Intel 537EX manual Modem Connection Overview

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Introduction

1.3Modem Connection Overview

The DCE (modem) operates in one of two states: command or online. In each state, both data and commands (including DCE responses) are transferred through the UART THR (Transmit Holding register) and the RBR (Receiver Buffer register).

The modem defaults to the command state. In the command state, the DTE (host) communicates to the modem through AT commands and S-registers. AT commands are character strings that help guide modem operation. S-registers are internal modem registers that the DTE can access. The S- registers contain modem status and configuration information. Many of the AT commands indirectly affect the contents of the S-registers. The AT command set and S-registers are divided into the following modes: Group 3 fax, data, V.44/V.42 bis/V.42/MNP, and voice. Note that supported AT commands are firmware revision-dependent (that is, not all commands are supported by all modem models or all firmware revisions).

All command lines sent to the modem, except for A/, must be preceded by an ‘AT’ (which stands for ‘attention’) and terminated by the contents of S-register S3 (typically a carriage return <CR>). The ‘AT’ prompts the modem to receive a command line from the DTE. A <CR> informs the modem that the entire command string has been transmitted and that the modem should start processing all the commands within the command line.

A command line may include one or more AT commands that may or may not be separated by a space. AT commands may be either upper- or lower-case characters, but all characters for a given command must use the same case. If there are multiple commands in a line, a semicolon (;) must be placed after each fax or voice command. The modem can be configured to send back (echo) to the DTE any data that the DTE sends to the modem (while in command state only). The last command may be repeated by typing A/ without using a carriage return. Each command line may include up to 80 characters and spaces.

Examples of AT command strings:

ATS1?<CR>

A/

AT &C1 &D2 +FCLASS=? <CR>

AT &C1 &D2 +FCLASS=?; S0=1 <CR>

The modem provides status information to the DTE in the form of response codes. These response codes can be expressed in text or numeric form. The supported response codes are provided in Table 4 on page 12.

Examples of modem responses:

+MCR: V90

+MRR: 28800

CONNECT 50666

In the online state, the DCE is off-hook and communicating with a remote modem. Any data sent from the DTE to the DCE is transmitted to the remote modem. Similarly, any data that the DCE receives from the remote modem is transmitted to the DTE.

Note: In the online state, the DCE does not ‘echo-back’ any of the data that the DTE sent to the DCE.

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536EX Chipset Developer’s Manual

Intel Confidential

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Contents 537EX Chipset Developer’s ManualIntel Confidential Contents Figures Tables Date Revision Description Revision History001 Initial release Introduction Controllerless Modem Driver OverviewWindows 95 and Windows Unimodem V.90/V.92 and V.34 Data ModesTapi Intelsdb.VXDModem Connection Overview DCE-to-DCE Data Rates for Each Mode AT Commands OverviewDTE-to-DCE Data Rates for Each Mode DCE-to-ISP Data Rates for V.90 ModeDTE-Modem Data Rate Response Codes Sending CommandsDelayed Call Numeric TextDial Modifier Command FunctionAT Escape Sequences Dialing digitsData Mode Command Summary Command Function Default Range Reported By &VnIntel Confidential Intel Confidential Intel Confidential +ESR +EB+ESA +ETBM44/V.42/V.42 bis MNP Command Summary Processes flow control characters and passes to local Fax Identity Command Summary Fax Class 1 Command SummaryVoice DTE→DCE Character Pairs IS-101 Voice Command SummaryResponse Hex Code Function DEL Voice DTE →DCE Character PairsVoice DTE←DCE Character Pairs ESCRegister Summary Register Function Default Range Units Reported by &VnDial Modifiers AsciiRegister Function Default Range Units Modem Responses and Command Echo En, Vn, Xn, Wn, Qn Using AT Commands to Access the S-Registers Sn?, Sn=x, ?Modem Setup Host Modem Response Command Data Reporting Wn Mapping Disable EnableDTE Resets and then configures the modem to Nvram user profile Establishing a Modem Connection A, D, DS = n, S0 AT Commands Product InformationProduct Identification Information Hanging Up Hn, S10, Zn, &D2 Online Command Mode Escape Codes, OnModem-to-Modem Connection Data Rates Intel Confidential Modem-on-Hold Incoming Voice Call in Data Mode Modem-on-Hold Initiating a Voice Call in Data Mode Intel Confidential Supported Modulation Types Carrier DescriptionDiagnostic Testing S18, &Tn Local Analog Loopback AT&T1Local Analog Loopback With Self-Test AT&T8 Local Modem or Test ModemTime-Independent Escape Sequence AT Escape SequencesLicensing Requirements for Hayes Escape Sequence Example Command Default Description Data Mode Command DescriptionsHayes* Escape Sequence Echo disabled Previously stored in the Nvram with the AT&Zn=x commandHost in either online or off-line command mode Echo enabledDTE ATI2Sn=x Numeric or verbose form CommandModem dials a telephone number touch tone dialing Numeric formResets the modem and recalls user profile DisconnectingSubsequent commands to be ignored DCD or Rlsd signalStored Profile AT&V0Active Profile Telephone NumbersSelect profile S-register configurations into the Nvram user profile ‘n’Command to see the stored telephone number = 0-9 a B C D # * T P R W @Command Default Indication Definition+EB Secondary channel operation, and vice versa CRC generation and checking disabledNrzi encoding and decoding disabled 12/V.34+ESR +ETBM+IFC +GMR+GSN +ILRR=m= carrier,carrier,…carrier +MS command description+MA? will display a list of enabled alternative modulations If +MS = ,0,, no alternative modulations will be availableBELL212 Carrier DescriptionBELL103 +MS=m See ‘m’Value Description +PHSW=+PMHF +PMHREnable Short Phase Conjunction with the +PSS commandEnable Short Phase 1 and Short Phase Disable short Phase 1 and Short PhaseMode Features Operating ModesResulting +ES Connection Types 44/V.42/V.42 bis and MNP Data Modem Command Descriptions+ES Settings Answer Modem +ES=1, 0 +ES=4, 4 +ES=3, 0 +ES=3, 2\Bn \Kn +DS=m +DR=mDirection Max string3768 +EFCS=m+ER=m Display messages when +ER =Decimal value and the format is as follows +ER LapmNon-error control operation Setting is ignored if origrqst=6Control during non-error control operation +ES=mFax Identity Command Descriptions Fax Identity CommandsFax Class 1 Commands +FMFR?/+FMIMod Selection Table Value Modulation Speed bps30 Hdlc Frame Format Class 1 DTE-Generated Hdlc Frame Information AT+FTH=mod+FCLASS? Fax Mode Command Descriptions+FCLASS +FRH=m +FRS=m+FTH=m IS-101 Voice Mode AT Commands Dtmf Detection Reporting Voice Mode Command DescriptionsRelay Control +FLO=m Enable report Function +VDR=m See ‘m’Event Description Defaults = ‘C’, BB860980, BFE63883, BB863EE0Caller ID report Command Reserved Distinctive ringing All +VEM=m See ‘m’EX Value BIT Value Event EIGHT-DIGIT HEX Code B B 8 6 3 E EHEX Digit Location 128 Nominal transmit level Local telephone, or speaker+VIP Label Preassigned Voice I/O Labels+VLS=m Relay/Playback Control Voice I/O Primitive CodesPrimitive Code Description +VRX +VSD=m See ‘m’+VSM=m +VSM=? command to obtain supported sampling rates141 AD3 3-bit Adaptive differential pulse code modulation Range 4800, 7200, 8000, and 11025 samples/secondHard Disk CmlSerial Compression100 Factory default is ‘0’100 Default value 1 second Range 5-255 units of 0.01 secondsSpecified by +VTD=m Dual tones may be sent using the following format+VTS=m None This sends a 500 ms period of silenceCommand Default Description Register Command Descriptions S10 Escape sequences Range Seconds Default 0 secondsS16 S25 S21S22 118 S30Sleep mode is disabled by setting S33 to ‘0’ Modem exits sleep mode whenever the host reads or writes toModem or when a ring signal is detected Inactive state whenCaller ID Tags for Formatted Reporting Tag DescriptionRing Uart Emulation in the Controllerless Modem Uart Emulation in Intelsdb.VxDTHR UartRBR Parallel Host Interface Uart Register Bit Assignments Scratch Register SCR Uart Register DefinitionsModem Status Register MSR Line Status Register LSR Bit Framing errorOE Overrun Error-Not supported StackModem Control Register MCR IER Interrupt Enable registerProcedure is as follows Line Control Register LCRFifo Control Register FCR BitInterrupt Control Functions Interrupt Identity Register IIRID1 ID0 Transmitter Holding Register THR Interrupt Enable Register IERID bit 2 for Fifo mode Dlab =Programmable Data Rates Receiver Buffer Register RBRDivisor Latch Registers DLM and DLL Data Rate Divisor Number Divisor Latch Hex16C550A Uart Fifo Operation Fifo Interrupt Mode OperationFifo Polled Mode Operation 102536EX Chipset Developer’s Manual 103

537EX specifications

The Intel 537EX is a powerful and innovative embedded processor designed for a range of applications, particularly in the fields of industrial automation, telecommunications, and transport management systems. This processor is a member of Intel's embedded product line, tailored specifically to meet the demands of systems that require high reliability and long lifecycle support.

One of the main features of the Intel 537EX is its multi-core architecture, which enables efficient parallel processing capabilities. This allows for the execution of multiple tasks simultaneously, significantly improving overall system performance. The processor also incorporates Intel’s advanced power management technology, which ensures that the device consumes energy efficiently, enhances thermal performance, and prolongs the lifespan of the system.

The Intel 537EX supports a range of connectivity options, including high-speed Ethernet and Serial ATA interfaces. This ensures that it can easily integrate into existing systems, seamlessly supporting applications that require robust data transfer capabilities. Additionally, the processor is equipped with multiple I/O ports, facilitating the connection of various peripherals and sensors, which is crucial in industrial applications.

One of the standout technologies within the Intel 537EX is its support for hardware virtualization. This feature allows for the creation of multiple virtual environments within a single physical structure, optimizing resource utilization and enhancing system flexibility. Additionally, Intel’s integrated security technologies provide a significant layer of protection against potential threats, ensuring that embedded systems remain secure.

Another characteristic of the Intel 537EX is its extensive software support, which includes compatibility with various operating systems and development environments. This versatility makes it an attractive choice for developers looking to build or upgrade their embedded systems. With access to Intel's comprehensive software tools, developers can quickly optimize applications to take full advantage of the processor's capabilities.

The Intel 537EX also boasts excellent thermal performance, allowing it to operate efficiently in harsh environments. This is crucial for embedded applications in industrial settings where temperature fluctuations are common. Overall, the Intel 537EX is engineered to deliver high-performance processing power, superior connectivity, and enhanced security, solidifying its position as a reliable choice for demanding embedded applications.