Intel 536EX manual Intel Confidential, Fax Class 1 AT Commands, T.30 HDLC Frame Format

Page 66

Figure 8. T.30 HDLC Frame Format

Fax Class 1 AT Commands

When the modem transfers data to the DTE, the DTE must filter the data stream by removing all character pairs beginning with <DLE>. The DTE also must recognize <DLE><ETX> as the stream terminator. Upon detecting <DLE><DLE>, the DTE must reinsert a single <DLE> in its place. The modem buffers up to 512 bytes of fax data received from the remote modem if the DTE cannot read the data immediately (AT+FRM command).

For the AT+FTH and AT+FRH commands, data is sent and received using HDLC formatting. The format for HDLC framing is provided below. When sending the HDLC data, the modem automatically generates the flags and the frame checking sequence (Frame Check Sum). All the other fields are transmitted to or received from the DTE (that is, these fields are under the control of the DTE).

Figure 8. T.30 HDLC Frame Format


					Facsimile	Facsimile	Frame
			Address	Control	Facsimile	Facsimile	Checking
	Flag	Flag	Address	Control	Control	Information	Checking	Flag
	Flag	Flag	Field	Field	Control	Information	Sequence	Flag
			Field	Field	Field	Field	Sequence
					Field	Field	(FCS)
							(FCS)

After receiving a frame correctly using the AT+FRH command (FCS is OK), the DCE returns an ‘OK’ message to the DTE. If the frame is received in error (FCS is not OK, carrier is lost, or data is lost due to data overflow), the DCE returns an ‘ERROR’ message to the DTE; the DTE should then discard the frame.

Note: If the telephone line is on-hook, the modem responds back to the DTE with an ‘ERROR’ message whenever any of the fax AT commands, except the +FCLASS command, are sent to the modem.

Figure 9. CLASS 1 DTE-Generated HDLC Frame Information (AT+FTH=<mod>)

Address

Field

Control

Field

Facsimile

Control

Field

Facsimile

Information

Field

Figure 10. CLASS 1 DTE Reception of HDLC Frame Information (AT+FRH=<mod>)

Address

Field

Control

Field

Facsimile

Control

Field

Facsimile

Information

Field

Frame

Checking

Sequence

(FCS)

Like the data modem mode, the DTE needs to issue an ATD string or ATA command to the modem to originate or answer a fax call. Unlike the data modem mode, auto-answering is not supported by the modem while in fax mode. It is recommended that S-register S0 be set to ‘0’ (that is, use ‘ATA’) whenever the modem is expected to receive a fax call.

66	536EX Chipset Developer’s Manual

Intel Confidential

Image 66

Contents 536EX Chipset Developer’s ManualJanuary Intel Confidential 536EX Chipset Developer’s ManualContents ContentsFigures Tables Revision Revision HistoryDate DescriptionIntroduction 1.1Controllerless Modem Driver OverviewUser applications Figure 1. WDM Driver Block Diagram1.1.2Windows 95 and Windows Kernel - ring0Figure 2. VxD Mini Port Driver Block Diagram 1.2V.90/V.92 and V.34 Data Modes1.3Modem Connection Overview Table 1. DTE-to-DCEData Rates for Each Mode Table 2. DCE-to-DCEData Rates for Each ModeTable 3. DCE-to-ISPData Rates for V.90 Mode 1.4.1Sending Commands Table 4. DTE-ModemData Rate Response Codes1.4.2AT Escape Sequences 1.4.3Dial ModifierAT Command Summary Tables AT Command Summary TablesTable 5. Data Mode Command Summary Table 5. Data Mode Command Summary Continued Result code type Intel Confidential Generate data mode calling tone Table 6. V.44/V.42/V.42 bis MNP Command Summary connect state, transmits Table 7. Fax Identity Command Summary Table 8. Fax Class 1 Command SummaryTable 9. IS-101Voice Command Summary Table 10. Voice DTE→DCE Character PairsTable 10. Voice DTE→DCE Character Pairs Continued Table 11. Voice DTE←DCE Character PairsTable 11. Voice DTE←DCE Character Pairs Continued Table 12. Dial ModifiersTable 13. S-RegisterSummary Table 13. S-RegisterSummary Continued Data Mode AT COMMANDS Data Mode AT COMMANDSATW0 Table 14. Data Reporting Wn MappingFigure 3. Example of a Remote Connection •ATW2Data Mode AT COMMANDS +FMFR?, +FMDL?, +FREV? 3.6Online Command Mode Escape Codes, On 3.7Hanging Up Hn, S10, Zn, &D23.8Modem-to-ModemConnection Data Rates Data Mode AT COMMANDS +VCID=1 +PMH=0+PCW=0 +++ATData Mode AT COMMANDS hook to connect the call. Now you can answer the phone and talk. After completing your voice conversation, the modem will issue another +PMHF and ATO command to initiate a Quick Connect. If the server rejects the request to go on hold, the user can stay on line ATO command issued or disconnect from his initial data connection ATH command issued Table 16. Supported Modulation Types 3.9Diagnostic Testing S18, &Tn 3.9.1Local Analog Loopback AT&T1Figure 6. Local Analog Loopback Test 3.9.2Local Analog Loopback With Self-TestAT&T8LOCAL MODEM Local Modem or Test Modem3.10.1Time-IndependentEscape Sequence Licensing Requirements for Hayes Escape Sequence<char1><char2><char3><AT command><contents of S3> Formatchar1 = char2 = char3 = escape character S2 Table 18. Data Mode Command Descriptions 3.10.2Hayes* Escape SequenceData Mode AT COMMANDS Sn=x Data Mode AT COMMANDS Intel Confidential536EX Chipset Developer’s Manual Intel Confidential AT&V0 Data Mode AT COMMANDS Command Default IndicationDefinition 1, 0, Data Mode AT COMMANDS +ESR +ETBM1, 1, +IFC +GMR+GSN +ILRR=mmodulations +MS=m <carrier>Description see ‘m’<value> +PHSW=+PMHF +PMHRData Mode AT COMMANDS Error Correction and Data Compression4 Error Correction and Data CompressionTable 19. Operating Modes Table 20. Resulting +ES Connection Types NOTESError Correction and Data Compression Intel Confidential536EX Chipset Developer’s Manual Error Correction and Data Compression +DS=m +DR=mdirection <max string>3768 +EFCS=m+ER=m +ES=m 5.2Fax Class 1 Commands Fax Class 1 AT Commands5.1Fax Identity Commands Fax Class 1 AT CommandsTable 23. <mod> Selection Table Figure 8. T.30 HDLC Frame Format Table 24. Fax Mode Command Descriptions Refer to Table 23 on page Table 24. Fax Mode Command Descriptions Continued+FRH=m shown in Table 23 on page+FTH=m IS-101Voice Mode AT Commands IS-101Voice Mode AT CommandsTable 25. Voice Mode Command Descriptions 6.1DTMF Detection Reporting6.2Relay Control +FLO=m m = <deassert>, <assert>m=<enable>, <report> +VDR=mm = <mask> +VEM=mIntel Confidential +VIP Preassigned Voice I/O Labels +VLS=mVoice I/O Primitive Codes Relay/Playback Control: cont+VRX m = <sds>, <sdi>+VSD=m m= <cml>, <vsr>, <scs>, <sel> +VSM=mTransmission: Range: Compression Method Selection: cont +VSP=mfactory default is ‘0’ +VTS=m noneDescription CommandDefault DTMF and Tone Generation: contS-Registers Table 26. S-RegisterCommand DescriptionsS-Registers Intel Confidential S-Registers536EX Chipset Developer’s Manual Intel Confidential S-Registers536EX Chipset Developer’s Manual Intel Confidential S-Registers536EX Chipset Developer’s Manual Intel Confidential Caller ID Caller IDTable 27. Caller ID Tags for Formatted Reporting <DLE> R RING DATE = TIME = NMBR = NAME = DOE JOHN MESG =RING RING NMBR =Parallel Host Interface 16C450/16C550A UART Parallel Host Interface 16C450/16C550AUART Figure 11. UART Emulation in Intelsdb.VxDUART Transmitter Flow Diagram UART Receiver Flow DiagramADDRESS REGISTERBIT NUMBER NAMEFigure 14. Scratch Register SCR 9.2.1Scratch Register SCR9.2.2Modem Status Register MSR Figure 15. Modem Status Register MSR9.2.3Line Status Register LSR Figure 16. Line Status Register LSRFigure 17. Modem Control Register MCR 9.2.4Modem Control Register MCR9.2.5Line Control Register LCR Figure 18. Line Control Register LCR9.2.6FIFO Control Register FCR RegisterFigure 19. FIFO Control Register FCR 9.2.7Interrupt Identity Register IIR Figure 20. Interrupt Identity Register IIRTable 28. Interrupt Control Functions 9.2.9Transmitter Holding Register THR 9.2.8Interrupt Enable Register IERFigure 21. Interrupt Enable Register IER Figure 22. Transmitter Holding Register THRFigure 23. Receiver Buffer Register RBR 9.2.10Receiver Buffer Register RBR9.2.11Divisor Latch Registers DLM and DLL Figure 24. Divisor Latch Registers DLM and DLL9.316C550A UART FIFO Operation 9.3.1FIFO Interrupt Mode Operation9.3.2FIFO Polled Mode Operation Intel Confidential Parallel Host Interface 16C450/16C550A UART536EX Chipset Developer’s Manual