Technics MT5634SMI-34, MT5634SMI-92 User Manual

Embedded Data/Fax Global Modem

MT5634SMI-34
MT5634SMI-92

Serial Build

Parallel Build

Medical Device Build

Industrial Temperature Build

Developer’s Guide

SocketModem Developer’s Guide
Serial: MT5634SMI-34, MT5634SMI-92
Parallel: MT5634SMI-P-92
Medical Device: MT5634SMI-HV-92, MT5634SMI-P-HV-92
Industrial Temperature: MT5634SMI-ITP-92, MT5634SMI-P-ITP-92

PN S000263B, Version B

Copyright

This publication may not be reproduced, in whole or in part, without prior expressed written permission from
Multi-Tech Systems, Inc. All rights reserved.
Copyright © 2003, by Multi-Tech Systems, Inc.

Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents hereof and
specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Furthermore,
Multi-Tech Systems, Inc. reserves the right to revise this publication and to make changes from time to time in
the content hereof without obligation of Multi-Tech Systems, Inc. to notify any person or organization of such
revisions or changes.

Revisions

Revision Level Date Description

A 08/09/02 First release. Includes global configuration and V.92 protocol.
B 06/19/03 Add V.34 documentation.

Trademarks

Trademarks of Multi-Tech Systems, Inc. are SocketModem and the Multi-Tech logo.
Microsoft and Microsoft Windows are either registered trademarks or trademarks of Microsoft Corporation in the
United States and/or other countries.

World Headquarters

Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, Minnesota 55112
Phone: [phone] or 800-328-9717
Fax: [phone]

Technical Support
Country By Email By Phone

France: [e-mail] (33) 1-64 61 09 81
India: [e-mail] 91 (124) 6340778
U.K.: [e-mail] (44) 118 959 7774
U.S. and Canada: [e-mail] [phone]
Rest of the World: [e-mail] [phone]

Internet Address: http://www.multitech.com

Table of Contents

Chapter 1 – Product Description and Specifications ..............................................................................6

Introduction ................................................................................................................................................6

Product Description.................................................................................................................................... 6

Features Matrix ..........................................................................................................................................7

Technical Specifications and Features ......................................................................................................8

Chapter 2 – Mechanical Specifications...................................................................................................10

Physical Dimensions – All Models ...........................................................................................................10

Pin Configurations.................................................................................................................................... 11

Chapter 3 – Electrical Characteristics ....................................................................................................14

Introduction ..............................................................................................................................................14

I/O Electrical Characteristics.................................................................................................................... 14

5V Serial – Standard (SMI) and Medical Device (SMI-HV) Build Options ..........................................14

3.3V Serial – Industrial Temperature (SMI-ITP) Build Option .............................................................14

5V Parallel – Standard (SMI) and Medical Device (SMI-HV) Build Options .......................................14

3.3V Parallel – Standard (SMI) and Industrial Temperature (SMI-ITP) Build Options........................15

Timing Requirements............................................................................................................................... 15

Timing Requirements for Parallel Write .............................................................................................. 15

Timing Requirements for Parallel Read ..............................................................................................15

Handling Precautions............................................................................................................................... 15

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description ....................................16

SocketModem Parallel Interface Internal Registers ................................................................................16

SocketModem MIMIC (MMM) Operation .................................................................................................16

Time Out Interrupts ..................................................................................................................................18

Register Functional Descriptions .............................................................................................................18

Internal Registers..................................................................................................................................... 18

SCR Scratch ............................................................................................................................................22

DLL Divisor Latch (LSByte)...................................................................................................................... 22

DLM Divisor Latch (MSByte)....................................................................................................................22

Chapter 5 – AT Commands, S-Registers, and Result Codes ...............................................................23

Introduction ..............................................................................................................................................23

AT Command Summary .......................................................................................................................... 23

AT Commands .........................................................................................................................................25

Escape AT Commands ............................................................................................................................34

V.92 Commands ......................................................................................................................................35

S-Registers ..............................................................................................................................................40

Result Codes ...........................................................................................................................................42

Chapter 6 - Voice Commands ..................................................................................................................44

Introduction ..............................................................................................................................................44

Voice S-Register Summary......................................................................................................................45

Voice Commands..................................................................................................................................... 45

Commands That Change for Voice Mode Support.................................................................................. 45

Voice +V Commands Summary............................................................................................................... 46

Voice +V Commands Detail.....................................................................................................................46

Interface Configuration Commands......................................................................................................... 57

Flow Control............................................................................................................................................. 58

Voice Mode Result Codes .......................................................................................................................58

Unsolicited Voice Mode Result Codes..................................................................................................... 59

Valid Complex Event Report Tags ......................................................................................................59

Voice Mode Shielded Codes....................................................................................................................60

Sample Sessions .....................................................................................................................................62

SocketModem Global MT5634SMI Developer’s Guide 3

Sample Rate Selection and Suggested Compression Method ...........................................................62

Answer Phone, Play Greeting Message, and Record Message Example.......................................... 63

DTE/DCE Interface Rates........................................................................................................................ 65

Related Manuals ......................................................................................................................................65

Additional Information ..............................................................................................................................65

Chapter 7 – Fax Commands.................................................................................................................... 66

Chapter 8 - Remote Configuration and Country Code Configuration .................................................67

Remote Configuration ..............................................................................................................................67

Basic Procedure ..................................................................................................................................67

Setup ...................................................................................................................................................67

Country Code Configuration ....................................................................................................................68

Using the Global Wizard Utility............................................................................................................ 68

Using AT Commands .......................................................................................................................... 68

Chapter 9 – Firmware Upgrade Procedure............................................................................................. 69

Introduction ..............................................................................................................................................69

Flash Upgrade Firmware..................................................................................................................... 69

Multi-Tech’s Flash Programming Protocol ..........................................................................................69

Upgrade Overview ...................................................................................................................................69

Upgrade Steps .........................................................................................................................................69

Step 1: Identify the Modem Firmware .................................................................................................69

Step 2: Identify the Current Version of the Firmware.......................................................................... 70

Step 3: Download the Upgrade File ....................................................................................................70

Step 4: Install the Flash Wizard...........................................................................................................70

Step 5: Extract the Firmware Upgrade (.Hex) Files ............................................................................70

Step 6: Document Your Stored Parameters........................................................................................70

Step 7: Upgrade the Modem’s Firmware ............................................................................................71

Using the Flash Wizard .......................................................................................................................71

Step 8: Restore Your Parameters .......................................................................................................71

Multi-Tech Systems, Inc. Flash Programming Protocol........................................................................... 72

1. Programming the Modem................................................................................................................72

2. Other Supported Boot Code Commands ........................................................................................73

3. Other Programming Concerns....................................................................................................73

Intel Hex Format.................................................................................................................................. 74

Appendix A – Mechanical Details ............................................................................................................76

Serial Test/Demo Board Components .....................................................................................................76

5V / 3.3V Jumper – JP1 ...........................................................................................................................77

Serial Test/Demo Board Block Diagram ..................................................................................................77

Parallel Test/Demo Board Components .................................................................................................78

Parallel Test/Demo Board Block Diagram ...............................................................................................79

Appendix B - Product Approvals, Design Considerations, and Regulatory Information.................. 80

Safety and EMC Approvals...................................................................................................................... 80

Telecom Approvals ..................................................................................................................................80

Regulatory Design Considerations ..........................................................................................................81

Hardware Considerations ........................................................................................................................81

Safety....................................................................................................................................................... 82

5V Tolerant Inputs for 3.3V Modules .......................................................................................................83

FCC Part 15 Regulation........................................................................................................................... 84

FCC Part 68 Telecom ..............................................................................................................................85

Telecom Labeling Requirements .............................................................................................................85

From FCC PART 68 Subpart D – Conditions for Registration.................................................................86

Fax Branding Statement ..........................................................................................................................87

Canadian Limitations Notice ....................................................................................................................87

Industry Canada CS-03 ........................................................................................................................... 88

International Modem Restrictions ............................................................................................................88

SocketModem Global MT5634SMI Developer’s Guide 4

EMC, Safety, and R&TTE Directive Compliance.....................................................................................88

New Zealand Telecom Warning Notice ...................................................................................................89

South African Notice ................................................................................................................................ 89

Appendix C – Country Configuration and Result Codes ......................................................................90

Index........................................................................................................................................................... 95

SocketModem Global MT5634SMI Developer’s Guide 5

Chapter 1 – Product Description and Specifications

Chapter 1 – Product Description and

Specifications

Introduction

Multi-Tech’s SocketModem creates communication-ready devices by integrating data/fax/voice functionality into
a single product design. The SocketModem is a space-efficient (1" × 2.5"), embedded modem that provides
V.92/56K communication. The complete, ready-to-integrate modem dramatically reduces development time and
costs for system designers. The SocketModem complies with global Telecom requirements, can be shipped
worldwide, and is globally configurable.

This guide provides the hardware, software, testing and troubleshooting information needed to effectively
integrate the SocketModem into your equipment. It also provides:

· commands a developer can use to configure and control a data/fax/voice modem and

· result codes the modem issues in response to the commands.

Fax Commands Documents

Two separate fax command documents along with an informational fax document are available on CD and from
Multi-Tech. They are also available on the Multi-Tech Web site, or you can contact OEM Sales at:

[e-mail]
[phone].

Product Description

The MT5634SMI SocketModem is used for integrating data and fax communications:

· It is a single-port modem, which integrates the controller, DSP, and DAA in a 1" x 2.5" form factor and
communicates to a host controller via an asynchronous serial interface

· It is available with an 8-bit parallel interface.

· It supports the ITU-T V.92 protocol.

Two SocketModem kits are available, one for serial and the other for parallel. The serial kit allows you to plug in
the SocketModem and use it as a serial modem for testing, programming, and evaluation. The parallel kit turns
the parallel module into an ISA modem. Each kit includes one development board with an RS-232 DB-25
connector, wall power adapter, RJ-11 jack, and RS-232 cable.

SocketModem Global MT5634SMI Developer’s Guide 6

Chapter 1 – Product Description and Specifications

Features Matrix

Parallel Interface (16C550)

v.92/56K Max. Data Speed

Model Build Option

MT5634SMI MT5634SMI-92 X X X X X X X X X

MT5634SMI-P-92 X X X X X X X X X

MT5634SMI-HV-92 X X X X X X X X

MT5634SMI-P-HV-92 X X X X X X X X

MT5634SMI-IT-92 X X X X X X X X X

MT5634SMI-P-IT-92 X X X X X X X X X

MT5634SMI-34 X X X

Serial Interface

V.34/33.6K Max. Data Speed

V.17 Fax Class 1, 1.0, and

Class 2

Fax Class 2.0 and 2.1

V.42 Error Correction

V.42bis Data Compression

DTMF Detection

Distinctive Ring

Voice Record and Playback

Note: SMI-92 indicates a serial build.

SMI-P-92 indicates a parallel V.92 build.
SMI-HV-92 indicates a serial V.92 high voltage medical device build.
SMI-P-HV-92 indicates a parallel V.92 high voltage medical build.
SMI-IT-92 indicates a serial V.92 industrial temperature build.
SMI-P-IT-92 indicates a parallel V.92 industrial temperature build.
SMI-34 indicates a serial V.34 build.

SocketModem Global MT5634SMI Developer’s Guide 7

Chapter 1 – Product Description and Specifications

Technical Specifications and Features

The SocketModem meets the following specifications:

Client-to-Server Data Rates

Client-to-Client Data Rates

Fax Data Rates

Data Format

Data Compatibility

Fax Compatibility

Voice Compatibility

Error Correction

Data Compression

Serial Speeds

Modes of Operation

Supports V.92 and V.90 data rates

33,600; 31,200; 28,800; 26,400; 24,000; 21,600; 19,200; 16,800;
14,400; 12,000; 9600; 7200; 4800; 2400; 1200; 0-300 bps

33,600; 31,200; 28,800; 26,400; 24,000; 21,600; 19,200; 16,800;
14,400; 12,000; 9600; 7200; 4800; 2400; 1200; 0-300 bps

Serial, binary, asynchronous (available with parallel interface)

V.92, V.34 enhanced, V.34, V.32bis, V.32, V.22bis, V.22; Bell 212A and
103/113, V.21 & V.23

ITU-T “Super” Group 3; Class 1.0, 2.0, 2.1;
Group 3, Class 1 and 2, T.4, T.30, V.21, V.27ter, V.29, V.34, V.17, and
TIA/EIA TR29.2

IS-101 AT+V commands (no CODEC for speakers/microphone
interface)

V.42 (LAP-M or MNP 3–4)

ITU-T V.44 (6:1 throughput); V.42bis (4:1 throughput);
MNP 5 (2:1 throughput)

Serial port data rates adjustable to 300, 1200, 2400, 4800, 9600,
19,200, 38,400, 57,600, 115,200, and 230,400 bps

Fax online modes; full duplex over dial-up lines; data mode, command
mode, and online command mode, V.54 test mode

Flow Control

Command Buffer

Transmit Level

Frequency Stability

Receiver Sensitivity

AGC Dynamic Range

Interface

Diagnostics

Weight

Dimensions

DAA Isolation

XON/XOFF (software), RTS/CTS (hardware)

60 characters

–11 dBm (varies by country setting)

±0.01%

–43 dBm under worst-case conditions

43 dB

TTL serial or 8-bit parallel interface

Local analog loop, local digital loop, remote digital loop

0.02 Kg. (0.04 lb.)

1.045" × 2.541" × 0.680"
(2.7 x 6.5 x 1.8 cm)

MT5634SMI-92

1500 Vac

MT5634SMI-HV-92 (High Voltage {5V Medical Device} Build Option)

3000 Vac

SocketModem Global MT5634SMI Developer’s Guide 8

Chapter 1 – Product Description and Specifications

Power Consumption

Operating Voltage

Operational Temperature
Range

Storage Temperature

Cleaning

Standard

Typical: 245 mA (1.25 W @ 5V DC)
Standby or Sleep Mode: 148mA
Maximum: 420 mA (2.1 W @ 5.25V DC)

MT5634SMI-IT-92 (Industrial Temperature {3.3V} Build Option)

Typical: 180 mA (0.59 W @ 3.3V DC)
Standby or Sleep Mode: 88mA
Maximum: 290 mA (1.04 W @ 3.6V DC)

Standard

5V DC +/- 5%
Absolute Maximum Supply Voltage: 6V DC

MT5634SMI-IT-92 (Industrial Temperature {3.3V} Build Option)

3.3V DC, 180mA
Absolute Maximum Supply Voltage: 3.6V DC

Standard

0–+70° C ambient under closed conditions; humidity range 20–90%
(non-condensing)

MT5634SMI-IT-92 (Industrial Temperature {3.3V} Build Option)

-40–+85° C ambient under closed conditions; humidity range 20–90%
(non-condensing)

-50–+100° C

No cleaning/washing due to the manufacturing process used to produce
this product

Intelligent Features

fully AT command compatible
leased line operation
sleep mode
autodial, redial
pulse or tone dial
dial pauses
auto answer
adaptive line probing
automatic symbol and carrier frequency during start-up, retrain, and
rate renegotiations
DTMF detection
call status display, auto-parity and data rate selections
keyboard-controlled modem options
on-screen displays for modem option parameters
remote configuration
DTR dialing
phone number storage
flash memory for firmware updates
NVRAM storage for user-defined parameters

SocketModem Global MT5634SMI Developer’s Guide 9

Chapter 2 – Mechanical Specifications

Chapter 2 – Mechanical Specifications

Physical Dimensions – All Models

Figure 2–1. Maximum Component Height

CAUTION: If any component(s) is placed under the SocketModem or if any component(s) should extend to the

point where part of it is under the SocketModem, the component(s) must NOT exceed .060 inches in height.

SocketModem Global MT5634SMI Developer’s Guide 10

Chapter 2 – Mechanical Specifications

Pin Configurations

The MT5634SMI SocketModem uses a 20-pin interface to provide an on-board DAA with tip and ring
connections, audio circuit for call-progress monitoring, LED driver for call status annunciation, and serial
interface.

Figure 2–2. Serial SocketModems Pins

Pin Descriptions for Serial SocketModem Devices

Pin # Signal Name I/O Type Description

26 DGND
33 –RTS I
34 –RXD O

35 –TXD I

36 –RI O

37 –DSR O

38 –CTS O

Digital Ground
Request to Send. RTS signal is used for hardware flow control.
Received Data. The modem uses the RXD line to send data received from

the telephone line to the DTE and to send modem responses to the DTE.
During command mode, –RXD data presents the modem responses to the
DTE. Modem responses take priority over incoming data when the two signals
are in competition for –RXD. When no data is transmitted, the signal is held in
mark condition.
Transmitted Data. The DTE uses the –TXD line to send data to the modem
for transmission over the telephone line or to transmit commands to the
modem. The DTE should hold this circuit in the mark state when no data is
being transmitted or during intervals between characters.
Ring Indicate. –RI output ON (low) indicates the presence of an ON segment
of a ring signal on the telephone line. The modem will no go off-hook when –RI
is active; the modem waits for –RI to go inactive before going off-hook.
Data Set Ready. –DSR indicates modem status to the DTE. –DSR OFF
(high) indicates that the DTE is to disregard all signals appearing on the
interchange circuits except Ring Indicator (–RI). It reflects the status of the
local data set and does not indicate an actual link with any remote data
equipment.
Clear To Send. –CTS is controlled by the modem to indicate whether or not
the modem is ready to transmit data. –CTS ON indicates to the DTE that
signals presented on TXD will be transmitted to the telephone line. –CTS OFF

SocketModem Global MT5634SMI Developer’s Guide 11

Chapter 2 – Mechanical Specifications

u

s

r

indicates to the DTE that it should not transfer data across the interface on
TXD.

39 –DCD O

40 –DTR I

41 DGND GND
61 VCC PWR
63 AGND GND

64 SPKR

LED driver outputs are open-drain inverter-driven (74HCT05) lines with 1.5K ohms pull-up resistors. Max
output current 25 mA.

1 Tip I/O
2 Ring I/O
24 –RESET I

29 DCDIND O
30 RXIND O
31 DTRIND O
32 TXDIND O

Data Carrier Detect. –DCD output is ON (low) when a carrier is detected on
the telephone line or OFF (high) when carrier is not detected.
Data Terminal Ready (Active Low). The –DTR input is turned ON (low) by
the DTE when the DTE is ready to transmit or receive data. –DTR ON
prepares the modem to be connected to the telephone line, and, once
connected, maintains the connection. –DTR OFF places the modem in the
disconnect state.

+5V or 3.3V Supply (depends upon model).
Analog Ground. Analog ground is tied common with DGND on the

SocketModem. To minimize potential ground noise issues, connect audio
circuit return to AGND.
Speaker Output. SPKR is a single ended-output. SPKR is tied directly to the
CODEC.

Tip Signal from Telco.
Ring Signal from Telco.
Modem Reset (with weak pull-up). The active low –RESET input resets the

SocketModem logic and returns the AT command set to the original factory defa
values or to "stored values" in NVRAM. –RESET is tied to VCC through a 400m
time constant circuit for "Power-on-Reset" functionality. The modem is ready to
accept commands within 6.5 seconds of power-on or reset. Reset must be asse
for 300 ns.

Active High DCD status.
Active High RDX status
Active High DTR status
Active High TXD status

SocketModem Global MT5634SMI Developer’s Guide 12

Chapter 2 – Mechanical Specifications

The MT5634SMI-P (Parallel) SocketModem uses a 22-pin interface to provide an on-board DAA with tip and ring
connections, audio circuit for call-progress monitoring, and parallel interface.

Figure 2–3. Parallel SocketModem Pins

Pin Descriptions for a Parallel SocketModem Device

Pin #

1 Tip I/O
2 Ring I/O
24 –RESET I

26 DGND GND
25, 31,34A0, A1,A2I

30 INT O

32 –WR I

33 –RD I

40 –DS I
61 VCC PWR
63 AGND GND

64 SPKR O

Signal
Name

I/O Description

Tip Signal from Telco
Ring Signal from Telco
Modem Reset (with weak pull-up). The active low –RESET input resets the

SocketModem logic and returns the AT command set to the original factory default
values or to "stored values" in NVRAM.
The modem is ready to accept commands within 6.5 seconds of power-on or reset.
Reset must be asserted for a minimum of 300 ns.

Digital Ground
Host Bus Address Lines 0 and 2. During a host read or write operation, A0

through A2 select an internal 16C450 or 16C550-compatible register. The state of
the divisor latch access bit (DLAB) affects the selection of certain registers.
Host Bus Interrupt. INT output is set high when the receiver error flag, receiver
data available, transmitter holding register empty, or modem status interrupt have
an active high condition. INT is reset low upon the appropriate interrupt service or
master reset operation.
Host Bus Write. –WR is an active low, write control input. When –DS is low, –WR
low allows the host to write data or control words into a selected modem register.
Host Bus Read. –RD is an active low, read control input. When –DS is low, –RD
low allows the host to read status information or data from a selected modem
register.

Host Bus Device Select. –DS input low enables the modem for read or write.
+5V or 3.3V Supply (depends upon model).
Analog Ground. This is tied common with DGND on the SocketModem. To

minimize potential ground noise issues, connect audio circuit return to AGND.
Speaker Output. SPKR is a single ended-output. It is tied directly to the CODEC.

SocketModem Global MT5634SMI Developer’s Guide 13

Chapter 3 – Electrical Characteristics

Chapter 3 – Electrical Characteristics

Introduction

Electrical characteristics for the 5V Serial SocketModem, 3.3V Serial SocketModem, 5V Parallel SocketModem,
and the 3.3V Parallel SocketModem are presented in this chapter.

I/O Electrical Characteristics

5V Serial – Standard (SMI) and Medical Device (SMI-HV) Build Options

5 Vdc Characteristics (TA = 0 °C to 50 °C; VDD = 5 V ± 0.25 V) VDDMAX = 5.25 V

Digital Inputs

–DTR (40), –TXD (35), –RTS (33), –RESET (24)

Digital Outputs

–DCD (39), –CTS (38), –DSR (37), –RI (36), –RXD (34)

Digital Input Capacitance 5 PF

Input High

Min 3.675 V

Output High

Min. 4 V

Input Low

Max 1.4 V

Output Low

Max 0.4 V

Current Drive

2 ma

3.3V Serial – Industrial Temperature (SMI-ITP) Build Option

3.3 Vdc Characteristics (TA = -40 °C to 85 °C; VDD = 3.3 V ± 0.3 V) VDDMAX = 3.6 V

Digital Inputs

–DTR (40), –TXD (35), –RTS (33), –RESET (24)

Digital Outputs

–DCD (39), –CTS (38), –DSR (37), –RI (36), –RXD (34)

Digital Input Capacitance 5 PF

Input High

Min 2.52 V

Output High

Min. 2.3 V

Input Low

Max 0.9 V

Output Low

Max 0.4 V

Current Drive

2 ma

5V Parallel – Standard (SMI) and Medical Device (SMI-HV) Build Options

5 Vdc Characteristics (TA = 0 °C to 50 °C; VDD = 5 V ± 0.25 V) VDDMAX = 5.25 V

Digital Inputs

–DS (40)

Input High

Min. 3.675 V

Max. 1.4 V

Digital Inputs (hysteresis input buffer)

A0 (31), A1 (25), A2 (34), –WR (32), –RD (33)

Digital Input / Output
Output buffer can source 12 mA at 0.4 V

DO (37), D1 (38), D2 (29), D3 (39), D4 (35), D5 (36), D6
(41), D7 (27)

Digital Output

INT (30)

Digital Input Capacitance 5 PF

Input High

Min. 3.675 V

Input High

Min. 3.675 V

Output High

Min. 4 V

Input Low

Max. 1.4 V

Input Low

Max. 1.4 V

Output Low

Max 0.4 V

Current Drive

2 ma

SocketModem Global MT5634SMI Developer’s Guide 14

Chapter 3 – Electrical Characteristics

3.3V Parallel – Standard (SMI) and Industrial Temperature (SMI-ITP) Build Options

Electrical characteristics for Parallel MT5634SMI SocketModem devices are presented below.

3.3 Vdc Characteristics (TA = –40 °C to 85 °C; VDD = 3.3 V ± 0.3 V)

VDDMAX = 3.6 V

Digital Inputs

–DS (40)

Digital Inputs (hysteresis input buffer)

A0 (31), A1 (25), A2 (34), –WR (32), –RD (33)

Digital Input/Output
Output buffer can source 12 mA at 0.4 V

DO (37), D1 (38), D2 (29), D3 (39), D4 (35), D5 (36), D6
(41), D7 (27)

Digital Output

INT (30)

Digital Input Capacitance 5 PF

Input High

Min 2.52 V

Input High

Min 2.52 V

Input High

Min 2.52 V

Output High

Min 2.3 V

Input Low

Max 0.9 V

Input Low

Max 0.9 V

Input Low

Max 0.9 V

Output Low

Max 0.4 V

Timing Requirements

Timing Requirements for Parallel Write

Parameter Min Max Unit

–DS to –WR Setup (low to low) 10 - ns
A0, A1, A2 to –WR Setup (valid to low) 15 - ns
–WR Pulse Width (low to high) 40 - ns
D0–D7 to –WR Setup (valid to high) 30 - ns
–WR to –DS hold (high to high) 0 - ns
–WR to A0–A2 Hold (high to invalid) 0 - ns
–WR to D0–D7 Hold (high to invalid) 0 - ns
–WR interaccess (high to low)

Non-MIMIC Accesses
MIMIC Accesses

10
110

-

-

ns
ns

Current Drive

2 ma

Timing Requirements for Parallel Read

Parameter Min Max Unit

–DS to –RD Setup (low to low) 10 - ns
A0, A1, A2 to –RD Setup (valid to low) 15 - ns
–RD Pulse Width (low to high) 40 - ns
–RD to –DS hold (high to high) 0 - ns
–RD to A0–A2 Hold (high to invalid) 0 - ns
–WR interaccess (high to low)

Non-MIMIC Accesses
MIMIC Accesses

10
110

-

-

ns
ns

Handling Precautions

All MOS devices must be handled with certain precautions to avoid damage due to the accumulation of static charge.
Although input protection circuitry has been incorporated into the devices to minimize the effect of this static buildup,
proper precautions should be taken to avoid exposure to electrostatic discharge during handling and mounting.

SocketModem Global MT5634SMI Developer’s Guide 15

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

Chapter 4 – SocketModem Parallel

Interface – A Programmer’s

Description

SocketModem Parallel Interface Internal Registers

The SocketModem parallel interface is a mimic of a 16C550A UART. It is similar to the MIMIC interface used in
the Zilog Z80189. The SocketModem mimic (MMM) takes advantage of this standard interface while replacing
the serial to parallel data transfer with a less complicated parallel to parallel data transfer.

The MMM interface controls an 8-bit parallel data transfer which is typically interrupt driven. Interrupts usually
indicate one or both of two conditions: (1) the receive (RX) FIFO has either reached a trigger level or time-out
condition and needs to be emptied and/or (2) the transmit (TX) FIFO is empty and waiting for more data from the
Host. An interrupt can also be triggered by a change in the modem status register (i.e., loss of carrier) or by the
occurrence of errors in the line status register (overrun, parity, framing, break detect).

In addition to the receive and transmit FIFOs, there are twelve other control/status registers called the MMM
register set which can be accessed through this interface.

SocketModem MIMIC (MMM) Operation

Data flow through MMM is bi-directional. Simultaneously, data can flow from the host through the transmit FIFO
to the SocketModem controller, and data can flow from SocketModem controller through the receive FIFO to the
Host. In the receive path, 8-bit data is asynchronously received (from the SocketModem controller) by the
receive FIFO where it is stored along with associated three error bits. The error bits must arrive (via a
SocketModem controller I/O write to MMM shadow line status register) prior to receiving the actual data bits. The
error bits are then temporarily stored so they may be written, with associated data bits, to the 11-bit wide RX
FIFO.

After every data write, the RX FIFO write pointer is incremented. RX FIFO trigger levels, data ready signal, and
time-out counter are checked to see if a Host interrupt needs to be sent. The data ready signal will be activated
and MMM sits poised to accept another data word.

We highly recommend the host should read the MMM IIR register to determine the type of interrupt. Then it might
check bit 7 of the LSR to see if there are any errors in the data currently residing in the receive FIFO. Finally, it
will (1) alternately read a data word through the RX FIFO read pointer and the error bits via the MMM LSR until
the FIFO is empty, or (2) read successive data words (knowing there were no errors in the FIFO) until the trigger
count is met.

A similar sequence occurs when data flows in the other direction (from host through transmit FIFO), except there
is no error bit manipulation/checking involved.

SocketModem Global MT5634SMI Developer’s Guide 16

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

FIFO Operation

The 16-byte transmit and receive data FIFOs are enabled by the FIFO Control Register (FCR) bit-0. You can set
the receive trigger level via FCR bits 6/7. The receiver FIFO section includes a time-out function to ensure data is
delivered to the external host. An interrupt is generated whenever the Receive Holding Register (RHR) has not
been read following the loading of a character or the receive trigger level has been reached.

Receive (RX) FIFO

The RX FIFO can be configured to be 16 words deep and 11 bits wide. Each word in the RX FIFO consists of 8
data bits and 3 error bits. The RX block of the MMM contains read and write pointers and status flag circuitry
that need only to be presented with data (for input), reset, read/write control signals, and read/write clock signals.
The RX block of the MMM internally manages the FIFO register file and pointers, and it provides simultaneous
read/write capability (no contention problems).

The RX block of the MMM provides data (for output), FIFO full flag, FIFO empty flag, and an almost full flag
which uses an associated predefined trigger level (obtained from the MMM FCR control register) to signal when
the trigger level has been met. Four possible trigger levels may be selected by programming bits 6-7 of the FCR
control register.

A typical (interrupt driven) write to the RX block is a two-step process. The MMM micro-controller must first write
the 3 error bits to a shadow MMM LSR status register. Next, the micro-controller writes the data to the RX FIFO
and during this write operation, the 3 error bits are directly loaded from the LSR shadow register into the bits 8­10 of the selected (11 bit-wide) FIFO register. These error bits represent the parity error, framing error, and break
interrupt signals associated with each data work transmission into the receive FIFO. When the receive FIFO is
read, these error bits are loaded directly into bits 2-4 of the MMM LSR register.

A2 A1 A0 Register Name Register Description Host Access

0
0
0
0
0
0
1
1
1
1

0
0
1
1

0
0
0
1
1
1
0
0
1
1

0
0
1
0

0
0
1
0
0
1
0
1
0
1

0
1
1
0

RBR
THR
IER
IIR
FCR
LCR
MCR
LSR
MSR
SCR

DLL
DLM
DLX
MCX

Receive Buffer (RX FIFO)
Transmit Holding (TX
FIFO)
Interrupt Enable
Interrupt Identification
FIFO Control
Line Control
Modem Control
Line Status
Modem Status
Scratch pad
LSB of Divisor Latch
MSB of Divisor Latch
Divisor Latch
Status/Control

DLAB = 0 R only
DLAB = 0 W only
DLAB = 0 R/W
DLAB = X R only
DLAB = X W only
DLAB = X R/W
DLAB = 0 R/W
DLAB = X R only
DLAB = X R only
DLAB = 0 R/W

DLAB = 1 R/W
DLAB = 1 R/W
DLAB = 1 R/W
DLAB = 1 R/W

Note 1* The General Register set is accessible only when DS is a logic 0.
Note 2* The Baud Rate register set is accessible only when DS is a logic 0 and LCR bit-7 is a logic 1.

SocketModem Global MT5634SMI Developer’s Guide 17

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

Time Out Interrupts

The interrupts are enabled by IER bits 0-3. Care must be taken when handling these interrupts. Following a reset
the transmitter interrupt is enabled, the SocketModem will issue an interrupt to indicate that transmit holding
register is empty. This interrupt must be serviced prior to continuing operations.

The LSR register provides the current singular highest priority interrupt only. A condition can exist where a higher
priority interrupt may mask the lower priority interrupt(s). Only after servicing the higher pending interrupt will the
lower priority interrupt(s) be reflected in the status register. Servicing the interrupt without investigating further
interrupt conditions can result in data errors. When two interrupt conditions have the same priority, it is important
to service these interrupts correctly.

Receive Data Ready and Receive Time Out have the same interrupt priority (when enabled by IER bit-3). The
receiver issues an interrupt after the number of characters received have reached the programmed trigger level.
In this case the MMM FIFO may hold more characters than the programmed trigger level. Following the removal
of a data byte, the user should recheck LSR bit-0 for additional characters. A Receive Time Out will not occur if
the receive FIFO is empty. The time out counter is reset at the center of each stop bit received or each time the
receive holding register (RHR) is read.

Register Functional Descriptions

The following table delineates the assigned bit functions for the twelve internal registers. The assigned bit
functions are more fully defined in the following paragraphs.

Internal Registers

A2 A1 A0 Register

[Default]
Note *3

General Register Set: Note 1*

0 0 0 RBR [XX] Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
0 0 0 THR [XX] Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
0 0 1 IER [00] 0 0 0 0 Modem

0 1 0 IIR [XX] FIFO

0 1 0 FCR [00] RX

0 1 1 LCR [00] Divisor

1 0 0 MCR [00] 0 0 0 Loop

1 0 1 LSR [60] RX

1 1 0 MSR [X0] CD RI DSR CTS Delta

1 1 1 SCR [FF] Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0

Special Register Set: Note *2

0 0 0 DLL [00] Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
0 0 1 DLM [00] Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0

Note 1* The General Register set is accessible only when DS is a logic 0.
Note 2* The Baud Rate register set is accessible only when DS is a logic 0 and LCR bit-7 is a logic 1.
Note 3* The value between the square brackets represents the register's initialized HEX value, X = N/A.

BIT-7 BIT-6 BIT-5 BIT-4 BIT-3 BIT-2 BIT-1 BIT-0

enable

Trigger
(MSB)

latch
access
(DLAB)

FIFO
data
error

FIFO
enable
RX
trigger
(LSB)

Set
break

TX
empty
THR
empty

Receive
Status
Interrupt

0 0 InterruptIDInterruptIDInterruptIDInterrupt

Detect
change
in FCR

Stick
parity

THR
Empty

TX
FIFO
overrun
bit
Even
parity

back
Break
interrupt

DMA
mode
select

Parity
enable

INT
enable
Framing
error

-CD

Line

Status

interrupt

XMIT

FIFO

reset

0 Word

OUT 1 -RTS -DTR

Parity

error

Delta

-RI

Transmit
Holding
Register
interrupt

RCVR
FIFO
reset

length
bit-1

Overrun
error

Delta

-DSR

Receive
Holding
Register
interrupt

Pending
FIFO
enable

Word
length
bit-0

Receive
data
ready

Delta

-CTS

SocketModem Global MT5634SMI Developer’s Guide 18

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

RBR Receive Buffer (RX FIFO)

All eight bits are used for receive channel data (host read/data in; host write/data out). The three error bits per
byte are copied into bits 2, 3, and 4 of the LSR during each host I/O read; therefore, they are available for
monitoring on a per-byte basis.

THR Transmit Holding Register (TX FIFO)

All eight bits are used for transmit channel data (host write/data out; host read/data in).

IER Interrupt Enable

Bits 4–7: Reserved and will always read 0.
Bits 0-3: Set by host software only and cleared by software control or host reset.
Bit 3: Enables modem status IRQ. If bits 0–3 of the MSR are set and this bit is set to 1 (enabled), a host

interrupt is generated.

Bit 2: Enables receive line status IRQ. If bits 1–4 (overrun, parity, framing, break errors) of the LSR are

set and this bit is set to a logic 1, a host interrupt is generated.

Bit 1: Enables transmit holding register IRQ. If bit 5 (transmit holding register empty) of the LSR is set

and this bit is set to a 1, a host interrupt is generated.

Bit 0: Enables received data available IRQ. If bit 0 (data ready) of the LSR is set and this bit is set to a 1,

a host interrupt is generated.

IIR Interrupt Identification (Read Only)

Bits 6–7: (FIFO enabled bits). These bits will read a 1 if FIFO mode is enabled and the 16450 enable bit is 0

(no force of 16450 mode).

Bits 4–5: Reserved and always read a 0.
Bits 1–3: Interrupt ID bits.
Bit 0: Interrupt pending. If logic 0 (in default mode), an interrupt is pending.

When the host accesses IIR, the contents of the register are frozen. Any new interrupts will be recorded, but not
acknowledged during the IIR access. This requires buffering bits (0–3, 6–7) during IIR reads.

Bit 3 Bit 2 Bit 1 Priority Interrupt Source Interrupt Reset Control

011HighestOverrun, parity, framing, error

or break detect bits set by
SocketModem Controller

0102ndReceived data trigger level RX FIFO drops below trigger

1102ndReceiver time-out with data in

RX FIFO

0013rdTX holding register empty Writing to TX holding register

Reading the LSR

level
Read RX FIFO

or reading IIR when TX
holding register is source of
error

0004thMODEM status: CTS, DSR,

RI or DCD

Reading the MSR

SocketModem Global MT5634SMI Developer’s Guide 19

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

FCR FIFO Control

Bits 6–7: Used to determine RX FIFO trigger levels.
Bit 5: Used to detect a change in the FCR.
Bit 4: TX FIFO overrun bit.
Bit 3: DMA mode select. If bit 3 is a 0, the 16450 mode is enabled which does only single-byte transfers.

When bit 3 is a 1, it enables a multiple byte (FIFO mode) data transfer.

Bit 2: TX FIFO reset. This will cause TX FIFO pointer logic to be reset (any data in TX FIFO will be lost).

This bit is self clearing; however, a shadow bit exists that is cleared only when read by the host,
thus allowing the host to monitor a FIFO reset.

Bit 1: RX FIFO reset. This will cause RX FIFO pointer logic to be reset (any data in RX FIFO will be lost).

This bit is self clearing; however, a shadow bit exists that is cleared only when read by the host,
thus allowing the host to monitor a FIFO reset.

Bit 0: FIFO enable. The host writes this bit to logic 1 to put the block in FIFO mode. This bit must be a 1

when writing other bits in this register or they will not be programmed. When this bit changes state,
any data in the FIFOs or the RBR and THR registers will be lost and any pending interrupts are
cleared.

Bit 7 Bit 6 16 Deep FIFO Trigger Levels (# of bytes)

Default

001
014
108
1114

LCR Line Control

Bit 7: Divisor latch access bit. This bit allows the host, access to the divisor latch. Under normal

circumstances, the bit is set to 0 (provides access to the RX and TX FIFOs at address 0). If the bit
is set to 1, access to transmitter, receiver, interrupt enable, and modem control registers is
disabled. In this case, when an access is made to address 0, the divisor latch least (DLL)
significant byte is accessed. Address 1 accesses the most significant byte (DLM). Address 7
accesses the DLX divisor latch register. Address 4 accesses the MCX status/control register.

Bit 6: Used to denote a host-generated set break condition.
Bits 0,1,3,4,5: Used only in parity bit generation for the 7 bit data byte case. Bits 0 and 1 are used for word

length select (b0 = 0 and b1 = 1 is used for 7 bit data). Bit 3 is parity enable. Bit 4 is even parity
select. Bit 5 is stick parity.

MCR Modem Control

Bits 5–7: Reserved, and will always be 0.
Bit 4: Used for loopback. When a 1, bits 0–3 of the MCR are reflected in modem status register (MSR) as

follows: RI <= OUT1, DCD <= OUT2, DSR <= DTR,CTS <= RTS. Emulation of loopback feature of
16550 UART must be done by the host except for the above conditions. Also, when this bit is set, it
allows for data loop back. This means the host can write a data word to the TX and immediately
read back the same data word from the RX (in a manner similar to the 16550A).

Bit 3: Controls the signal used to 3-state the host interrupt. If 0, then an active-low L33xV output will be

set to 0, and this signal will be used to 3-state the host interrupt output pin.

Bits 0–2: Used during LOOP function.
Bit 2: OUT1.
Bit 1: Request to Send (RTS).
Bit 0: Data terminal ready (DTR).

SocketModem Global MT5634SMI Developer’s Guide 20

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

LSR Line Status

Bit 7: Error in RX FIFO. This bit is always set to 1 if at least one data byte in the RX FIFO has an error.

This will clear when there are no more errors in the RX FIFO.

Bit 6: Transmitter empty. This bit is the same as LSR bit 5 (THRE) in MMM
Bit 5: Transmitter holding register empty. This bit is set to 1 when either the transmitter holding register

has been read (emptied) by the micro-controller (16450 mode) or the TX FIFO is empty (16550
mode). This bit is set to 0 when either the THR or the TX FIFO becomes not empty in 16450 mode.
In 16550 mode, it is set to 0 only after the trigger level has been met since the last occurrence of
TX FIFO empty. If the transmitter timer is enabled, a shadow bit exists which delays the timer
setting this bit to 1. When reading this bit, the micro-controller will not see the delay. Both shadow
and register bits are cleared when the host writes to the THR or TX FIFO in 16450 mode. The
trigger level must be reached to clear the bit in 16550 (FIFO) mode.

Bits 2–4: Used for parity error, framing error, and break detect. These bits are written, indirectly, by the

micro-controller as follows: The bits are first written to the shadow bit locations when the micro­controller write accesses the LSR. When the next character is written to the receive buffer (RBR) or
the RX FIFO, the data in the shadow bits is then copied to the RBR (16450 mode) or RX FIFO
(16550 mode). In FIFO mode, bits become available to the host when the data byte associated with
the bits is next to be read. In FIFO mode, with successive reads of the receiver, the status bits will
be set if an error occurs on any byte. Once the micro-controller writes to the RBR or RX FIFO, the
shadow bits are auto cleared. The register bits are updated with each host read.

Bit 1: Overrun error. This bit is set if the micro-controller makes a second write to RBR before the host

reads data in the buffer (16450 mode) or with a full RX FIFO (16550 mode). No data will be
transferred to the RX FIFO under these circumstances. This bit is reset when the host reads the
LSR.

Bit 0: Data ready bit. This bit is set to 1 when received data is available, either in the RX FIFO (16550

mode) or the RBR (16450 mode). This bit is set immediately upon the micro-controller writing data
to the RBR or FIFO if the receive timer is not enabled, but it is delayed by the timer interval if the
receive timer is enabled. For micro-controller read access, a shadow bit exists so that the micro­controller does not see the delay that the host sees. Both bits are cleared to logic 0 immediately
upon reading all data in either RBR or RX FIFO.

MSR Modem Status

Bits 4 through 7 of the MSR can also take on the MCR bits 0 through 3 value when in MCR loop mode (i.e. when
MCR b4 = 1). The transfer of bits in loop back has a null modem twist (i.e. MCR b0 goes to MSR b5 and MCR
b1goes to MSR b4).

Bit 7: Data carrier detect (DCD) bit.
Bit 6: Ring indicator (RI) bit.
Bit 5: Data set ready (DSR) bit.
Bit 4: Clear to send (CTS) bit.
Bit 3: Delta data carrier detect pin. This bit is set to a 1 whenever the data carrier detect bit changes

state. It is reset when the host reads the modem status register.

Bit 2: Trailing edge ring indicator bit. This bit is set to 1 on the falling edge of the ring indicator bit. It is

reset when the host reads the modem status register.

Bit 1: Delta data set ready bit. This bit is set to 1 whenever the data set ready changes state. It is reset

when the host reads the modem status register.

Bit 0: Delta clear to send bit. This bit is a one whenever the clear to send bit changes state. It is reset

when the host reads the modem status register.

SocketModem Global MT5634SMI Developer’s Guide 21

Chapter 4 – SocketModem Parallel Interface – A Programmer’s Description

SCR Scratch

The host programmer uses this register for temporary data storage.

DLL Divisor Latch (LSByte)

This register contains low-order byte for the 16-bit clock divider. It is kept to maintain register set compatibility
with the 16C550A interface. However, it is not used for clock generation since MMM does not require the
generation of a real baud clock.

DLM Divisor Latch (MSByte)

This register contains high-order byte for the 16-bit clock divider. It is kept to maintain register set compatibility
with the 16C550A interface. However, it is not used for clock generation, since MMM does not require the
generation of a real baud clock.

Programming the Baud Rate Generator Registers DLM (MSB) and DLL (LSB) provides a user capability for
selecting the desired final baud rate. The example in the Table below, shows the selectable baud rates available
when using a 1.8432 MHz external clock input.

BAUD RATE GENERATOR PROGRAMMING TABLE

Baud Rate 16 x Clock Divisor (Decimal) DLM Value (HEX) DLL Value (HEX)

110
300
600
1200
2400
4800
9600

19.2K

38.4K

57.6K

115.2K

1047
384
192
96
48
24
12
6
3
2
1

04
01
00
00
00
00
00
00
00
00
00

17
80
C0
60
30
18
0C
06
03
02
01

SocketModem Global MT5634SMI Developer’s Guide 22

Chapter 5 – AT Commands, S-Registers, and Result Codes

Chapter 5 – AT Commands, S-Registers,

and Result Codes

Introduction

The AT commands are used to control the operation of your modem. They are called AT commands because the
characters AT must precede each command to get the ATtention of the modem.

AT commands can be issued only when the modem is in command mode or online command mode.

· The modem is in command mode whenever it is not connected to another modem.

· The modem is in data mode whenever it is connected to another modem and ready to exchange data.

Online command mode is a temporary state in which you can issue commands to the modem while
connected to another modem.

· To put the modem into online command mode from data mode, you must issue an escape sequence (+++)
followed immediately by the AT characters and the command, e.g., +++ATH to hang up the modem. To
return to data mode from online command mode, you must issue the command ATO.

To send AT commands to the modem you must use a communications program, such as the HyperTerminal
applet in Windows 98/95 and NT 4.0, or some other available terminal program. You can issue commands to the
modem either directly, by typing them in the terminal window of the communications program, or indirectly, by
configuring the operating system or communications program to send the commands automatically. Fortunately,
communications programs make daily operation of modems effortless by hiding the commands from the user.
Most users, therefore, need to use AT commands only when reconfiguring the modem, e.g., to turn auto answer
on or off.

The format for entering an AT command is ATXn, where X is the command and n is the specific value for the
command, sometimes called the command parameter. The value is always a number. If the value is zero, you
can omit it from the command; thus, AT&W is equivalent to AT&W0. Most commands have a default value,
which is the value that is set at the factory. The default values are shown in the “AT Command Summary” (See
below).

You must press ENTER (it could be some other key depending on the terminal program) to send the command
to the modem. Any time the modem receives a command, it sends a response known as a result code. The most
common result codes are OK, ERROR, and the CONNECT messages that the modem sends to the computer
when it is connecting to another modem. See a table of valid result codes at the end of this chapter.

You can issue several commands in one line, in what is called a command string. The command string begins
with AT and ends when you press ENTER. Spaces to separate the commands are optional; the command
interpreter ignores them. The most familiar command string is the initialization string, which is used to configure
the modem when it is turned on or reset, or when your communications software calls another modem.

AT Command Summary

Organization of AT Commands on the following pages: 1st, by the initial command character (e.g., &, +, %, etc.)
2nd, alphabetized by the second command character (Except for listing of AT).

Command Description
AT

A
A/
Bn
Ds
DS=y
En
Fn
Hn
In
Mn

SocketModem Global MT5634SMI Developer’s Guide 23

Attention Code
Answer
Repeat Last Command
Communication Standard Setting
Dial
Dial Stored Telephone Number
Echo Command Mode Characters
Echo Online Data Characters
Hook Control
Information Request
Monitor Speaker Mode

Chapter 5 – AT Commands, S-Registers, and Result Codes

Nn
On
P
Qn
Sr=n
Sr?
T
Vn
Wn
Xn
Zn
&Cn
&Dn
&En
&Fn
&Gn
&Kn
&Ln
&Pn
&Qn
&Sn
&Tn
&V
&Wn
&Zy=x
\An
\Bn
\Kn
\Nn
\Qn
\Tn
\Vn

-Cn
%A
%B
%Cn
%DCn
%En
%Hn
%Rn
%Sn
$EBn
$Dn
$MBn
$SBn
#CBAn
#CBDn
# CBF?
# CBFR
# CBIn
# CBNy=n
# CBPn
# CBRy
# CBSn
#Pn
#Sx
#S=x
+VDR=x, y
+++AT<CR>
%%%AT<CR>
V.92 Commands

Modulation Handshake
Return Online to Data Mode
Pulse Dialing
Result Codes Enable/Disable
Set Register Value
Read Register Value
Tone Dialing
Result Code Format
Result Code Options
Result Code Selection
Modem Reset
Data Carrier Detect (DCD) Control
Data Terminal Ready (DTR) Control
XON/XOFF Pass-Through
Load Factory Settings
V.22bis Guard Tone Control
Flow Control Selection
Leased Line Operation
Pulse Dial Make-to-Break Ratio Selection
Asynchronous Communications Mode
Data Set Ready (DSR) Control
Loopback Test (V.54 Test) Commands
Display Current Settings
Store Current Configuration
Store Dialing Command
Select Maximum MNP Block Size
Transmit Break
Break Control
Error Correction Mode Selection
Flow Control Selection
Inactivity Timer
Protocol Result Code
Data Calling Tone
Adaptive Answer Result Code Enable
View Numbers in Blacklist
Data Compression Control
AT Command Control
Fallback and Fall Forward Control
Direct Connect Enable
Cisco Configuration
Command Speed Response
Asynchronous Word Length
DTR Dialing
Online BPS Speed
Serial Port Baud Rate
Callback Attempts
Callback Delay
Callback Failed Attempts Display
Callback Failed Attempts Reset
Local Callback Inactivity Timer
Store Callback Password
Callback Parity
Callback Security Reset
Callback Enable/Disable
Set 11-bit Parity
Enter Setup Password
Store Setup Password
Distinctive Ring Report
Escape Sequence
Remote Configuration Escape Sequence

SocketModem Global MT5634SMI Developer’s Guide 24

Chapter 5 – AT Commands, S-Registers, and Result Codes

AT Commands

Command: AT Attention Code
Values: n/a
Description: The attention code precedes all command lines except A/, A: and escape sequences.

Command: ENTER Key
Values: n/a
Description: Press the ENTER (RETURN) key to execute most commands.

Command: AAnswer
Values: n/a
Description: Answer call before final ring.

Command: A/ Repeat Last Command
Values: n/a
Description: Repeat the last command string. Do not precede this command with AT. Do not press E

to execute.

Command: Bn Communication Standard Setting
Values: n = 0–3, 15, 16
Default: 0 and 15
Description: B0 Select ITU-T V.22 mode when modem is at 1200 bps.

B1 Select Bell 212A when modem is at 1200 bps.
B2 Deselect V.23 reverse channel (same as B3).
B3 Deselect V.23 reverse channel (same as B2).
B15 Select V.21 when the modem is at 300 bps.
B16 Select Bell 103J when the modem is at 300 bps.

NTER

Command: Ds Dial
Values: s = dial string (phone number and dial modifiers)
Default: none
Description: Dial telephone number s, where s may up to 40 characters long and include the 0–9, *, #, ,

B, C, and D characters, and the L, P, T, V, W, S, comma (,), semicolon (;), !, @, ^ and $ dial
string modifiers.

Dial string modifiers:
L Redial last number. (Must be placed immediately after ATD.)
P Pulse-dial following numbers in command.
T Tone-dial following numbers in command (default).
V Switch to speakerphone mode and dial the following number. Use ATH command to

hang up.

W Wait for a new dial tone before continuing to dial. (X2, X4, X5, X6, or X7 must be

selected.)

, Pause during dialing for time set in register S8.
; Return to command mode after dialing. (Place at end of dial string.)
! Hook flash. Causes the modem to go on-hook for one-half second, then off-hook

again.

@ Wait for quiet answer. Causes modem to wait for a ringback, then 5 seconds of

silence, before processing next part of command. If silence is not detected, the modem
returns a NO ANSWER code.

^ Disable data calling tone transmission.
$ Detect AT&T call card “bong” tone. The character should follow the phone number and

precede the user’s call card number: ATDT1028806127853500$123456789

Command: DS=y Dial Stored Telephone Number
Values: n = 0–2
Default: none
Description: Dial a number previously stored in directory number y by the &Zy=x command. Example:

ATDS=2

SocketModem Global MT5634SMI Developer’s Guide 25

Chapter 5 – AT Commands, S-Registers, and Result Codes

Command: En Echo Command Mode Characters
Values: n = 0 or 1
Default: 1
Description: E0 Do not echo keyboard input to the terminal.

E1 Do echo keyboard input to the terminal.

Command: Fn Echo Online Data Characters
Values: n = 1
Default: 1

F0 Enable online data character echo. (Not supported.)
F1 Disable online data character echo (included for backward compatibility with some

software).

Command: Hn Hook Control
Values: n = 0 or 1
Default: 0
Description: H0 Go on-hook (hang up).

H1 Go off-hook (make the phone line busy).

Command: In Information Request
Values: n = 0–5, 9, 11
Default: None
Description: I0 Display default speed and controller firmware version.

I1 Calculate and display ROM checksum (e.g., 12AB).
I2 Check ROM and verify the checksum, displaying OK or ERROR.
I3 Display default speed and controller firmware version.
I4 Display firmware version for data pump (e.g., 94).
I5 Display the board ID: software version, hardware version, and country ID
I9 Display the country code (e.g., NA Ver. 1).
I11 Display diagnostic information for the last modem connection, such as DSP and

firmware version, link type, line speed, serial speed, type of error correction/data
compression, number of past retrains, etc.

Command: Mn Monitor Speaker Mode
Values: n = 0, 1, 2, or 3
Default: 1
Description: M0 Speaker always off.

M1 Speaker on until carrier signal detected.
M2 Speaker always on when modem is off-hook.
M3 Speaker on until carrier is detected, except while dialing.

Command: Nn Modulation Handshake
Values: n = 0 or 1
Default: 1
Description: N0 Modem performs handshake only at communication standard specified by S37 and the

B command.

N1 Modem begins handshake at communication standard specified by S37 and the B

command. During handshake, fallback to a lower speed can occur.

Command: On Return Online to Data Mode
Values: 0, 1, 3
Default: None
Description: O0 Exit online command mode and return to data mode (see +++AT<CR> escape

sequence ).
O1 Issue a retrain and return to online data mode.
O3 Issue a rate renegotiation and return to data mode.

Command: P Pulse Dialing
Values: P, T
Default: T
Description: Configures the modem for pulse (non-touch-tone) dialing. Dialed digits are pulsed until a T

command or dial modifier is received.

Command: Qn Result Codes Enable/Disable
Values: n = 0 or 1

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Default: 0
Description: Q0 Enable result codes.

Q1 Disable result codes.
Q2 Returns an OK for backward compatibility with some software.

Command: Sr=n Set Register Value
Values: r = S-register number; n varies
Default: None
Description: Set value of register Sr to value of n, where n is entered in decimal format. E.g., S0=1.

Command: Sr? Read Register Value
Values: r = S-register number
Default: None
Description: Read value of register Sr and display it in 3-digit decimal form. E.g., S2? gives the response

043.

Command: T Tone Dialing
Values: P, T
Default: T
Description: Configures the modem for DTMF (touch-tone) dialing. Dialed digits are tone dialed until a P

command or dial modifier is received.

Command: Vn Result Code Format
Values: n = 0 or 1
Default: 1
Description: V0 Displays result codes as digits (terse response).

V1 Displays result codes as words (verbose response).

Command: Wn Result Code Options
Values: n = 0, 1, or 2
Default: 2
Description: W0 CONNECT result code reports serial port speed, disables protocol result codes.

W1 CONNECT result code reports serial port speed, enables protocol result codes.
W2 CONNECT result code reports line speed, enables protocol result codes.

Command: Xn Result Code Selection
Values: n = 0–7
Default: 4
Description: X0 Basic result codes (e.g., CONNECT); does not look for dial tone or busy signal.

X1 Extended result codes (e.g., CONNECT 46000 V42bis); does not look for dial tone or

busy signal.

X2 Extended result codes with NO DIALTONE; does not look for busy signal.
X3 Extended result codes with BUSY; does not look for dial tone.
X4 Extended result codes with NO DIALTONE and BUSY.
X5 Extended result codes with NO DIALTONE and BUSY.
X6 Extended result codes with NO DIALTONE and BUSY.
X7 Basic result codes with NO DIALTONE and BUSY.

Command: Zn Modem Reset
Values: n = 0 or 1
Default: None
Description: Z0 Reset modem to profile saved by the last &W command.

Z1 Same as Z0.

Command: &Cn Data Carrier Detect (DCD) Control
Values: n = 0, 1, 2
Default: 1
Description: &C0 Forces the DCD circuit to be always high.

&C1 DCD goes high when the remote modem’s carrier signal is detected, and goes low

when the carrier signal is not detected.

&C2 DCD drops on disconnect for time set by S18. It then goes high again (for some PBX

phone systems).

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Command: &Dn Data Terminal Ready (DTR) Control
Values: n = 0, 1, 2, or 3
Default: 2
Description: &D0 Modem ignores the true status of the DTR signal and responds as if it is always on.

&D1 If DTR drops while in online data mode, the modem enters command mode, issues

an OK, and remains connected.

&D2 If DTR drops while in online data mode, the modem hangs up. If the signal is not

present, the modem will not answer or dial.

&D3 If DTR drops, the modem hangs up and resets as if an ATZ command were issued.

Command: &En XON/XOFF Pacing Control
Values: n = 12 or 13
Default: 12
Description: &E12 Disables XON/XOFF pacing.

&E13 Enables XON/XOFF pacing.

Command: &Fn Load Factory Settings
Values: n = 0
Default: None
Description: &F0 Load factory settings as active configuration.

Note: See also the Z command.

Command: &Gn V.22bis Guard Tone Control
Values: n = 0, 1, or 2
Default: 0
Description: &G0 Disable guard tone.

&G1 Set guard tone to 550 Hz.
&G2 Set guard tone to 1800 Hz.

Note: The &G command is not used in North America.

Command: &Kn Flow Control Selection
Values: n = 0, 3, or 4
Defaults: 3
Description: &K0 Disable flow control.

&K3 Enable CTS/RTS hardware flow control.
&K4 Enable XON/XOFF software flow control.

Command: &Ln Leased Line Operation
Values: n = 0, 1, or 2
Defaults: 0
Description: &L0 The modem is set for standard dial-up operation.

&L1 The modem is set for leased line operation in originate mode.
&L2 The modem is set for leased line operation in answer mode.

Note: For &L1 and &L2, there is a 30-second window between power up and the starting of

the leased line handshake. During this time, you can turn off the command, if desired.

Command: &Pn Pulse Dial Make-to-Break Ratio Selection
Values: n = 0, 1, or 2
Default: 0
Description: &P0 60/40 make-to-break ratio

&P1 67/33 make-to-break ratio
&P2 20 pulses per second

Note: The &P2 command is available only if the country code is set to Japan.

Command: &Qn Asynchronous Communications Mode
Values: n = 0, 5, 6, 8, or 9
Default: 5
Description: &Q0 Asynchronous with data buffering. Same as \N0.

&Q5 Error control with data buffering. Same as \N3.
&Q6 Asynchronous with data buffering. Same as \N0.
&Q8 MNP error control mode. If MNP error control is not established, the modem falls back

according to the setting in S36.

&Q9 V.42 or MNP error control mode. If neither error control is established, the modem

falls back according to the setting in S36.

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Command: &Sn Data Set Ready (DSR) Control
Values: n = 0 or 1
Default: 0
Description: &S0 DSR is always high (on).

&S1 DSR goes high only during a connection.

Command: &Tn Loopback Test (V.54 Test) Commands
Values: n = 0, 1, 3, 6
Default: None
Description: The modem can perform selected test and diagnostic functions. A test can be run only when

the modem is operating in non-error-correction mode (normal or direct mode). For tests 3
and 6, a connection between the two modems must be established. To terminate a test in
progress, the escape sequence (+++AT) must be entered.
&T0 Stops any test in progress.
&T1 Starts a local analog loopback, V.54 Loop 3, test. If a connection exists when this

command is issued, the modem hangs up. When the test starts, a CONNECT
message is displayed.

&T3 Starts local digital loopback, V.54 Loop 2, test. If no connection exists, ERROR is

returned.

&T6 Initiates a remote digital loopback, V.54 Loop 2, test without self-test. If no connection

exists, ERROR is returned.

Command: &V Display Current Settings
Values: n/a
Description: Displays the active modem settings.

Command: &Wn Store Current Configuration
Values: n = 0 or 1
Default: 1
Description: &W0 Stores current modem settings in non-volatile memory and causes them to be loaded

at power-on

or following the ATZ command instead of the factory defaults. See also the &F

command.

&W1 Clears user default settings from non-volatile memory and causes the factory defaults

to be loaded at power-on or following the ATZ command.

Command: &Zy=x Store Dialing Command
Values: y = 0–2

x = Dialing command
Default: None
Description: Stores dialing command x in memory location y. Dial the stored number using the command

ATDS=y. See Also the #CBS command, a callback security command.

Command: \An Select Maximum MNP Block Size
Values: n = 0, 1, 2, or 3
Default: 3
Description: \A0 64-character maximum.

\A1 128-character maximum.

\A2 192-character maximum.

\A3 256-character maximum.

Command: \Bn Transmit Break
Values: n = 0–9 in 100 ms units
Default: 3
Description: In non-error-correction mode only, sends a break signal of the specified length to a remote

modem. Works in conjunction with the \K command.

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Command: \Kn Break Control
Values: n = 0–5
Default: 5
Description: Controls the response of the modem to a break received from the computer, the remote

modem, or the \B command. The response is different for each of three different states.

Data mode. The modem receives the break from the computer:

\K0 Enter online command mode, no break sent to the remote modem.

\K1 Clear data buffers and send break to the remote modem.

\K2 Same as \K0.

\K3 Send break immediately to the remote modem .

\K4 Same as \K0.

\K5 Send break to the remote modem in sequence with the transmitted data.

Data mode. The modem receives the break from the remote modem:

\K0 Clear data buffers and send break to the computer.

\K1 Same as \K0.

\K2 Send break immediately to the computer.

\K3 Same as \K2.

\K4 Send break to the computer in sequence with the received data.

\K5 Same as \K4.

Online command mode. The modem receives a \Bn command from the computer:

\K0 Clear data buffers and send break to the remote modem.

\K1 Same as \K0.

\K2 Send break immediately to the remote modem.

\K3 Same as \K2.

\K4 Send break to the remote modem in sequence with the transmitted data.

\K5 Same as \K4.

Command: \Nn Error Correction Mode Selection
Values: n = 0–5, or 7
Default: 3
Description: \N0 Non-error correction mode with data buffering (buffer mode; same as &Q6).

\N1 Direct mode.

\N2 MNP reliable mode. If the modem cannot make an MNP connection, it disconnects.

\N3 V.42/MNP auto-reliable mode. The modem attempts first to connect in V.42 error

correction mode, then in MNP mode, and finally in non-error correction (buffer) mode

with continued operation.
\N4 V.42 reliable mode. If the modem cannot make a V.42 connection, it disconnects.
\N5 V.42, MNP, or non-error correction (same as \ N3).
\N7 V.42, MNP, or non-error correction (same as \ N3).

Command: \Qn Flow Control Selection
Values: n = 0, 1, or 3
Default: 3
Description: \Q0 Disable flow control (same as &K0).

\Q1 XON/XOFF software flow control (same as &K4).
\Q2 CTS-only flow control. Not supported.
\Q3 RTS/CTS hardware flow control (same as &K3).

Command: \Tn Inactivity Timer
Values: n = 0, 1–255
Default: 0
Description: Sets the time (in minutes) after the last character is sent or received that the modem waits

before disconnecting. A value of zero disables the timer. Applies only in buffer mode.
Note: You can also set the inactivity timer by changing the value of S30.

Command: \Vn Protocol Result Code
Values: n = 0, 1, or 2

Default: 1
Description: \V0 Disables the appending of the protocol result code to the DCE speed.

\V1 Enables the appending of the protocol result code to the DCE speed.
\V2 Same as \V1.

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