Silicon Laboratories Si2493 Manual
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Silicon Laboratories Si2493 Manual

Silicon Laboratories Si2493 Manual

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Si2493/57/34/15/04 (Revisions D and D1) and Si2494/39
(Revisions A and A1) Modem Designer 's Guide

1. Introduction

The Si2494/93/57/39/34/15/04 ISOmodem chipset family consists of a 38-pin QFN (Si2494/39) or 24-pin TSSOP
(Si2493/57/34/15/04) or 16-pin SOIC (Si2493/57/34/15/04) low-voltage modem device, and a 16-pin SOIC line-
side DAA device (Si3018/10) connecting directly with the telephone local loop (Tip and Ring). This modem solution
is a complete hardware (controller-based) modem that connects to a host processor through a UART, parallel or
SPI interface. Parallel and EEPROM interfaces are available only on the 38-pin QFN or 24-pin TSSOP package
option. Refer to Table 4, "ISOmodem Capabilities," on page 10 for available part number, capability and package
combinations. Isolation is provided by Silicon Laboratories' isolation capacitor technology, which uses high-voltage
capacitors instead of a transformer. This isolation technology complies with global telecommunications standards
including FCC, ETSI ES 203 021, JATE, and all known country-specific requirements.
Additional features include programmable ac/dc termination and ring impedance, on-hook and off-hook intrusion
detection, Caller ID, loop voltage/loop current monitoring, overcurrent detection, ring detection, and the hook-
switch function. All required program and data memory is included in the modem device. When the modem
receives a software or hardware reset, all register settings revert to the default values stored in the on-chip
program memory. The host processor interacts with the modem controller through AT commands used to change
register settings and control modem operation. Country, EMI/EMC, and safety test reports are available from
Silicon Laboratories representatives and distributors.
This application note is intended to supplement the Si2494/39 Revision A/A1, Si2493 Revision D/D1, and the
Si2457/34/15/04 Revision D/D1 data sheets. It provides all the hardware and software information necessary to
implement a variety of modem applications, including reference schematics, sample PCB layouts, AT command
and register reference, country configuration tables, programming examples and more. Particular topics of interest
can be easily located through the table of contents or the comprehensive index located at the back of this
document.
CLKOUT
Rev. 1.4 11/13
XTI
PLL
Clocking
EESD
EEPROM
EECLK
Interface
EECS
RXD
TXD
CTS
UART
RTS
Interface
DCD
ESC
RI
CS
WR
Parallel
RD
Interface
A0
D0-D7
SDI
SDO
SPI
Interface
SCLK
SS
INT
RESET
Figure 1. Functional Block Diagram
Copyright © 2013 by Silicon Laboratories
XTO
Data Bus
DAA
Interface
ROM
RAM
Program Bus
Si3000
Interface
AN93
C1
To Phone
Line
C2
AOUT
AOUTb
FSYNC
SDO
SDI
MCLK
AN93

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Summary of Contents for Silicon Laboratories Si2493

  • Page 1: Introduction

    Country, EMI/EMC, and safety test reports are available from Silicon Laboratories representatives and distributors. This application note is intended to supplement the Si2494/39 Revision A/A1, Si2493 Revision D/D1, and the Si2457/34/15/04 Revision D/D1 data sheets. It provides all the hardware and software information necessary to implement a variety of modem applications, including reference schematics, sample PCB layouts, AT command and register reference, country configuration tables, programming examples and more.
  • Page 2 AN93 Rev. 1.4...

  • Page 3: Table Of Contents

    AN93 ABLE O F ONTENTS Section Page 1. Introduction ............. . 1 1.1.
  • Page 4 AN93 2.7.6.1. Boot Command Example ........37 2.7.6.2.
  • Page 5 AN93 5.7.9. U4D (Modem Control Register 1—MOD1) ......110 5.7.10. U4E (Pre-Dial Delay Time Register)....... 112 5.7.11.
  • Page 6 AN93 6.6. Intrusion/Parallel Phone Detection ........173 6.6.1.
  • Page 7 AN93 7.5.6. Answer ............211 7.5.7.
  • Page 8 AN93 8.2.1.2. Session Example ......... . 242 9.

  • Page 9: Selection Guide

    Tables 1 through 3 list the modulations, protocols, carriers, tones and interface modes supported by the Si2494/39 and Si2493/57/34/15/04 ISOmodem family. The Si2493 supports all modulations and protocols from Bell 103 through V.92. The Si2457 supports all modulations and protocols from Bell 103 through V.90. The Si2434 supports all modulations and protocols from Bell 103 through V.34.
  • Page 10 –43 dBm/–48 dBm Originate/answer (M/S) 2225/2025 1270/1070 –43 dBm/–48 dBm Table 4. ISOmodem Capabilities Part Numbers Package UART EEPROM Parallel Voice Speakerphone /    Si2493/57/34/15/04 SOIC-16      Si2493/57/34/15/04 TSSOP-24       Si2494/39...

  • Page 11: Modem (System-Side) Device

    AN93 2. Modem (System-Side) Device The Si24xx ISOmodem system-side devices contain a controller, a DSP, program memory (ROM), data memory (RAM), UART, SPI and parallel interfaces, a crystal oscillator, and an isolation capacitor interface. The following sections describe the reset sequence, the host interface, the isolation interface, low-power modes, SSI/voice mode and the EEPROM interface.

  • Page 12: Reset Strapping: General Considerations

    AN93 6. Set non-default frequency values—Ring. 7. Set non-default filter parameters. 8. Set non-default S-register values. The modem is now ready to detect rings, answer another modem, call, or dial out to a remote modem. Some key default settings for the modem after reset or powerup include the following: ...

  • Page 13: Reset-Strap Options For 16-Pin Soic Package

    AN93 2.1.3. Reset-Strap Options for 16-Pin SOIC Package The clock frequency and interface on the 16-pin SOIC package are selected according to Table 5 below. The parallel interface, EEPROM and autobaud options are not available in the 16-pin SOIC package. Table 5.

  • Page 14: Reset Strapping Options For Tssop-24 With Uart-Interface

    AN93 2.1.4.1. Reset Strapping Options for TSSOP-24 with UART-Interface UART-interface options for the 24-pin TSSOP package are shown in Table 6 below. Table 6. TSSOP-24 UART-Interface Options Mode Reset-Strap Pins Input Clock Autobaud Three-Wire Pin 4 Pin 11, CTS Pin 17 Pin 18 Pin 23 Disabled?

  • Page 15: Reset Strapping Options For Tssop With Spi-Interface

    AN93 2.1.4.3. Reset Strapping Options for TSSOP with SPI-Interface Table 8 lists the SPI-interface options for the 24-pin TSSOP package. Table 8. TSSOP-24 SPI-Interface Clock-Frequency Options Mode Reset-Strap Pins Input Clock Three-Wire Pin 4 Pin 9, RXD Pin 16 Pin 17 Pin 23 EEPROM FSYNC...

  • Page 16: Reset Strapping Options For Qfn Parts With Spi Operation

    AN93 2.1.5.2. Reset Strapping Options for QFN Parts with SPI Operation Table 10 lists the reset strapping options for QFN parts with SPI operation. Table 10. Reset Strapping Options for QFN parts with SPI Operation Input Clk Three-Wire FSYNCH AOUT EECLK MISO EEPROM...

  • Page 17: System Interface

    AN93 2.2. System Interface The ISOmodem can be connected to a host processor through a UART, SPI or parallel interface. Connection to the chip requires low-voltage CMOS signal levels from the host and any other circuitry interfacing directly. The following sections describe the digital interface options in detail. 2.2.1.
  • Page 18 AN93 Table 14. Pin Functions vs. Interface Mode (QFN-38) Pin # UART Mode SPI Mode Parallel Mode GPIO18 GPIO18 GPIO17 GPIO17 GPIO16 GPIO16 GPIO23 GPIO23 GPIO24 GPIO24 MOSI MISO SCLK GPIO11 GPIO11 Rev. 1.4...

  • Page 19: Interface Signal Description

    Data input from host TXD pin Output Data output to host RXD pin Input Active-low request-to-send input for flow control Output Clear to send: Si2493 is ready to receive data on the TXD pin (active low) Table 16. SPI-Interface Signals Signal Direction Description SCLK...

  • Page 20: Autobaud

    AN93 The UART interface synchronizes on the start bits of incoming characters and samples the data bit field and stop bits. The interface is designed to accommodate character lengths of 8, 9, 10, and 11 bits giving data fields of 6, 7, 8, or 9 bits.

  • Page 21: Flow Control

    AN93 Table 19. Serial Formats Detected in Autobaud Mode Symbol Data bits Parity Stop bits None (mark) None (mark) None (space) Even None (mark) Even None (mark) Note: For 7N1, the modem is programmed to 7 data bits, mark parity and one stop bit. This may be changed with the AT\P and AT\B commands.
  • Page 22 AN93 Table 20. Register U70 Signals INT Can Monitor Signal U70 Bit Function Data Carrier Detect—active high (inverse of DCD pin) Ring Indicator—active high (inverse of RI pin) Parallel Phone Detect Overcurrent Detect Caller ID Preamble Detect 1024 Character Elastic Tx Buffer SRAM CTS Deasserts 796 Characters...

  • Page 23: Parallel And Spi Interface Operation

    AN93 A block diagram of the UART in the serial interface mode is shown in Figure 5. 11 Bits to Data Bus RX FIFO TX FIFO TX Shift RX Shift CONTROL Register Register (10) (11) (16) Figure 5. UART Serial Interface 2.2.4.
  • Page 24 AN93 11 Bits to Data Bus TX FIFO RX FIFO 14 Characters 12 Characters Shared-Serial/Parallel CONTROL Parallel I/F Parallel I/F Register 0 Register 1 (16) (17) (18) (22) (23) (24) (10) (11) (15) Parallel Interface Unique Figure 6. Parallel Interface Rev.

  • Page 25: Hardware Interface Register 0

    AN93 Table 21. Hardware Interface Register Bit Map Action Register Read HIR0 Modem data or command from receive FIFO Write Modem data or command to transmit FIFO Read HIR1 INTM Write *Note INTM *Note *Note: REM and INT are read-only bits. 2.2.4.1.

  • Page 26: Parallel Interface Operation

    AN93 Bit 6 (TXE) is a read/write bit that gives the status of the 14-byte deep transmit FIFO. If TXE = 0, the transmit FIFO contains three or more bytes. If TXE = 1, the transmit FIFO contains two or fewer bytes. Writing TXE = 0 clears the interrupt but does not change the state of TXE.
  • Page 27 AN93 Figure 7. Parallel Interface Read Timing Figure 8. Parallel Interface Write Timing Rev. 1.4...

  • Page 28: Spi Interface Operation

    2.2.4.4. SPI Interface Operation SPI interface operation is supported in the Si2493/57/34/15/04 Revision D or later and the Si2494/39 Revision A or later. When the device is powered up for SPI interface, the modem becomes an SPI slave, and the pins are configured to SS (chip select input, active low), MOSI (serial data input to modem), MISO (serial data output from modem) and SCLK (serial data clock input).

  • Page 29: Isolation Capacitor Interface

    AN93 2.3. Isolation Capacitor Interface The isolation capacitor is a proprietary high-speed interface connecting the modem chip and the DAA chip through a high-voltage isolation barrier provided by two capacitors. It serves three purposes. First, it transfers control signals and transmit data from the modem chip to the DAA chip. Second, it transfers receive and status data from the DAA chip to the modem chip.

  • Page 30: Controlling Gpios (38-Pin Qfn Only)

    AN93 2.5. Controlling GPIOs (38-Pin QFN Only) The Si2494 and Si243939 have pins that are configurable as general-purpose I/Os. I/O pads are physically assigned to the GPIO pins of 38-pin packages as shown in Table 25. Depending on the application, other pins may be configured as GPIOs, but, to avoid conflicts with defined pin functions, in general, it is best to use the pins described below.
  • Page 31 AN93 AT:W5F | 0004 // Write a 1 to GPIO18; this will make the port high impedance AT:Q5F // Read the port status, bit 2 should reflect the state of the port AT*Y0 // Close the special AT*Y254 command Table 26. PSEL11_10 Bit Map (0x0085) Name Function 15:14...
  • Page 32 AN93 Table 30. Port Mode 0 Bit Map (0x005C) Name Function 15:0 P0MD[15:0] Port Mode. Configures mode of GPIO 0 through 15. 0 = Corresponding P.n output is open drain 1 = Corresponding P.n output is push-pull Table 31. Port Mode 1 Bit Map (0x005D) Name Function 15:10...

  • Page 33: Ssi/Voice Mode (24-Pin Tssop And 38-Pin Qfn Only)

    AN93 2.6. SSI/Voice Mode (24-Pin TSSOP and 38-Pin QFN Only) Voice mode is supported in the Si2439 and the Si2494. Table 34 lists the pin connections for the ISOmodem SSI interface. This interface enables Voice Mode operation. See "7. Handset, TAM, and Speakerphone Operation" on page 185 for additional information.

  • Page 34: Eeprom Interface (24-Pin Tssop And 38-Pin Qfn Only)

    AN93 2.7. EEPROM Interface (24-Pin TSSOP and 38-Pin QFN Only) The 24-pin TSSOP and 38-pin QFN packages feature an optional three-wire interface (EESD, EECS and EECLK) that may be directly connected to SPI EEPROMs. An EEPROM may contain custom default settings, firmware upgrades, and/or user-defined AT command macros for use in custom AT commands or country codes.
  • Page 35 AN93 Table 37. EEPROM Timing Parameter Symbol Min. Typ. Max. Unit EESD tristated before last falling EECLK edge during read cycle. Last positive half of EECLK cycle is extended to provide — — both 500 ns minimum EOH and 100 ns EESD before EECLK falling edge.

  • Page 36: Three-Wire Spi Interface To Eeprom

    AN93 2.7.2. Three-Wire SPI Interface to EEPROM To enable the 3-wire SPI interface to EEPROM on the 24-pin TSSOP package, appropriate pins must be reset strapped according to Table 6 on page 14, or Table 8 on page 15, depending on the interface selected. The EEPROM option is not available on the 24-pin TSSOP package if the parallel host interface is selected.

  • Page 37: At Command Macros (Customized At Commands)

    AN93 The commands end with a <CR>, which, in combination with the final<CR>, provides the <CR><CR> delimiter. Boot commands must be the first entry in the EEPROM and are used to set the modem up with custom defaults, such as settings for specific countries, auto answer, or other special settings upon power up or after a hardware or software reset.

  • Page 38: At Command Macro Example

    AN93 2.7.6.2. AT Command Macro Example This example creates the AT command macro ATN<CR> to configure the ISOmodem for operation in Norway. The AT commands required to do this manually are: AT:U2C,00B0,0080<CR> AT:U67,000C,0010,0004<CR> AT:U4D,001<CR> To implement this as an AT command macro, the EEPROM contents should be: N<CR>...

  • Page 39: Combination Example

    AN93 2.7.6.4. Combination Example This example shows boot commands and custom AT commands stored in the same EEPROM. Table 38. Combination Example Command Function Start of EEPROM contents BOOT<CR> <commands><CR> <commands><CR> End of BOOT string <CR> Start of Custom AT Command 1 <Custom AT Command Name 1><CR>...
  • Page 40 AN93 Table 39. ASCII Chart Display Display Display Display <NUL> <space> <SOH> <STX> “ <ETX> <EOT> <ENQ> <ACK> & <BEL> <BS> <HT> <LF> <VT> <FF> <CR> <SO> <SI> <DLE> <DC1> <DC2> <DC3> <DC4> <NAK> <SYN> <ETB> <CAN> <EM> <SUB> <ESC> <FS>...

  • Page 41: Daa (Line-Side) Device

    AN93 3. DAA (Line-Side) Device The Si3018/10 DAA or line-side device, contains an ADC, a DAC, control circuitry, and an isolation capacitor interface. The Si3018/10 and surrounding circuitry provide all functionality for telephone line interface requirement compliance, including a full-wave rectifier bridge, hookswitch, dc termination, ac termination, ring detection, loop voltage and current monitoring, and call-progress monitoring.

  • Page 42: Ac Termination

    AN93 3.2. AC Termination The ISOmodem has four ac termination impedances when used with the Si3018 line-side device, selected by the ACT bits in Register U63. The four available settings for the Si3018 are listed in Table 40. If an ACT[3:0] setting other than the four listed in Table 40 is selected, the ac termination is forced to 600 ...
  • Page 43 AN93 Bit 15 represents the polarity of the Tip-Ring voltage, and a reversal of this bit represents a Tip-Ring polarity reversal. LVS = 0x0000 if the Tip-Ring voltage is less than 3.0 V and, in the on-hook state, can be taken as “no line connected.”...
  • Page 44 AN93 ILIM = 1 ILIM = 0 Loop Curre nt (m A) Figure 16. Typical Loop Current LCS Transfer Function Table 41. Loop Current Transfer Function LVCS[4:0] Condition 00000 Insufficient line current for normal operation. 11111 Loop current overload. Overload is defined as 128 mA or more, except in TBR21, where overload is defined as 56 mA or more.

  • Page 45: Legacy-Mode Line Voltage And Loop Current Measurement

    AN93 3.6. Legacy-Mode Line Voltage and Loop Current Measurement The 5-bit LVCS register, U79 (LVCS) [4:0], reports line voltage measurements when on-hook and loop current measurements when off-hook. Using the LVCS bits, the user can determine the following:  When on-hook, detect if a line is connected. ...

  • Page 46: Hardware Design Reference

    AN93 4. Hardware Design Reference This section describes hardware design requirements for optimum Si24xx ISOmodem chipset implementation. There are three important considerations for any hardware design. First, the reference design and components listed in the associated bill of materials should be followed exactly. These designs reflect field experience with millions of deployed units throughout the world and are optimized for cost and performance.

  • Page 47: Ringer Network

    AN93 The second mode is a 32.768 kHz fundamental mode parallel-resonant crystal. Typical crystals require a 12.5 pF load capacitance. This load is calculated as the series combination of the capacitance from each crystal terminal to ground, including parasitic capacitance due to package pins and PCB traces. The parasitic capacitance is estimated as 7 pF per terminal.
  • Page 48 AN93 FROM LINE RING Figure 17. Billing-Tone Filter Table 42. Optional Billing Tone Filters Component Values Symbol Value C1,C2 0.027 µF, 50 V, ±10% 0.01 µF, 250 V, ±10% 3.3 mH, >120 mA, <10 , ±10% Coilcraft RFB0810-332 or equivalent 10 mH, >40 mA, <10 , ±10% Coilcraft RFB0810-103 or equivalent Rev.
  • Page 49 AN93 Rev. 1.4...

  • Page 50: Schematic

    AN93 4.2. Schematic Rev. 1.4...

  • Page 51: Bill Of Materials

    On Semi Notes: 1. C52 and C53 should not be populated with the Si2493 16-pin package option. 2. Several diode bridge configurations are acceptable. For example, a single DF04S or four 1N4004 diodes may be used. 3. Murata BLM18AG601SN1 may be substituted for R15–R16 (0 ) to decrease emissions.

  • Page 52: Layout Guidelines

    AN93 4.4. Layout Guidelines The key to a good layout is proper placement of the components. It is best to copy the placement shown in Figure 20. Alternatively, follow the following steps, referring to the schematics and Figure 21. It is strongly recommended to complete the checklist in Table 43 on page 54 while reviewing the final layout.
  • Page 53 AN93 8. After the previous step, there should be some space between the grouping around U2 and the grouping of components around the RJ11 jack. Place the rest of the components in this area, given the following guidelines: a.Space U2, Q4, Q5, R1, R3, R4, R10 and R11 away from each other for best thermal performance. b.The tightest layout can be achieved by grouping R6, C10, Q2, R3, R5, and Q1.

  • Page 54: Isomodem Layout Check List

    AN93 Traces, pad sites and vias enclosed in box are in the DAA U1 Si24HS section, and must be separated from all other circuits by 5 mm. XTALI XTALO VDD3.3 VDD3.3 VDDB VDDA R12* DCT2 IGND DCT3 R13* VREG VREG2 RNG1 RNG2 *Note: Do NOT use ferrite...
  • Page 55 AN93 Table 43. Layout Checklist (Continued) Layout Items Required Place R7 and R8 as close as possible to the RNG1 and RNG2 pins (pins 8 and 9), ensuring a minimum trace length from the RNG1 or RNG2 pin to the R7 or R8 resistor. In order to space the R7 component further from the trace from C2 to the C2B pin, it is acceptable to orient it 90 degrees relative to the RNG1 pin (pin 8).
  • Page 56 AN93 Table 43. Layout Checklist (Continued) Layout Items Required The trace from C3 to the D1/D2 node should be short and direct. Provide a minimum of 5 mm creepage (or use the capacitor terminal plating spacing as a guideline for small form factor applications) from any TNV component, pad or trace, to any SELV component, pad or trace.

  • Page 57: Module Design And Application Considerations

    AN93 4.4.2. Module Design and Application Considerations Modem modules are more susceptible to radiated fields and ESD discharges than modems routed directly on the motherboard because the module ground plane is discontinuous and elevated from the motherboard’s ground plane. This separation also creates the possibility of loops that couple interfering signals to the modem. Moreover, a poor motherboard layout can degrade the ESD and EMI performance of a well-designed module.

  • Page 58: Analog Output

    AN93 4.5. Analog Output The call progress tone provided by AOUT and discussed in this section comes from a PWM output pin on the ISOmodem. AOUT is a 50% duty cycle, 32 kHz square wave, pulse-width modulated (PWM) by voice band audio, such as call progress tones.

  • Page 59: Audio Quality

    AN93 4.5.2. Audio Quality The mulipole filter illustrated in this diagram is designed to shape the response for a pleasant sound and remove interference, but note that, when PWM is demodulated in this way, it carries all the audio spectrum noise that is present in the power supply of the modem minus 6 dB.
  • Page 60 AN93 Table 44. Power Dissipation (Continued) 176 mW 172 mW 166 mW 130 mW D1,D2 120m A x 0.8 V 56 mA x 0.75 V 96 mW each 42 mW each Other 257 mW (Si3018) 243 mW (Q1+Q2+Si3018) Total 1.498 W 2.077 W Rev.

  • Page 61: Modem Reference Guide

    AN93 5. Modem Reference Guide This section provides information about the architecture of the modem, its functional blocks, its registers, and their interactions. The AT command set is presented, and options are explained. The accessible memory locations (S registers and U registers) are described. Instructions for writing to and reading from them are discussed along with any limitations or special considerations.

  • Page 62: Dsp

    AN93 5.2. DSP The DSP (data pump) is primarily responsible for modulation, demodulation, equalization, and echo cancellation. Because the ISOmodem is controller-based, all interaction with the DSP is via the controller through AT commands, S registers, and/or U registers. 5.3. Memory The user-accessible memory in the ISOmodem includes the S registers, accessed via the ATSn command, and the U registers, accessed via the AT:Rhh and AT:Uhh commands.
  • Page 63 AN93 Table 46. Command Examples Command Result Comment E = 001 Configuration status of basic AT commands. M = 000 Q = 000 V = 001 X = 004 Y = 000 AT&$ &D = 001 Configuration of &AT commands. &G = 017 &H = 000 (Si2457)
  • Page 64 AN93 Table 48. Consecutive U-Register Writes on a Single Line Command Result AT:U00,0078,67EF,C4FA 0x0078 written to U00 0x67EF written to U01 0xC4FA written to U02 Caution: Some U-register addresses are reserved for internal use and hidden from the user. Consequently, there are gaps in the addresses of available U registers.
  • Page 65 B = Revision B, etc. Display Si24xx firmware revision code (numeric). Display line-side revision code. 18 (10)C = Si3018/10 Revision C. Display the ISOmodem model number. 2404 = Si2404 2415 = Si2415 2434 = Si2434 2457 = Si2457 2493 = Si2493 Rev. 1.4...
  • Page 66 AN93 Table 49. Basic AT Command Set (Continued) Command Action Diagnostic Results 1. Format RX <rx_rate>,TX <tx_rate> PROTOCOL: <protocol> LOCAL NAK <rre> REMOTE NAK <rte> RETRN/RR <rn> DISC REASON <dr> Diagnostic Results 2. Format RX LEVEL <rx_level> TX LEVEL <tx_level> EFFECTIVE S/N <esn>...
  • Page 67 AN93 Table 49. Basic AT Command Set (Continued) Command Action List contents of all S registers. Display contents of S-register n. Set S-register n to value x (n and x are decimal values). Sn=x Result code type (See Table 54) Numeric result codes.
  • Page 68 Program RAM write: this command is used to upload firmware supplied by Silicon Labs to the ISOmodem. The format for this command is AT:Phhhh,xxxx,yyyy,..where hhhh is the first address in hexadecimal, and xxxx,yyyy,..is data in hexadecimal. Only one :P command is allowed per AT command line.
  • Page 69 AN93 Table 49. Basic AT Command Set (Continued) Command Action Special Access Mode—This command enables special modes and data memory access. [sequence] Description 254:Waaaa,dddd Write hexadecimal data value dddd to hexadeci- mal data address aaaa. Only one 254:W command per line. 254:Qaaaa Read hexadecimal address aaaa.
  • Page 70 Max_string_tx 32 to 255 Max_string_rx 32 to 255 Max_history_tx  512 Max_history_rx  512 *Note: Si2493 only Enable synchronous access mode A – specifies the mode of operation when initiating a modem con- nection D = Disable synchronous access mode 6 = Enable synchronous access mode when connection is com- pleted and data state is entered.
  • Page 71 AN93 Table 49. Basic AT Command Set (Continued) Command Action Synchronous access mode control options A – Specifies action taken if an underrun condition occurs during transparent sub-mode 0 = Modem transmits 8-bit SYN sequences (see +ESA[G]) on idle. B – Specifies action taken if an underrun condition occurs after a flag during framed sub-mode 0 = Modem transmits 8-bit HDLC flags on idle.
  • Page 72 AN93 Table 49. Basic AT Command Set (Continued) Command Action Class 1 Transmit Carrier. Mode Transmit V.21 (980 Hz) tone and detect (2100/2225 Hz). Stop transmit 980 Hz when (2100/2225 Hz is detected. Same as &T4, but transmit V.29 7200 bps. Data pattern set by S40 register.
  • Page 73 AN93 Table 49. Basic AT Command Set (Continued) Command Action Country settings: Automatically configure all registers for a particular country. Country Australia Austria Belgium Brazil Bulgaria Canada China Columbia Czech Republic Denmark Ecuador Finland France Germany Greece Hong Kong Hungary India Ireland Israel...
  • Page 74 AN93 Table 49. Basic AT Command Set (Continued) Command Action List current country code setting (response is: + GCI:<setting>) +GCI? List all possible country code settings. +GCI = ? Specifies the flow control to be implemented. Specifies the flow control method used by the host to control data from the modem 0 None +IFC Options...
  • Page 75 AN93 Table 49. Basic AT Command Set (Continued) Command Action Transmit Flow Control Thresholds. +ITF = <high>, <high> Threshold above which the modem will generate a flow <low>, off signal. The parameter's unit is a byte. The valid range is 0-1023. The <report_period>...
  • Page 76 ITU-T V.22bis (default for Si2404) ITU-T V.32 V32B ITU-T V.32bis (default for Si2415) ITU-T V.34 (default for Si2434) ITU-T V.90 (default for Si2457) ITU-T V.92 (default for Si2493) +MS Options Automatic modulation negotiation +MS = A Disabled +MS = A,B...
  • Page 77 AN93 Table 49. Basic AT Command Set (Continued) Command Action Initiate MOH. Requests the DCE to initiate or to confirm a MOH proce- dure. Valid only if MOH is enabled. Mode V.92 MOH request denied or not available. MOH with 10 s timeout granted. MOH with 20 s timeout granted.
  • Page 78 AN93 Table 49. Basic AT Command Set (Continued) Command Action Selection of full or short startup procedures. Mode The DCEs decide to use short startup procedures. +PSS=X Forces the use of short startup procedures on next and subse- quent connections. Forces the use of full startup procedures on next and subsequent connections.
  • Page 79 AN93 Table 49. Basic AT Command Set (Continued) Command Action +VIP Load Voice Factory Defaults. DTE/DCE Inactivity Timer. +VIT The <timer> parameter has a range of 0–255 with units of seconds. The default is 0 (disable). +VLS = n Analog Source / Destination Select. Description ISOmodem on-hook.
  • Page 80 AN93 Table 49. Basic AT Command Set (Continued) Command Action +VRN = n Ringing Tone Never Appeared Timer. This command sets the amount of time in seconds the ISOmodem will wait looking for Ringing Tone. If the ISOmodem does not detect Ringing Tone in this time period, the ISOmodem shall assume that the remote station has gone off-hook and return an OK result code.
  • Page 81 AN93 Table 49. Basic AT Command Set (Continued) Command Action +VTD = n DTMF / Tone Duration Timer. This command sets the default DTMF / tone generation duration in 10 ms units for the +VTS command. Default time is 1 second (n = 100).
  • Page 82 AN93 Table 50. Basic ATI Command Set AT Command Si2493/57/34/15/04 Si2494/39 Patch Chip Revision D/D1 A/A1 ATI0 None ATI1 ATI0 Revision B (rb_pX_YYYY) ATI1 ATI0 Revision C (rc_pX_YYYY) ATI1 ATI0 Revision D/D1 (rd_pX_YYYY) ATI1 ATI0 Revision A/A1 (ra_pX_YYYY) ATI1 Note: Gray cell = not allowed.

  • Page 83: Extended At Commands

    AN93 5.5. Extended AT Commands The extended AT commands, described in Tables 51–53, are supported by the ISOmodem. Table 51. Extended AT& Command Set Command Action &$ Display AT& current settings (see text for details). &Dn Escape pin function (similar to DTR) &D0 Escape pin is not used.
  • Page 84 Bell 103 only (300 bps) &H10 ITU-T V.21 only (300 bps) &H11 V.23 (1200/75 bps) &H12 V.92 with automatic fallback (default for Si2493) &Pn Japan pulse dialing* &P0 Configure ISOmodem for 10 pulse-per-second pulse dialing &P1 Configure ISOmodem for 20 pulse-per-second pulse dialing (Japan) &Tn...
  • Page 85 AN93 Table 51. Extended AT& Command Set (Continued) Built-in modem self-test. This test checks the RAM and calculates ROM CRC. If the RAM check fails, it will display the offending RAM address, and return ERROR. If the RAM check passes, it will &T7 display the ROM CRC and return OK.
  • Page 86 AN93 Table 52. Extended AT% Command Set Command Action Display AT% command settings (see text for details). Report blacklist. See also S42 register. Data compression. Disable V.42bis and MNP5 data compression. Enable V.42bis in transmit and receive paths. If MNP is selected (\N2), %C1 enables MNP5 in transmit and receive paths. Enable V.42bis in transmit path only.
  • Page 87 AN93 Table 52. Extended AT% Command Set (Continued) Automatic Line Status Detection - Adaptive Method. Description: Before going off-hook with the ATD, ATO, or ATA commands, the ISOmodem compares the line voltage (via LVCS) to the NLIU (U85) register: Loop Voltage Action 0 ...
  • Page 88 AN93 Table 53. Extended AT\ Command Set (Continued) Command Action Wire mode (no error correction, no compression). MNP reliable mode. The ISOmodem attempts to connect with the MNP protocol. If unsuccessful, the call is dropped. Compression is controlled by %Cn. V.42 auto-reliable—The ISOmodem attempts to connect with the V.42 protocol.
  • Page 89 AN93 Table 53. Extended AT\ Command Set (Continued) Command Action 2400 bps 4800 bps 7200 bps 9600 bps 12.0 kbps 14.4 kbps. 19.2 kbps \T10 38.4 kbps \T11 57.6 kbps \T12 115.2 kbps \T13 230.4 kbps \T14 245.760 kbps \T15 307.200 kbps \T16 Autobaud On...
  • Page 90 AN93 Table 53. Extended AT\ Command Set (Continued) Command Action Report connect message only (exclude protocol message). Report connect and protocol message with both upstream and downstream connect rates. Notes: 1. When in autobaud mode, \B0, \B1, and \P1 is not detected automatically. The combination of \B2 and \P3 is detected. This is compatible with seven data bits, no parity, two stop bits.
  • Page 91 Signal detected Notes: 1. Numeric mode: Result code <CR>. 2. This message is supported only on the Si2493, Si2457, Si2434, and Si2415. 3. This message is supported only on the Si2493, Si2457, and Si2434. 4. X is not preceded by <CR><LF>.
  • Page 92 ALTERNATE, +CLASS 3 Notes: 1. Numeric mode: Result code <CR>. 2. This message is supported only on the Si2493, Si2457, Si2434, and Si2415. 3. This message is supported only on the Si2493, Si2457, and Si2434. 4. X is not preceded by <CR><LF>.
  • Page 93 Notes: 1. Numeric mode: Result code <CR>. 2. This message is supported only on the Si2493, Si2457, Si2434, and Si2415. 3. This message is supported only on the Si2493, Si2457, and Si2434. 4. X is not preceded by <CR><LF>.
  • Page 94 AN93 Table 55. Disconnect Codes Disconnect Code Reason 8002 Handshake stalled. No dial tone detected. 8008 No line available. No loop current detected. 8009 Parallel phone pickup disconnect. No ringback. Busy signal detected. V.42 requested disconnect. MNP requested disconnect. Drop-dead timer disconnect. 8014 Loop-current loss.

  • Page 95: S Registers

    AN93 5.6. S Registers S registers are typically used to set modem configuration parameters during initialization and are not usually changed during normal modem operation. S-register values other than defaults must be written via the ATSn=x command after every reset event. S registers are specified as a decimal value (S1 for example), and the contents of the register are also decimal numbers.
  • Page 96 AN93 Table 56. S-Register Descriptions (Continued) Definition S Register Function Default Range Units (Decimal) (Decimal) Carrier loss timer—The time a remote modem carrier 1–255 0.1 second must be lost before the ISOmodem disconnects. Set- ting this timer to 255 disables the timer, and the modem does not time out and disconnect.
  • Page 97 AN93 Table 56. S-Register Descriptions (Continued) Definition S Register Function Default Range Units (Decimal) (Decimal) V.34 symbol rate - Symbol rate for V.34 when using 0–5 – the &T4 and &T5 commands. 0 – 2400 symbols/second 1 – 2743 symbols/second 2 –...

  • Page 98: U Registers

    AN93 5.7. U Registers U registers (user-access registers) are 16-bit registers written by the AT:Uhh command and read by the AT:R (read all U registers) command or AT:Rhh (read U-register hh) command. See the AT command list in Table 49 on page 64.
  • Page 99 AN93 Table 57. U-Register Descriptions (Continued) Register Name Description Default Value DT4A0 Dial-tone detection filter stage 4 biquad coefficients. 0x0400 DT4B1 0x70D2 DT4B2 0xC830 DT4A2 0x4000 DT4A1 0x80E2 Dial-tone detection filter output scaler. 0x0009 DTON Dial-tone detection ON threshold. 0x00A0 DTOF Dial-tone detection OFF threshold.
  • Page 100 AN93 Table 57. U-Register Descriptions (Continued) Register Name Description Default Value BMTT Busy cadence minimum total time in seconds multiplied by 7200. 0x0870 BDLT Busy cadence delta in seconds multiplied by 7200. 0x25F8 BMOT Busy cadence minimum on time in seconds multiplied by 7200. 0x0438 RMTT Ringback cadence minimum total time in seconds multiplied by 7200.
  • Page 101 AN93 Table 57. U-Register Descriptions (Continued) Register Name Description Default Value Flash hook time—(ms units). 0x01F4 LCDN Loop current debounce on time (ms units). 0x015E LCDF Loop current debounce off time (ms units). 0x00C8 XMTL Transmit level adjust (1 dB units) 0x0000 MOD2 This is a bit-mapped register.
  • Page 102 AN93 Table 57. U-Register Descriptions (Continued) Register Name Description Default Value NLIU Line-in-use/No-line threshold. If %V2 is set, NLIU sets the threshold refer- 0x0000 ence for the adaptive algorithm (see %V2). 3 V/bit when LLP (UAD [4] = 1 (default); 1 V/bit when LLP = 0. V9AGG V.90 rate reduction in 1333 bps units.

  • Page 103: U-Register Summary

    AN93 5.7.1. U-Register Summary Table 58. Bit-Mapped U-Register Summary Register Name Bit 14 Bit 13 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MOD1 TOCT NHFP NHFD CLPD SPDM GT18 GT55...

  • Page 104: U00-U16 (Dial Tone Detect Filter Registers)

    AN93 5.7.2. U00–U16 (Dial Tone Detect Filter Registers) U00–U13 set the biquad filter coefficients for stages 1–4 of the dial-tone detection filter. U14, U15, and U16 set the dial-tone detection output scaler, on threshold and off threshold, respectively. The thresholds are empirically found scalars and have no units. These coefficients are programmed as 16-bit, two’s complement values.

  • Page 105: U17-U30 (Busy Tone Detect Filter Registers)

    AN93 5.7.3. U17–U30 (Busy Tone Detect Filter Registers) U17–U2A set the biquad filter coefficients for stages 1–4 of the busy-tone detection filter, and U2B, U2C, and U2D set the busy-tone detection output scalar on threshold and off threshold, respectively (see Table 60). The thresholds are empirically found scalars and have no units.
  • Page 106 AN93 Table 61. BPF Biquad Values BPF Biquad Stage 1 Stage 2 Stage 3 Stage 4 Output Scalar Values 310/510 (Default Busy and Dial Tone) 0x0800 0x00A0 0x00A0 0x0400 — 0x0000 0x6EF1 0x78B0 0x70D2 — 0x0000 0xC4F4 0xC305 0xC830 — 0x0000 0xC000 0x4000...
  • Page 107 AN93 Table 61. BPF Biquad Values (Continued) BPF Biquad Stage 1 Stage 2 Stage 3 Stage 4 Output Scalar Values — — — — 0x0005 400/440 0x0020 0x0200 0x0400 0x0040 — 0x7448 0x7802 0x73D5 0x75A7 — 0xC0F6 0xC0CB 0xC2A4 0xC26B —...

  • Page 108: U31-U33 (Ringback Cadence Registers)

    AN93 5.7.4. U31–U33 (Ringback Cadence Registers) U31, U32, and U33 set the ringback cadence minimum total time (RMTT), ringback cadence delta time (RDLT), and ringback cadence minimum on time (RMOT) (see Table 62). Country-specific settings for ringback cadences are specified as a range for “on” time (minimum “on” and maximum “on”) and a range for “off” time (minimum “off” and maximum “off”).

  • Page 109: U46-U48 (Dtmf Dial Registers)

    AN93 Table 64. Pulse Dial Registers Register Name Description Default Number of pulses to dial 0. 0x000A Number of pulses to dial 1. 0x0001 Number of pulses to dial 2. 0x0002 Number of pulses to dial 3. 0x0003 Number of pulses to dial 4. 0x0004 Number of pulses to dial 5.

  • Page 110: U49-U4C (Ring Detect Registers)

    AN93 5.7.8. U49–U4C (Ring Detect Registers) U49, U4A, U4B, and U4C set a representation of the maximum ring frequency, the difference between the highest and lowest valid ring frequency, minimum ring “on” time, and maximum ring cadence time (time on plus time off), respectively.
  • Page 111 AN93 Table 67. Register U4D Bit Map Name Function Reserved Read returns zero. TOCT Turn Off Calling Tone. 0 = Disable. 1 = Enable. Reserved Read returns zero. NHFP No Hook-Flash Pulse. 0 = Disable. 1 = Enable. NHFD No Hook-Flash Dial. 0 = Disable.

  • Page 112: U4E (Pre-Dial Delay Time Register)

    AN93 5.7.10. U4E (Pre-Dial Delay Time Register) U4E sets the delay time between the ATD command carriage return and when the modem goes off-hook and starts dialing (either tone or pulse—see Table 68). This delay establishes the minimum time the modem must be on-hook prior to going off-hook and dialing.

  • Page 113: U53 (Modem Control Register 2)

    AN93 Table 71. Transmit Level Register Register Name Description Default XMTL Transmit level adjust (–1 dB units). 0x0000 5.7.14. U53 (Modem Control Register 2) U53 (MOD2) is a bit-mapped register with all bits, except bit 15, reserved (see Table 72). The AT&H11 command sets the V.23 1200/75 bps mode.
  • Page 114 AN93 Table 74. U62 Bit Map (Continued) OHS2 On-Hook Speed 2 This bit, in combination with the OHS bit and the SQ[1:0] bits on-hook speeds specified are measured from the time the OH bit is cleared until loop current equals zero. OHS2 SQ[1:0] Mean On-Hook Speed...

  • Page 115: U67-U6A (International Configuration Registers)

    AN93 Table 76. U65 Bit Map Name Function Reserved Read returns zero. PWMG PWM gain. 0 = No gain. 1 = 6 dB gain applied to AOUT. Power Down. 0 = Normal. 1 = Power Down. 12:7 Reserved Read returns zero. Reserved Do not change (use read-modify-write).
  • Page 116 AN93 When DCR = 1, the device presents a dc line impedance of 800 ,which can be used to enhance operation with a parallel phone, for improved low line voltage performance, and for overload. This bit must be set to 0 when the modem is on-hook.
  • Page 117 AN93 Table 77. U66 Bit Map Name Function 15:7 Reserved Read returns zero. Frame Detect. 0 = ISOcap frame lock not established 1 = ISOcap frame lock established Reserved Read returns zero. Table 78. U67 Bit Map* Name Function 15:14 Reserved Read returns zero. 13:12 MINI[1:0] Minimum Operational Loop Current.
  • Page 118 AN93 Table 78. U67 Bit Map* (Continued) Name Function Ringer Threshold Select. Used to satisfy country requirements on ring detection. Signals below the lower level do not generate a ring detection; signals above the upper level are guaranteed to generate a ring detection.

  • Page 119: U6C (Line-Voltage Status Register)

    AN93 Table 80. U6A Bit Map* Name Function Reserved Read returns zero. Spark quenching. See OHS2. Reserved Read returns zero. Spark quenching. See OHS2. 11:3 Reserved Read returns zero. Overload Detected. This bit has the same function as ROV, but clears itself after the overload has been removed. This bit is only masked by the off-hook counter and is not affected by the BTE bit.
  • Page 120 AN93 Table 82. U6E Bit Map Name Function 15:13 Reserved Do not modify. 12:8 CLKOUT Divider (Default = 11111b) Reserved Read returns 101b. Do not modify. Hardware Reset 0 = Normal operation. 1 = Device will perform hardware reset. All registers will return to default settings. Reserved Read returns 0.
  • Page 121 AN93 Table 84. U70 Bit Map Name Function Enable Hardware Escape Pin. 0 = Disable. 1 = Enable. Reserved Read returns zero. Enable Escape (+++). 0 = Disable. 1 = Enable. CIDM Caller ID Mask. 0 = Change in CID does not affect INT. 1 = CID low-to-high transition triggers INT.
  • Page 122 AN93 U71 IO1 D14 D13 D12 D11 D10 Name COMP Type Reset settings = 0x0000 Name Function 15:5 Reserved Read returns zero. COMP 0 – Disables compression (PCM mode). 1 – Enables linear compression. Reserved 0 – Disables PCM mode. 1 –...
  • Page 123 AN93 Table 85. U76 Bit Map Name Function 15:9 OHSR Off-Hook Sample Rate for Intrusion Detection (40 ms units). (1 second default) FACL Force ACL. 0 = While off-hook, ACL is automatically updated with LVCS value. 1 = While off-hook, ACL saves previously written value. Differential Current Level (3 mA units, 6 mA default) Absolute Current Level (3 mA units, 0 mA default) U77 is a bit-mapped register that controls parameters relating to intrusion detection and overcurrent detection.
  • Page 124 AN93 A O C = 1 O P E = 0 C o un te r : N = U 1 D D O FF HO O K W a i t ( O H T) O P E = 1 Ti m er T1 = 2 5 0 m s N = 0 ? O N H O O K...
  • Page 125 AN93 Bits 8:0 (OHT) set the delay between the time the modem goes off-hook and LVCS or LCS is read for an overcurrent condition. The default value for this register is 30 ms (see Table 86). U78 is a bit-mapped register that controls intrusion detection blocking and intrusion suspend. U78 resets to 0x0000 with a power-on or manual reset (see Table 87).
  • Page 126 AN93 Table 88. Monitor Mode Values On-Hook Voltage Monitor Mode Off-Hook Current Monitor Mode 00000 = No line connected. 00000 = No loop current. 00001 = Minimum line voltage (VMIN = 2.5 V ±0.5 V). 00001 = Minimum loop current. 11111 = Maximum line voltage (87 V ±20%) 11110 = Maximum loop current.
  • Page 127 AN93 Table 90. U7A Bit Map (Continued) Name Function V29EM Use EM shielding to change direction of half duplex V.29FC. 0 = EM shielding 1) <EM><rrn>=<0x19><0xBC> to receive a V29FC packet. 2) <EM><rtn>=<0x19><0xBD> to send a V29FC packet. 1 = RTS pin toggle. Reserved Read returns zero.
  • Page 128 AN93 Bit 12 (TCAL) = 0 (default) when set to 1 forces the DAA to calibrate at a programmable time after going off-hook. The time between going off-hook and the start of calibration is programmed with U54 [15:8] in 32 ms units. Bit 11 (OHCT) = 0 (default) when set to 1 forces the DAA to calibrate at the start of dialing.

  • Page 129: U80 (Transmit Delay For V.22 Fast Connect)

    AN93 5.7.20. U80 (Transmit Delay for V.22 Fast Connect) U80 controls delay parameters when the modem is in V.22 Fast Connect mode (+MS=V22, AT:U7A,3) and the server does not respond with a short answer tone prior to scrambled data or HDLC flags. U80 configures the modem to operate without these tones.

  • Page 130: U87 (Synchronous Access Mode Configuration Register)

    AN93 5.7.21. U87 (Synchronous Access Mode Configuration Register) U87 SAM Synchronous Access Mode Configuration Options Name Function 15:11 Reserved Read returns zero. MINT Minimal Transparency Host software must always set this bit. 0 = Generate two-byte <EM> transparency sequences. This option will use codes <EM><T5>...

  • Page 131: Uaa (V.29 Mode Register)

    AN93 5.7.22. UAA (V.29 Mode Register) UAA V.29 MODE Name Function 15:3 Reserved Read returns zero. RUDE 0 = Disables rude disconnect. 1 = Enables rude disconnect. V29ENA 0 = Disables V.29. 1 = Enables V.29. Reserved Read returns zero. UAD is a bit mapped register that defaults to 0x0000.
  • Page 132 AN93 UAE is a bit-mapped register that sets the parameters for the enhanced intrusion detection algorithm. In general, an intrusion is declared when the measured current is less than ACLM by an amount that is more than DCLM. UAE resets to 0x0000 with a power-on or manual reset. The enhanced intrusion algorithm is enabled by setting AEM = 1 and initializing DCLM with a positive number.

  • Page 133: Firmware Upgrades

    Additionally, the ISOmodem contains on-chip program RAM to accommodate minor changes to ROM firmware. This allows Silicon Labs to provide future firmware updates to optimize the characteristics of new modem designs and those already deployed in the field.

  • Page 134: Escape Methods

    AN93 Table 96. Load Technique and Speed Table* Start Condition Delay Load time, 6235-Byte Approach Used With Between Patch, 115 kbaud UART Lines Reset, then 0.5 ms 0.694 Embedded systems ATE0 and ATQ1 1 ms 0.771 Embedded systems 2 ms 0.925 Embedded systems 5 ms...

  • Page 135: 9Th Bit" Escape

    AN93 Leading Guard Trailing Guard Tim e Tim e Guard Tim e = S12 (20 m sec units) Default Guard Tim e S12 = 50 (1.0 sec) Guard Tim e Range = 10–255 (0.2–5.1 sec) Figure 29. +++ Escape Timing 5.9.2.

  • Page 136: Data Compression

    No data compression and \N0 and %C0 no error correction *Note: V.44 is available only on Si2493. 5.11. Error Correction The ISOmodem can employ error correction (reliable) protocols to ensure error-free delivery of data sent between two modems. The error control methods are based on grouping data into frames with checksums determined by the contents of each frame.

  • Page 137: Epos (Electronic Point Of Sale) Applications

    This delay can be important for some NAC servers. 5.13.2. EPOS V.29 Fast Connect In addition to the low modulation speed fast-connect modes, the modem (only Si2493/57/34/15 and Si2494/39) also supports a fast-connect mode based on the 9600 bps V.29 fax modulation standard.

  • Page 138: Mode

    AN93 5.15. V.80 Mode As shown in Table 99, the synchronous access mode is chosen by using the AT+ES=6,,8 command setting. When using the synchronous access mode, it is expected that the AT\N0 command will be used to disable all other error correction protocols that may interfere with V.80 synchronous access mode operation.
  • Page 139 AN93 Table 100. EM In-Band Commands and Statuses Supported Supported Command– Transmit Direction Receive Direction in Framed Indicator pair Code Transparent Submode Submode <EM><t1> 0x5C Transmit one 0x19 byte Received one 0x19 byte <EM><t2> 0x76 Transmit one 0x99 byte Received one 0x99 byte <EM><t3>...
  • Page 140 AN93 Table 100. EM In-Band Commands and Statuses (Continued) Supported Supported Command– Transmit Direction Receive Direction in Framed Indicator pair Code Transparent Submode Submode Detected a non-flag to flag transition. <EM><err> 0xB2 Transmit an Abort Preceding data are not a valid frame.
  • Page 141 AN93 Table 100. EM In-Band Commands and Statuses (Continued) Supported Supported Command– Transmit Direction Receive Direction in Framed Indicator pair Code Transparent Submode Submode Retrain/Rate Reneg com- pleted, following octets <tx><rx> indicate tx and rx rates. 0x20–1200 bps 0x21–2400 bps 0x22–4800 bps 0x23–7200 bps 0x24–9600 bps...
  • Page 142 AN93 Given the example initialization settings shown in Table 101, after an ATDT command has been sent to establish a connection, the modem responds with the following: ATDT12345 CONNECT 1200 PROTOCOL: NONE <0x19> <0xBE> <0x20> <0x20> <0x19> <0xB1> The first <EM><rate> indicator shows that the modem connected with a transmit rate of 1200 bps and a receive rate of 1200 bps.
  • Page 143 In the receive direction, assuming that the remote modem is another Si2493/57/34/15, this is the expected sequence at the remote receiver DTE, representing the frame sequence of: <0x10><0x11><0x12><0x13><0x14><0x15>...

  • Page 144: Programming Examples

    AN93 6. Programming Examples The following programming examples are intended to facilitate the evaluation of various modem features and serve as example command strings that can be used singly or in combination to create the desired modem operation. 6.1. Quick Reference Table 102 summarizes the modem function/feature and the associated hardware pins, AT commands, S registers, and U registers.

  • Page 145: Country-Dependent Setup

    +DS44, +DR V.92 +PIG *Note: Si2493 only. 6.2. Country-Dependent Setup Configuring the ISOmodem for operation in different countries is done easily with AT commands. In all but rare instances, no hardware change is required (the exceptions being an optional maximum ringer impedance, a billing- tone filter, etc.).

  • Page 146: Country Configuration

    AN93 6.2.2. Country Configuration The modem default settings are for the US-like countries. Many countries use at least some of the default register settings. Default values do not have to be written when configuring the modem to operate in a particular country, assuming the modem was reset just prior to the configuration process.
  • Page 147 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=A AT:U14,7 AT:U35,10E0 AT:U46,9B0 Austria AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 Bahamas Defaults AT+GCI=2E AT:U35,10E0 Bahrain* AT:U46,9B0 AT:U62,904 Belarus* AT+GCI=73 AT+GCI=F AT:U14,7 AT:U35,10E0 AT:U46,9B0 Belgium AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 Bermuda Defaults AT+GCI=16 Brazil AT:U67,8...
  • Page 148 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=26 China AT:U67,8 Colombia AT+GCI=27 Costa Rica Defaults AT+GCI=2E AT:U35,10E0 Croatia* AT:U46,9B0 AT:U62,904 AT+GCI=2E AT:U35,10E0 Cyprus* AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=2E AT:U35,10E0 Czech Republic AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=31 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Denmark AT:U4F,64 AT:U52,2 AT:U62,904...
  • Page 149 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=2E AT:U35,10E0 Estonia* AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=3C AT:U14,7 AT:U35,10E0 AT:U46,9B0 Finland AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 AT+GCI=3D AT:U14,7 AT:U35,10E0 AT:U46,9B0 France AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 AT+GCI=1B French Polynesia* AT:U62,904 Georgia* AT+GCI=73 AT+GCI=42 AT:U14,7...
  • Page 150 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=46 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Greece AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 AT+GCI=1B Guadeloupe* AT:U62,904 AT:U67,8 Guam Defaults Hong Kong AT+GCI = 50 AT+GCI=51 Hungary AT:U35,10E0 AT:U62,904,33 AT+GCI=2E Iceland* AT:U62,904 AT+GCI=53 India AT:U63,3 AT:U67,8 Indonesia Defaults...
  • Page 151 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=59 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Italy AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 Japan AT+GCI=0 AT+GCI=16 Jordan* AT:U49,22,7A Kazakhstan* AT+GCI=73 AT+GCI=61 Korea (South) AT:U67,A Kuwait Defaults Kyrgyzstan* AT+GCI = 73 AT+GCI=1B AT:U35,10E0 Latvia* AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=2E...
  • Page 152 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=69 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Luxembourg AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 Macao Defaults AT+GCI=6C Malaysia AT:U46,A80 AT+GCI=2E AT:U35,10E0 Malta* AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=1B AT:U62,904 Martinique* AT:U67,8 ATS007=50 Mexico AT+GCI=73 Moldova* AT+GCI=73 AT+GCI=2E AT:U35,10E0 Morocco* AT:U46,9B0...
  • Page 153 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=7E AT:U38,9,8,7,6 AT:U3D,4,3,2,1 New Zealand AT:U46,8A0 AT:U52,2 AT:U67,8 AT+GCI=1B Nigeria* AT:U62,904 AT+GCI=82 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Norway AT:U4F,64 AT:U52,2 AT:U62,904 ATS006=3 Oman* AT+GCI=89 AT+GCI=89 Pakistan* AT:U46,8A0 Paraguay AT+GCI=87 Peru Defaults Philippines AT+GCI=89 AT+GCI=8A AT:U14,7 AT:U52,2...
  • Page 154 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=16 Qatar* AT:U49,22,7A AT+GCI=1B Reunion* AT:U62,904 AT:U67,8 AT+GCI=73 Romania* AT:U62,904,33 AT+GCI=B8 AT:U67,4 Russia AT:U62,0080 AT:U69,0D86 AT:U46,0690 Saudi Arabia Defaults Singapore AT+GCI=9C AT+GCI=73 AT:U35,10E0 Slovakia* AT:U47,5A,5A AT:U62,904,33 AT+GCI=2E AT:U35,10E0 Slovenia* AT:U46,9B0 AT:U62,904 AT:U67,8 AT+GCI=9F AT:U63,33...
  • Page 155 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=A5 AT:U14,7 AT:U35,10E0 AT:U37,1,2,3,4,5,6,7,8,9,A AT:U46,9B0 Sweden AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 AT+GCI=A6 AT:U14,7 AT:U35,10E0 AT:U46,9B0 Switzerland AT:U4F,64 AT:U52,2 AT:U62,904 ATS006=3 AT+GCI=16 Syria* AT:U49,22,7A AT+GCI=FE Taiwan AT:U67,8 AT+GCI=6C Thailand* AT:U46,240 AT:U67,4 AT+GCI=51 AT:U46,680 Tunisia* AT:U52,1...
  • Page 156 AN93 Table 104. Country Initialization Table (Continued) Country Initialization AT+GCI=B4 AT:U14,7 AT:U35,10E0 AT:U46,9B0 United Kingdom AT:U4F,64 AT:U52,2 AT:U62,904 AT:U67,8 ATS006=3 Uruguay Defaults Uzbekistan Defaults Venezuela Defaults Yemen Defaults AT+GCI=2E AT:U35,10E0 Zambia* AT:U46,9B0 AT:U62,904 *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut.

  • Page 157: Country-Setting Register Tables

    AN93 6.2.2.2. Country-Setting Register Tables Table 105. International Call Progress Registers Register Value Function Dial Tone Control U0–U14 Dial Tone Detect Filter Coefficients DTON Dial Tone On Threshold DTOF Dial Tone Off Threshold DTWD Dial Tone Detect Window DMOT Dial Tone Minimum On Time Busy Tone Control U17–U2B Busy Tone Detect Filter Coeffi-...

  • Page 158: Special Requirements For Serbia And Montenegro

    AN93 Table 106. Dial Registers Register Value Function Pulse Dial Control U37–U40 Pulse per Digit Definition PDBT Pulse Dial Break Time PDMT Pulse Dial Make Time PDIT Pulse Dial Interdigit Time DTMF Control DTPL DTMF Power Level (and Twist) DTNT DTMF On Time DTFT DTMF Off Time...

  • Page 159: Blacklisting

    AN93  Out-of-band energy: not specified  Pulse Dial: 1.6/1 ±15 % (pulse/pause) Rep Rate: 10 pps  Interdial Pause: 250 ms <x> 800 ms, ±10 %   Ring signal: 25 Hz 80–90 V  Dial Tone: 425 Hz ±15 % Level: –8 dBm >...

  • Page 160: Force Caller Id Monitor (Always On)

    6.3.5. DTMF Caller ID DTMF Caller ID is supported in the Si2493/57/34/15/04 Revision D or above and Si2494/39 Revision A or above. DTMF Caller ID detection is needed to provide complete CID support for Brazil, China and other countries. The ISOmodem detects the preamble and start code (0x41, or ASCII 'A'), then echoes CIDM to the host.

  • Page 161: Sms Support

    AN93 ISOmodem assembles the rest of the characters in the message and sends them to the host. It detects the stop code (0x44, or ASCII 'D') and proceeds with the rest of the call processing. For ISOmodems that support voice mode, detection of DTMF CID is done automatically in +FCLASS = 8 mode after being enabled by a “+VLS = 14”...
  • Page 162 AN93 To enable the SMS features on the ISOmodem, the host must send AT+FCLASS = 256 to the modem prior to handling an SMS call. The host can then dial or answer an SMS call using ATDTxxxx; (where xxxx is the number to be dialed), or ATDT;...

  • Page 163: Type Ii Caller Id/Sas Detection

    AN93 6.5. Type II Caller ID/SAS Detection When a call is in progress, the Subscriber Alerting Signal (SAS) tone is sent by the central office to indicate a second incoming call. The central office may also issue a CPE Alert Signal (CAS) after the SAS to indicate that call waiting Caller ID (CWCID) information is available.
  • Page 164 AN93 The even-numbered registers, (UA0, UA2, etc.), control the amount of time the tone is expected to be present, and the odd-numbered registers select the amount of time the tone must not be present. The values are expressed in 10 millisecond units. For example, a cadence of on 500 ms, off 300 ms then on for 500 ms may be selected by writing 0x0032 to UA0, 0x001E to UA1 and 0x0032 to UA2.
  • Page 165 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0003 UA0 = 0x0014 Call Waiting Aruba 0.2 – 0.2 – 0.2 – 4.4 UA1 = 0x0014 Tone UA2 = 0x0014 UA3 = 0x01B8 U9F = 0x0003 UA0 = 0x0014...
  • Page 166 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0005 China Waiting Tone 0.4 – 4.0 UA0 = 0x0028 UA1 = 0x0190 U9F = 0x0003 Call Waiting Croatia 0.3 – 8.0 UA0 = 0x001E Tone UA1 = 0x0320...
  • Page 167 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0001 Gibraltar Waiting Tone 0.1 – 3.0 UA0 = 0x000A UA1 = 0x012C U9F = 0x0003 UA0 = 0x001E Call Waiting Greece 0.3 –...
  • Page 168 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0001 Call Waiting UA0 = 0x000F Israel 1x(0.15 – 10.0 – 0.15) Tone UA1 = 0x03E8 UA2 = 0x000F U9F = 0x0001 UA0 = 0x0032 UA1 = 0x0000 to 0x0190 UA2 = 0x0005...
  • Page 169 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0003 UA0 = 0x000A Kiribati Waiting Tone 0.1 – 0.2 – 0.1 – 4.7 UA1 = 0x0014 UA2 = 0x000A UA3 = 0x01D6 U9F = 0x000 UA0 = 0x0019 Korea (Republic Of)
  • Page 170 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0001 UA0 = 0x0019 Waiting Tone Ii 0.25 – 0.25 – 0.25 – 3.25 UA1 = 0x0019 UA2 = 0x0019 UA3 = 0x0145 U9F = 0x0008 UA0 = 0x0014 UA1 = 0x012C...
  • Page 171 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers Russia Waiting Tone 950/1400/1800 3×0.333 – 1.0 U9F = 0x0007 U9F = 0x0000 UA0 = 0x0032 St.-Kitts-and-Nevis Waiting Tone 0.5 – 10.0 – 0.5 UA1 = 0x03E8 UA2 = 0x0032 U9F = 0x0003...
  • Page 172 AN93 Table 115. SAS Cadence for Supported Countries* (Continued) Country Tone Frequency (Hz) Cadence (seconds) U Registers U9F = 0x0003 Call Waiting UA0 = 0x0014 Sweden 0.2 – 0.5 – 0.2 Tone I UA1 = 0x0032 UA2 = 0x0014 U9F = 0x0007 Call Waiting Tajikistan 950/1400/1800...

  • Page 173: Intrusion/Parallel Phone Detection

    AN93 6.6. Intrusion/Parallel Phone Detection The modem may share a telephone line with a variety of other devices, especially telephones. In most cases, the modem has a lower priority for access to the phone line. Someone dialing 911 in an emergency, for example, has a higher priority than a set-top box updating billing information.

  • Page 174: Line Not Present/In Use Indication (Method 2-Adaptive)

    AN93 6.6.1.2. Line Not Present/In Use Indication (Method 2—Adaptive) This method is enabled through %V2. This feature checks the line status before going off-hook and again before dialing. While on-hook, the part monitors line voltage and updates U85 (5 (NLIU) [15:0] with this value. Before going off-hook with the ATD, ATO, or ATA command, the ISOmodem reads the line voltage and compares it with the stored reference.
  • Page 175 AN93 if LVCS(t) = LVCS (t - 40 ms x OHSR) and ACL - LVCS(t) < DCL then ACL = LVCS(t) if (ACL - LVCS x (t - 40 ms x OHSR) > DCL and ACL - LVCS x t > DCL then PPD = 1 and the INT pin (or the INT bit in parallel or SPI mode) is asserted (PPDM = 1) Using either algorithm, when an intrusion is detected, U70[2] (PPD), Parallel Phone Detect is set.

  • Page 176: Modem-On-Hold

    AN93 The ISOmodem has an internal analog-to-digital converter used to monitor the loop voltage when on-hook and loop current when off-hook to check for parallel devices going off-hook. The host measures loop voltage and current by reading U79 [4:0] (LVCS) or U6C[15:8] (LVS) and U63[15:8] (LCS). To set the ISOmodem to monitor loop voltage in the on-hook state, the host issues the following commands: Command Function...

  • Page 177: Receiving Modem-On-Hold Requests

    6.7.2. Receiving Modem-On-Hold Requests If modem-on-hold is enabled via the +PMH=1 command, the Si2493 may be placed on hold by a remote modem. The maximum time the modem will remain on hold is configured with the +PMHT setting. Possible values of +PMHT are given in Table 121.
  • Page 178 AN93 First, the data will be analyzed to point out the occurrence of bit errors and spurious data. Secondly, a simple algorithm to filter the data will be proposed. Finally, the resulting valid data will be presented. Table 118 lists an initial analysis of some recurring data patterns. Table 118.
  • Page 179 AN93 Table 118. Bit Errors (Continued) Data Meaning Good Packet 30 93 19 B1 Beginning of Packet A 1-bit error is received in an HDLC flag. The modem 19 B2 assumes a new single-byte packet. Since a 1-byte packet is invalid, 19 B2 is generated by modem. Beginning of Packet Good Packet 30 93...
  • Page 180 AN93 Table 118. Bit Errors (Continued) Data Meaning Spurious data FF 98 89 18 Data byte with more than 6 mark bits in a row. The 19 B0 modem looks for HDLC flags. HDLC Flag detected 19 B2 Beginning of Packet Spurious data 92 6E EF 14 65 Data byte with more than 6 mark bits in a row.

  • Page 181: Overcurrent Detection

    AN93 The following steps will allow the spurious data and bit errors to be eliminated while preserving the valid data. 1. Ignore 19 B0. 2. Use 19 B2 to discard all collected receive data. The filtered version of the HDLC frames, based on this algorithm, is shown below with the valid data in bold. 0D 0A 43 4F 4E 4E 45 43 54 20 31 32 30 30 0D 0A 19 BE 20 20 19 B1 19 B0 19 B2 30 93 19 B1 19 B2 30 93 19 B1 19 B2 30 93 19 B1 19 B2 30 93 19 B1 19 B2 19 B2 B6 9E F7 46 19 B0 19 B2 29 C6 19 B0 19 B2 FF 98 89 18 19 B0 19 B2 92 6E EF 14 65 19 B0 19 B2 DA...

  • Page 182: Method 2: Single Off-Hook Transition

    AN93 6.10.2. Method 2: Single Off-Hook Transition Use this method if it is undesirable for the modem to go off-hook more than once or to DTMF dial a single digit. This method is somewhat more complicated and is best illustrated with an example, dialing the number 12345 below. Set bit 7 of U-register 7A (U7A [7] (DOP) = 1) and send ATDT1;<CR>...

  • Page 183: Telephone Voting Mode

    6.12. V.92 Quick Connect The Si2493 supports ITU-T V.92 shortened Phase 1 and Phase 2 to decrease the time required to connect to a server modem using the V.90 modulation. After the first call, the Si2493 will retain line parameters that allow it to use shortened Phase 1 and 2 to reduce the total negotiation time.

  • Page 184: Abort The Dialing Operation In Voice Mode

    AN93 Table 122. AT+PQC Parameters <Value> Description Enable Short Phase 1 and Short Phase 2 Enable Short Phase 1 Enable Short Phase 2 Disable Short Phase 1 and Short Phase 2 Table 123. AT+PSS Parameters <Value> Description The DCEs decide whether or not to use the short startup procedures.

  • Page 185: Handset, Tam, And Speakerphone Operation

    AN93 7. Handset, TAM, and Speakerphone Operation This section covers the voice functionality of the Si2494/39. The voice features of the Si2494/39 are divided into three major categories: handset, telephone answering machine (TAM), and speakerphone. The Si2494/39 implements ITU-T V.253 commands for TAM and speakerphone operation. The TAM voice compression support includes the following formats: ...
  • Page 186 AN93 Table 124. Extended AT+ Command Set (Continued) Command Action Caller ID Type <n> Description After ring only Always on +VCDT = <n> Japan DTMF after polarity reversal DTMF after polarity reversal (off-hook reception) Always-on DTMF DTMF after ring Caller ID Enable <pmode>...
  • Page 187 AN93 Table 124. Extended AT+ Command Set (Continued) Command Action Analog Source / Destination Selection <label> Description DCE is on-hook. AOUT disabled. Tone detectors disabled. Si3000 sample pass-through to DAA is inactive. DCE is off-hook. AOUT disabled. Tone detectors disabled. DCE is on-hook.
  • Page 188 AN93 Table 124. Extended AT+ Command Set (Continued) Command Action Repeat Caller ID <rmode> Description Display Caller ID information of the last incoming call in formatted +VRID = <rmode> form. Display Caller ID information of the last incoming call in unformatted form.
  • Page 189 AN93 Table 124. Extended AT+ Command Set (Continued) Command Action Voice Speakerphone State <mode> Description Speakerphone AEC and AES disabled. In handset mode, FIR +VSP = <mode> handset coefficients are selected and LEC is enabled. Speakerphone AEC, AES and LEC enabled. Speakerphone FIR filter coefficients are selected.

  • Page 190: Dle> Commands (Dte-To-Dce)

    AN93 7.1.3. <DLE> Commands (DTE-to-DCE) The characters listed in the Code column of Table 125 are referenced throughout this document with the <> notation. Simple action commands consist of a <DLE> character plus a simple action-command character (two bytes total). Table 125.

  • Page 191: Dle> Events (Dce-To-Dte)

    AN93 7.1.4. <DLE> Events (DCE-to-DTE) 7.1.4.1. Simple Event Reporting Table 126. <DLE> Simple Events (DCE-to-DTE) Format: <DLE>[Code] Code Description <DLE> 0x10 The DCE will shield a 0x10 character in the voice stream to create a 0x10 0x10 sequence sent to the DTE. <SUB>...
  • Page 192 AN93 Table 126. <DLE> Simple Events (DCE-to-DTE) (Continued) Format: <DLE>[Code] Code Description 0x75 Transmit buffer underrun. 0x63 Fax Calling. DCE has detected T.30 1100 Hz tone. 0x65 Data Calling. DCE has detected V.25 1300 Hz tone. 0x68 Line voltage collapsed (phone line detached). 0x48 Line voltage restored (phone line reattached).

  • Page 193: Complex Event Reporting

    AN93 7.1.4.2. Complex Event Reporting Table 127. <DLE> Complex Event Reports (DCE-to-DTE) Format: <DLE><X>[Response]<DLE><.> Response Description DRON Distinctive Ring Cadence On-time tag. See +VDR for details. DROF Distinctive Ring Cadence Off-time tag. See +VDR for details. DATE CID DATE tag. Full format is DATE=HHMM. Type I and II supported. TIME CID TIME tag.
  • Page 194 AN93 Table 128. Voice Mode U Registers (Continued) Register Address Name Description Default U156 0x0156 HTXFIR1 0x4000 U157 0x0157 HTXFIR2 0x0000 U158 0x0158 HTXFIR3 0x0000 U159 0x0159 HTXFIR4 0x0000 U15A 0x015A HTXFIR5 0x0000 U15B 0x015B HTXFIR6 0x0000 U15C 0x015C HTXFIR7 0x0000 U15D 0x015D...
  • Page 195 AN93 Table 128. Voice Mode U Registers (Continued) Register Address Name Description Default U16B 0x016B HRXFIR1 0x4000 U16C 0x016C HRXFIR2 0x0000 U16D 0x016D HRXFIR3 0x0000 U16E 0x016E HRXFIR4 0x0000 U16F 0x016F HRXFIR5 0x0000 U170 0x0170 HRXFIR6 0x0000 U171 0x0171 HRXFIR7 0x0000 U172 0x0172...
  • Page 196 AN93 Table 128. Voice Mode U Registers (Continued) Register Address Name Description Default U1A0 0x01A0 STXFIR1 0x0000 U1A1 0x01A1 STXFIR2 0x0000 U1A2 0x01A2 STXFIR3 0x0000 U1A3 0x01A3 STXFIR4 0x0000 U1A4 0x01A4 STXFIR5 0x0000 U1A5 0x01A5 STXFIR6 0x0000 U1A6 0x01A6 STXFIR7 0x0000 U1A7 0x01A7...
  • Page 197 AN93 Table 128. Voice Mode U Registers (Continued) Register Address Name Description Default U1B5 0x01B5 SRXFIR1 0x0000 U1B6 0x01B6 SRXFIR2 0x0000 U1B7 0x01B7 SRXFIR3 0x0000 U1B8 0x01B8 SRXFIR4 0x0000 U1B9 0x01B9 SRXFIR5 0x0000 U1BA 0x01BA SRXFIR6 0x0000 U1BB 0x01BB SRXFIR7 0x0000 U1BC 0x01BC...
  • Page 198 AN93 Table 129. U199 and U19E Register Bit Maps Name Bits Bit8 Bit7 Bit6 Bits Bit 3 Bit 2 Bit 1 Bit 0 15-9 U199 VPCTRL SSP_LOCTALK SSP_PTT SSP_FLAG MMUTE SPCAL SMUTE U19E AECREF SPKREF MICREF The SMUTE bit (U199 [1]) mutes the speaker output audio path. The bit should be cleared for normal speakerphone operation.

  • Page 199: Voice Reference-Overview

    AN93 7.2. Voice Reference—Overview This document uses the term “handset mode” to describe the use of the microphone (MIC) and speaker (SPKRL/ SPKRR) connections on the Si3000. The term “hands-free or speakerphone mode” describes the use of the line input (LINEI) and line out (LINEO) connections on the Si3000. The term “handset”...
  • Page 200 AN93 Rev. 1.4...
  • Page 201 AN93 Rev. 1.4...
  • Page 202 AN93 Table 131. Voice Mode Operations (+FCLASS=8) Active +VLS Mode Primitive Description +VTX +VRX +VSP +VTS Detectors None On-Hook Ring, CID1 Voice mode is disabled. TAM operation for call answer with OGM playback FDV DTMF RS232- DAA- RS232- and record message using Off-Hook 2Tones* >DAA...
  • Page 203 AN93 Table 131. Voice Mode Operations (+FCLASS=8) (Continued) Active +VLS Mode Primitive Description +VTX +VRX +VSP +VTS Detectors Ring, CID1 Await call with tone genera- RS232- On-Hook FDV DTMF tor connections to AOUT for >AOUT 2Tones* control beeps, ring tone, etc. * 2Tones = Detector for 2 pro-...

  • Page 204: Si3000 Configuration

    AN93 7.3. Si3000 Configuration 7.3.1. Microphone and Speaker Ports The TAM and Speakerphone applications use two sets of microphones and speakers: one for the handset and one for hands-free operation. For the Si24xxVMB REV 2.0, the handset circuit uses the MIC input and SPKR_L output. The Si24xxVMB REV 2.0 allows configuration of the MIC, SPKR_L, and matching ground signals on any handset pinout.
  • Page 205 AN93 Reading the Si3000 control registers is a two-step process. First, the value of the desired Si3000 control register must be loaded into the U72 register; then, the value of U72 can be read. For example, to read the value of Si3000 control register 5, use the following AT command sequence: AT+FCLASS=8 AT+VLS=14...

  • Page 206: Tam Pstn

    AN93 7.3.3.6. TAM PSTN This mode is used to answer an incoming call with OGM playback and ICM recording. The caller may perform local TAM operations (i.e. record OGM, review ICM) via remote DTMF control. The modem is off-hook routing audio between the DAA and the DTE interface;...

  • Page 207: Initialization

    AN93 7.4. Initialization The following sequence is used after power up or hardware reset to prepare the modem for voice operations. This procedure occurs in the Initialize state presented in Figure 33. After initialization, the system will be in the TAM Hands-Free mode, which is discussed in "7.3.3.1.
  • Page 208 AN93 Table 133. Initialization Sequence (Continued) AT:U196,5000 Set output limiter threshold gain. AT:U197,2000 Set input limiter threshold gain. AT:U19C,2400 Set AEC reference gain. AT:U19D,1800 Set AEC microphone gain. AT:U19A,01E0 Set AEC filter length. AT:U19B,001F Set AEC adjustable delay. AT:U04F,01F4 Set flash hookswitch period. AT:U156,FF10,FFA2,FFD7,FF35,FEF3,FE68,FB7E AT:U15D,F90C,FDDF,091D,4F51,091D,FDDF,F90C Set Handset Transmit FIR coefficients.

  • Page 209: Handset

    AN93 Table 133. Initialization Sequence (Continued) Configure Si3000 Register 7: 0 dB RX PGA gain AT:U72,075E Enable SPKRL Mute SPKRR Configure Si3000 Register 9: AT:U72,0900 0 dB Line Out attenuation 0 dB Speaker output attenuation Disable Si3000-to-DAA transmit gain AT:U0B1,0 path.
  • Page 210 AN93 Table 134. Handset Configuration Modem to Host Host to Modem Commands / Data Result Codes/ Local Modem Actions Data Mute the microphone and speaker paths to AT:U199|A the codec. Disable voice mode. Used as a transition AT+VLS=0 point between non-zero +VLS voice modes. Setup off-hook voice mode.

  • Page 211: Call - Automatic Tone Dial

    AN93 7.5.3. Call – Automatic Tone Dial Table 135 lists the commands that occur after the configuration defined in Table 134. Table 135. Handset Automatic Tone Dial Host to Modem Modem to Host Result Local Modem Actions Commands / Data Codes/Data Perform automatic tone dial of 102.

  • Page 212: Terminate

    AN93 7.5.7. Terminate Upon detection of the Handset Lowered Event, the host should issue the commands in Table 138 to transition to the TAM Hands-Free mode. Table 138. Handset to TAM Hands-Free Transition Host to Modem Modem to Host Result Local Modem Actions Commands / Data Codes/Data...

  • Page 213: Speakerphone Transition

    AN93 7.5.8. Speakerphone Transition In the Handset mode, the SP Button On Event will trigger the transition from Handset to Speakerphone mode. See "7.7. Speakerphone" on page 225 for details on Speakerphone mode. The voice driver should track the handset hook switch state, such that if the user exits Speakerphone mode, the system will switch back to Handset configuration without losing the active call.

  • Page 214: Telephone Answering Machine

    AN93 7.6. Telephone Answering Machine 7.6.1. Overview The Si2494/39 supports telephone answering machine (TAM) operations. These parts use the V.253 command set to control operation. This section covers the three major TAM-related system voice modes. Some modes offer multiple operations. The TAM Hands-Free mode is the general voice idle mode.

  • Page 215: Record Ogm

    AN93 7.6.2.1. Record OGM The Si3000-to-RS232 gain register UC0 in the ISOmodem can be used to adjust the voice stream gain. Use the +VGR command to adjust the UC0 value in command mode. It is best to maintain two versions of +VGR: one for Si3000-to-RS232 and another for DAA-to-RS232.

  • Page 216: Review Ogm

    AN93 7.6.2.2. Review OGM The RS232-to-Si3000 gain register UB8 in the ISOmodem can be used to adjust the voice stream gain. Use the +VGT command to adjust the UB8 value in command mode. It is best to maintain two versions of +VGT: one for RS232-to-Si3000 and another for RS232-to-DAA.
  • Page 217 AN93 Table 143. TAM Handset Record OGM Modem to Host to Modem Commands / Data Host Result Local Modem Actions Codes/Data Mute the microphone and speaker paths to AT:U199|A the codec. Configure Si3000 Register 1: Enable speaker driver AT:U72,0110 Disable line output driver Disable telephone instrument driver Enable MBIAS output Configure Si3000 Register 5:...
  • Page 218 AN93 Table 143. TAM Handset Record OGM (Continued) Trigger receive operation. The first byte after the newline character following the AT+VRX CONNECT CONNECT message will be the first data stream byte. Receive OGM voice stream. During voice stream capture, the user can adjust the UC0 value via the <DLE><u>...

  • Page 219: Review Ogm

    AN93 Table 143. TAM Handset Record OGM (Continued) Configure Si3000 Register 9: AT:U72,0900 0 dB Line Out attenuation 0 dB Speaker output attenuation Enable speaker for local ring tone/alert AT:U199&FFF7 tones. 7.6.3.2. Review OGM The host will prompt the user to lift the handset to begin OGM review. The procedure restores the TAM Hands-Free settings before completion.
  • Page 220 AN93 Table 144. TAM Handset Review OGM (Continued) Select G.711U -law PCM, 8-bit, 64 kbps AT+VSM=4 format. The voice driver will need to track the OGM format with the OGM PCM file. AT+VTX CONNECT Trigger transmit operation. TX Underrun. Appears at the start of +VTX <DLE><u>...

  • Page 221: Record Local Icm

    AN93 7.6.3.3. Record Local ICM The Record Local ICM is identical to the Record OGM procedure provided in Table 143 on page 217. The main difference is that one of the ADPCM formats is generally used and the PCM file is stored with the other ICM files recorded from the PSTN.
  • Page 222 AN93 Table 145. TAM PSTN Normal Answer – OGM Playback with ICM Record (Continued) Disable voice mode. Used as a transition AT+VLS=0 point between non-zero +VLS voice modes. Setup off-hook voice to PSTN. See AT+VLS=15 Table 131 on page 202 for details.

  • Page 223: Interrupted Answer - Ogm Playback With Dtmf Menu Entry

    AN93 Table 145. TAM PSTN Normal Answer – OGM Playback with ICM Record (Continued) Disable DAA-to-Si3000 receive gain path. AT:U0B5,0 This ensures line events such as CID and ring tone are not heard via the codec. AT:U199|2 Mute the microphone. Enable speaker for local ring tone/alert AT:U199&FFF7 tones.
  • Page 224 AN93 Table 146. TAM PSTN Interrupted Answer – OGM Playback with DTMF Menu Entry (Continued) Modem to Host Result Host to Modem Commands / Data Local Modem Actions Codes/Data Set the RS232-to-DAA transmit gain regis- AT+VGT=128 ter (UB3) for TAM PSTN. Set sensitivity level for ICM recording AT+VSD=129 silence detection.

  • Page 225: Speakerphone Transition

    AN93 Table 146. TAM PSTN Interrupted Answer – OGM Playback with DTMF Menu Entry (Continued) Modem to Host Result Host to Modem Commands / Data Local Modem Actions Codes/Data AT+VTS=[500,0,100] Play special administrator tone. Using the +VTX command, the voice driver can playback a menu and monitor DTMF [Playback Menu Options] digit events to perform operations...
  • Page 226 AN93 Figure 34. Transmit Gain Reference Measurements Figure 35 illustrates the setup used to set the transmit gain. Here the modem has the AEC/AES disabled with AT+VSP=0. Using the Si24xx-VMB, call the remote phone and establish a voice call. Use the command sequence in Table 147.
  • Page 227 AN93 Table 147. Transmit/Receive Gain Calibration – Dial Remote Telephone Host to Modem Commands Modem to Host Result Local Modem Actions / Data Codes/Data Reset the modem. AT+FCLASS=8 Enter voice mode. AT:U199|4 Set SPCAL (U199 [2]) to enable calibration. AT*Y254:W59|1 Enable the SSI interface to the Si3000.

  • Page 228: Receive Gain Calibration-Speakerphone Disabled

    AN93 7.7.2.2. Receive Gain Calibration—Speakerphone Disabled Figure 36 illustrates the reference setup where the commercial speakerphone is active with speaker set to maximum volume. Using the reference commercial speakerphone, call the remote telephone and establish a voice call. Place a sound source such as a PC speaker at a distance of one foot from the remote telephone microphone. Play out white noise as the far-end speech through the sound source, and adjust the white noise level so that the level at the speakerphone’s Tip/Ring is -15 dBm.

  • Page 229: Speakerphone Calibration-Aec Gain Calibration

    AN93 7.7.2.3. Speakerphone Calibration—AEC Gain Calibration Figure 38 illustrates the setup used to set AEC speaker reference gain (U19C) and the AEC microphone input signal gain (U19D). Here the modem has the AEC/AES enabled (AT+VSP=1) with the calibrated UB1 and UB5 values, which where obtained from the two previous sections.
  • Page 230 AN93 Table 148. AEC Gain Calibration – Dial Remote Telephone Host to Modem Modem to Host Result Local Modem Actions Commands / Data Codes/Data Reset the modem. AT+FCLASS=8 Enter voice mode. AT:U199|4 Set SPCAL (U199 [2]) to enable calibration. AT*Y254:W59|1 Enable the SSI interface to the Si3000.

  • Page 231: Speakerphone Configuration

    AN93 7.7.3. Speakerphone Configuration This section covers the speakerphone call and answer cases, and the switching between the handset mode and speakerphone mode. Table 149 contains the initial configuration that is used by all dialing use cases. The sequence is also sent for the answer case. The user will have been notified of the incoming call through a local +VTS ring tone and a SP Button On Event would prompt the Speakerphone Configuration sequence to answer the call.

  • Page 232: Simplex Speakerphone Configuration

    AN93 7.7.4. Simplex Speakerphone Configuration Simplex Speakerphone (SSP) is a special case of speakerphone operation. Like speakerphone, it allows two-way hands-free voice communication over a telephone line, but SSP allows communication in only one direction at a time. The direction of voice transmission can be controlled automatically, based on the presence of local and remote speech at the modem, or manually using a push-to-talk function.

  • Page 233: Call-Automatic Tone Dial

    AN93  U1D8 less than U1D6: the break-through threshold U1D8 takes over and the speaker level threshold U1D6 becomes inactive.  The default value for U1D8 is 7FFFh. A typical value for U1D8 is 0x1000. Adjust U1D8 according to the needs of the application.

  • Page 234: Call-Automatic Pulse Dial

    AN93 7.7.7. Call—Automatic Pulse Dial Table 154 lists the commands that occur after the configuration defined in Table 149. Table 154. Speakerphone Automatic Pulse Dial Host to Modem Modem to Host Result Local Modem Actions Commands / Data Codes/Data Perform automatic pulse dial of 102. Modem will return OK.

  • Page 235: Termination

    AN93 Table 155. Speakerphone to Handset Transition (Continued) AT:U72,0900 Configure Si3000 Register 9: 0 dB Line Out attenuation 0 dB Speaker output attenuation AT+VSP=0 Select handset voice path. See Figure 31 on page 200 for details. AT:U199&FFF5 Enable the microphone and speaker paths to the codec.

  • Page 236: Security Protocols

    AN93 8. Security Protocols The Si24xx ISOmodem can handle a variety of security protocols. Two are specifically described here. The "Ademco® Contact ID Protocol" and the SIA protocol. 8.1. Implementing the SIA Protocol The SIA protocol defines communication between an alarm panel and a central station. In a traditional security system, the alarm panel always calls the central station and sends data;...

  • Page 237: Considerations When Disconnecting The Session

    AN93 4. Issuing ATO to modem will start the V.32bis handshake. The host then waits for the CONNECT message before sending data. (For an originating modem, the ATO command must be sent as soon as possible so the modem will be ready when the remote answering modem starts. For an answering modem, the ATO should be delayed a little to give the remote originating modem a chance to get ready first.) 5.
  • Page 238 AN93 Table 156. AT Commands Provided to Support SIA Level-3 Protocol Communication (Continued) AT Command  Modem Function Remarks AT+F1 Enable B103 Receiver for Data Block Modem enables FSK receiver, waits for >12T marks reception. to be detected, then sends CONNECT message to DTE to indicate a received Data Block follows.
  • Page 239 AN93 Table 157 lists the definitions of result codes typically expected in an SIA session. Table 157. Definitions of Result Codes Typically Expected in an SIA Session Result Code Meaning Remarks Ready for next command When it comes as a response to the +F2 command, “OK”...

  • Page 240: Implementing The Ademco® Contact Id Protocol

    AN93 ® 8.2. Implementing the Ademco Contact ID Protocol Contact ID is a communications protocol for security applications. It is a de facto standard which was developed and is owned by the Ademco Group. The following is a brief overview of the Contact ID protocol. The complete standard is available at the following web site: http://webstore.ansi.org/RecordDetail.aspx?sku=SIA+DC-05-1999.09 Communication is between an alarm panel and a central station.

  • Page 241: Modem Specific Implementation Details

    AN93 8.2.1. Modem Specific Implementation Details The DTMF transmitters and receivers are used to send and receive data. Voice mode operation (documented in "7. Handset, TAM, and Speakerphone Operation" on page 185) is used to transmit and receive the tones. A summary of the necessary tone transmission AT commands is shown in Table 158.

  • Page 242: Handshake Tone Detection

    AN93 8.2.1.1. Handshake Tone Detection Two tone detectors are reconfigured for detection of the 1400Hz and 2300Hz tones. When a valid tone burst is detected the modem reports it to the host DTE in the V.253 event format as follows. Event Modem-to-DTE indication Remarks...
  • Page 243 AN93 ® Table 159. Ademco Mode of Operation (Continued) AT:U181,334,0,0,12C Change 1400 Hz detector to detect 800 ±300 msec tone burst, i.e. Kissoff tone. Delay 250 msec before transmit- Host DTE should adjust this delay so that the fol- ting Data Tones message. lowing +VTS DTMF transmission will start between 250 to 300 msec after the reception of <DLE><e>...

  • Page 244: Chinese Epos Sms

    AN93 9. Chinese ePOS SMS 9.1. Introduction An ePOS transaction normally begins with the ePOS terminal calling the server and transmitting data first. In this instance the terminal initiates the call, so it is known as the Originate modem, while the server is the Answer modem.

  • Page 245: Sms At Command Set

    AN93 9.2. SMS AT Command Set Table 160 shows the AT commands that the host (DTE) uses to control the transmission or reception of SMS messages. Table 160. AT Commands for SMS AT Command ISOmodem Response Description &D1 ESC (pin 22) escapes to command mode from data mode if also enabled by HES (Enable Hardware Escape Pin): U70, bit 15.
  • Page 246 In the script, “C” stands for comment, “S” stands for send, and “E” stands for expect. the number at the end of each line is time in milliseconds. C"Si2493 SMS POS No CAS test"0 C"1) Load the patch. 2) run the script"0 S"ATZ\r"0...
  • Page 247 AN93 C"Disabled CAS tone detection"0 S"ATE0:UCD&FFFE\r"0 E"\r\nOK\r\n"0 L""5 S"AT+FRM=200\r"0 E"\r\nCONNECT 2\r\n"0 E"1\r\n"0 E"\r\nOK\r\n"0 C"TX delay=100ms"0 S"AT:UD1,A\r"0 E"\r\nOK\r\n"0 S"AT+FTM=202\r"0 E"\r\nCONNECT \r\n"0 S"\x00\x00\xc7"0 S"\xc8\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10"0 S"\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f "0 S"!"#$%&'()*+,-./0"0 S"123456789:;<=>?@"0 S"ABCDEFGHIJKLMNOP"0 S"QRSTUVWXYZ[\\]^_`"0 S"abcdefghijklmnop"0 S"qrstuvwxyz{|}~\x7f\x80"0 S"\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90"0 S"\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0"0 S"\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0"0 S"\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0"0 S"\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xb6\xbf\x10\x03"0 E"\r\nOK\r\n"0 C"+FRM=200 timeout(2.5s)"0 S"ATE1:UD2,FA\r"0 E"\r\nOK\r\n"0 X""0 S""200 S"ATH\r"0...

  • Page 248: Sms User Registers

    AN93 9.2.1. SMS User Registers User registers that set up SMS operations are shown in Table 161. The default settings are shown in bold. Table 161. User Registers for SMS Operations Register Bits Name Description Default (Hex) Enables ESC (pin 22). After sending transmit data to the modem, the host should wait a minimum of 150 ms before activating the ESC pin.

  • Page 249: Procedure

    AN93 9.2.2. Procedure To enable the SMS features on the Si24xx, the host sends “AT+FCLASS=256” to the modem prior to an SMS call. To enable the hardware escape pin functions, the host would set HES with the command “AT:U70|8000”. After setting the other U-registers according to the configurations of the Originate and Answer modems, the host can dial an SMS call using the command “ATDTxxxx;”...

  • Page 250: Example

    AN93 Table 162. UD4 SMS CAS Tone Detector Threshold Level (Continued) UD4 (Hex) CAS level (dBm) 13F4 –20 191E –19 1F9F –18 27D0 –17 321E –16 3F19 –15 4F6F –14 6400 –13 7DE4 –12 If there is no response from the receive modem, the transmit modem will time out, go on hook and report NO CARRIER to  the  host.  The transmitter  can't resend the data before  the time  out has  expired,  because this will cause a character abort. This scenario can be avoided by including the command AT+VNH = 1 or AT+VNH = 2 in the ...

  • Page 251: Response 1

    AN93 To set up the modem for Protocol 2 SMS: AT:UCA,0,12C,4E This sets up the modem for Bell 103 modulation, Protocol 2, 300 bit Channel Seizure, 78 Mark bits in the message header. AT+FTM=202 Transmit a Protocol 2 SMS frame <CR><LF>CONNECT <CR><LF>...

  • Page 252: Example Session

    AN93 9.3. Example Session The example below shows a typical session. The user determines the values of the U-registers. transmit "AT+FCLASS=256<CR>" ;Enable SMS POS mode waitfor "OK" transmit "AT+VNH=1<CR>" ;Disable automatic hangup for NO CARRIER waitfor "OK" transmit "AT:UCA,0,12C,4E<CR>" ;Set SMS POS parameters waitfor "OK"...
  • Page 253 AN93 Transmit a frame such as: 0x82 0x00 0x05 0x6c 0xea 0x50 0x6b 0x00 0x68 transmit "`x10`x03" ; Send <DLE><ETX> at the end of frame waitfor "OK`x0d`x0a"   Server TS  2 CAS Ack (Complete the CAS Handshake) Send FSK Packet Send FSK Packet Send FSK Packet Figure 40.
  • Page 254 AN93 For Figure 41, assume that the originating modem transmits first and that the two modems alternate transmitting and receiving. For simplicity, this figure does not show the provisions for timeout cases.     H ES = 1      ...

  • Page 255: Testing And Diagnostics

    AN93 10. Testing and Diagnostics 10.1. Prototype Bring-Up (Si3018/10) 10.1.1. Introduction This section provides tips for the debugging of initial prototypes. Although most ISOmodem prototype designs function as expected, there is the potential for layout errors, omitted or incorrect components used in the initial assembly run, and host software problems.
  • Page 256 AN93  AT OK? The modem responds with an OK to the command AT<CR>. This indicates that the host processor/software is communicating with the modem controller, and problems are in one of the following areas:  Inappropriate Commands Verify that all AT commands used are supported by the ISOmodem and comply with the proper format. Be sure each command and argument is correct.

  • Page 257: Host Interface Troubleshooting

    AN93 10.1.4. Host Interface Troubleshooting The methods described in this section are useful as a starting point for debugging a prototype system or as a continuation of the troubleshooting process described previously. The procedures presented in this section require a known good ISOModem evaluation board and data sheet. This section describes how to substitute the evaluation board for the entire modem circuitry in the prototype system.
  • Page 258 AN93 Start with power off and the phone line disconnected. Measure the resistance of all Si3018/10 pins with the Ohmmeter’s black lead on pin 15 (IGND). Compare these measurements with the values in Table 163. Next, measure the resistance across the components listed in Table 164 and compare the readings to the values listed in the table.
  • Page 259 AN93 Prototype System Host Host Si24xx Si3018 Discretes Controller UART Phone Line RS232 Si24xx Si3018 Discretes Transceiver  Connect the prototype ground to the EVB ground.  Lift prototype C1 and C2 and EVB C1 and C2 so the Si3018 is disconnected from the Si24xx on both modems. ...
  • Page 260 AN93 On-Hook Off-Hook DCT2 1.6 V DCT2 2.2 V IGND 3.4 V IGND 1.6 V DCT3 2.5 V DCT3 2.8 V 0.5 V 2.1 V 0.5 V 0.9 V 0.9 V 1.8 V ~2.3 V VREG VREG2 2.3 V VREG VREG2 ~1.0 V RNG1...
  • Page 261 AN93 Table 164. Resistance across Components Si3018/10 Resistance < 1  < 1  > 20 M  1.07 k  150  3.65 k  2.49 k  100 k  100 k  4.5 or 16 M  4.5 or 16 M ...

  • Page 262: Self Test

    AN93 10.2. Self Test The Si24xx ISOmodem’s advanced design provides the system manufacturer with an enhanced ability to determine system functionality during production tests and to support end-user diagnostics. In addition to local echo, a loopback mode allows increased test coverage of system components. For the loopback test mode, a line- side power source is required.

  • Page 263: Board Test

    AN93 10.3. Board Test The modem and DAA chips come from Silicon Laboratories 100% functionally tested on automatic test equipment to guarantee compliance with the published chip specifications. The functionality of a finished product containing an ISOmodem chipset depends not only on the functionality of the modem chipset after assembly but also on discrete components and product-related software.
  • Page 264 AN93 V.90 modems must be tested with a digital modem, such as the USR Courier I. If a digital modem isn’t used as illustrated in Figure 49, the highest connection speed a V.90 modem will support is 33.6 kbps. A call can be placed or received in either direction at the speed set in the modems.

  • Page 265: Compliance Testing

    AN93 10.4. Compliance Testing Regulatory compliance testing requires the modem to be configured in specific ways and controlled to perform specific operations necessary to make required measurements. Compliance testing commands and configuration information are provided. Some helpful commands for conducting compliance testing on the ISOmodem are listed in Table 167. The modem register defaults configure the modem for FCC operation.

  • Page 266: Emi

    AN93 The data sent during &T4 and &T5 transmission tests is controlled by the S40 register. The data rate for &T4 and &T5 commands is controlled by the existing &G command. In V.34 cases, where a data rate may use multiple symbol rates, the symbol rate is controlled by the S41 register.

  • Page 267: Safety

    AN93 10.4.2. Safety Designs using the ISOmodem pass all overcurrent and overvoltage tests for UL1950 3rd Edition with the addition of a 1.25 A Fuse or PTC, as shown in Figure 50. In a cost-optimized design, compliance to UL1950 does not always require overvoltage tests.

  • Page 268: Am-Band Interference

    AN93 10.5. AM-Band Interference In certain areas, AM-band interference causes poor connectivity rates and error rates. A good EMI common-mode filter may be necessary in some situations. An example of an off-the-shelf unit designed to plug directly into the phone line is the Coilcraft TRF-RJ11, which can be used for debugging or fixing problem locations. Figure 51.

  • Page 269: Debugging The Dte Interface

    AN93 10.6. Debugging the DTE interface A hardware-based serial RS232 monitoring product, such as the Parascope Plus, is an invaluable tool for debugging the DTE/DCE Interface. It captures and records details of DTE - DCE interaction. Hexadecimal and bit- shifted views are possible, and it timestamps every character exchanged with much greater precision than a software-based monitor.

  • Page 270: Appendix A-Epos Applications

    AN93 A—EPOS A PPENDIX PPLICATIONS EPOS applications generally require nearly flawless call connection reliability and a very short overall transaction time. The message length of a typical EPOS terminal is between 120 to 260 bytes of information. Due to the relatively small message length, the need for reliable connections under all line conditions, and short connection times, the preferred modulations have traditionally been variations of V.22 (1200 bps) or Bell 212 (1200 bps).

  • Page 271: Recommendation V.80

    AN93 Another consideration for EPOS applications is the method of error detection and error correction. Early EPOS terminals adopted the Zilog 85C30 Serial Communications Controller (SCC) in conjunction with a synchronous modem to implement an HDLC/SDLC-based data link layer. The complexities of the HDLC handling is done by the SCC, while the modem performs strict data pump function.
  • Page 272 AN93 In the end, the only thing that matters in an EPOS application is the ability to send and receive HDLC frames across the DTE. For this, the ability of the host to tell the modem “end of transmit frame” and the ability for the modem to tell the host “CRC successful”...

  • Page 273: The Isomodem In Epos Applications

    Rev C. Please contact Silicon Laboratories, Inc. for latest patch. "5.8. Firmware Upgrades" on page 133 outlines how to use this patch. The Si2494/39 and Revision D of the Si2493/57/34/15 do not require a patch for V.29 Fast Connect.

  • Page 274: A V.29 Fastpos Sample Program

    V.29 FastPOS or V.22bis; it was not possible for the modem to “train down” to V.22bis. To address these issues, a new interface has been implemented in the Rev D Si2493/57/34/15 and Rev A Si2494/ 39 and is available as a patch in the RevC ISOmodem. This interface allows the call to start as a V.29 FastPOS and can train down to V.22bis if the server NAC can answer as either a V.29 FastPOS or V.22bis.
  • Page 275 The tel_no.txt file must contain a complete telephone number dialing line followed by a CR, e.g. ATDT8,5551212. // V29_test.cpp : Defines the entry point for the console application. // Copyright 2005 Silicon Labs Inc. All rights reserved. // Rev 0.0602 #include "stdafx.h"...
  • Page 276 AN93 COMMTIMEOUTS sCOMMTIMEOUTS; iCharCount; char *cpInputRd, *cpInputRd_temp, cpInput_test[255]; char caUA_PKT_STR[] = {(char)0x30, (char)0x73, (char)0x19, (char)0xb1, (char)0 }; char caRR_PKT_STR[] = {(char)0x30, (char)0x19, (char)0xa0, (char)0x19, (char)0xb1, (char)0 }; char caSNRM_PKT_STR[] = {(char)0x30, (char)0x93, (char)0x19, (char)0xb1, (char)0 }; char caRX_PKT_STR[] = {(char)0x19, (char)0xb1, (char)0 }; void AlternateCall(void);...
  • Page 277 AN93 // 0,,,, modem transmits SYN if underrun during transparent mode // ,0... modem tx's flags after underrun after flag happens in framed sub mode // ,,0,, modem tx's abort on underrun in frame middle during framed sub mode // ,,,,1 enables CRC generation and checking // "AT:U87,050A Synch access mode config // 0x0400 bit 10 Minimal transparency <EM><T1 thru T4>...
  • Page 278 AN93 Skip waiting for the speed packet. cpInputRd = WaitForResponse("\0x19\0xbe\0x24\0x24\0x19\0xb1", cpInputRd, 6000); // ??? // Long training happens now! cpInputRd = WaitForResponse(caSNRM_PKT_STR, cpInputRd, 6000); Delay(50); //Delay to allow the line to turn around AssertRTS(true); //RTS=1 for transmitting Delay(300); //Delay to allow the line to turn around Alternatively use USE CTS iLength = strlen(caUA_PKT_STR);...
  • Page 279 AN93 BOOL bSuccess; hCom = CreateFile(pcCommPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); if (hCom == INVALID_HANDLE_VALUE) // Handle the error. printf ("CreateFile failed with error %d.\n", GetLastError()); exit(1); // Build on the current configuration, and skip setting the size // of the input and output buffers with SetupComm.
  • Page 280 AN93 char *cpResponse, int iTimeoutMs) unsigned long ulNoOfbytes; strcpy(cpOutBuffer, cpCommand); WriteFile(hCom, (long *)cpOutBuffer, strlen((char *)cpOutBuffer), &ulNoOfbytes, 0); if(iTimeoutMs) cpInBuffRd = WaitForResponse(cpResponse, cpInBuffRd, iTimeoutMs); if(!cpInBuffRd) exit(0); return cpInBuffRd; // Check for a specific response in the input buffer, and return ptr to what // follows.
  • Page 281 AN93 if(bError) strcat(cpErrorString, "Read Error\r\n"); exit(10); // implement a write to file before exit(0) cpInputWr += ulNoOfbytes; // check for a timeout sCurrentTime = clock(); iPasses++; if( sCurrentTime > (sStartTime + sWaitTime) ) strcat(cpErrorString, "Timeout of "); strcat(cpErrorString, cpResponse); printf ("\n%s\n", cpErrorString); strncpy(cpInput_test, cpInputBuffer, iCharCnt);...
  • Page 282 AN93 dcb.fDtrControl = RTS_CONTROL_DISABLE; // dis-assert RTS bSuccess = SetCommState(hCom, &dcb); if (!bSuccess) // Handle the error. printf ("SetCommState failed with error %d.\n", GetLastError()); exit(1); return; void Delay(long iMs) clock_t wait; // covert ms's to clock_t by mutiplying by CLOCKS_PER_SEC/1000 wait = (clock_t)(iMs*CLOCKS_PER_SEC)/1000;...
  • Page 283 AN93 // Returns FALSE when at end of file // Stops after first LF. bool GetFileTextLine(char *cpIn) *cpIn = 0; char cpInChar[8]; cpInChar[1] = 0; while(!feof(hpPatchFile)) cpInChar[0] = fgetc(hpPatchFile); strcat(cpIn, cpInChar); if(*cpInChar == '\n') return TRUE; return FALSE; Rev. 1.4...
  • Page 284 AN93 V.29 FastPOS Detailed Wave Files The following is a wave file that shows a V.29 FastPOS SDLC transaction. It was captured with the program listed above with a keep-alive loop. See "Appendix B—Line Audio Recording" on page 286 for details on how to capture wave files.
  • Page 285 AN93 V.29 FastPOS DTE Trace This is recorded while the program listed above is running. The patch load is left out for brevity. CR LF CR LF O CR LF CR CR LF O CR LF CR CR LF O CR LF CR LF C &...

  • Page 286: Appendix B-Line Audio Recording

    One way to rule out the possibility of a hardware problem is to call the server or modem where the connect issue is found using the Silicon Labs EVB module.
  • Page 287 AN93 The larger of the Connect the R11 two jacks (3.5 mm) jack in parallel carries audio to with Tip/Ring of the PC modem Figure 54. Hardware Setup Setting PC Microphone Input for Recording Use the following procedure: 1. Open the application that controls the audio input. 2.

  • Page 288: Audio Playback And Analysis

    AN93 Audio Playback and Analysis Below are two displays showing the results of recording a good V.22 transaction using Adobe Audition. We need to examine the signal both in the time domain and the frequency domain, with the frequency domain being a much more useful view.
  • Page 289 AN93 Figure 56. Adobe Audition Spectral View of a Good V.22 Transaction An important parameter that is not obvious at first glance is the resolution in “bands” of the spectral display. There is a tradeoff that must always be considered. This is set up in the Options->Settings Display tab in the Adobe Audition product.
  • Page 290 AN93 Figure 57. 256 Band Spectral Display Figure 58. 2048 Band Spectral Display Rev. 1.4...
  • Page 291 AN93 Audio-Recording Pitfalls To facilitate communications protocol debugging, it is imperative that audio recordings be made properly. The two most common conditions that degrade the quality of audio recordings are:  "Waveform clipping due to excessive recording level  "Time-varying levels due to use of AGC (automatic gain control) Figure 59.
  • Page 292 There are many possible variations of these examples, both in and out of compliance with published standards, in common use. There are also very unusual variations that Silicon Labs has made efforts to support in order to allow customers to connect to non-standard and essentially broken modems. Some of these are described in a later section.
  • Page 293 AN93 Answering modem’s Unscrambled Binary scrambled binary Ones (USB1) signal. ones and scrambled Two tones at 2250 data; visually indis- and 2850 Hz. tinguishable from each other. 2100 Hz Answer Tone. The three short horizontal lines are the S1 signal Calling modem’s that triggers V.22bis train- Scrambled Binary...
  • Page 294 AN93 As shown in Figure 65, the V.29 FastPOS protocol looks different than the older, slower V.22-like protocols. It is also half-duplex, and each participating modem uses the entire spectral space available on the telephone line. A receiving modem recognizes that the calling modem is V.29-capable by detecting the V.29 calling tone at 980 Hz. Another example with some more SDLC-oriented data is provided later in this document.
  • Page 295 AN93 A V.22 bis server with unpredictable and undesirable gaps during the USB1 signal. A V.22 bis server with a 2225 answer tone instead of 2100 Hz. Figure 66. Examples of EPOS Server Misbehavior Rev. 1.4...
  • Page 296 AN93 The Answer Tone is too short at 400 ms. Innocent, answer modem generated, guard tone. Figure 67. Example of EPOS Server Misbehavior Rev. 1.4...

  • Page 297: Examples Of Line Impairments

    AN93 Examples of Line Impairments DTMF Distorted by Low Line Level Figure 68. Defective DTMF Figure 69. Normal DTMF Solutions:  Fix the telephone line.  Lower the DTMF level with AT:U46, 0BD0 or AT:U46, 0CF0  Check the loop-current level with AT:R79 and AT:R6C. Rev.
  • Page 298 AN93 Power Line Related Noise Figure 70. Odd Harmonics of 50 Hz Manifest as Horizontal Lines Spaced at 100 Hz Causes:  Unbalanced phone line  High ac leakage supply  Poor CMR in modem Solutions:  Fix the telephone line. ...
  • Page 299 AN93 UltraCOM Terminal Emulator UltraCOM is a powerful serial terminal tool developed by Silicon Laboratories for use with the ISOmodem devices. UltraCOM is capable of supporting up to four concurrent DTE Terminal windows, which interface to serial COM ports. The DTE Terminal provides file transfer tools for patch loading and block data transfer. It supports a full range of COM port settings, including baud rate, data size, parity, mark bits, flow control, and timeouts.
  • Page 300 AN93 Command History Panel The Command History panel provides access to the command history, which is accumulated from direct typing in the Main Terminal panel or read from a text file. Script Overview A script is a text file that is used to send and receive commands and data to and from an ISOmodem . Each line of the script consists of three fields: command, data, and control.
  • Page 301 AN93 Once the script is written, it is executed using the Script Execution dialog box (Figure 73). In this example, there is one DTE terminal active; the script is to be executed once, and the signal on the audio input is recorded to a PCM file, which, by default, is call.wav in the UltraCOM directory.

  • Page 302: Appendix C-Parallel/Spi Interface Software Implementation

    AN93 C—P /SPI I PPENDIX ARALLEL NTERFACE OFTWARE MPLEMENTATION This appendix describes the software interface requirements for communication with the ISOmodem in parallel or SPI mode. Figure 75 shows a typical connection between a PC and the modem using the MCU C8051F12x as interface: Figure 75.

  • Page 303: Software Description

    AN93 Software Description Hardware Access Layer This layer contains all the routines to access the MCU and modem hardware at the most basic level. The application layer typically does not need to access these functions directly. Interrupt Service and Polling Layer This block contains the interrupt service routines for both modem access and MCU to PC UART access.
  • Page 304 AN93 Interrupt Service Routine (ISR) Method Transmitting and receiving data to and from the modem is accomplished by servicing the interrupts generated by the modem. The interrupt sources are described below. Whenever new communication is initiated after a period of idling with respect to the TXE interrupt, the interrupt must be "jump-started"...
  • Page 305 AN93 Figure 76. Parallel- or SPI-Port Interrupt-Service Flowchart Rev. 1.4...

  • Page 306: Document Change List

    Added "6.5. Type II Caller ID/SAS Detection".  Updated for Si2493/57/34/15/04 Revision D.  Added "6.7. Modem-On-Hold".  Added Si2493 and Si2439 configuration and voice functions.  Added "6.12. V.92 Quick Connect". Revision 1.2 to Revision 1.3 Revision 0.6 to Revision 0.7 ...

  • Page 307: Contact Information

    Patent Notice Silicon Labs invests in research and development to help our customers differentiate in the market with innovative low-power, small size, analog- intensive mixed-signal solutions. Silicon Labs' extensive patent portfolio is a testament to our unique approach and world-class engineering team.

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