536EX Chipset Developer’s Manual January 2002 Order Number: 273584-002
Information in this document is provided in connection with Intel® products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document.
Contents Contents 1 Introduction...................................................................................................................................... 7 1.1 1.2 1.3 1.4 Controllerless Modem Driver Overview ................................................................................ 7 1.1.1 Windows* Millennium Edition (Windows Me), Windows 2000, Windows XP, and Windows NT* 47 1.1.2 Windows 95 and Windows 98...............................................................................
Contents 9.3 9.2.1 Scratch Register (SCR) ......................................................................................... 95 9.2.2 Modem Status Register (MSR).............................................................................. 95 9.2.3 Line Status Register (LSR) .................................................................................... 96 9.2.4 Modem Control Register (MCR) ............................................................................ 97 9.2.
Contents Tables 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 DTE-to-DCE Data Rates for Each Mode .................................................................................... 11 DCE-to-DCE Data Rates for Each Mode.................................................................................... 11 DCE-to-ISP Data Rates for V.90 Mode ...................................................................................... 11 DTE-Modem Data Rate Response Codes.........
Contents Revision History Date Revision Description January 2002 002 Changed references to “HaM Data Fax Voice” to “Intel 536EP V.92 Modem.
1 Introduction This developer’s manual describes the software interface for Intel® 536EX (controllerless and controller) chipset solutions. The controllerless-based solutions include the 536EP for PCI and Mini-PCI. Refer to the chipset datasheets for the detailed chipset descriptions (public order numbers 273503-001, 273xxx-001, 273xxx-001, 273xxx-001, and 273xxx-001). The controllerless-based chipset, as the name implies, does not have a dedicated hardware controller.
Introduction Figure 1. WDM Driver Block Diagram User applications User applications Kernel - ring0 Modem drivers stack virtual COM port, channel protocols layer WDM driver Intels51.sys PCI bus Hardware 1.1.2 Windows 95 and Windows 98 When the controllerless modem chipsets are used with Microsoft Windows 95 and Windows 98 applications, the traditional UART and serial port emulations are replaced by the proprietary HaM Mini Port driver (see Figure 2).
Introduction When the controllerless chipsets are used with MS-DOS* applications, however, a UART emulation is required. Intel provides an additional driver called Intelsdb.VxD, which includes a UART emulation. Please refer to Section 9.1, “UART Emulation in the Controllerless Modem” on page 92 for an explanation of the 536EX UART emulation. The Intelsdb.VxD driver interacts directly with the VCOMM.VxD driver using the Win16 and Win32 Communication APIs. Figure 2.
Introduction 1.3 Modem 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.
Introduction The modem recognizes AT commands from the DTE at any valid data rate from 300 bps to 115,200 bps (that is, the modem autobauds up to 115,200 bps); however, the DTE should use the data rate specified for each mode according to the transmitting direction—DTE-to-modem (Table 1) or modem-to-modem (Table 2). The V.90 and V.92 data rates are effective only in DCE-to-ISP connections. Table 1. DTE-to-DCE Data Rates for Each Mode Mode Table 2. Data (V.34) 2400–115,200 Data (V.
Introduction 1.4.1 Sending Commands All command lines sent to the modem, except for A/, must be preceded by an ‘AT’ and terminated by the contents of S-register S3 (typically a carriage return ). AT stands for ‘attention’ and prompts the modem to receive a command line from the DTE. A informs the modem that the entire command string has been transmitted and to begin processing all the commands in the command line. A command line can include one or more AT commands.
Introduction 1.4.2 AT Escape Sequences The 536EX provides the industry-standard escape sequence, TIES (Time Independent Escape Sequence). TIES is designed to work with existing communication software written for the Hayes Escape Sequence. Upon special request, Ambient provides the Hayes* Escape Sequence; however, please note that licensing can be required. TIES/Hayes* Escape Sequences The 536EX modem chipset is manufactured with TIES (Time Independent Escape Sequence) as the default setting.
AT Command Summary Tables 2 AT Command Summary Tables This section contains summary tables of all AT commands, S-registers, and between AT commands and S-registers. These commands are fully described in the relevant sections of the 536EX Developer’s Manual. Table 5.
AT Command Summary Tables Table 5.
AT Command Summary Tables Table 5.
AT Command Summary Tables Table 5.
AT Command Summary Tables Table 5. Data Mode Command Summary (Continued) Note * Command -Cn Function Default Generate data mode calling tone -C0 Calling tone disabled -C1 1300 Hz calling tone enabled -C2 V.8 calling tone and 1300 Hz calling tone Reported by &Vn Range 0 0–2 no +A8E=m V.8 and V.
AT Command Summary Tables a. For Data mode, the factory default setting is AT+MS=V92, 1, 0, 0, 0, 0 to send at speeds of 33,600 bps or below and receive at speeds of 53,333 bps and below. Note: Table 6. See the relevant sections in the 536EX Developer’s Manual for full command description and parameter ranges. V.44/V.42/V.
AT Command Summary Tables Table 6. V.44/V.42/V.
AT Command Summary Tables Table 6. V.44/V.42/V.42 bis MNP Command Summary (Continued) Note Command * * Table 7. Function Range Reported by &Vn +DS44=m V.44 Data Compression 3, 0, 0, 471, 942, 140, 140, 1884, 3768 +EFCS Controls the 32-bit frame check sequence option in V.42 0 0–2 no +ER=m Controls error control reporting 0 0, 1 no 3, 0, 2 See note yes m=0 Disabled m=1 Enabled +ES=m Error control selection no Value saved in NVRAM.
AT Command Summary Tables Table 9.
AT Command Summary Tables Table 10. Voice DTE→DCE Character Pairs (Continued) Response Hex Code Function 7F DTMF transition to off u 75 Bump up the volume d 64 Bump down the volume 1B End receive data state ! 21 Receive data abort 18 Clear transmit buffer of voice data ? 3F Transmit buffer space available query Table 11.
AT Command Summary Tables Table 11. Voice DTE←DCE Character Pairs (Continued) Response Hex Code Function f 66 Data answer detected (2225 Hz) R 52 Incoming ring % ‘ (,) 25, 26, 27, 28, 29 Manufacturer-specified Table 12.
AT Command Summary Tables Table 13. S-Register Summary (Continued) Note Register Function Default Range Units Reported by &Vn S16 Modem test options 0 – – no * S18 Modem test timer 0 0–255 second yes * S21 Bit-mapped options 48 – – no * S22 Bit-mapped options 118 – – no * S25 Detect DTR change 5 0–255 0.01 second yes * S30 Disconnect inactivity timer 0 0–255 minute yes * S33 Sleep mode timer 10 0–90 second yes * Value saved in NVRAM.
Data Mode AT COMMANDS 3 Data Mode AT COMMANDS The 536EX chipsets implement: • Standard Hayes*-compatible AT commands and S-registers in data mode • Standard EIA/TIA-578 AT commands in Class 1 fax mode • Additional AT command sets for error correction, data compression and voice mode In data mode, the AT commands configure the DCE (modem) to establish a connection with a remote data modem. In data mode, the 536EX chipsets execute the AT commands for error correction (MNP 2-4, V.
Data Mode AT COMMANDS Host Command Modem Setup No Echo, Numeric (E0, V0) No Echo, Text (E0, V1) Modem Response AT 0 ATS0? 0000 AT OK ATS0? 000OK The DCE can be configures to use different response codes depending on the V.250 command that is enabled (AT+MR, AT+ER, AT+DR, and AT+ILRR). Alternatively, the ATWn command can be used to set these V.250 commands. The mapping for the ATWn command to V.
Data Mode AT COMMANDS • ATW3 +MCR: V90 +MRR: 28800 +ER: LAPM +DR: V42B +ILRR: 115200 CONNECT 50666 • ATW4 +MCR: V90 +MRR: 28800 +ER: LAPM +DR: V42B CONNECT 50666 3.3 Modem Reset and NVRAM Commands [DS=m, Zn, &F, &Vn, &Yn, &Wn, &Zn=x] On powering-up, the DCE defaults to the configuration specified in NVRAM. The DCE may then be configured as needed. The DTE stores the DCE configuration in the NVRAM by first setting up the current configuration and then sending an AT&Wn command.
Data Mode AT COMMANDS 3.4 Modem Identification Commands [In, +FMI, +FMR, +FMM, +GMI, +GMM, +GMR, +GSN, +FMFR?, +FMDL?, +FREV?] The modem provides product identification AT commands that help determine the modem’s manufacturer, model number, and product revision. To provide flexibility with older software application programs, the modem supports several commands that can be used to request a single item of identification (such as a modem model number).
Data Mode AT COMMANDS ATDT 9,444-5555 Automatically dials the telephone number with DTMF tones. After dialing a ‘9’, the comma (,) causes the modem to pause two seconds before dialing the rest of the telephone number. modem 1: ATD; When establishing a manual-to-manual connection, the designated modem 2: ATA originating modem should receive the ATD command from its DTE just before the designated answering modem receives the ATA command from its DTE.
Data Mode AT COMMANDS In Data mode, the 56K chipsets can transmit up to 48,000 bps (V.92 mode) or 33,600 bps (V.90 mode) and receive up to 53,333 bps. Note that the chipsets are capable of achieving 56,000 bps, but power limitations by the FCC limit actual speeds to 53,333 bps. The 56K receive data rates can be achieved only in connections with equipment-compatible ISPs (Internet Service Providers). In V.
Data Mode AT COMMANDS Figure 4.
Data Mode AT COMMANDS Figure 5. Modem-on-Hold: Initiating a Voice Call in Data Mode Enable MOH (+PMH=0) Command Mode (+++AT) Request to go on hold (+PMHR) Server Accepts Request ? No (Returns 0) Yes (Returns 1-13) Disconnect ? No Flash Hook (+PMHF) Yes Initiate Call End Data Connection (ATH) Finish Call Flash Hook (+PMHF) Go Back Online (ATO) A9112-01 The following sequence describes how to configure the modem for MOH to process an incoming voice call while online. First, MOH must be enabled.
Data 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). The next sequence describes how to initiate a voice call while online. First, enable the MOH feature by setting +PMH=0.
Data Mode AT COMMANDS Table 16. Supported Modulation Types Description Bell 103 300 bps Bell 212A 1200 bps V21 V.21 300 bps V22 V.22 1200 bps V22B V.22 bis 1200 and 2400 bps V23C V.23, with constant carrier; 1200 bps forward and 75 bps reverse V32 V.32 4800 and 9600 bps V32B V.32 bis 7200, 9600, 12,000, and 14,400 bps V34 V.34 asymmetrical connections: 2400, 4800, 7200, 9600, 12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400, 28,800, 31,200, and 33,600 bps 56K V.
Data Mode AT COMMANDS Table 17. Resulting Modem-to-Modem Connection Rates with Non-Default Values Originating Modem 3.9 Answering Modem Resulting Connection Speed +MS = V34, 1, 0, 0, 0, 0; the UART data rate = 115,200 bps +MS = V32, 1, 0, 9600, 0, 0; the UART data rate = 14,400 bps 9600 bps: the originating modem is configured to attempt a maximum 28,800 bps connection, but the answering modem is configured to attempt a maximum data rate of 9600 bps.
Data Mode AT COMMANDS Figure 6. Local Analog Loopback Test LOCAL MODEM TXD TRANSMITTER DTE RXD RECEIVER Local Modem (or Test Modem) AT&F &W Returns the modem to the factory defaults. AT S18 = 0 &T1 Causes the modem to run local analog loopback without self-test. CONNECT 115200 Modem response code indicates that analog loopback is enabled with a DTE speed of 115200. This is a test. Test string that the user could type at the keyboard.
Data Mode AT COMMANDS Local Modem (or Test Modem) AT&F &W AT S18=20 &T8 OK AT OK 000 OK AT S18=0 &T8 OK AT OK AT&T0 000 OK 3.10 Returns the modem to the factory defaults. Causes the modem to start local analog loopback with self-test for 20 seconds. After starting analog loopback, the modem goes back to command mode. The modem responds to new commands. After 20 seconds, the modem stops analog loopback, sends an error count to the DTE, and enters command mode.
Data Mode AT COMMANDS The DTE implements the escape sequence by sending the escape character (as defined in S2) three times, followed by a valid AT command, and then the contents of S3 (typically a ). Upon detecting the three consecutive escape characters, the modem changes to TIES command mode and starts an internal EPD (Escape Prompt Delay) timer (with the time limit defined by S12).
Data Mode AT COMMANDS DTE: DCE: Note: 3.10.2 +++ AT OK TIES requires that the three-character escape sequence be contiguous and not repeated. The character immediately preceding the first character of the three-character sequence cannot be the same as the escape character. Therefore, ‘+++ AT’ is valid, but ‘++++ AT’ is not. Hayes* Escape Sequence In this escape sequence, implemented with +++, the DTE sends the modem an escape character three times, preceded and followed by guard times.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Dial Command: This command causes the modem to immediately go off-hook as an originating modem and dial a telephone number with corresponding dial modifiers. Dial modifiers are parameters that define how the modem should dial the telephone number.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Identification/Checksum Option: This command causes the modem to send product code and hardware setup information to the DTE.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default T none Description Select Tone Dialing: This command configures the modem to use DTMF tones the next time the modem dials a telephone number (touch tone dialing). Result Code Form: This command selects whether the modem’s basic syntax response codes are in numeric or verbose form.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Long Space Disconnect: This command determines whether the modem disconnects after receiving 1.6 seconds of silence and whether the modem sends a period of silence to the remote modem before disconnecting. Yn Zn 0 0 n = 0* Disables long space disconnect n=1 Enables long space disconnect. The modem disconnects after receiving 1.6 seconds of silence from the remote modem.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Dial Pulse Ratio: This command determines the make/break (that is, off-hook/on-hook) ratio during pulse dialing. &Pn 0 n = 0* Make = 39%; Break = 61% at 10 pulses per second—for use in the United States. n=1 Make = 33%; Break = 67% at 10 pulses per second—for use in the United Kingdom and Hong Kong. DSR (Data Set Ready) Option: This command controls how the modem treats the DSR signal.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Store Active Profile: This command causes the modem to store a subset of the active profile command and S-register configurations into the NVRAM user profile ‘n’. &Wn 0 n = 0* Store in user profile 0 n=1 Store in user profile 1 Select Stored Profile on Power-up: This command selects the particular stored user profile from the NVRAM to be loaded into the active profile upon modem power-up.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description V.8 and V.8 bis Operation Controls: This command configures V.8 and V.8 bis operation. If issued when the DCE is on-hook, this command is a compound parameter used to precondition V.8 and V.8 bis originating and answering operation. It is not supported as an action command while the DCE is off-hook. If enabled, V.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Break Handling: Controls break handling in error control operation. It accepts three numeric subparameters: Syntax: +EB = , , specifies the type of break to be signaled to the remote DCE upon detecting one from the local DTE.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Synchronous Access Mode Configuration: controls the manner of operation of the Synchronous Access Mode in the DCE (if present). Syntax: +ESA=[[,[,[,[,[,[,[,]]]]]]]] specifies the bit sequence transmitted by the DCE when a transmit data buffer underrun condition occurs, while operating in Transparent sub-Mode.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Selective Repeat: Controls the use of selective repeat (SREJ) option in V.42. +ESR 1 0 Do not use SREJ 1 Use SREJ if available in remote DCE; continue without it if not 2 Use SREJ if available in remote DCE; disconnect if SREJ is not available Call Termination Buffer Management: Controls the handling of data remaining in the DCE buffers upon call termination.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command +GMR Default Description none Identify Product Revision: This command causes the DCE to report the modem chipset revision level. This command is identical to AT+FREV? and AT+FMR. The response message depends on the firmware version. AT+GMR 536EP Release 4.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Modulation Automode Control: This command specifies the alternative to the preferred modulation specified in the +MS= command. Alternative modulations are only available when +MS=, enables automode. The alternative modulations available for the +MA command are limited to all modulations the modem supports below the preferred modulation specified by +MS=.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Modulation Selection: This command sets the preferred modulation, whether alternative modulations can be tried, and the transmit and receive DCE bit rates.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Call Waiting Enable: This command controls the action to be taken upon detection of call waiting in a V.92 DCE. +PCW=m 0 0 Toggle V.24 Circuit 125 and collect Caller ID if enabled by +VCID 1 Hang up 2 Ignore V.92 call waiting This command causes the DCE to activate/de-activate the hook relay for supporting the 2C relay.
Data Mode AT COMMANDS Table 18. Data Mode Command Descriptions (Continued) Command Default Description Modem on Hold Timer: This command controls whether or not the modem will grant or deny a Modem on-hold (MOH) request as well as setting the Modem-on-Hold-Time-Out. +PMHT=m 0 0 Deny V.
Error Correction and Data Compression Error Correction and Data Compression 4 The 536EX chipsets support two types of data mode error correction (MNP 2–4 and V.42) and data compression (V.44, MNP 5, and V.42 bis). V.42 error correction uses LAPM as the primary errorcontrol protocol and uses MNP 2-4 as an alternative. V.44 provides enhanced data compression over the existing V.42 bis standard. Data compression is up to on average 40% faster than previous methods.
Error Correction and Data Compression Table 20. Resulting +ES Connection Types +ES Settings (Answer Modem) +ES Settings (Originate Modem) +ES=1, 0, 1 (Buffer) +ES=4, 4, 6 (MNP Reliable) +ES=3, 0, 2 (V.42 Auto-reliable) +ES=3, 2, 4 (V.42 Reliable) +ES=1, 0, 1 (Buffer) +ES=4, 4, 6 (MNP Reliable) +ES=3, 0, 2 (V.42 Autoreliable) +ES=3, 2, 4 (V.
Error Correction and Data Compression Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued) Command Default Description MNP Block Size: This command specifies the maximum number of data bytes in an MNP data frame. A smaller frame size may improve throughput on high-impairment (noisy) telephone lines.
Error Correction and Data Compression Table 21. V.44/V.42/V.
Error Correction and Data Compression Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued) Command Default Description Data Compression Reporting: Controls whether the “+DR:” result code is transmitted from the DCE to DTE once a connection with has been made. If enabled the result code displayed shall represent the current negotiated DCE-DCE data compression type and is issued after the Error Control Report (+ER) and before the final result code CONNECT.
Error Correction and Data Compression Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued) Command Default Description V.44 Data Compression: This command controls the V.44 data compression function if provided in the DCE.
Error Correction and Data Compression Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued) Command Default Description Error Control Reporting: Controls whether the “+ER:” result code is transmitted from the DCE to the DTE once a connection has been made. If enabled the result code displayed shall represent the current negotiated DCE-DCE error control type and is issued after the Modulation Report (+MCR and +MRR) and before the final result code Data Compression Report (+DR:).
Error Correction and Data Compression Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued) Command Default Description Error Control Selection: The +ES=m command controls the operation of the V.42 error detection and correction protocol in the DCE. Once a connection has been established between the DCE and DTE, the subparameter can put the interface into synchronous access mode. In the default settings, synchronous access mode is disabled.
Fax Class 1 AT Commands 5 Fax Class 1 AT Commands The 536EX chipsets implement the EIA-578 data/fax Class 1 AT command set standard. This AT command set allows a DTE (with Class 1 communication software) and a 536EX-based modem to communicate with Group 3 fax machines. In addition, these chipsets provide fax identity and test commands. Fax identity commands are described in Table 22; all other fax AT commands are provided in Table 24 on page 67. 5.
Fax Class 1 AT Commands The fax AT+FCLASS command is used for changing between fax classes, determining the current class selection, and determining the supported fax classes. Both data/fax Class 0 (data modem mode) and Class 1 (fax modem mode) are implemented by the modem. In Class 0, the DTE-tomodem data rate can be set from 300 bps to 115,200 bps. In Class 1, it is recommended that the DTE-to-modem data rate is set to 19,200 bps. The silence-time timers consist of AT+FTS=
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 . The DTE also must recognize as the stream terminator. Upon detecting , the DTE must reinsert a single 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).
Fax Class 1 AT Commands The ATDT command string causes the modem to originate a fax call. After dialing the telephone number, the modem sends out a calling tone (1100 Hz), recognizes the remote fax modem answer tone, and looks for the remote fax HDLC flags at 300 bps. If the HDLC flags are detected, the modem sends the DTE a ‘CONNECT’ message followed by the Class 1 HDLC frame information.
Fax Class 1 AT Commands Table 24. Fax Mode Command Descriptions (Continued) Command Default Description Receive HDLC Data: The +FRH= command causes the modem to receive HDLC-framed data using the modulation mode selected in . The modem then delivers the next-received frame to the DTE. If the modem detects the selected carrier signal with an HDLC flag, the modem sends a ‘CONNECT’ result code to the DTE.
Fax Class 1 AT Commands Table 24. Fax Mode Command Descriptions (Continued) Command Default Description Transmit HDLC Data: The +FTH= command causes the modem to transmit data framed in HDLC protocol using the modulation mode selected. may have the values shown in Table 23 on page 65. After receiving the +FTH command, the modem sends a ‘CONNECT’ result code to the DTE.
IS-101 Voice Mode AT Commands IS-101 Voice Mode AT Commands 6 The 536EX chipsets implement a voice mode AT command set that allows a DTE to record and play back voice messages. This product is compatible with the EIA/TIA IS-101 voice command set. This section lists supported commands and a detailed description of each command (see Table 25 on page 71). When multiple commands are placed on a line, a semicolon (;) must be placed after each voice (and fax) command.
IS-101 Voice Mode AT Commands 6.1 DTMF Detection Reporting DTMF detection information is reported by the modem to the DTE by a shielded command as outlined in Section 6.5 of the ITU V.253 specification. When the DTMF burst is detected in Voice mode, the modem sends to the DTE a followed by a sequence of <-> is inserted to indicate the end of the determination interval. For example, a single 280ms burst of DTMF 5 would report: <5><5><5><5><-> 6.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Flow Control Select: This command allows the DTE to identify and select the types of flow control used. DCEs using the IS-101 standard must support in-band XON/XOFF flow control. XON is the ASCII character (11h); XOFF is the ASCII character (13h). The DCE may provide ITU-Ts V.24 CTS (circuit 106) and RTS (circuit 133) for flow control.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Distinctive Ring Selection: This command contains two parameters. The first selects whether the modem reports distinctive ring cadence information. The second parameter controls the timing of the RING event code report. m=, Defaults = 0, 0 Ring Reporting: The DCE reports the length of the ring period.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Event Reporting and Masking: This command selects which detection events are supported in voice mode. Each event is represented by a single bit of a four-digit hex number (see the following table). Setting an event number bit to 0 means that event is not reported. Setting a bit to 1 indicates that a detected event is reported.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Event Reporting and Masking: (cont.) Example 1. Viewing Supported Events: To determine what events are supported by the modem, send ‘AT+VEM=?’. AT+VEM=? ‘C’ ← Feature Class DB860980 ← Playback mode events OFEE0883 ← Record mode events BB863EE0 ← Command mode events OK Example 2. Setting the Event Mask: +VEM=m (cont.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command +VGT=m Default Description 128 Volume Selection: This command sets the volume level for the modem’s playback voice mode. A different playback level may be needed for each type of playback device (telephone line, local handset, local telephone, or speaker).
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Relay/Playback Control: This command controls the four µP relay drivers and controls hardware paths for voice playback/record transmit and receive. Preassigned Voice I/O Labels
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Relay/Playback Control: (cont.) Voice I/O Primitive Codes +VLS=m (cont.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Record Mode: This command causes the modem to enter record mode to record voice messages. Upon receiving the AT+VRX command, the modem responds to the DTE with a ‘CONNECT’ message at the current DTE-to-modem rate. It is important that the UART DTE-to-modem rate be equal or higher to the compression-scheme-required UART data rate (for example, CL1 at 4800 samples/ second requires 57,600 bps).
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Compression Method Selection: This command contains four parameters that specify the voice compression method, voice sampling rate, silence compression sensitivity, and the degree of silence expansion. The DCE can support different capabilities for each compression method.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description Compression Method Selection: (cont.) Silence Expansion: This command enables the DTE to modify the amount of silence expansion. This parameter represents the maximum period of silence the DCE expands a period of silence compressed by the parameter. The DCE ignores the parameter if is zero.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command #VSPS=m Default 1 Description Speakerphone Type Selection: This command determines which speakerphone type is used when the modem receives a +VSP=m command. This allows the application software to select whether telephone emulation or digital speakerphone is used for +VSP=m. Upon powering-up, the modem determines whether it can support a digital speakerphone mode.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description DTMF and Tone Generation: This command causes the modem to generate DTMF tones or pulse tones in voice mode. The code aborts the playback of tones, sends the ‘OK’ result code, and returns the modem to the voice command state. The DTE/DCE inactivity timer is in place during tone production. The command +VTS sent without a parameter assumes the default value, which is a null string.
IS-101 Voice Mode AT Commands Table 25. Voice Mode Command Descriptions (Continued) Command Default Description DTMF and Tone Generation: (cont.) 3. Single DTMF tones or hook flashes are sent enclosed in braces “{ }”. A duration must be included, as the duration set in +VTD=m does not apply. Use the following format: AT+VTS={,} For example: AT+VTS={2,30} This command sends DTMF tone 2 with a duration of 300 ms.
S-Registers 7 S-Registers The 536EX chipsets provide direct access to the internal registers known as S-registers. The DTE uses S-registers to set up and check modem configurations. The contents of these registers can be changed using the ATSn=x command, where ‘n’ is the register number and ‘x’ is the value to be stored. The contents of the S-registers can be read using the ATSn? command. Most S-registers can be read from or written to; however, some S-registers (such as S14) are read-only.
S-Registers Table 26. S-Register Command Descriptions (Continued) Command S5 Default Description 8 Backspace Character: S5 specifies the backspace character that is used to delete the lastentered character. After receiving a backspace character, the modem sends three characters to the DTE: a backspace character, a space character, and then another backspace character.
S-Registers Table 26. S-Register Command Descriptions (Continued) Command Default Description Guard Time: S12 is used to specify guard and detect times used for the Hayes and TIES escape sequences. S12 50 For the Hayes Escape Sequence, S12 specifies the minimum-delay timer (or guard time) before and after the three escape characters that is required for the modem to detect the Hayes Escape Sequence.
S-Registers Table 26. S-Register Command Descriptions (Continued) Command Default Description Bit-Mapped Options: S21 is a read-only register that indicates AT command settings.
S-Registers Table 26. S-Register Command Descriptions (Continued) Command Default Description Sleep Mode Timer: S33 determines when the modem enters sleep or power-down mode. When enabled (S33 ≠ 0), the controller enters sleep mode whenever the modem has been inactive for a user-programmable time delay (S33).
Caller ID 8 Caller ID This section describes Caller ID for the United States. Caller ID is a service that lets the called party know the telephone number of the caller before the call is answered. The information transmitted to the called party via Caller ID includes the caller’s name, call date, the call time, and the call number. This service is not available everywhere due to central office telephone equipment limitations and legal prohibition in some locations.
Caller ID Example 1: The following example of formatted form report (AT+VCID=1) illustrates the case when the DCE does not recognize the tag of one given data item from a packet of data items (data or fax command mode). RING DATE TIME NMBR NAME MESG RING RING = = = = = 0321 1405 5045551234 DOE JOHN 060342424231 Example 2: The following example illustrates the unsolicited response (AT+VCID=1) form of voice mode (voice, command, playback, and record modes).
Parallel Host Interface 16C450/16C550A UART Parallel Host Interface 16C450/16C550A UART 9 9.1 UART 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.
Parallel Host Interface 16C450/16C550A UART modem for each data interrupt, instead of only a single byte, as in 16C450 mode. The following diagram shows how the FIFO is used. Host software using this FIFO capability can significantly reduce system overhead by reducing the number of times that interrupt service routines are called. Figure 12.
Figure 13.
Parallel Host Interface 16C450/16C550A UART 9.2 UART Register Definitions 9.2.1 Scratch Register (SCR) Figure 14. Scratch Register (SCR) Register 7 SCR This is an 8-bit read/write register used by the DTE for temporary storage of data. 9.2.2 Modem Status Register (MSR) Figure 15. Modem Status Register (MSR) Register 6 DCD RI DSR CTS DDCDD TERI DDSR DCTS This register provides four bits (bits 7:4) that show current modem state and four bits (bits 3:0) that provide modem change information.
9.2.3 Line Status Register (LSR) Figure 16. Line Status Register (LSR) Register 5 RCVR Err TEMT THRE BI FE PE OE DR This read-only register provides UART status information to the host. Bits 4:1 report error conditions. These bits are reset to ‘0’ any time the host reads this register. An interrupt is generated to the host whenever any one of the bits (4:1) is set to ‘1’ and the RLSIE (receiver line status interrupt) has been enabled.
Parallel Host Interface 16C450/16C550A UART 9.2.4 Modem Control Register (MCR) Figure 17. Modem Control Register (MCR) Register 4 0 0 0 Loop Out 2 Out 1 RTS DTR This register controls the DTE-DCE UART interface. Bit 7:5 Not used—These bits are permanently set to ‘0’. Loop Bit—When set to ‘1’, this bit configures the UART for loopback diagnostic testing. In diagnostic mode, any data that is written to the THR (Transmit Holding register) is looped back to the RBR (Receiver Buffer register).
Parallel Host Interface 16C450/16C550A UART Bit 4 EPS (Even Parity Select)—When even parity select (LCR4) and parity enable (LCR3) are set to ‘1’, an even number of logic 1’s are transmitted or checked. When even parity select (LCR4) is a ‘0’ and parity enable (LCR3) is a ‘1’, an odd number of logic 1’s are transmitted or checked.
Parallel Host Interface 16C450/16C550A UART 9.2.7 Interrupt Identity Register (IIR) b Figure 20. Interrupt Identity Register (IIR) Register 2 FIFO EN FIFO EN 0 VDMA Int. ID 2 Int. ID 1 Int. ID 0 Int. Pen. (read-only) This read-only register indicates when the transmitter and receiver FIFOs are enabled, and the source of highest-priority pending interrupt to the DTE.
Parallel Host Interface 16C450/16C550A UART Bit 3 Interrupt ID Bit 2—In 16C450 mode, this bit is always a ‘0’. In FIFO mode, both this bit and bit IIR2 are set whenever a time-out interrupt is pending. Bits 2:1 Interrupt ID Bits ID0 and ID1—These two bits are used to identify the highest-priority interrupt as shown in Table 28. Bit 0 Interrupt Pending—This bit indicates when a modem interrupt is pending. Whenever this bit is equal to ‘0’, then one or more interrupts are pending.
Parallel Host Interface 16C450/16C550A UART 9.2.10 Receiver Buffer Register (RBR) Figure 23. Receiver Buffer Register (RBR) Register 0 RBR (DLAB = 0) The RBR (Receiver Buffer register) is a read-only register used for receiving data and AT command responses from the modem. 9.2.11 Divisor Latch Registers (DLM and DLL) Figure 24.
Parallel Host Interface 16C450/16C550A UART 9.3 16C550A UART FIFO Operation The modem 16C550A UART FIFO works in both interrupt and polled operation. A description of each type of operation is provided below. 9.3.1 FIFO Interrupt Mode Operation Both the modem receiver and transmitter UART FIFOs can be set up for interrupt mode operation. The RCVR FIFO trigger level and character time-out interrupts have the same priority as the current received data available interrupt.
Parallel Host Interface 16C450/16C550A UART • • • • LSR7 indicates when any errors occur in the RCVR FIFO. TEMT indicates when both the XMIT FIFO and Shift registers are empty. The THRE bit (LSR5) is set to ‘1’ whenever the XMIT FIFO is empty. LSR1 through LSR4 specify when a break interrupt, framing error, parity error, or overrun error occurs. • The DR bit (LSR0) is set to ‘1’ as long as there is at least one byte in the RCVR FIFO.
