C15

.1

C14

.1

DECOUPLING CAPS

VCC

VCC

C12

TO DAA

OH*

RXA

.1

INTERFACE

TXA1

A.2 68-Pin PLCC Design for Parallel Interface

LS1

161201

220

16V

C16

TXA2

RING*

U6

1

6

F

C19

.1

C5

5

LM386

+

2

pF

2200

3

7

C10

-

C13
8

4

C11

.1

C18

1000 pF

10

16V

C6

22

10V

VCC

.1

2

8

1

NC

NC

VCC

U2

CS

DI

SK

DO GND

5

4

R4

HY93C46J

6 7

2.2K

3

VCC

C

56PF

R12

100

5%

L1

47

VCC

Y1

3

12

10%

20V

C9

C8

.1

16.000312MHZ
1 2

C1

5329492852275026472545245148232243384033323136393534554254561913

VAA

U7

VCC

156659581257166173741444630182021626364656768

R13

10K

56P

5%

TDACI

TDACO

MODEO

NMI*

XTLO

XTLI

TRSTI

MODEI

TRSTO

RRSTO

IDLENO

TEST*

HINT

HCS*

HCS*

HINT

TSTBI

RSTBI

RRSTI

HDISNCNCNCNCNCNCNCIDLENI

HDIS

TSTBO

RSTBO

RADCI

RAGCI

RADCO

RAGCO

TLKRLY*

HD0

HD0

HD1

RXA

TXA1

TXA2

OHRLY*

HD1

HD2

HD3

HD4

HD2

HD3

HD4

RING*

HD5

125

HD5

HD6

VC

A/A1*

HD6

HD7

HD7

RFILO

AGCIN

HWT*

HRD*

4

HWT*

HRD*

SLEEP*

SLEEPI*

HA0

HA1

11

108146061

HA0

HA1

HA2

PH2

SPKR

NVRDIO

HA2

RESET*

DGND1

RESET*

7

NVRSK

NVRCS

DGND2

AGND

39

R6781

D224ATLVDSC Conexant A-7

Appendix A: RC224ATF Modem Designs

RC224ATL/224ATLV

A.2 68-Pin PLCC Design for Parallel Interface

Figure A-4. Parallel Interface Design DAA

J4

TELCO4/6

12345

0

R10

687

TOP

RV1

EmbeddedModem Family

J3

TELCO4/6

12345

687

TOP

C1

10%

1KV

.001

0

R11

C2

.001

10%

1KV

18

1W

R1

V150LA2

C3

.47

10%

250V

R2

7.5K1WD1

1N970B

D2

1N970B

K1

1

423

VCC

LINE

T1

C4

.01

.1

C20

TTC143

R9

RELAY

1.5K

D4

1N749A

VCC

D5

R3

100K

1N749A

U1

D3

1N4148

1

3

2

4N35

6

4

5

R6

536

1%

OH*

RXA

TXA1

TXA2

RING*

A-8 Conexant D224ATLVDSC

RC224ATL/224ATLV

Appendix A: RC224ATF Modem Designs

EmbeddedModem Family

A.2 68-Pin PLCC Design for Parallel Interface

Table A-2. Parallel Billing Materials (1 of 2)

Item Quantity Reference Part

12C2,C1 0.001

2 1 C3 0.47

3 1 C4 0.01

4 1 C5 2200 pF

51C6 22

6 2 C7,C17 56 pF

7 8 C8,C10,C11,C12,C14,C15,C20,

C21

81C9 12

91C13 10

10 1 C16 220

0.1

11 1 C18 1000 pF

12 1 C19 0.1 µF

13 2 D1,D2 1N970B

14 1 D3 1N4148

15 2 D5,D4 1N749A

16 2 J4,J3 TELCO4/6

17 1 K1 RELAY

18 1 LS1 161201

19 1 L1 47

20 1 RV1 V150LA2

21 1 R1 18

22 1 R2 7.5 k

23 1 R3 100 k

24 1 R4 2.2 k

25 1 R6 536

26 1 R9 1.5 k

27 2 R11,R10 0

28 1 R12 100

29 1 R13 10 k

D224ATLVDSC Conexant A-9

Appendix A: RC224ATF Modem Designs

RC224ATL/224ATLV

A.2 68-Pin PLCC Design for Parallel Interface

Table A-2. Parallel Billing Materials (2 of 2)

Item Quantity Reference Part

30 1 T1 TTC143

31 1 U1 4N35

32 1 U2 HY93C46J

33 1 U6 LM386

34 1 U7 R6781

35 1 Y1 16.000312 MHz

EmbeddedModem Family

A-10 Conexant D224ATLVDSC