Intel 537EX manual Uart Emulation in the Controllerless Modem, Uart Emulation in Intelsdb.VxD

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Parallel Host Interface 16C450/16C550A UART

Parallel Host Interface 16C450/16C550A

UART

9

9.1UART Emulation in the Controllerless Modem

When controllerless modems are used with Windows applications, the communication driver architecture eliminates the need for a UART emulation (see Section 1.1, “Controllerless Modem Driver Overview” on page 7). However, MS-DOS applications used with controllerless modems retain the need for a UART emulation. Therefore, Intel provides the Intelsdb.VXD driver, which includes this UART emulation and also interacts directly with the Windows VCOMM.VxD driver (see Figure 11).

Figure 11. UART Emulation in Intelsdb.VxD

MS-DOSAPPLICATION

Intelsdb.VXD

WINDOWSAPPLICATION

UART EMULATION

HAM PORT DRIVER

VCOMM.VXD

The parallel host interface of the FastPath family emulate the electrical and register functions of a 16550A and 16C450 UART. Upon modem reset, the modem defaults to a 16C450. The host (DTE) can then configure the UART to function as a 16C550A UART.

In 16C450 emulation mode, the DTE and modem transfer data back and forth a byte at a time. In 16C550A emulation mode, the modem provides two 16-byte FIFO buffers, one for the transmitter and another for the receiver. Thus, up to 16 bytes of data may be sent to or received from the

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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 001 Initial release Revision HistoryDate Revision Description Introduction Controllerless Modem Driver OverviewWindows 95 and Windows V.90/V.92 and V.34 Data Modes TapiUnimodem Intelsdb.VXDModem Connection Overview AT Commands Overview DTE-to-DCE Data Rates for Each ModeDCE-to-DCE Data Rates for Each Mode DCE-to-ISP Data Rates for V.90 ModeSending Commands Delayed CallDTE-Modem Data Rate Response Codes Numeric TextCommand Function AT Escape SequencesDial Modifier Dialing digitsData Mode Command Summary Command Function Default Range Reported By &VnIntel Confidential Intel Confidential Intel Confidential +EB +ESA+ESR +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 SummaryResponse Hex Code Function IS-101 Voice Command SummaryVoice DTE→DCE Character Pairs Voice DTE →DCE Character Pairs Voice DTE←DCE Character PairsDEL ESCRegister Function Default Range Units Reported by &Vn Dial ModifiersRegister Summary AsciiRegister Function Default Range Units Modem Setup Host Modem Response Command Using AT Commands to Access the S-Registers Sn?, Sn=x, ?Modem Responses and Command Echo En, Vn, Xn, Wn, Qn DTE Disable EnableData Reporting Wn Mapping Resets and then configures the modem to Nvram user profile Product Identification Information AT Commands Product InformationEstablishing a Modem Connection A, D, DS = n, S0 Modem-to-Modem Connection Data Rates Online Command Mode Escape Codes, OnHanging Up Hn, S10, Zn, &D2 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 ModemLicensing Requirements for Hayes Escape Sequence AT Escape SequencesTime-Independent Escape Sequence Example Hayes* Escape Sequence Data Mode Command DescriptionsCommand Default Description Previously stored in the Nvram with the AT&Zn=x command Host in either online or off-line command modeEcho disabled Echo enabledSn=x ATI2DTE Command Modem dials a telephone number touch tone dialingNumeric or verbose form Numeric formDisconnecting Subsequent commands to be ignoredResets the modem and recalls user profile DCD or Rlsd signalAT&V0 Active ProfileStored Profile Telephone NumbersS-register configurations into the Nvram user profile ‘n’ Command to see the stored telephone numberSelect profile = 0-9 a B C D # * T P R W @Command Default Indication Definition+EB CRC generation and checking disabled Nrzi encoding and decoding disabledSecondary channel operation, and vice versa 12/V.34+ESR +ETBM+GMR +GSN+IFC +ILRR=m+MS command description +MA? will display a list of enabled alternative modulations= carrier,carrier,…carrier If +MS = ,0,, no alternative modulations will be availableCarrier Description BELL103BELL212 +MS=m See ‘m’+PHSW= +PMHFValue Description +PMHRConjunction with the +PSS command Enable Short Phase 1 and Short PhaseEnable Short Phase Disable short Phase 1 and Short PhaseMode Features Operating Modes44/V.42/V.42 bis and MNP Data Modem Command Descriptions +ES Settings Answer ModemResulting +ES Connection Types +ES=1, 0 +ES=4, 4 +ES=3, 0 +ES=3, 2\Bn \Kn +DR=m Direction+DS=m Max string3768 +EFCS=mDisplay messages when +ER = Decimal value and the format is as follows+ER=m +ER LapmSetting is ignored if origrqst=6 Control during non-error control operationNon-error control operation +ES=mFax Identity Commands Fax Class 1 CommandsFax Identity Command Descriptions +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 Relay Control Voice Mode Command DescriptionsDtmf Detection Reporting +FLO=m Enable report Function +VDR=m See ‘m’Defaults = ‘C’, BB860980, BFE63883, BB863EE0 Caller ID report Command Reserved Distinctive ringing AllEvent Description +VEM=m See ‘m’HEX Digit Location EIGHT-DIGIT HEX Code B B 8 6 3 E EEX Value BIT Value Event +VIP Local telephone, or speaker128 Nominal transmit level +VLS=m Preassigned Voice I/O LabelsLabel Primitive Code Description Voice I/O Primitive CodesRelay/Playback Control +VRX +VSD=m See ‘m’+VSM=? command to obtain supported sampling rates 141 AD3 3-bit Adaptive differential pulse code modulation+VSM=m Range 4800, 7200, 8000, and 11025 samples/secondCml SerialHard Disk CompressionFactory default is ‘0’ 100 Default value 1 second100 Range 5-255 units of 0.01 secondsDual tones may be sent using the following format +VTS=m NoneSpecified by +VTD=m This sends a 500 ms period of silenceCommand Default Description Register Command Descriptions S10 S16 Range Seconds Default 0 secondsEscape sequences S21 S22 118S25 S30 Modem exits sleep mode whenever the host reads or writes to Modem or when a ring signal is detected Sleep mode is disabled by setting S33 to ‘0’ Inactive state whenCaller ID Tags for Formatted Reporting Tag DescriptionRing Uart Emulation in the Controllerless Modem Uart Emulation in Intelsdb.VxDRBR UartTHR Parallel Host Interface Uart Register Bit Assignments Modem Status Register MSR Uart Register DefinitionsScratch Register SCR Bit Framing error OE Overrun Error-Not supportedLine Status Register LSR StackIER Interrupt Enable register Procedure is as followsModem Control Register MCR Line Control Register LCRFifo Control Register FCR BitID1 ID0 Interrupt Identity Register IIRInterrupt Control Functions Interrupt Enable Register IER ID bit 2 for Fifo modeTransmitter Holding Register THR Dlab =Receiver Buffer Register RBR Divisor Latch Registers DLM and DLLProgrammable Data Rates Data Rate Divisor Number Divisor Latch HexFifo Interrupt Mode Operation Fifo Polled Mode Operation16C550A Uart Fifo Operation 102536EX Chipset Developer’s Manual 103
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