Silicon Laboratories SI2493/57/34/15/04 Designer's Manual
  1. Manuals
  2. Brands
  3. Silicon Laboratories Manuals
  4. Modem
  5. SI2493/57/34/15/04
  6. Designer's manual
Silicon Laboratories SI2493/57/34/15/04 Designer's Manual

Silicon Laboratories SI2493/57/34/15/04 Designer's Manual

Isomodem chipset family
Hide thumbs Also See for SI2493/57/34/15/04:
Table of Contents

Advertisement

Quick Links

Download this manual See also: User Manual
Si2493/57/34/15/04 (Revision D) and Si2494/39
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, Si2493 Revision D, and the Si2457/34/
15/04 Revision D 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. 1.3 8/11
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
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
SPI
SDO
Interface
SCLK
SS
INT
RESET
Figure 1. Functional Block Diagram
Copyright © 2011 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

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the SI2493/57/34/15/04 and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Silicon Laboratories SI2493/57/34/15/04

Summary of Contents for Silicon Laboratories SI2493/57/34/15/04

  • Page 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.
  • Page 2 AN93 Rev. 1.3...

  • Page 3: Table Of Contents

    2. Modem (System-Side) Device ........
  • Page 4 Required Modem Reset Time ........
  • Page 5 5.7.14. U53 (Modem Control Register 2) ....... . . 106...
  • Page 6 6.7.1. Initiating Modem-On-Hold........
  • Page 7 8.2. Implementing the Ademco® Contact ID Protocol ......228 8.2.1. Modem Specific Implementation Details ......229 8.2.1.1.
  • Page 8 Modem Interrupt Service Sample Code ........

  • 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 2400 Bell 103 1270/1070 Originate/answer (M/S) 2225/2025 Part Numbers Package SOIC-16 Si2493/57/34/15/04 TSSOP-24 Si2493/57/34/15/04 QFN-38 Si2494/39 Notes: 1. Die Revision D or later 2. The EEPROM interface option is available only when the UART or SPI interface is selected. Table 3. Carriers and Tones...

  • Page 11: Modem (System-Side) Device

    For example the INT output pin of the modem (and perhaps others) can be strapped low with a 10 k resistor to request SPI operation. If that mode is chosen, the host should take care not to enable this interrupt input before the modem reset since the INT signal will transition from high to low and back up during reset in this case and can generate an unexpected interrupt.

  • Page 12: Reset Strapping: General Considerations

    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

    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. Mode Interface Input Clock UART...

  • 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 Input Clock Autobaud Three-Wire Disabled? EEPROM Interface? 32 kHz 4.9152 MHz 27 MHz 2.1.4.2.

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

    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 Input Clock Three-Wire EEPROM Interface? 32 kHz 4.9152 MHz 27 MHz 2.1.5. Reset Strapping Options for QFN Parts 2.1.5.1.

  • 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 EEPROM Interface 32 kHz 4.9152 MHz...

  • Page 17: System Interface

    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 GPIO18 GPIO18 GPIO17 GPIO17 GPIO16 GPIO16 GPIO23 GPIO23 GPIO24 GPIO24 MOSI MISO SCLK GPIO11 GPIO11 Rev. 1.3 Parallel Mode...

  • Page 19: Interface Signal Description

    The UART interface allows the host processor to communicate with the modem controller through a UART driver. In this mode, the modem is analogous to an external “box” modem. The interface pins are 5 V tolerant and communicate with TTL-compatible, low-voltage CMOS levels. RS232 interface chips, such as those used on the modem evaluation board, can be used to make the UART interface directly compatible with a PC or terminal serial port.

  • 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

    Symbol Data bits 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. In autobaud mode, 7N1 is properly interpreted and echoed, but the AT\P and AT\B commands must be sent prior to dialing in order to lock the parity and format to 7N1.
  • 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 14-Character Tx Data Hardware Buffer Parallel...

  • Page 23: Parallel And Spi Interface Operation

    The SPI likewise operates with 8-bit data transfers, using a single address bit. When the parallel or SPI interface mode is selected, the modem must be configured for a DTE interface or 8N1 only. The host processor must calculate parity for the MSB.
  • Page 24 AN93 TX FIFO 14 Characters Parallel I/F Register 0 (16) (17) (18) (22) 11 Bits to Data Bus Shared-Serial/Parallel CONTROL Parallel I/F Register 1 (23) (24) Parallel Interface Unique Figure 6. Parallel Interface Rev. 1.3 RX FIFO 12 Characters (10) (11) (15)

  • Page 25: Hardware Interface Register 0

    Hardware Interface Register 0 (HIR0) is the eight-bit wide read/write location where modem data and commands are exchanged with the host. Writing a byte to the HIR0 adds that byte to the modem’s transmit FIFO (AT command buffer in command mode or data transmission in data mode). If data are available (modem data in data mode or command responses, such as OK, in command mode), reading from the HIR0 fetches data from the modem’s receive FIFO.

  • 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. 1.3...

  • 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

    DAA chip. Second, it transfers receive and status data from the DAA chip to the modem chip. Finally, it provides power from the modem chip to the DAA chip while the modem is in the on-hook condition.

  • Page 30: Ssi/Voice Mode (24-Pin Tssop And 38-Pin Qfn Only)

    Figure 10. AT commands HOST Responses TDMA Interface FSYNC Si3000 Voice Codec Figure 10. Voice Mode Block Diagram Pin Number (TSSOP-24) Si24xx Modem FSYNC CLKOUT MCLK Rev. 1.3 Pin Number (QFN-38) 2- wire Si30xx Handset...

  • Page 31: Eeprom Interface (24-Pin Tssop And 38-Pin Qfn Only)

    2.6. 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 32 AN93 Parameter 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. EECS disable time between accesses EECS asserted after final EECLK edge EESD *Note:...

  • Page 33: Three-Wire Spi Interface To Eeprom

    2.6.3. Detailed EEPROM Examples Upon powerup, if the option is selected, the ISOmodem attempts to detect an EEPROM. The modem looks for a carriage return in the first 10 memory locations. If none is found, the modem assumes the EEPROM is not programmed and stops reading it.

  • Page 34: At Command Macros (Customized At Commands)

    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 35: At Command Macro Example

    With this macro installed in the EEPROM, the command ATN<CR> configures the modem for operation in Norway. 2.6.6.3. Autoloading Firmware Upgrade Example This example stores a firmware upgrade in EEPROM that is automatically loaded into the modem after power-up or hardware/software reset if the EEPROM option is selected.

  • Page 36: Combination Example

    AN93 2.6.6.4. Combination Example This example shows boot commands and custom AT commands stored in the same EEPROM. Command BOOT<CR> <commands><CR> <commands><CR> <CR> <Custom AT Command Name 1><CR> <commands><CR> <commands><CR> <CR> <Custom AT Command Name 2><CR> <commands><CR> <commands><CR> <CR> <Custom AT Command Name 3><CR> <commands><CR>...
  • Page 37 Display <NUL> <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> <GS> <RS> <US> Table 30. ASCII Chart Display <space> “ &...

  • Page 38: 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 39: Ac Termination

    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 31. If an ACT[3:0] setting other than the four listed in Table 31 is selected, the ac termination is forced to 600 ...
  • Page 40 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 41 Figure 16. Typical Loop Current LCS Transfer Function Table 32. Loop Current Transfer Function LVCS[4:0] 00000 Insufficient line current for normal operation. 00001 Minimum 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 42: Legacy-Mode Line Voltage And Loop Current Measurement

    Although the DAA remains off-hook during a billing-tone event, the received data from the line is corrupted (or a modem disconnect or retrain may occur) in the presence of large billing tones. To receive data in the presence of a billing tone, an external LC filter must be added.

  • Page 43: Hardware Design Reference

    The crystal oscillator circuit has three operating frequencies/modes that are selected by using the correct clock source and by installing the correct pulldown resistors on the modem in order to signal the ISOmodem which mode to operate. Selecting among these modes of operation is described in "2.1. Resetting the Device" on page 11.

  • Page 44: Ringer Network

    To operate without degradation during billing tones in Germany, Switzerland, and South Africa, an external LC notch filter is required. (The Si3018/10 will remain off-hook during a billing tone event, but modem data may be lost, or a modem disconnect or retrain may occur, in the presence of large billing-tone signals.) The notch filter design requires two notches: one at 12 kHz and one at 16 kHz.
  • Page 45 FROM LINE RING Figure 17. Billing-Tone Filter Table 33. Optional Billing Tone Filters Component Values Symbol 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 46 AN93 VD3.3 IGND Rev. 1.3...

  • Page 47: Schematic

    4.2. Schematic VD3.3 IGND Rev. 1.3 AN93...

  • Page 48: Bill Of Materials

    AN93 4.3. Bill of Materials Component C1, C2 C5, C6, C50, C52 C8, C9 C51, C53 D1, D2 FB1, FB2 Q1, Q3 Q4, Q5 R5, R6 R7, R8 R12, R13 R15, R16 32.768 kHz, 12 pF, 100 ppm, 50 k max ESR Notes: 1.

  • Page 49: Layout Guidelines

    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 34 on page 51 while reviewing the final layout.
  • Page 50 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 51: Isomodem Layout Check List

    U1 Si24HS XTALI XTALO VDD3.3 VDD3.3 VDDB VDDA R12* R13* *Note: Do NOT use ferrite beads in place of R12 and R13. Note: Encircled references are described in the numbered paragraphs in Appendix A. This is not a complete schematic. Only critical component placement and nets are drawn. Figure 21.
  • Page 52 AN93 Table 34. Layout Checklist (Continued) The area of the loop from C50 to U1 pin 4 and from C51 to pin 13 back to pin 12 (DGND) should be minimized. The return traces to U2 pin 12 (DGND) should be on the component side.

  • Page 53: Module Design And Application Considerations

    Bypassing and filtering components should be placed as close to the modem chip as possible with the shortest possible traces to a solid ground. It is recommended that a pi filter be placed in series with the module V Figure 22 on the reset line.

  • Page 54: Analog Output

    When modifying the circuit shown in Figure 23, it is important to examine the reset timing and know that when external reset is applied to the modem, the AOUT pin still has time to rise to VCC due to the pullup installed on it.

  • Page 55: Audio Quality

    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. This requires VCC to be as clean as one wants the call progress audio to be.

  • Page 56: Modem Reference Guide

    SPI interface option, and a DAA interface. An optional voice mode is supported through an SSI interface and an external Si3000 voice codec. The modem software is permanently stored in the on-chip ROM. Only modem setup information (other than defaults) and other software updates need to be stored on the host or optional external EEPROM and downloaded to the on-chip RAM during initialization.

  • Page 57: Dsp

    AT\$ ATSn? ATS$ AT:Rhh AT:R AT+VCID? The examples in Table 36 assume the modem is reset to its default condition. Each command is followed by a carriage return. Table 35. Configuration Status Action Displays status of a group of settings.
  • Page 58 ATS2? AT:R2C The modem has a 48-character buffer, which makes it possible to enter multiple AT commands on a single line. The multiple commands can be separated with spaces or linefeed characters to improve readability. AT, space and linefeed characters are not loaded into the buffer and are not included in the 48-character count. The command line must end with carriage return for the modem to begin executing it.
  • Page 59 Blind dialing (dialing without waiting for dial tone) is enabled by ATX0, ATX1, and ATX3. Whether or not blind dialing is enabled, use of the W dial modifier causes the modem to look for a dial tone before dialing the number string after the W.
  • Page 60 The dial command, which may be followed by one or more dial command modifiers, dials a phone number: Local DTE echo. Disable. Enable. Hook-switch. Go on-hook (hang up modem). Go off-hook. Identification and checksum. Display Si24xx revision code. A = Revision A. B = Revision B, etc.
  • Page 61 Table 39. Basic AT Command Set (Continued) Command ATI1 Revision B Patch (rb_pX_YYYY) AT Command ATI0 ATI1 ATI0 ATI1 Revision C Patch (rc_pX_YYYY) AT Command ATI0 ATI1 ATI0 ATI1 Command Display line-side revision code. 18 (10)C = Si3018/10 Revision C. Display the ISOmodem model number.
  • Page 62 AN93 Table 39. Basic AT Command Set (Continued) Command Speaker Volume Medium High Very High Speaker operation (via AOUT). Speaker is always off. Speaker is on while dialing and handshaking; off in data mode. Speaker is always on. Speaker is off while dialing; on during handshaking and retraining. Return to data mode from command mode.
  • Page 63 Extended results, full CPM. X1 with dial and busy tone detec- tion. Extended results—Full CPM enabled including ringback detection. X4 with ring back detection. Long space disconnect—Modem hangs up after 1.5 seconds or more of continuous space while on-line. Disable data memory access by disallowing :W and :Q Com- mands.
  • Page 64 AN93 Table 39. Basic AT Command Set (Continued) Command 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 65 Table 39. Basic AT Command Set (Continued) Command Special Access Mode—This command enables special modes and data memory access. [sequence] 254:Waaaa,dddd 254:Qaaaa *Y[sequence] Data compression reporting. Mode Disabled Enabled If enabled, the intermediate result code is transmitted at the point after error control negotiation.
  • Page 66 +DS44 = A,B,C,D,E,F,G, *Note: Si2493 only Enable synchronous access mode A – specifies the mode of operation when initiating a modem connection +ES = A, B, C B – This parameter should not be used. C – Specifies the mode of operation when answer a modem...
  • Page 67 0 = Modem transmits abort on underrun in middle of +ESA = frame. A,B,C,D,E,F,G 1 = Modem transmits flag on underrun in middle of frame and notifies host of underrun or overrun. D – Specifies V.34 half duplex operation. This parameter should not be used.
  • Page 68 AN93 Table 39. Basic AT Command Set (Continued) Command Class 1 Transmit Carrier. +FTM = X tocol 1 message. tocol 2 message. Action 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.
  • Page 69 Taiwan United Kingdom United States (default) Note: U registers are configured to Silicon Laboratories’ recommended values. Changes may be made by writing individual registers after sending the AT+GCI command. The +GCI command resets U registers through U86 and S6 (in Japan) to default values before setting country-specific values.
  • Page 70 0 None 1 Local XON/OFF flow control. Does not pass XON/XOFF modem. 2 Hardware flow control (RTS) Specifies the flow control method used by the modem to con- 0 None 1 Local XON/OFF flow control. 2 Hardware flow control (CTS).
  • Page 71 Disables V.92 MOH. V.92 MOH hook flash. This command causes the DCE to go on- +PMHF=X hook and then return off-hook. If this command is initiated and the modem is not On Hold, Error is returned. Action Disabled Enabled (default)
  • Page 72 AN93 Table 39. Basic AT Command Set (Continued) Command Initiate MOH. Requests the DCE to initiate or to confirm a MOH procedure. Valid only if MOH is enabled. +PMHR=X Controls access to MOH request and sets the timeout value. +PMHT=X V.92 Phase 1 and Phase 2 Control.
  • Page 73 Table 39. Basic AT Command Set (Continued) Command 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 sub- sequent connections. Forces the use of full startup procedures on next and subse- quent connections.
  • Page 74 AN93 Table 39. Basic AT Command Set (Continued) Command Transmit Gain Selection. The <gain> parameter has a range of 112-134 with 128 being the nominal value. This represents a range of -48 to 18 dB. The default +VGT is 128 (0 dB). This command is used to control the transmit gain at the DTE to either the Si3000 Codec or the DAA.
  • Page 75 The ISOmodem only uses this command in call origination trans- actions. This command sets the amount of time in 0.1 second units the ISOmodem shall wait between Ringing Tone before it can assume that the remote modem has gone off-hook. Default time is five seconds. +VRID = n Repeat Caller ID.
  • Page 76 AN93 Table 39. Basic AT Command Set (Continued) Command +VSM = n Voice Compression Method. 0 Signed PCM 1 Unsigned PCM 4 G.711 µ-Law 5 G.711 A-Law 129 ADPCM 2-bit (2 kB/s storage) 131 ADPCM 4-bit (4 kB/s storage) +VSP Voice Speakerphone State <mode>...

  • Page 77: Extended At Commands

    &D1 setting bit HES (Enable Hardware Escape Pin, U70 bit 15). Escape pin assertion during a modem connection causes the modem to go on-hook and return to &D2 command mode. The escape pin must be enabled by setting bit HES (Enable Hardware Escape Pin, U70 bit 15).
  • Page 78 Configure ISOmodem for 20 pulse-per-second pulse dialing (Japan) &Tn Test mode. Initiate ITU-T V.54 (ANALOOP) test. Modem mode set by &H. Test loop is through the DSP and DAA interface section of the ISOmodem only. ISOmodem echoes data from TX pin (Hardware Inter- &T2 face Register 0 in parallel or SPI mode) back to RX pin (Hardware Interface Register 0 in parallel or SPI mode).
  • Page 79 Table 40. Extended AT& Command Set (Continued) Automatic determination of telephone line type. Result code: WXYZn 0 = line supports DTMF dialing. 1 = line is pulse dial only. 0 = line supports 20 pps dialing. &X1 1 = line supports 10 pps dialing only. 0 = extension network present (PBX).
  • Page 80 If the HOI bit (U77, bit 11) is set, LINE IN USE is reported upon intrusion. Action Action Report NO LINE and remain on-hook. Report LINE IN USE and remain on-hook. Go off-hook and establish a modem connection. Rev. 1.3...
  • Page 81 4. Default is \T16 if autobaud is selected by reset-strap option; otherwise default is \T9 (19.2 kbps). Action Report NO LINE and remain on-hook. Report LINE IN USE and remain on-hook. Go off-hook and establish a modem connection. Action Rev. 1.3 AN93...
  • Page 82 Disable all flow control—This may only be used if the DTE speed and the line (DCE) speed are guar- anteed to match throughout the call. Use CTS only. Use RTS/CTS. Enable XON/XOFF flow control for modem-to-DTE interface. Does not enable modem-to-modem flow control. DTE rate 300 bps...
  • Page 83 Table 42. Extended AT\ Command Set (Continued) Command 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 \T17...
  • Page 84 6. This message is supported only on the Si2493 and Si2457. 7. V.44 with data compression disabled (+DS = 0) emits this result code. 8. If data compression is disabled (+DS = Q), the modem returns the message PROTOCOL:V42. Table 43. Result Codes...
  • Page 85 6. This message is supported only on the Si2493 and Si2457. 7. V.44 with data compression disabled (+DS = 0) emits this result code. 8. If data compression is disabled (+DS = Q), the modem returns the message PROTOCOL:V42. Table 43. Result Codes (Continued)
  • Page 86 6. This message is supported only on the Si2493 and Si2457. 7. V.44 with data compression disabled (+DS = 0) emits this result code. 8. If data compression is disabled (+DS = Q), the modem returns the message PROTOCOL:V42. Table 43. Result Codes (Continued)
  • Page 87 8018, 8019 Soft-reset command received. V.42 Protocol error. MNP Protocol error. 801c Loss-of-carrier disconnect. 801e Long-space disconnect. 801f Character-abort disconnect. 802a Rate request failed. 802b Answer modem energy not detected. 802c V.8 negotiation failed. TX data timeout. Rev. 1.3 Reason AN93...

  • Page 88: 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 89 ISOmodem disconnects. Set- ting this timer to 255 disables the timer, and the modem does not time out and disconnect. If S10 is less than S9, even a momentary loss of carrier causes a disconnect. Use for V.22bis and lower data rates.
  • Page 90 BLACKLIST FULL result code. Numbers are added to the blacklist only if the modem connection fails. The %B command lists the numbers on the blacklists. 0 – disabled 1 –...

  • Page 91: U Registers

    Additionally, some bits within available U registers are reserved. Any attempt to write to a non- listed U register or to write a reserved bit can cause unpredictable modem operation. There are two types of U registers. The first represents a single 16-bit term, such as a filter coefficient, threshold, delay, or other quantity.
  • Page 92 AN93 Table 46. U-Register Descriptions (Continued) Register Address Name (Hex) 0x000F DT4A0 0x0010 DT4B1 0x0011 DT4B2 0x0012 DT4A2 0x0013 DT4A1 0x0014 0x0015 DTON 0x0016 DTOF 0x0017 BT1A0 0x0018 BT1B1 0x0019 BT1B2 0x001A BT1A2 0x001B BT1A1 0x001C BT2A0 0x001D BT2B1 0x001E BT2B2 0x001F BT2A2...
  • Page 93 Table 46. U-Register Descriptions (Continued) Register Address Name (Hex) 0x002E BMTT 0x002F BDLT 0x0030 BMOT 0x0031 RMTT 0x0032 RDLT 0x0033 RMOT 0x0034 DTWD 0x0035 DMOT 0x0037 0x0038 0x0039 0x003A 0x003B 0x003C 0x003D 0x003E 0x003F 0x0040 0x0042 PDBT 0x0043 PDMT 0x0045 PDIT 0x0046 DTPL...
  • Page 94 AN93 Table 46. U-Register Descriptions (Continued) Register Address Name (Hex) 0x004E PRDD 0x004F 0x0050 LCDN 0x0051 LCDF 0x0052 XMTL 0x0053 MOD2 0x0062 DAAC1 0x0063 DAAC3 0x0065 DAAC4 0x0066 DAAC5 0x0067 ITC1 0x0068 ITC2 0x006A ITC4 0x006C 0x006E 0x006F PTME 0x0070 0x0071 0x0076 GEN1...
  • Page 95 Table 46. U-Register Descriptions (Continued) Register Address Name (Hex) 0x0086 V9AGG 0x0087 SAMCO 0x009F SASF 0x00A0 0x00A1 0x00A2 0x00A3 0x00A4 0x00A5 0x00A6 0x00A7 0x00A8 0x00A9 0x00AA V29MODE This is a bit-mapped register. UIDA 0x01DA Notes: 1. See Table 100 for details. 2.

  • Page 96: U-Register Summary

    AN93 5.7.1. U-Register Summary Table 47. Bit-Mapped U-Register Summary Register Name MOD1 TOCT MOD2 CALT DAAC1 DAAC3 DAAC4 DAAC5 ITC1 MINI ITC2 ITC4 PTME GEN1 GEN2 GEN3 GEN4 GENA GENC GEND XMITDEL V22F V29MODE Bit 9 Bit 8 Bit 7 NHFP NHFD CLPD...

  • Page 97: U00-U16 (Dial Tone Detect Filter Registers)

    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 98: 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 49). The thresholds are empirically found scalars and have no units.
  • Page 99 BPF Biquad Stage 1 Values 310/510 (Default Busy and Dial Tone) 0x0800 0x0000 0x0000 0x0000 0x0000 — 0x0800 0x0000 0x0000 0x0000 0x0000 — 0x0078 0x67EF 0xC4FA 0x4000 0x0214 — 0x0100 0x71CC 0xC777 0x4000 0x81C2 — 0x0800 0x7DAF 0xC1D5 0x4000 0x8000 Table 50.
  • Page 100 The hexadecimal values are stored in the appropriate registers using the AT:Uhh command. Detection parameters can be wider than the minimum specifications. This is often done in the modem defaults and other suggested settings so that one set of parameters can cover a broad number of different country requirements.

  • Page 101: U31-U33 (Ringback Cadence Registers)

    5.7.5. U34–U35 (Dial Tone Timing Register) U34 determines the period of time the modem attempts to detect a dial tone. U35 sets the time within this window that the dial tone must be present in order to return a valid dial tone detection. The value stored in U35 is the hexadecimal representation of the time in seconds multiplied by 7200.

  • Page 102: U46-U48 (Dtmf Dial Registers)

    AN93 Register Name Number of pulses to dial 0. Number of pulses to dial 1. Number of pulses to dial 2. Number of pulses to dial 3. Number of pulses to dial 4. Number of pulses to dial 5. Number of pulses to dial 6. Number of pulses to dial 7.

  • Page 103: U49-U4C (Ring Detect Registers)

    (tone or pulse) for the entire AT command. Bit 7 (SPDM) = 0 (default) causes the modem to pulse dial if an ATDP command is given. If this bit is set to 1 the pulse dial modifier, P, is ignored, and the dial command is carried out as a tone dial (ATDT).
  • Page 104 AN93 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. 1 = Enable. CLPD Check Loop Current Before Dialing.

  • Page 105: U4E (Pre-Dial Delay Time Register)

    5.7.11. U4F (Flash Hook Time Register) U4F sets the time the modem goes on-hook as a result of a “!” or “&” dial modifier (flash hook). The value is stored in the register in milliseconds (see Table 58).

  • Page 106: U53 (Modem Control Register 2)

    Setting this bit to 1 enables reversing transmit and receive speeds. Reversing is initiated by the modem in the “origination mode” (low speed TX and high speed RX). U53 resets to 0x0000 with a power-on or manual reset.
  • Page 107 Si24xx chips. The bit takes effect at the carriage return of the AT command setting this bit high. Once this bit is set, the modem must be reset via the RESET pin to become active. When reset, the modem reverts to the default settings.

  • Page 108: U67-U6A (International Configuration Registers)

    U67 is a bit-mapped register with bits 5:4, 8, 11:10, and 15:14 reserved (see Table 67). U67 resets to 0x0008 with a power-on or manual reset. Bit 7 (DCR) is used to set the dc line termination of the modem. DCR = 0 is the normal mode of operation with dc impedance selected by U67 [3:2] (DCV).
  • Page 109 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. Name 15:14 Reserved Read returns zero. 13:12 MINI[1:0] Minimum Operational Loop Current. Adjusts the minimum loop current at which the DAA can operate. Increasing the minimum oper- ational loop current can improve signal headroom at lower Tip-Ring voltages.
  • Page 110 AN93 Name 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. 0 = 11 to 22 V 1 = 17 to 33 V U68 is a bit-mapped register with bits 15:3 reserved.

  • Page 111: U6C (Line-Voltage Status Register)

    5.7.19. U6E–U7D (Modem Control and Interface Registers) Modem Control and Interface registers include registers U6E, U70–U71, and U76–U79. These are bit-mapped registers that control functions including TX/RX gain, clocking, I/O, SSI codecs, intrusion detection, and LVCS (line voltage current sense).
  • Page 112 AN93 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 113 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. OCDM Overcurrent Detect Mask.
  • Page 114 3 mA units. The default value is 2 (6 mA). Bits 4:0 (ACL): ACL provides a means of detecting a parallel phone intrusion during the time between the modem going off-hook and the U77 [15:12] (IST) time value. If ACL = 0, the ISOmodem has no reference and must use the loop current sample from the first off-hook event as a reference for parallel phone intrusion detection.
  • Page 115 800 , thus, reducing the current. If AOC = 0, the overcurrent condition is only reported by U70 [3] (OCD). Bits 8:0 (OHT) set the delay between the time the modem goes off-hook and LVCS is read for an overcurrent condition. The default value for this register is 30 ms (see Table 75).
  • Page 116 U79 is a bit-mapped register. Bits 15:6 are reserved. Bits 5:0 represent the line voltage, loop current, or on-hook line monitor (see Table 77). While the modem is on- hook, the value in the LVCS register measures loop voltage (see Table 78). This value can be used to determine if a line is connected or if a parallel phone or other device goes off-hook or on-hook.
  • Page 117 See "5.14. Legacy Synchronous DCE Mode/V.80 Synchronous Access Mode" on page 125 for more details on these modes. Bit 0 controls whether the normal ITU/Bellcore modem handshake (default) or a special fast-connect handshake is used. Fast connect is typically used in specialized applications, such as point-of-sale terminals, where it is important to connect and transfer a small amount of data rapidly (see Table 79).
  • Page 118 U7D is a bit-mapped register with bits 15,13:9, and bits 8:2 reserved. U7D resets to 0x4001 with a power-on or manual reset. Bit 14 (NLM) = 0 (default) causes the modem to automatically detect loop current absence or loss. When bit 14 = 1, this feature is disabled.

  • Page 119: U80 (Transmit Delay For V.22 Fast Connect)

    HDLC flags. U80 configures the modem to operate without these tones. Bit 15 turns this function on. After the end of dialing, the modem waits for a time set by U80 [14:0], then begins transmitting scrambled data (or HDLC Flags).

  • Page 120: U87 (Synchronous Access Mode Configuration Register)

    AN93 5.7.21. U87 (Synchronous Access Mode Configuration Register) U87 SAM Synchronous Access Mode Configuration Options Name 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 121: Uaa (V.29 Mode Register)

    This register, which is reset to 0, allows the user to add a delay in increments of milliseconds to the time the modem waits before responding to an answer tone. This is useful in dealing with non-standard answering modems. 5.8. Firmware Upgrades The Si24xx ISOmodem family contains an on-chip program ROM that includes the firmware required for the features listed in the data sheet.

  • Page 122: Method 2

    60 ms, then sampled asserted for at least 60 ms. The modem is then prepared to accept AT commands, regardless of whether OK has been sent to the host. If the modem is already in command mode, the modem does not send OK.

  • Page 123: Escape

    The “escape pin is controlled by U70 [15] (HES). This bit is 0 by default, which disables the escape pin, ESC. If HES is set to a 1, a high level on the ESC pin causes the modem to transition to the on-line command mode. The ESC pin status is polled by the processor, and there is a latency before OK is received and the modem is in command mode.

  • Page 124: Data Compression

    V.42bis, and MNP5 protocols. Data compression attempts to increase throughput by compressing the information to be sent before actually sending it. The modem is thus able to transmit more data in a given period of time. Table 83 details the ISOmodem error correction and data compression modes of operation.

  • Page 125: Epos (Electronic Point Of Sale) Applications

    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) also supports a fast-connect mode based on the 9600 bps V.29 fax modulation standard. V.29 Fast Connect is available as a patch.
  • Page 126 AN93 Prior to sending the ATDT to establish a synchronous access mode connection, the following commands and registers require initialization: +MS, +ES, +ESA, +ITF, +IFC, U87, and U7A. As an example, the closest equivalent to the Legacy Synchronous DCE Mode is the following initialization setting. With either Synchronous Access Submode, once a connection has been established, payload data are multiplexed with command/indicator information by use of <EM>...
  • Page 127 Table 86. EM In-Band Commands and Statuses Command– Transmit Direction Indicator pair Code <EM><t1> 0x5C Transmit one 0x19 byte <EM><t2> 0x76 Transmit one 0x99 byte <EM><t3> 0xA0 Transmit one 0x11 byte <EM><t4> 0xA1 Transmit one 0x13 byte <EM><t5> 0x5D Transmit two 0x19 bytes <EM><t6>...
  • Page 128 AN93 Table 86. EM In-Band Commands and Statuses (Continued) Command– Transmit Direction Indicator pair Code <EM><err> 0xB2 Transmit an Abort <EM><under> 0xB4 not applicable <EM><tover> 0xB5 not applicable <EM><rover> 0xB6 not applicable Resume after a data <EM><resume underrun or overrun 0xB7 >...
  • Page 129 2. The actual value represented in <octnum0><octnum1> = (octnum0 / 2) + (octunum1 x 64) 3. <EM><0x45> indicates that an unrecognized <EM> command was sent to the modem. In addition, a common Point-of-Sale V.22 Fast Connect Handshake Protocol (with transparent HDLC) requires...
  • Page 130 If +ESA[C] = 1, the modem transmits an HDLC flag at the point of the transmit underrun, and the DCE continues to send only HDLC flags until the host sends an <EM><resume> command. The <EM><resume> is then followed by the <EM><unum>...
  • Page 131 <EM><eot> command will cause the modem to go to command mode and stop the transmitter; however, the modem does not go back on hook until ATH. The other method is to use the <EM><esc> command to escape to command mode, and then issue the ATH command. The main difference is that the <EM><esc> does not shut off the transmitter.

  • Page 132: Programming Examples

    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 88 summarizes the modem function/feature and the associated hardware pins, AT commands, S registers, and U registers.

  • Page 133: Country-Dependent Setup

    (the exceptions being an optional maximum ringer impedance, a billing- tone filter, etc.). For this reason, the ISOmodem is truly a global modem solution. Modem initialization commands for various countries are presented in "6.2.2.1. Country Initialization Table". All U-register values are in hexadecimal.

  • Page 134: Country Configuration

    Sweden, on the other hand, requires one pulse for 0, two pulses for 1, and so on. Japan requires both the usual 10 pps pulse dialing and 20 pps pulse dialing. To configure the modem for 20 pps, set U42 (PDBT) = 0x0022, U43 (PDMT) = 0x0010, and U45 (PDIT) = 0x0258. The %P command may also be used.
  • Page 135 Table 90. Country Initialization Table (Continued) Country 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 Brunei* AT+GCI=9C...
  • Page 136 AN93 Table 90. Country Initialization Table (Continued) China Colombia Costa Rica Croatia* Cyprus* Czech Republic Denmark Dominican Republic Dubai Egypt* El Salvador Ecuador *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut. Country Initialization AT+GCI=26...
  • Page 137 Table 90. Country Initialization Table (Continued) Country 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 AT:U35,10E0 AT:U46,9B0...
  • Page 138 AN93 Table 90. Country Initialization Table (Continued) Greece Guadeloupe* Guam Hong Kong Hungary Iceland* India Indonesia Ireland Israel *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut. Country Initialization AT+GCI=46 AT:U14,7...
  • Page 139 Table 90. Country Initialization Table (Continued) Country 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 AT:U35,10E0 Lebanon*...
  • Page 140 AN93 Table 90. Country Initialization Table (Continued) Luxembourg Macao Malaysia Malta* Martinique* Mexico Moldova* Morocco* Netherlands *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut. Country Initialization AT+GCI=69 AT:U14,7 AT:U35,10E0 AT:U46,9B0...
  • Page 141 Table 90. Country Initialization Table (Continued) Country 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 Poland AT:U62,904...
  • Page 142 AN93 Table 90. Country Initialization Table (Continued) Qatar* Reunion* Romania* Russia Saudi Arabia Singapore Slovakia* Slovenia* South Africa Spain Sri Lanka* *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut. Country Initialization AT+GCI=16...
  • Page 143 Table 90. Country Initialization Table (Continued) Country 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 ATS007=50 AT+GCI=1B...
  • Page 144 AN93 Table 90. Country Initialization Table (Continued) United Kingdom Uruguay Uzbekistan Venezuela Yemen Zambia* *Note: These countries do not have a built-in +GCI support but are using the settings of other countries as a shortcut. Country Initialization AT+GCI=B4 AT:U14,7 AT:U35,10E0 AT:U46,9B0 AT:U4F,64 AT:U52,2...

  • Page 145: Country-Setting Register Tables

    6.2.2.2. Country-Setting Register Tables Table 91. International Call Progress Registers Register U0–U14 U17–U2B Value Function Dial Tone Control 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 Busy Tone Detect Filter Coeffi- cients...

  • Page 146: Special Requirements For India

    AN93 Register U37–U40 Table 93. Line Interface/Control Registers Register Bit U67: 13:12 MINI 9 ILIM 6.2.2.3. Special Requirements for India To output a 0 dBm sine wave, use the following commands: AT:PF800, C4DD, 7B5C, 595F AT*Y254:W50, 0, 5B86,1 AT:U46,0 AT*Y1X1DT1 This command string turns off the high-frequency DTMF tone, leaving only the low-frequency DTMF tone when an ATDT is sent.

  • Page 147: Special Requirements For Serbia And Montenegro

    6.2.2.4. Special Requirements for Serbia and Montenegro The following are special network requirements for Serbia and Montenegro. These specifications are based on the best information available and are believed to be correct.  DC Feed: 48 or 60 V Feeding Bridge: 2 x 400  or 2 x 500  ...

  • Page 148: Caller Id

    When the CID signal ends, the ISOmodem hangs up and echoes NO CARRIER to the host. The modem then waits for the normal ring signal. Table 95 shows the AT command strings that configure the ISOmodem for Japan Caller ID.

  • Page 149: Dtmf Caller Id

    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 150 SMS data. To receive Protocol 1 or Protocol 2 data, the host must send AT+FRM = 200. This causes the modem to return to data mode silently, listening for data from the remote SMS server. If the modem detects a valid Protocol 1 or Protocol 2 packet, it responds with a CONNECT 1 or CONNECT 2 message respectively, followed by the SMS message (without channel seizure and mark).

  • Page 151: Type Ii Caller Id/Sas Detection

    The ISOmodem is configured through the +PCW command to toggle the RI pin (+PCW=0), hang up (+PCW=1), or do nothing (+PCW=2) upon receipt of the SAS tone. The default is to ignore the SAS tone. The modem, enabled through the +VCID command, will collect Caller ID information if +PCW is set to toggle the RI pin. The AT:I command can be used to verify receipt of the SAS and CWCID data.
  • Page 152 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 153 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Call Waiting Aruba Tone Call Waiting Australia Tone Austria Waiting Tone Bermuda Waiting Tone Bhutan Waiting Tone Botswana Waiting Tone Brazil Waiting Tone British Virgin Waiting Tone Islands Brunei Call Waiting Darussalam Tone Channel Islands:...
  • Page 154 AN93 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone China Waiting Tone Call Waiting Croatia Tone Call Waiting Cyprus Tone Call Waiting Czech Republic Tone Dominica Call Waiting (Commonwealth of) Tone Call Waiting Ecuador Tone Call Waiting Estonia Tone Call Waiting Ethiopia...
  • Page 155 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Gibraltar Waiting Tone Call Waiting Greece Tone Guyana Waiting Tone Call Waiting Honduras Tone Call Waiting Hong Kong Tone Hungary Waiting Tone Iceland Waiting Tone Iran Waiting Tone Frequency (Hz) Cadence (seconds) 0.1 –...
  • Page 156 AN93 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Call Waiting Israel Tone Call Waiting Japan Tone I Call Waiting Tone Ii Call Waiting Tone Iii Call Waiting Tone Iv Jordan Waiting Tone Call Waiting Kenya Tone Frequency (Hz) Cadence (seconds) 1x(0.15 –...
  • Page 157 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Kiribati Waiting Tone Korea (Republic Of) Waiting Tone Lao P.D.R. Waiting Tone Lithuania Waiting Tone Call Waiting Macau Tone Call Waiting Madagascar Tone Malaysia Waiting Tone Call Waiting Maldives Tone Montserrat Waiting Tone Netherlands...
  • Page 158 AN93 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Waiting Tone Ii Waiting Tone Call Waiting Nigeria Tone Oman Waiting Tone Papua New Guinea Waiting Tone Paraguay Waiting Tone Poland Waiting Tone Call Waiting Portugal Tone Frequency (Hz) Cadence (seconds) 0.25 –...
  • Page 159 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Russia Waiting Tone St.-Kitts-and-Nevis Waiting Tone Call Waiting St. Lucia Tone Call Waiting Saudi Arabia Tone Sierra Leone Waiting Tone Call Waiting Singapore Tone Slovenia Waiting Tone Solomon Waiting Tone Call Waiting South Africa Tone...
  • Page 160 AN93 Table 101. SAS Cadence for Supported Countries* (Continued) Country Tone Call Waiting Sweden Tone I Call Waiting Tajikistan Tone Trinidad and Waiting Tone Tobago Call Waiting Turkey Tone Turks and Caicos Waiting Tone Islands Call Waiting United States Tone Uruguay Waiting Tone Call Waiting...

  • Page 161: 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 162: 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 163 NLIU Line-in-use/No Line Threshold %V2 Command Function AT:R79 Host reads the loop voltage from the LVCS Register U79 bits 4:0 while the modem is on-hook. Command Function ATH1 To go off-hook AT:R79 Host reads loop current from the LVCS Register U79 bits 4:0 while the modem is off- hook.

  • Page 164: Modem-On-Hold

    If the server refuses to grant a modem-on-hold request, the modem will use the +PMHT setting to determine what to do. If +PMHT = 0, the modem will remain connected to the server. If +PMHT is set to a non-zero value, the modems will disconnect.

  • Page 165: Receiving Modem-On-Hold Requests

    The DCD pin will be deasserted while the modem is on hold, and the CONNECT result code will indicate a return to data mode. A modem disconnect due to a timeout or failed negotiation will result in a NO CARRIER result code.
  • Page 166 Beginning of Packet Good Packet. Beginning of Packet If a 1-bit error is received in an HDLC flag, the modem assumes a new single-byte packet. Since a 1-byte packet is invalid, 19 B2 is generated by modem. Beginning of Packet...
  • Page 167 FF 98 89 18 19 B0 Rev. 1.3 Meaning A 1-bit error is received in an HDLC flag. The modem assumes a new single-byte packet. Since a 1-byte packet is invalid, 19 B2 is generated by modem. Good Packet A 1-bit error is received in an HDLC flag. The modem assumes a new single-byte packet.
  • Page 168 HDLC Flag Detected If there is 1-bit error received in an HDLC flag, the modem assumes a new single-byte packet. Since a 1- byte packet is invalid, 19 B2 is generated by the modem. Loss of Carrier Detected Rev. 1.3...

  • Page 169: Overcurrent Detection

    This allows the modem to detect an improper line condition. The overcurrent detect feature is enabled by setting U70 [11] (OCDM) = 1. During the time after the modem goes off-hook, loop current is measured and set by U77 [8:0] (OHT). The default delay is 16 ms. After the delay, current is sampled every 1 ms.

  • Page 170: Method 2: Single Off-Hook Transition

    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 1234 below.

  • Page 171: Telephone Voting Mode

    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 172 AN93 <Value> <Value> Table 108. AT+PQC Parameters 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 109. AT+PSS Parameters Description The DCEs decide whether or not to use the short startup procedures.

  • Page 173: Handset, Tam, And Speakerphone Operation

    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 174 AN93 Table 110. Extended AT+ Command Set (Continued) Command Caller ID Type <n> +VCDT = <n> Caller ID Enable <pmode> +VCID = <pmode> Distinctive Ring Cadence Reporting <enable>,<report>Mode 0, x +VDR = <enable>, 1, 0 <report> codes only. DROF and DRON are reported in 100 ms units. 1, 1 codes as well as well as a Ring result code x/10 seconds after the falling edge of a ring pulse.
  • Page 175 The DCE only uses this command in call origination transactions. This command sets +VRA = <interval> the amount of time in 0.1 second units the DCE shall wait between Ringing Tone before it can assume that the remote modem has gone off-hook. Default time is five seconds. Repeat Caller ID <rmode>...
  • Page 176 AN93 Table 110. Extended AT+ Command Set (Continued) Command Ringing Tone Never Appeared Timer This command sets the amount of time in seconds the DCE will wait looking for Ring- +VRN ing Tone. If the DCE does not detect Ringing Tone in this time period, the DCE shall assume that the remote station has gone off-hook and return an OK result code.
  • Page 177 Table 110. Extended AT+ Command Set (Continued) Command DTMF and Tone Generation This command can be used to produce single-frequency tones and double-frequency tones (i.e. DTMF digit). All three parameters are required for correct operation. <freq1> +VTS = [<freq1>, <freq2> <freq2>, <dur>],[...]...

  • Page 178: Dle> Commands (Dte-To-Dce)

    AN93 7.1.3. <DLE> Commands (DTE-to-DCE) The characters listed in the Code column of Table 111 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 111.

  • Page 179: Dle> Events (Dce-To-Dte)

    7.1.4. <DLE> Events (DCE-to-DTE) 7.1.4.1. Simple Event Reporting Table 112. <DLE> Simple Events (DCE-to-DTE) Code <DLE> 0x10 The DCE will shield a 0x10 character in the voice stream to create a 0x10 0x10 sequence sent to the DTE. <SUB> 0x1A DLE DLE in datastream <ETX>...
  • Page 180 AN93 Table 112. <DLE> Simple Events (DCE-to-DTE) (Continued) Code 0x6F Receive buffer overrun 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 181: Complex Event Reporting

    7.1.4.2. Complex Event Reporting Table 113. <DLE> Complex Event Reports (DCE-to-DTE) Response 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 182 AN93 Table 114. Voice Mode U Registers (Continued) Register Address U156 0x0156 U157 0x0157 U158 0x0158 U159 0x0159 U15A 0x015A U15B 0x015B U15C 0x015C U15D 0x015D U15E 0x015E U15F 0x015F U160 0x0160 U161 0x0161 U162 0x0162 U163 0x0163 U164 0x0164 U165 0x0165 U166...
  • Page 183 Table 114. Voice Mode U Registers (Continued) Register Address Name U16B 0x016B HRXFIR1 U16C 0x016C HRXFIR2 U16D 0x016D HRXFIR3 U16E 0x016E HRXFIR4 U16F 0x016F HRXFIR5 U170 0x0170 HRXFIR6 U171 0x0171 HRXFIR7 U172 0x0172 HRXFIR8 U173 0x0173 HRXFIR9 U174 0x0174 HRXFIR10 U175 0x0175 HRXFIR11...
  • Page 184 AN93 Table 114. Voice Mode U Registers (Continued) Register Address U1A0 0x01A0 U1A1 0x01A1 U1A2 0x01A2 U1A3 0x01A3 U1A4 0x01A4 U1A5 0x01A5 U1A6 0x01A6 U1A7 0x01A7 U1A8 0x01A8 U1A9 0x01A9 U1AA 0x01AA U1AB 0x01AB U1AC 0x01AC U1AD 0x01AD U1AE 0x01AE U1AF 0x01AF U1B0...
  • Page 185 Table 114. Voice Mode U Registers (Continued) Register Address Name U1B5 0x01B5 SRXFIR1 U1B6 0x01B6 SRXFIR2 U1B7 0x01B7 SRXFIR3 U1B8 0x01B8 SRXFIR4 U1B9 0x01B9 SRXFIR5 U1BA 0x01BA SRXFIR6 U1BB 0x01BB SRXFIR7 U1BC 0x01BC SRXFIR8 U1BD 0x01BD SRXFIR9 U1BE 0x01BE SRXFIR10 U1BF 0x01BF SRXFIR11...
  • Page 186 AN93 Table 115. Name Bits Bit8 15-9 U199 VPCTRL SSP_LOCTALK SSP_PTT SSP_FLAG U19E AECREF SPKREF The SMUTE bit (U199 [1]) mutes the speaker output audio path. The bit should be cleared for normal speakerphone operation. For recording during hands-free TAM, the bit should be set to mute the speaker output. The MMUTE bit (U199 [3]) mutes the microphone input audio path.

  • Page 187: 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 188 AN93 Rev. 1.3...
  • Page 189 AN93 Rev. 1.3...
  • Page 190 AN93 Table 117. Voice Mode Operations (+FCLASS=8) +VLS Mode Primitive None On-Hook Off-Hook On-Hook Off-Hook M1S1T Off-Hook On-Hook Off-Hook On-Hook Active Description Detectors Ring, CID1 Voice mode is disabled. TAM operation for call answer with OGM playback FDV DTMF and record message using 2Tones* DTE voice stream pass through with no audio moni-...
  • Page 191 Detectors Ring, CID1 Await call with tone genera- FDV DTMF tor connections to AOUT for 2Tones* control beeps, ring tone, etc. Current Modem Settings +VNH = 1 +VNH = 2 +VNH = 0 OFF-HK, ON-HK, +VNH = 0 +FCLASS = 0...

  • Page 192: Si3000 Configuration

    7.3.3.4. Handset This mode is used to conduct a private voice call. The modem is off-hook and routing audio between the Si3000 and DAA. The modem voice path is configured for full-duplex audio with speakerphone algorithm disabled. Side tone is enabled.

  • Page 193: Tam Pstn

    DAA and the DTE interface; however, audio is also available at the Si3000 (via UB5 path) so call screening is possible via the speaker (LINEO) while the microphone is muted. The modem voice path is configured for half-duplex audio with the speakerphone algorithm disabled. Side tone is disabled. Handset TX/RX coefficients are applied.

  • Page 194: Initialization

    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 31. After initialization, the system will be in the TAM Hands-Free mode, which is discussed in "7.3.3.1.
  • Page 195 Table 119. Initialization Sequence (Continued) AT:U196,5000 AT:U197,2000 AT:U19C,2400 AT:U19D,1800 AT:U19A,01E0 AT:U19B,001F AT:U04F,01F4 AT:U156,FF10,FFA2,FFD7,FF35,FEF3,FE68,FB7E AT:U15D,F90C,FDDF,091D,4F51,091D,FDDF,F90C AT:U164,FB7E,FE68,FEF3,FF35,FFD7,FFA2,FF10 AT:U16B,0041,00B1,00AA,0001,FF92,0042,0183 AT:U172,0165,FEC0,FB05,3940,FB05,FEC0,0165 AT:U179,0183,0042,FF92,0001,00AA,00B1,0041 AT:U1A0,0000,0000,0000,0000,0000,0000,0000 AT:U1A7,0000,0000,0000,0000,0000,0000,0000 AT:U1AE,0000,0000,0000,0000,0000,0000,4000 AT:U1B5,0173,0273,045A,043B,0121,FD54,FE41 AT:U1BC,0197,0543,FD03,30D6,FD03,0543,0197 AT:U1C3,FE41,FD54,0121,043B,045A,0273,0173 AT:U72,0108 AT:U72,05D7 AT:U72,065E Set output limiter threshold gain. Set input limiter threshold gain. Set AEC reference gain. Set AEC microphone gain.

  • Page 196: Handset

    This mode uses the voice pass-through connection to route SSI data between the Si3000 and the DAA. The modem remains in AT command mode and provides V.253 event notifications. The host controller is responsible for detecting the status of the handset position. The following sections provides detailed examples of originating and answering a voice call with the handset.
  • Page 197 Host to Modem Commands / Data AT:U199|A AT+VLS=0 AT+VLS=13 AT:U0B1,0500 AT:U0B5,0200 AT:U72,0110 AT:U72,05B3 AT:U72,065C AT:U72,075E AT:U72,0900 AT+VSP=0 AT:U199&FFF5 Table 120. Handset Configuration Modem to Host Result Codes/ Data Mute the microphone and speaker paths to the codec. Disable voice mode. Used as a transition point between non-zero +VLS voice modes.

  • Page 198: Call - Automatic Tone Dial

    Configuration procedure defined in Table 120 should be used to answer the call. For ring detection and local ring tone/melody generation, see "7.6.2. TAM Hands-Free—Idle" . Codes/Data Perform automatic tone dial of 102. Modem will return OK. Depending on the number of rings the host may receive <DLE><r> events for ring-back notifications. If the line is busy, a <DLE><b>...

  • Page 199: Terminate

    Disable voice mode. Used as a transition point between non-zero +VLS voice modes. Setup on-hook voice mode. See details. This will return the modem to on-hook state. Disable Si3000-to-DAA transmit gain path. This ensures codec tones are not sent to the FDV and DTMF.

  • Page 200: Speakerphone Transition

    Speakerphone mode, the system will switch back to Handset configuration without losing the active call. Table 125. Handset to Speakerphone Transition Host to Modem Modem to Host Result Commands / Data AT:U199|A AT:U72,0108...

  • Page 201: Telephone Answering Machine

    TAM PSTN mode also permits remote OGM and ICM record/review via DTMF tone control. The +VTX command is used to play voice menu options/prompts. All the use cases in this section start with the modem in TAM Hands-Free mode, which is configured in the initialization sequence in Table 119 on page 194.

  • Page 202: Record Ogm

    <DLE><u> and <DLE><d> commands. The host voice driver will need track the number of adjustments and update the +VGR value for future use. Terminate the receive operation. The modem will <DLE><ETX> respond with <DLE><ETX> to mark the end of the data stream.

  • Page 203: Review Ogm

    Using the handset to record the OGM will result in better message quality. The handset can also be used to screen messages in private. The host will need to correctly process the Handset Raised Event to keep the modem on- hook during record/review operations.
  • Page 204 AN93 Table 129. TAM Handset Record OGM Host to Modem Commands / Data AT:U199|A AT:U72,0110 AT:U72,05B3 AT:U72,065C AT:U72,075E AT:U72,0900 AT+VGR=128 AT:U0B1,0500 AT+VSD = 129 AT+VSM = 4 AT+VTS = [1000,0,100] AT:U199|8 AT:U199&FFFD Modem to Host Result Local Modem Actions Codes/Data Mute the microphone and speaker paths to the codec.
  • Page 205 +VGR value for future use. Terminate the receive operation. The modem will respond with <DLE><ETX> to mark the end of the data stream. The OK denotes the return to command mode. A Handset Lowered Event, timeout, or silence event can trigger the <DLE><!>...

  • Page 206: 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. The host will need to ensure the Handset Lowered Event is received before Table 130. TAM Handset Review OGM Host to Modem Commands / Data AT:U199|A AT:U72,0110...
  • Page 207 The host voice driver will need track the number of adjustments and update the +VGT value for future use. Terminate the transmit operation. The modem will respond with OK to denote the return to command mode. Mute the microphone and speaker paths to the codec.

  • Page 208: Record Local Icm

    7.6.4. TAM PSTN This system voice mode differs from the TAM Hands-Free and TAM Handset modes in that the modem is off-hook and connected to the PSTN. Due to the paired nature of the +VGR and +VGT, the voice driver should maintain two copies of each: one for RS232-to-Si3000 and another for RS232-to-DAA.
  • Page 209 +VGT value for future use. Terminate the transmit operation. The modem will respond with OK to denote the return to command mode. Select G.726 ADPCM, 4-bit, 32 kbps for- mat.

  • Page 210: Interrupted Answer - Ogm Playback With Dtmf Menu Entry

    DTMF digits that comprise the remote password. Table 132. TAM PSTN Interrupted Answer – OGM Playback with DTMF Menu Entry Host to Modem Commands / Data AT+VTS=[700,500,80] AT+VTS=[700,500,80]...
  • Page 211 DTMF 4 digit detected. The password of <DLE><4> 1234 has been matched. Abort answer <DLE></> sequence. Terminate the transmit operation. The modem will respond with OK to denote the return to command mode. Rev. 1.3 AN93 Local Modem Actions for details.

  • Page 212: Speakerphone Transition

    +VRX. A DLE<R> event report is sent to the DTE when a SAS Call Waiting tone is detected. If a CAS tone is detected, the modem mutes the Si3000 speaker while Caller ID Type II data are being captured. It then reports Caller ID info to the DTE as a DLE-shielded complex event.

  • Page 213: External Microphone/Speaker Calibration

    Figure 32. Transmit Gain Reference Measurements Figure 33 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 134.
  • Page 214 AN93 Figure 33. Transmit Gain Configuration Rev. 1.3...
  • Page 215 0 dB Line Out attenuation 0 dB Speaker output attenuation Setup off-hook voice mode. See Table 115 on page 186 for details. This command will switch the modem to off- hook state. The default value is +VSP=0 for disabled speakerphone.

  • Page 216: Receive Gain Calibration-Speakerphone Disabled

    Figure 34. Receive 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 135.

  • Page 217: Speakerphone Calibration-Aec Gain Calibration

    Figure 36 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. Using the Si24xx-VMB, call the remote phone and establish a voice call.
  • Page 218 Use calibrated value from “Receive Gain Calibration – Speakerphone Disabled” section. Setup off-hook voice mode. See Table 122 on page 198 for details. This command will switch the modem to off- hook state. Enable speakerphone voice path. See Table 136 for details.

  • Page 219: Speakerphone Configuration

    The UB1, UB5, UB6, and Si3000 register configurations vary with the customer’s production hardware. The UB5 register serves as the general volume control in this mode. Table 136. Speakerphone Configuration Host to Modem Commands / Data AT:U199|A AT+VLS=0 AT+VLS=13...

  • Page 220: Simplex Speakerphone Configuration

    AT:U199&FFF5 7.7.5. Simplex Speakerphone Configuration Configuring the modem to automatically switch between local talker and remote talker is as follows:  For the SSP auto-switch (VOX) function, set SSP_FLAG to 1 (U199 [6] = 1) and SSP_PTT to 0 (U199 [7] = 0).

  • Page 221: Call-Automatic Tone Dial

    Disable break-through Enable SSP, configure for automatic switch mode Codes/Data Perform automatic tone dial of 102. Modem will return OK. The user will not receive <DLE> events for dial tone, ring-back, busy, and quiet since the detectors are disabled. See Table 117 for details on active detectors.

  • Page 222: Call-Automatic Pulse Dial

    AT:U72,065C AT:U72,075E Codes/Data Perform automatic pulse dial of 102. Modem will return OK. The user will not receive <DLE> events for dial tone, ring-back, busy, and quiet since the detectors are disabled. See Table 122 on page 198 for details on active detectors.

  • Page 223: Termination

    Table 141. Speakerphone to Handset Transition (Continued) AT:U72,0900 AT+VSP=0 AT:U199&FFF5 7.7.11. Termination A SP Button Off Event (Handset On-Hook) will cause the system to return to the TAM Hands-Free mode. Use the same configuration listed in Table 124 on page 199. Note the voice driver is responsible for tracking the handset hook-switch state.

  • Page 224: Security Protocols

    1. Prior to making the call, the host issues AT+VNH=2 to modem. This will keep the modem off-hook when the host clears down the FSK data connection using ATH. 2. After the modem has negotiated a Listen-in period using the SIA protocol in Bell 103, the host clears down the FSK data link with ATH.

  • Page 225: Considerations When Disconnecting The Session

    Because AT+VNH=2 keeps the modem off-hook during a cleardown, the first ATH or DTR desertion will not put modem back on-hook but only force AT+VNH=0 (per V.253). The host must issue a second ATH to put the modem back in on-hook idle state. Alternatively the host could issue a AT+VNH=0, then ATH (or AT+VNH=0;H) Table 142 lists the AT Commands provided to support SIA Level-3 Protocol communication.
  • Page 226 DTE. It is usually a +F3(ACK), +F4(NACK) or +F5(ACK followed by Data Block transmission) command. Note1: Modem will wait for up to 1 second to detect >12T marks before unclamping RXD. After 1 sec- ond RXD will be unclamped regardless.
  • Page 227 When it comes as a response to the +F2 command, “OK” means ACK In SIA FSK mode, CONNECT means that the modem is in the data passing state ready to receive or transmit data. Note: there is an extra space character between the letter T and the carriage return delimiter.

  • Page 228: Implementing The Ademco® Contact Id Protocol

    AN93 8.2. Implementing the Ademco 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 229: Modem Specific Implementation Details

    Low Tone (Hz) 1400 Host commands modem to send DTMF digit 0. Modem responds with 5 characters as it receives two DTMF tones: 1 and 2. There are 2 preamble and 1 postamble characters in this example. Contact ID Protocol Tone Transmission AT Commands...

  • Page 230: Handshake Tone Detection

    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...
  • Page 231 Table 145. Ademco Step DTE-to-Modem Command AT:U181,78,0,0,1C ATDnnnnnnn AT+VTD=5;:U48,32 Wait for RECEIVER to answer with handshake tones AT:U181,334,0,0,12C Delay 250 ms before transmitting Data Tones message. ® Mode of Operation (Continued) Modem-to-DTE Indication Set up 1400 Hz detector to detect 100 ms Handshake tone burst.
  • Page 232 Octet D as A Octet E as B Octet F as C Note: OK is sent at end of trans- mission. 1.25 s has elapsed. But modem still has not reported <DLE><c> to DTE 01AF Check to see if start of a Kissoff Tone has been detected? A non zero response (i.e.
  • Page 233 Table 145. Ademco Step DTE-to-Modem Command AT:U48,64 Repeat from Step 6 for next call ® Mode of Operation (Continued) Modem-to-DTE Indication Restore DTMF parameters to comply with normal dialing requirements. Rev. 1.3 AN93 Remarks...

  • Page 234: Chinese Epos Sms

    The Answer modem recognizes which protocol is being sent and processes the incoming message accordingly. The modem strips off the Channel Seizure and Marks at the beginning and end of the data and provides the Data Frame to the host processor. It does not provide frame content verification of any kind.

  • Page 235: Sms At Command Set

    HES (Enable Hardware Escape Pin): U70, bit 15. ESC (pin 22) assertion during a modem connection causes the modem to go on-hook and return to com- mand mode. The escape pin must be enabled by set- ting bit HES: U70, bit 15.

  • Page 236: Sms User Registers

    10 ms units. Timed from the termination of the previous signal. Time that the Answer modem waits for the received sig- nal after it receives the +FRM command; in 10 ms units V.29FC Answer Tone Detector Threshold (in ms).

  • Page 237: Procedure

    Many SMS POS protocols perform handshaking using CAS and CAS ACK. CAS is a two-tone signal (2130 Hz / 2750 Hz); CAS ACK is a DTMF ‘D’. The terminal modem connects to the server, which sends CAS tones until it times out or the terminal modem replies to the server with CAS ACK.

  • Page 238: Response 1

    After a frame has been sent, the modem response will be: <CR><LF>OK<CR><LF> On the answer modem side, the command AT+FRM=200 causes the receiver to look for at least 32 bits of CS and for at least 60 bits of marks. The answer modem detects the protocol of the transaction by whether CS comes before the marks.

  • Page 239: Example Session

    "AT:UCA,0,12C,4E<CR>" ;Set SMS POS parameters waitfor "OK" transmit "ATD<phone number here>;<CR>" waitfor "OK`x0d`x0a" The ’;’ at the end of the dial string returns the modem to command mode after dialing. The modem will issue an OK after dialing. transmit "AT:UD1,3C<CR>" waitfor "OK"...
  • Page 240 AN93   Figure 38. Diagram of Handshake (Using CAS/CAS ACK) and Message Packet Exchange CAS Ack (Complete the CAS Handshake) Send FSK Packet Send FSK Packet Send FSK Packet Rev. 1.3 Server TS  2...
  • Page 241 For Figure 39, 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.                  ...

  • Page 242: Testing And Diagnostics

    The dc voltage across Tip and Ring should read approximately 40–52 V with the phone on-hook.  Reset the Modem Do a manual reset on the modem. Hold ISOmodem pin 12 (RESET) low for at least 5 ms, return to V and wait for at least 300 ms before executing the first AT command. ...

  • Page 243: Host Interface Troubleshooting

    If the modem goes off-hook and draws loop current as a result of giving the ATH1 command, go to "10.1.6. Si3018/10 Troubleshooting". If the modem does not go off-hook and draw loop current as a result of giving the ATH1 command and receiving an OK message, begin troubleshooting with the isolation capacitor at the ISOmodem. First, check all solder joints on the isolation capacitors, Si3018/10, and associated external components.

  • Page 244: Isolation Capacitor Troubleshooting

    AT<CR>. If an OK response is received, make a connection to the remote modem as in the previous step. If no OK response is received, debug host interface and/or software. If a connection is successful, go to the next step to isolate the problem in the prototype modem.
  • Page 245 Remove modem module from EVB  Disconnect host outputs from prototype modem  Connect EVB RS232 transceivers to prototype modem  Use PC with HyperTerminal to test prototype modem Figure 41. Test the Prototype Modem Si24xx Si3018 Si24xx Si3018 Figure 40. Test the Host Interface...
  • Page 246 Connect EVB C1 and C2 to the Si3018 pad of prototype system C1 and C2.  Connect the phone line to the RJ11 jack on the prototype system.  Use PC and HyperTerm and attempt to establish a modem connection. Figure 42. Test the Prototype Si3018/10 Circuitry Host Host...
  • Page 247 On-Hook DCT2 IGND DCT3 0.5 V 0.9 V ~2.3 V VREG VREG2 ~1.0 V RNG1 RNG2 ~1.0 V Voltages measured with respect to IGND (Si3018 pin 15) Figure 44. Si3018/10 Typical Voltages Table 148. Resistance to Si3018/10 Pin 15 Si3018/10 Pin 1 Pin 2 Pin 3...
  • Page 248 AN93 Table 149. Resistance across Components Si3018/10 Note: If two values are given, the resistance measured is dependent on polarity. Table 150. Voltages across Components with Diode Checker Q1, Q3, Q4, Q5: Base (red lead) to Emitter (black lead) Base (red lead) to Collector (black lead) (Verifies transistors are NPN) Emitter (red lead) to Base (black lead) Collector (red lead) to Base (black lead)

  • Page 249: Self Test

    Table 40 on page 77. The test is started with an AT&T2 or AT&T3 command. During the test, the modem is in data mode. To end the test, escape data mode using one of the “Escape” methods, such as +++, and end the test with ATH.

  • Page 250: 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 251: Isdn Modem

    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 47, 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 252: Compliance Testing

     It is not possible to configure the output tone to be as if from the answering or originating modem.  It is not possible to configure the data rate used in an analoop connection within a given modulation.

  • Page 253: Emi

    S41 register. If an invalid combination of data/symbol rate is selected, the modem chooses a valid symbol rate. It is the responsibility of the operator to select valid combinations for testing.

  • Page 254: 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 48. In a cost-optimized design, compliance to UL1950 does not always require overvoltage tests.

  • Page 255: 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 49.

  • Page 256: 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 257: Appendix A-Epos Applications

    Connect, have been adopted to reduce the transaction time. Some server manufacturers make changes to the modem with the intent of making it difficult for competing terminals to connect. Many EPOS servers have out-of- specification clocks and use reduced handshake timing. V.22bis (2400 bps) is occasionally used in EPOS terminals as well.

  • Page 258: Recommendation V.80

    SCC, while the modem performs strict data pump function. However, given the broad availability of UARTs, HDLC handling can be performed by the modem also. To facilitate this system partitioning, the V.80 protocol is used. V.80 allows the multiplexing of data, control, and status information so that the host processor can specifically control what frames are sent to, or received from, the modem across the asynchronous UART (DTE) interface.
  • Page 259 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 260: The Isomodem In Epos Applications

    A V.80 interface to V.29 Fast Connect is not supported on Rev B silicon and can be accomplished only as a patch on Rev C. Please contact Silicon Laboratories, Inc. for latest patch. "5.8. Firmware Upgrades" on page 121 outlines how to use this patch.

  • Page 261: A V.29 Fastpos Sample Program

    The description here shows how to set up and use the modem for V.29 FastPOS and also provides a sample program along with both a DTE trace and WAV files that capture what is happening at both ends of the modem.
  • Page 262 AN93 3. DTR is assumed to be connected to the ESC pin of the modem. It has been programmed to HANG UP when DTR is negated. 4. When the modem is in RECEIVE operation (RTS negated), it is not possible to communicate with the modem.
  • Page 263 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); int main(int argc, char* argv[]) // Initialize these buffers.
  • Page 264 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 cpInputRd = SendAndWaitFor("AT+ESA=0,0,0,,1\r", cpInputRd, "OK\r\n", 300);...
  • Page 265 AssertRTS(true); //RTS=1 for transmitting Delay(300); //Delay to allow the line to turn around iLength = strlen(caUA_PKT_STR); WriteFile(hCom, caUA_PKT_STR, iLength, &ulNoOfbytes, 0); Delay(100); while(1) // Short training happens now! AssertRTS(false); printf("RTS=0 Rx "); cpInputRd=WaitForResponse(caRX_PKT_STR,cpInputRd,3000);//Rx RR message iLength = strlen(cpInput_test); for (int i=0; i<iLength; i++) printf("%02x ", (unsigned char)cpInput_test[i]);printf("**%d //Alternatively use CTS Delay(150);...
  • Page 266 AN93 // Build on the current configuration, and skip setting the size // of the input and output buffers with SetupComm. bSuccess = GetCommState(hCom, &dcb); if (!bSuccess) // Handle the error. printf ("GetCommState failed with error %d.\n", GetLastError()); exit(1); // Fill in DCB: 57,600 bps, 8 data bits, no parity, and 1 stop bit. dcb.fBinary = TRUE;...
  • Page 267 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. If this times out or ERRORs before the response is found then a // NULL is returned; It keeps reading the ser channel while waiting char *WaitForResponse(char *cpResponse, char *cpInputBuffer, int iTimeOutInMs) unsigned long ulNoOfbytes;...
  • Page 268 AN93 sCurrentTime = clock(); iPasses++; if( sCurrentTime > (sStartTime + sWaitTime) ) strcat(cpErrorString, "Timeout of "); printf ("\n%s\n", cpErrorString); strncpy(cpInput_test, cpInputBuffer, iCharCnt); cpInput_test[iCharCnt]='\0'; //copy the received bytes for late display return cpInputBuffer; // ------------------------------------------------------------------------- void AssertRTS(bool bAssert) BOOL bSuccess; if(bAssert) dcb.fRtsControl = RTS_CONTROL_ENABLE;...
  • Page 269 > clock() ) void LoadAndSendPatch(void) char caOutGoing[256]; cpInputRd_temp = SendAndWaitFor("AT&T7\r", cpInputRd, "OK\r\n", 300); // Reset the modem printf ("Current %s \n", cpInputRd); cpInputRd=cpInputRd_temp; printf ("Loading patch:%s...\n", fnamePatch); if ((hpPatchFile = fopen(fnamePatch, "rb")) == NULL) fprintf(stderr, "The Patch File is missing.\n");...
  • Page 270 AN93 cpInChar[0] = fgetc(hpPatchFile); strcat(cpIn, cpInChar); if(*cpInChar == '\n') return TRUE; return FALSE; Rev. 1.3...
  • Page 271 DTE sends the calling modem a UA packet to transmit: <0x30>(0x73><EM><0xB1> Calling modem is receiving. Sends a Tx abort to DTE: <EM><0xB2> Then the received RR packet: <30><EM><0xA0><EM><B1> Rev. 1.3 AN93 Repeat DTE sends the calling modem an RR packet to transmit: <30><EM><0xA0><EM><B1>...
  • Page 272 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 LF O CR LF O CR LF LF O CR LF EM BE $ EM B1 0...

  • Page 273: 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 274 1. Click Start->Settings->Control Panel->Sounds and Multimedia to open the “Sounds and Multimedia Properties” window. 2. Click Audio Tab; click Volume to open the “Recording Control” window. 3. Select Microphone as input; adjust balance and volume. Figure 52. Hardware Setup Rev. 1.3 Connect the R11 jack in parallel with Tip/Ring of modem...
  • Page 275 AN93 Figure 53. Sounds and Multimedia Properties Setting PC Microphone Input for Recording (Windows 98) Use the following procedure: 1. Select Start->Settings->Control Panel->Multimedia Properties to open the Multimedia Properties window. 2. Select the “Audio” tab and then the “Recording” icon to open the Recording Control window. 3.
  • Page 276 AN93 Figure 54. Multimedia Properties Setting PC Microphone Input for Recording (Windows XP) Use the following procedure: 1. Select Start->Control Panel->Multimedia Properties to open the Sounds and Audio Devices Properties window. 2. Select the Audio tab and then the Sound Recording volume button to open the Recording Control window. 3.
  • Page 277 AN93 Figure 55. Sounds and Audio Devices Properties Rev. 1.3...
  • Page 278 AN93 Making the Recording with Windows Sound Recorder (Windows XP, NT or Windows 98) Use the following procedure: 1. Click Start->Programs->Accessories->Entertainment->Sound Recorder to open “Sound Recorder” window 2. Select the red record button to start recording, then File->Save when done. Figure 56.

  • Page 279: 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 280 AN93 Figure 59. 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 281 AN93 Figure 60. 256 Band Spectral Display Figure 61. 2048 Band Spectral Display Rev. 1.3...
  • Page 282 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 62.
  • Page 283 Details of Some Low-Speed Protocols The following annotated recordings give basic ideas of what to expect the EPOS modem transactions will look like. There are many possible variations of these examples, both in and out of compliance with published standards, in common use.
  • Page 284 This looks the same as the V.22 bis protocol above except for S1 signal used for signaling V.22 bis(ness) and for start of retrains. 2100 Hz Answer Tone. DTMF dialing. Figure 67. Appearance of V.22 Fast Connect Protocols Rev. 1.3 Answering modem’s scrambled binary ones and scrambled data; visually indis- tinguishable from each other.
  • Page 285 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 286 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 69. Examples of EPOS Server Misbehavior Rev. 1.3...
  • Page 287 The Answer Tone is too short at 400 ms. Innocent, answer modem generated, guard tone. Figure 70. Example of EPOS Server Misbehavior Rev. 1.3 AN93...

  • Page 288: Examples Of Line Impairments

    AN93 Examples of Line Impairments DTMF Distorted by Low Line Level 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. Figure 71. Defective DTMF Figure 72.
  • Page 289 Figure 73. 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.  Ground the system to earth or float completely using a battery. ...

  • Page 290: Appendix C-Parallel/Spi Interface Software Implementation

    SPI mode. Sample code was developed to run on the Silicon Labs C8051F12xx platform to allow basic communication between the modem and a PC using the parallel or SPI interface. Figure 74 shows a typical connection between a PC and the modem using the MCU C8051F12xx demo board as interface: Figure 74.
  • Page 291 Figure 75 illustrates the MCU software architecture, and the MCU and modem hardware connections. Application layer Buffer  management  layer status_control.c Interrupt service  and/or polling Hardware access layer modem_hardware.c Parallel interface Parallel interface Modem Hardware Interface  Register 1 (HIR1) Figure 75. MCU Software and Modem Interface modem_main.c application_buffers.c ISR_and_polling.c SPI master SPI slave UART interface...

  • Page 292: Software Description

    This code can be ported to other applications with minimal changes needed to compile on a given host platform. This file contains code to read from or write to the modem. The two functions below provide basic access to the...
  • Page 293 Polling HIR1 Method Transmitting and receiving data to and from the modem is accomplished by polling HIR1 status bits TXE and REM. Polling is implemented by the following code fragment, excerpted from modemCommunicationUpdate() , which must run in an infinite loop: static char bytesToSend == 12;...
  • Page 294 FIFO to clear the interrupt condition, or by clearing the TXE bit in the HIR1. However, if the FIFO is emptied by the modem faster than it is being filled, the TXE interrupt will either persist or trigger again.
  • Page 295 AN93 Figure 76. Parallel- or SPI-Port Interrupt-Service Flowchart Rev. 1.3...
  • Page 296 BUFFERSIZE ]; The above buffer is typically filled by UART0Interrupt() and emptied by modemInterrupt() . Once the buffer is empty, subsequent TXE (modem) interrupts have no effect. If the buffer is filled again after all TXE interrupts have...
  • Page 297 AN93 Figure 77. Circular-Buffer Flowchart Rev. 1.3...
  • Page 298 Sample code for this layer can be found in status_control.c file. This code can be ported to other applications with minimal changes needed to compile on the host platform. The modem status may be queried, and modem control flags may be set using the two functions below: void setControl( char controlCode, char action, char condition ) : Set modem control.

  • Page 299: Compiler Option: Dot Commands

    The modem attempts to empty and fill these buffers as quickly as possible. This results in transmit and receive data bursts at a much faster rate than the modem connection. The receive bursts are limited by the V.42 frame size and the V.42bis data compression ratio.

  • Page 300: Modem Interrupt Service Sample Code

    AN93 Modem Interrupt Service Sample Code The following is the C code for the modem ISR. Also refer to "Figure 76. Parallel- or SPI-Port Interrupt-Service Flowchart" for more explanations. Please contact Silicon Labs to obtain a complete C8051F12xx project bundle.
  • Page 301 // Note: If the host cannot empty its queue fast enough to keep up with the // modem or if it is going to have a long period of time (>:U6F setting) where // there won't be room in the FIFO, it would be better to completely disable // the interrupt until the host has made room for more data.
  • Page 302 AN93 // Insert code here to inform the host of the U70 interrupt // or service it application dependent), e.g. gU70Interrupt = 1; // ***TXE INTERRUPT*** if ( TXEInterrupt ) // Clear the data sent counter BytesSent = 0; // The transmit FIFO is fourteen bytes deep, therefore upon TXE interrupts // (two bytes or fewer in the transmit FIFO), it is possible to send up to // twelve bytes to the part without risking overflow.

  • Page 303: Document Change List

    Correction to SPI and 32.768 kHz and SPI strapping tables.  Added several registers.  Removed Appendix D.  Updated for Si2493/57/34/15/04 Revision D.  Added Si2493 and Si2439 configuration and voice functions. Revision 1.2 to Revision 1.3  Added Si2494 and Si2439 configuration and voice functions.

  • Page 304: Contact Information

    Silicon Laboratories products are not designed, intended, or authorized for use in applications intended to support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create a situation where per- sonal injury or death may occur.

This manual is also suitable for:

Si2494/39Si2493Si2457Si2434Si2415Si2404 ... Show all

Table of Contents