AM-Band Interference | Silicon Laboratories SI2494/39 manual

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. Published Coilcraft TRF-RJ11 Filter Performance

Rev. 1.3

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Silicon Laboratories SI2494/39, SI2493/57/34/15/04 AM-Band Interference, Published Coilcraft TRF-RJ11 Filter Performance

Contents

Introduction Functional Block Diagram AN93 Table of Contents AN93 AN93 AN93 AN93 Document Change List Contact Information Protocol Function Si2494/93 Si2457 Si2439/34 Si2415 Si2404 Selection GuideModulations Protocols Part Numbers Package Carriers and TonesISOmodem Capabilities Release Resetting the Device Reset SequenceModem System-Side Device Reset Strapping General Considerations Reset-Strap Options for 24-Pin Tssop Package SOIC-16 Reset-Strap OptionsReset-Strap Options for 16-Pin Soic Package Mode Reset-Strap Pins Interface Input Clock Pin 5, RXD/MISO TSSOP-24 Parallel-Interface Options TSSOP-24 UART-Interface Options TSSOP-24 SPI-Interface Clock-Frequency Options Reset Strapping Options for QFN Parts with Uart Operation Input Clk Reset Strapping Options for QFN parts with SPI Operation Pin Functions vs. Interface Mode SOIC-16 Pin Functions vs. Interface Mode TSSOP-24System Interface Pin Functions vs. Interface Mode QFN-38 UART-Interface Signals SPI-Interface SignalsParallel-Interface Signals DTE Rates Ideal DTE Rate bps Actual DTE Rate bps Approximate Error% Serial Formats Detected in Autobaud Mode Symbol Data bits Parity Stop bitsFlow Control OCD Can MonitorU70 Bit Function PPD Parallel and SPI Interface Operation Uart Serial Interface TX Fifo Hardware Interface Register Hardware Interface Register Bit Map Parallel Interface Signals Signal Function DirectionParallel Interface Operation Parallel Interface Read Timing Interface Communication Modes Bit Function Meaning when High Meaning when LowSPI Control-and-Address Bit Definitions SPI Interface Operation Sleep Mode Low-Power ModesPower-Down Mode Wake-on-Ring Mode SSI Interface Pin Connection SSI/Voice Mode 24-Pin Tssop and 38-Pin QFN OnlySignal Pin Number TSSOP-24 QFN-38 Clkout Fsync SDI SDO Reset Eeprom Timing Eeprom CommandsEeprom Interface 24-Pin Tssop and 38-Pin QFN Only Eeprom Status Register Any Other Bits are Unused Parameter Symbol Min Typ Max Unit EOZEcsh Eecs Eeprom Three-Wire SPI Interface to EepromBoot Commands Custom Defaults Detailed Eeprom Examples AT Command Macros Customized AT Commands Firmware UpgradesBoot Command Example Autoloading Firmware Upgrade Example AT Command Macro Example Command Function Combination ExampleCombination Example Dec Hex Display Ascii Chart DAA Line-Side Device Hookswitch and DC Termination Pulse Dialing and Spark Quenching AC Termination Settings for the Si3018 Line-Side DeviceAC Termination Ringer Impedance and Threshold Typical Loop Voltage LVS Transfer Function Ilim = Loop Current Transfer FunctionLVCS40 Condition Billing Tone Detection Legacy-Mode Line Voltage and Loop Current Measurement Component Functions Power Supply and Bias CircuitryHookswitch and DC Termination Hardware Design Reference Optional Billing-Tone Filter Ringer Network TIP From Line Ring DAA Symbol Value EMI/EMC Si3018/10 Schematic Schematic Component Value Suppliers Bill of Materials Layout Guidelines Reference Placement Layout Checklist ISOmodem Layout Check ListLayout Items Required AN93 Module Design and Application Considerations Module DesignMotherboard Design Analog Output Modem Module VCC and Reset Filter Audio Quality Audio Filter Response Controller Modem Reference Guide DSP AT Command SetConfiguration Status Command Action Command Result Command ExamplesMultiple AT Commands on a Single Line Command Result Comment Consecutive U-Register Writes on a Single Line Basic AT Command Set ATI0 ATI1 EnableNo Patch AT Command Chip Revision Modifier ATI0 AT Command Chip RevisionRevision B Patch rbpXYYYY Revision C Patch rcpXYYYY Speaker is always off Enable result codes See Table Command Action Verbal result codes Program RAM write this command is used to upload firmware +DRV42B RD Disabled+DR=X +DRNONE C,D Specifies the mode of operation when initiating a modemConnection = Disable synchronous access mode Specifies the mode of operation when answer a modem During transparent sub-mode = CRC generation checking disable= Nrzi encoding and decoding disabled Specifies action taken if an underrun condition occurs Class 1 Transmit Carrier Country United States default BPS +GCI?Fixed DTE Rate Automatically detect the baud rate ITU-T V.90 default for Si2457 V22B ITU-T V.22bis default for Si2404V32B ITU-T V.32bis default for Si2415 ITU-T V.34 default for Si2434 +PQC=X Enable Short Phase 1 and Short Phase+PMHR=X +PMHT=X Distinctive Ring DCEs decide to use short startup procedures= After ring only = Off ISOmodem on-hook. Aout disabled. Tone detec Command Action Transmit Gain SelectionLoad Voice Factory Defaults DTE/DCE Inactivity Timer Is five seconds Ringing Tone Goes Away TimerRinging Tone Never Appeared Timer OK result code. Default time is 0 seconds Signed PCM Speakerphone AEC, AES and LEC disabledDtmf / Tone Duration Timer Voice Compression Method Kbps max default for Si2457 transmit and Si2434 Extended AT CommandsExtended AT& Command Set Kbps max default for Si2415 Only 56 kbps to 28 kbps TIP + Disable automatic line-in-use detection Extended AT% Command SetEnable V.42bis in transmit and receive paths ISOmodem answers a call in answer mode Mode is not allowed with a parallel or SPI interface Extended AT\ Command Set \Q2 Use CTS only \P0 Even \T9 Kbps4 \T16 Autobaud On4\V0 Report connect and protocol message Numeric1 Meaning Verbal Response Result Codes Protocol None StasPolarity Reversal No Polarity Reversal UN-OBTAINABLE Number ALTERNATE, +CLASS Disconnect Code Reason Disconnect Codes Ascii Definition Register Function Default Range Units DecimalRegisters Register Descriptions All spaces 0s Symbol Rate Allowable Data Rates 2400 Symbols/second Register Address Name Description Default Hex DT4B2 U0FDT4A0 DT4B1 Bdlt U2EBmtt U2F FHT U4EPrdd U4F SC0 V9AGGSamco Sasf Register Summary Bit-Mapped U-Register Summary Register Name Description Default U0-U16 Dial Tone Registers2. U00-U16 Dial Tone Detect Filter Registers 3. U17-U30 Busy Tone Detect Filter Registers U17-U30 Busy Tone Detect Registers 320/630 310/510 Default Busy and Dial ToneBPF Biquad Stage Output Scalar 300/480 400/440 BPF Biquad Values 5. U34-U35 Dial Tone Timing Register Ringback Cadence RegistersDial Tone Timing Register 4. U31-U33 Ringback Cadence Registers Pulse Dial Registers Dtmf Dial Registers7. U46-U48 Dtmf Dial Registers Ring Detect Registers 8. U49-U4C Ring Detect Registers9. U4D Modem Control Register 1-MOD1 Register U4D Bit Map Transmit Level Register Pre-Dial Delay Timer RegisterFlash Hook Time Register Loop Current Debounce Registers U53 Bit Map U54 Bit MapU62 Bit Map U65 Bit Map U63 Bit Map = Normal operation Line-Side Chip Power Down17. U67-U6A International Configuration Registers PDL U67 Bit Map U66 Bit Map U68 Bit Map 19. U6E-U7D Modem Control and Interface Registers U6A Bit MapU6C Bit Map 18. U6C Line-Voltage Status Register U6E Bit Map U6F Bit MapPtmr U70 Bit Map Function 155 Reserved Read returns zero Type Reset settings = BitDisables PCM mode Enables PCM mode U71 IO1 Bit D15 D14 D13 D12 D11 D10 Name U77 Bit Map U76 Bit Map Monitor Mode Values U78 Bit MapU79 Bit Map U7A Bit Map = Normal Atdtw operationAdaptive Dialing Given time Synchronous Mode= Normal asynchronous mode Pin indicates valid ring signal 20. U80 Transmit Delay for V.22 Fast Connect = Disables No Loop Current Detect= Timed calibration disabled = ATZ enabled Framed Sub-Mode Startup Special Error Reporting Mode= Ignore unrecognized in-band commands Minimal Transparency Firmware Upgrades Method Patch, 115 kbaud Uart Lines Reset, thenEscape Methods Load Technique and Speed Table 1. +++ Escape Th Bit EscapeEscape Pin Escape To Enable Use AT Commands Error CorrectionWire Mode Enabling Error Correction/Data Compression Epos Electronic Point of Sale Applications Legacy Synchronous DCE Mode/V.80 Synchronous Access Mode15. V.80 Mode Synchronous Mode Overview AT\N0 Synchronous Access Mode Settings Command Hex Supported Transmit Direction Receive Direction Indicator pair Code Transparent SubmodeCRC EM In-Band Commands and Statuses Code Transparent Submode Fast Connect SettingsCommand Supported Transmit Direction Receive Direction ATDT12345 Connect 1200 Protocol None 0x190x190x110x11 Quick Reference Modem Feature vs. Hardware, AT Command and Register SettingFunction/Feature AT Commands Registers Programming Examples Reg Bit Val Function Country-Dependent SetupDC Termination Control Bits DC Termination Country Initialization Country ConfigurationCountry Initialization Table Country Initialization Table AT+GCI=9C AT+GCI=AAT+GCI=F AT+GCI=16 AT+GCI=6C AT+GCI=26AT+GCI=27 AT+GCI=31 AT+GCI=3C AT+GCI=3DAT+GCI=42 AT+GCI=58 AT+GCI=46AT+GCI=53 AT+GCI=57 AT+GCI=9F AT+GCI=59AT+GCI=0 AT+GCI=61 AT+GCI=7B AT+GCI=69 AT+GCI=87 AT+GCI=7EAT+GCI=82 AT+GCI=89 AT+GCI=A0 AT+GCI=B8 UAE AT+GCI=A5AT+GCI=A6 AT+GCI=FE AT+GCI=B4 International Call Progress Registers Line Interface/Control Registers Dial Registers S42 Blacklisting AT Command FunctionSpecial Requirements for Serbia and Montenegro Blacklisting Caller ID Modes Caller ID Protocol SMS CommandsSMS Support Japan Caller ID 150 Johndoe Type II Caller ID/SAS DetectionMdmf Parameters Character Description Hexadecimal Value Ascii Value SAS Cadence for Supported Countries SAS Tone Frequency Austria Country Tone Frequency Hz Cadence seconds RegistersAruba Australia Czech Republic Country Tone Frequency Hz Cadence seconds Registers ChinaCroatia Cyprus Hong Kong GreeceGuyana Honduras Jordan IsraelJapan 064 0.436 Lithuania KiribatiKorea Republic Lao P.D.R Paraguay NigeriaOman Papua New Guinea Saudi Arabia Country Tone Frequency Hz Cadence seconds Registers RussiaSt.-Kitts-and-Nevis St. Lucia Tobago SwedenTajikistan Trinidad Loop Voltage Action Intrusion/Parallel Phone DetectionOn-Hook Condition Line Not Present/In Use Indication Method 1-Fixed Off-Hook Condition Line Not Present/In Use Indication Method 2-Adaptive Intrusion Detection Register Bits Name FunctionATH1 Value Description Possible Responses to Pmhr Command from Remote ModemModem-On-Hold Initiating Modem-On-Hold Receiving Modem-On-Hold Requests Hdlc Bit Errors on a Noisy Line Bit Errors DCEBeginning of Packet Data Meaning Bit Errors 0D 0A 4E 4F 20 43 52 49 45 52 0D 0A Register Bit Value Function Overcurrent DetectionPulse/Tone Dial Decision Overcurrent Detection Automatic Phone Line Configuration Telephone Voting Mode Possible +PMHT Settings12. V.92 Quick Connect AT+PSS Parameters AT+PQC Parameters Extended AT+ Command Set Handset, TAM, and Speakerphone OperationSoftware Reference Distinctive Ring Cadence Reporting Command Action Caller ID TypeCaller ID Enable After ring only Command Action Analog Source / Destination Selection Compression Selection Method Command Action Ringing Tone Never Appeared TimerSpeakerphone AEC, AES and LEC disabled. Handset FIR filter +VTS command. Default time is 1 second dur = Transmit Voice Stream Command Action Dtmf and Tone Generation Format DLECode DLE Commands DTE-to-DCEDLE Commands DTE-to-DCE Code Hex Simple Action Command Description SUB DLE Simple Events DCE-to-DTEDLE Events DCE-to-DTE Simple Event Reporting Code Hex Description 180 Format DLEXResponseDLE Description Voice Mode U Registers AddressDescription Default Complex Event Reporting Register Address Name Description Default Voice Mode U Registers HRXFIR4 HRXFIR1HRXFIR2 HRXFIR3 STXFIR4 STXFIR1STXFIR2 STXFIR3 SRXFIR4 SRXFIR1SRXFIR2 SRXFIR3 U199 Bit Definitions U19E Voice Reference-Overview TAM, Handset, and Speakerphone Voice Paths Rev 189 +VTX +VRX +VSP +VTS Voice Mode Operations +FCLASS=8 ATZ or Input Current Modem Settings Command orEvent +VNH = ATH or DTR off &D2 Si3000 Configuration TAM Pstn System Voice Modes Initialization Sequence Initialization Rev 195 Handset Configuration HandsetOverview AT+VLS=0 AT+VLS=13AT+VSP=0 Handset Automatic Tone Dial Handset Manual Off-Hook DialHandset Automatic Pulse Dial Handset to TAM Hands-Free Transition TerminateAT+VLS=14 Handset to Speakerphone Transition Speakerphone TransitionAT+VSP=1 Telephone Answering Machine Local Ring Notification with Type I CID EventNAME=JONES Jennifer AT+VRX Connect TAM Hands-Free Record OGMRecord OGM ATU199&FFFD Review ICM TAM Hands-Free Review OGMReview OGM Record Local ICM TAM Handset Record OGM Trigger receive operation. The first byte TAM Handset Review OGM AT+VSM=4 Normal Answer OGM Playback with ICM Record TAM Pstn Normal Answer OGM Playback with ICM Record ICM AT+VLS=15 Interrupted Answer OGM Playback with Dtmf Menu Entry DLE1 Dtmf 1 digit detected Simplex Speakerphone Speakerphone External Microphone/Speaker Calibration Register Name Description Default ValueTransmit Gain Calibration-Speakerphone Disabled Simplex Speakerphone U Registers Transmit Gain Configuration AT+FCLASS=8 Transmit/Receive Gain Calibration Dial Remote Telephone Receive Gain Reference Measurements Receive Gain Configuration Reg Name Bit U19E Speakerphone Calibration-AEC Gain Calibration AEC Gain Calibration Dial Remote Telephone Speakerphone Configuration Speakerphone Configuration Simplex Speakerphone Configuration Call-Automatic Tone Dial Simplex Speakerphone ConfigurationSpeakerphone Automatic Tone Dial Speakerphone Manual Off-Hook Dial Speakerphone Automatic Pulse Dial Speakerphone to Handset TransitionCall-Automatic Pulse Dial Glossary ReferencesTermination Implementing the SIA Protocol Security Protocols AT+F0 Considerations when Disconnecting the Session AT+F4 AT+F1AT+F2 AT+F3 Result Code Meaning Remarks Implementing the Ademco Contact ID Protocol Kissoff Ademco Contact ID Protocol Tone Transmission AT CommandsDtmf Digit Low Tone Hz High Tone Hz Contact ID AT Command Modem Specific Implementation Details Event Modem-to-DTE indication Remarks Ademco Mode of OperationStep DTE-to-Modem Command Modem-to-DTE Remarks Indication Handshake Tone Detection Delay 250 ms before transmitting Data Tones Wait for Receiver to answer with handshake tonesMessage ATH Wait for Kissoff tone Rev 233 SMS Message Format Chinese ePOS SMS +FCLASS=256 SMS AT Command SetAT Commands for SMS AT Command ISOmodem Response Description SMS User Registers Register Bits Name Description Default Hex= Auto Mode User Registers for SMS Operations Procedure ExampleCrlfconnect Crlf Connect 2CRLF ResponseDleetxcrlfno Carriercrlf Connect 1CRLF Dleetxcrlfokcrlf Example Session POS SMS Process in Host and Modem Prototype Bring-Up Si3018/10 Testing and Diagnostics Host Interface Troubleshooting  Inappropriate Commands Command Timing  Register Configurations  Connect Evaluation Board to Prototype System Isolation Capacitor Troubleshooting10.1.6. Si3018/10 Troubleshooting Component Troubleshooting EVB Test the Host Interface Test the Prototype Si3018/10 Circuitry Si3018/10 Resistance Si3018/10 Typical Voltages Resistance to Si3018/10 Pin Component Voltage Resistance across ComponentsVoltages across Components with Diode Checker FB1 FB2 RV1 Loop Test Circuit Self Test Bell 103-V.34 Modem Functional Test Connection Board Test Test Coverage Teltone ILSIsdn Modem Modem Under Test Compliance Testing AT Commands for Compliance TestingAT Command/Test Method Desired Response Transmit Modulation Data Rate Symbol/Data RateS41 Symbol Rate Allowable Data Rates 29 Data Rate Surges Safety Published Coilcraft TRF-RJ11 Filter Performance AM-Band Interference Debugging the DTE Interface Debugging the DTE interface Modulation Appendix A-EPOS Applications Recommendation 0xFF 0x19 0xA0 0x19 0xB1 ISOmodem V.80 Protocol Hdlc Framing in Framed Sub-Mode ISOmodem in Epos Applications AT+FCLASS=1 Setup procedure29 FastPOS Sample Program AT&D2 Example Program in C/C++ How to use the program Rev 263 264 Rev 265 True Rev 267 = Rtscontrolenable Rev 269 270 FastPOS Detailed Wave Files RTS not RTS signal FastPOS DTE Trace When to Use Audio Recording Times When Audio Recording May Not HelpHardware Setup Larger of the two jacks 3.5 mm carries audio to the PC Setting PC Microphone Input for Recording Windows NT Sounds and Multimedia Properties Setting PC Microphone Input for Recording Windows Multimedia Properties Setting PC Microphone Input for Recording Windows XP Sounds and Audio Devices Properties Sound Recorder Making the Recording with Adobe Audition or WaveSurfer Adobe Audition Temporal View of a Good V.22 Transaction Audio Playback and Analysis Adobe Audition Spectral View of a Good V.22 Transaction Band Spectral Display Recording Made at Excessive Level Audio-Recording Pitfalls Appearance of Bell 212 Protocol Details of Some Low-Speed Protocols Appearance of V.22 bis Protocol Appearance of V.29 FastPOS Protocol Examples of Epos Server Misbehavior Example of Epos Server Misbehavior Dtmf Distorted by Low Line Level Examples of Line Impairments Power Line Related Noise Appendix C-PARALLEL/SPI Interface Software Implementation MCU  MCUhardware.c  modemhardware.c Hardware Access LayerInterrupt Service and Polling Layer Software Description Interrupt Service Routine ISR Method Polling HIR1 MethodRXF Interrupt Receive Fifo Almost Full Timer Interrupt Receive Fifo Not Empty TXE Interrupt Transmit Fifo Almost EmptyU70 Interrupt Parallel- or SPI-Port Interrupt-Service Flowchart Buffer Management Buffer Management, Status and Control Layer Circular-Buffer Flowchart Status and Control Application Layer Sample Application Data Bursts Compiler Option Dot CommandsModem Operation Making a Connection Sfrpagesave = Sfrpage Modem Interrupt Service Sample Code Rev 301 302 Revision 0.8 to Revision Revision 0.5 to RevisionRevision 0.6 to Revision Revision 0.7 to Revision Contact Information

Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual AM-Band Interference

Models: SI2493/57/34/15/04 SI2494/39

AN93

10.5. AM-Band Interference

Figure 49. Published Coilcraft TRF-RJ11 Filter Performance