Abstract:
A computer system is used with a telephone that is operable by a user to furnish a predetermined command. The processing unit and a control circuit. The central processing unit is connected to communicate with the interface port, and the control circuit is connected to the telephone. The control circuit is configured to detect the predetermined command and in response to detection of the predetermined command, change a connection status between the telephone and the interface port.

Description:
BACKGROUND 
     The invention relates to connecting a telephone. 
     Referring to FIG. 1, a typical computer  9  (e.g., a desktop or portable computer) has a modem  2  for establishing communication between the computer  9  and another telephone line device over a telephone line  6 . This telephone line device might be the modem of another computer or a telephone. 
     Quite often, the end of the telephone line  6  near the computer  9  includes a short segment  6   a  that extends from a wall-mounted telephone jack  1  to the computer  9 . The telephone line segment  6   a  typically has one connector (e.g., an RJ-11 connector) that is constructed to plug into the jack  1  and one connector that is constructed to plug into either the modem  2  or a telephone  3 . In recognition that both the telephone  3  and the modem  2  typically need to be connected to the telephone line segment  6   a , the modem  2  typically has two RJ-11 telephone jacks  5 . In this manner, the telephone line segment  6   a  is plugged into one of the jacks  5 , and the telephone  3  is plugged into the other jack  5 . 
     For the telephone  3  to access the telephone line  6 , the jacks  5  of the modem are electrically connected together. One way to accomplish this is to hardwire the jacks  5  of the modem  2  together (See FIG.  2 ). However, referring to FIG. 3, another modem  7  might have circuitry  7   a  to selectively connect the jacks  5  together based on when the modem  7  needs access to the telephone line  6 . 
     Typically, only one telephone line device (i.e., the modem  7  or the telephone  3 ) may use the telephone line  6  to the mutual exclusion of other telephone line devices. For example, when the modem  7  goes off-hook, or seizes the telephone line  6 , the modem  7  disconnects the telephone  3  from the telephone line  6 . In certain telephony modes, when the telephone  3  goes off-hook, the modem  7  may disconnect itself from the telephone line  6  and connect the telephone  3  to the telephone line  6 . These telephony modes include a telephone answering machine mode which permits a user of the telephone  3  to pick up the telephone  3  to stop recording of an incoming call, and thus, speak to the calling party. 
     Referring to back to FIG. 1, besides being used to access the telephone line  6 , the telephone  3  may also be used as a peripheral device of the computer  9 . The computer  9  might have an analog port  11  with an RJ-11 telephone jack  5  for connecting the modem  9  to the computer  9 . As a peripheral device, the telephone  3  might, for example, be used to select items of a menu-driven software program and retrieve stored voicemail messages from the computer  9 . 
     SUMMARY 
     In general, in one aspect, the invention features a computer system that is used with a telephone. The telephone is operable by a user to furnish a predetermined command. The computer system has a telephony interface port, a central processing unit and a control circuit. The central processing unit is connected to communicate with the interface port, and the control circuit is connected to the telephone. The control circuit is configured to detect the predetermined command and in response to detection of the predetermined command, change a connection status between the telephone and the interface port. 
     Implementations of the invention may include one or more of the following. The control circuit may he configured to change the connection status by connecting the telephone to the interface port. The control circuit may also be configured, in response to detection of the predetermined command, to change another connection status between the telephone and a telephone line. The control circuit may be configured to change this other connection status between the telephone and the telephone line by disconnecting the telephone from the telephone line. 
     The central processing unit may also be connected to communicate with the interface port to detect another predetermined command furnished by the user via the telephone. The central processing unit may also be connected to communicate with the control circuit to change the connection status between the telephone and the interface port in response to detection of the other predetermined command. The control circuit may be configured to change the connection status in response to the other predetermined command by disconnecting the telephone from the interface port. 
     The telephone may include a key pad, and the predetermined command may include a dial tone generated by the telephone in response to a predetermined key of the key pad being pressed. The predetermined command may include a dial tone generated by the telephone in response to the user speaking into the telephone. 
     The telephone may be configured to generate a signal indicative of the predetermined command, and the control circuit may include a switch circuit, a discrete signal processing engine and a controller. The switch circuit may be connected to the telephone and the interface port. The discrete signal processing engine may be configured to recognize the predetermined signal, and the controller may be configured to use the switch circuit to connect the telephone to the interface port in response to recognition of the predetermined signal by the engine. The engine and controller may be part of a modem, and at least a portion of the control circuit may be part of a modem. 
     In general, in another aspect, the invention features a system for use with a telephone. The telephone is operable by a user to furnish a predetermined command. The system includes a computer and a control circuit. The computer has a communication port, and the control circuit is connected to the telephone. The control circuit is configured to detect the predetermined command and in response to detection of the predetermined command, change a connection status between the telephone and the port. 
     In general, in another aspect, the invention features a method for use with a computer and a telephone. The telephone is capable of operation by a user to furnish a predetermined command. The method includes detecting the predetermined command and in response to detection of the predetermined command, changing a connection status between the telephone and the computer. 
     In general, in another aspect, the invention features a computer system for use with a telephone that is operable by a user to furnish a predetermined command. The computer system includes a modem that is configured to detect the predetermined command and operate in response to detection of the predetermined command. The computer system also has a central processing unit that is configured to interact with the modem. 
     Implementations of the invention may include one or more of the following. The modem may be configured to detect the command by using a caller ID function of the modem. The modem may be configured to operate by changing a connection status of the telephone. 
     In general, in another aspect, the invention features a computer system for use with a telephone that is operable by a user to furnish a predetermined command. The computer system includes a modem that has a caller ID function. The modem is configured to use the caller ID function to detect the predetermined command. The computer system also has a central processing unit that is configured to interact with the modem. 
     In general, in another aspect, the invention features a method for use with a computer system and a telephone that is operable by a user to furnish a predetermined command. The method includes using a modem to detect the predetermined command and operating the modem in response to detection of the predetermined command. 
     In general, in another aspect, the invention features a method for use with a computer system and a telephone that is operable by a user to furnish a predetermined command. The method includes using a caller ID function of the modem to detect the predetermined command. 
     Among the advantages of the invention are one or more of the following. Neither use of a keyboard of the computer nor physical connection/disconnection of telephone lines are required. A wireless phone may be used to control the computer. Only use of the telephone is required to retrieve stored voicemail messages from the computer. Some pre-existing circuitry and functions (e.g., caller ID circuitry) of the modem may be used. Minimal circuit space is consumed. 
     Other advantages and features will become apparent from the following description and from the claims. 
    
    
     DESCRIPTION 
     FIG. 1 is an electrical schematic diagram of a computer system of the prior art. 
     FIGS. 2 and 3 are electrical schematic diagrams of modems of the prior art. 
     FIG. 4 is an electrical schematic diagram of a computer system. 
     FIG. 5 is a schematic diagram of a modem of the computer system of FIG.  4 . 
     FIG. 6 is a flow diagram of an interrupt service routine. 
     FIG. 7 is a schematic diagram of another modem. 
    
    
     Referring to FIG. 4, a switch circuit  56  of a computer system  50  is configured to connect a telephone  3  (e.g., a desk telephone or a wireless telephone) to either an analog interface port  52  or a telephone line  6  based on commands received from a keypad  3   a  of the telephone  3 . The commands include a CONNECT_TO_PORT command to connect the telephone  3  to the port  52  and a CONNECT_TO_LINE command to connect the telephone  3  to the telephone line  6 . Each command is formed by pressing one or more predefined keys of the keypad  3   a  in a predefined sequence. 
     When connected to the port  52 , the telephone  3  may be used as a peripheral device of the computer system  50 , and as such, the key pad  3   a  may be operated to control functions of and retrieve data from the system  50 . For example, the key pad  3   a  may be used to select routines of a menu driven software program. One of the routines might be, for example, a voice mail retrieval routine that retrieves stored voicemail messages that a modem  58  stored when in a voicemail telephony mode. Continuing the example, once the key pad  3   a  selects the voicemail retrieval routine, the routine replays the stored messages over the telephone  3 . 
     At powerup and after reset of the computer system  50 , the switch circuit  56  connects the telephone  3  to the telephone line  6 . However, if the telephone  3  is connected to the port  52 , the user may desire to terminate use of the telephone  3  as a peripheral device and reconnect the telephone  3  back to the telephone line  6 . To accomplish this, the user uses the key pad  3   a  to enter the CONNECT_TO_LINE command. The computer system  50  responds to the CONNECT_TO_LINE command by instructing the modem  58  to disconnect the telephone  3  from the port  52  and connect the telephone  3  to the telephone line  6 . In this arrangement (which is the arrangement present at power up of the computer system  50 ), the telephone  3  and the modem  58  are connected in parallel to the telephone line  6 . 
     As is typical, the telephone  3  is configured to generate a unique set of dual tone multi-frequency (DTMF) dial tones for each key of the keypad  3   a  that is pressed. When the telephone  3  is connected to the telephone line  6  and the telephone  3  goes off-hook, the modem  58  monitors the output of the telephone  3  for the dial tones that represent the predetermined CONNECT_TO_PORT command. 
     Besides the switch circuit  56 , the modem  58  has other circuitry  57  that is configured to detect when a ring occurs on the telephone line  6 , to detect the CONNECT_TO_PORT command and to detect when the telephone  3  goes off-hook, a condition necessary for the generation of the dial tones which carry the CONNECT_TO_PORT command. 
     Referring to FIGS. 5 and 6, the circuitry  57  includes a controller  16  that is alerted at one of its interrupt inputs when either a ring is detected on the telephone line  6  or the telephone  3  goes off-hook. Once alerted, the controller  16  begins executing an interrupt service routine  21  (see FIG.  6 ). In the routine  21 , the controller  16  first wakes up the modem  58  (in steps  150  and  152 , if necessary) and determines the condition that generated the interrupt, i.e., the controller determines whether the telephone  3  is off-hook (step  164 ) or a ring on the telephone line  6  is detected (step  154 ). 
     If the telephone  3  is off-hook, the controller  16  determines  166  whether the CONNECT_TO_PORT command has been detected, and if so, the controller  16  (via the switch circuit  56 ) connects  167  the telephone  3  to the analog interface port  52  and returns from the interrupt service routine  21 . 
     To decode the CONNECT_TO_PORT command, the controller  16  uses a caller ID routine  19 . A typical modem with a built-in caller ID routine uses the routine to decode dial tones that are generated by the phone company. These dial tones represent information (e.g., name and phone number) about the calling party. 
     In addition to using the caller ID routine  19  (along with other circuitry (e.g., a discrete signal processing (DSP) engine  18 )) to decode dial tones generated by the phone company, the modem  58  also uses the caller ID function  19  to decode dial tones that are generated by the key pad  3   a.    
     Once a ring on the telephone line  6  is detected (i.e., the telephone  3  is not off-hook), the controller  16  starts executing  157  the caller ID routine  19  to decode information about the calling party. If neither the telephone  3  is off-hook, rings are present on the telephone line  6 , nor the CONNECT_TO_PORT command is detected, then the controller  16  returns the modem  58  to the idle state and returns from the interrupt service routine  21 . 
     In FIG. 5, the interrupt input of the controller  16  is connected to the outputs of ring detect logic  12  and off-hook detect logic  42 . The off-hook detect logic  42  monitors the output of the telephone  3  and pulses the interrupt input of the controller  16  with an interrupt signal when the telephone  3  goes off-hook. The ring detect logic  12  monitors the telephone line  6  for a ring signal when the telephone line  6  is idle. The ring detect logic  12  is connected to a line  11  that is electrically connected to the telephone line  6  when the modem  58  is not using the telephone line  6  to transmit or receive data. 
     The controller  16  interacts with the DSP engine  18  to analyze analog waveforms to determine whether the telephone  3  is off-hook or a ring is present on the telephone lines  6 . To convert the analog waveforms to digital signals for analysis by the DSP engine  18 , the modem  58  has analog-to-digital (A/D) converters which are part of a CODEC chip  15 . 
     Besides having A/D converters, the CODEC chip  15  also has current drivers that the controller  16  uses to operate relays. One of these relays is a relay  40  of the switch circuit  56  that the controller  16  uses to connect the telephone  3  to either the analog interface port  52  or the telephone line  6 . Another one of these relays is a caller ID relay  20  that the controller  16  uses to connect the line  11  to the CODEC  15  at the beginning of the interrupt service routine. The controller  16  also uses a driver of the CODEC chip  15  to selectively connect the telephone line  6  to either the CODEC chip  15  (when the modem is transmitting or receiving data over the telephone line  6 ) or the line  11 . 
     Among the other features of the modem  58  are digital-to-analog (D/A) converters of the CODEC  15 . The D/A converters are used to transmit signals from the DSP engine  18  to the telephone line  6 . The modem  58  also has an RJ-11 telephone jack  5  that mates with a telephone plug of the telephone line  6 . Inside the modem  58 , the wires of the jack  5  are connected to the relay  40 . 
     As is typical, the telephone line  6  has wires called tip and ring, and these wires carry the incoming and outgoing analog telephone signals, the ring signal, and the power to operate the telephone  3 . The voltages occurring on the telephone line  6  are ordinarily up to 50 volts. As a result, the telephone jack  5  is isolated from other components of the modem  58  through a line interface  8 . The interface  8  has an isolation element and a 2-wire to 4-wire converter which takes the tip and rings wires of the jack  5  and converts them to four wires (two for computer system microphone output and two for speaker input) suitable for routing within the computer system  50 . Similar to the line interface  8 , the analog interface port  52  also has an isolation element and a 2-wire to 4-wire converter. The port  52  also includes A/D and D/A converters. 
     Referring to back to FIG. 4, the computer system  50  includes a central processing unit (CPU)  82  that is coupled to a local bus  86 . The CPU  82  executes software of the computer system  50 , such as the menu driven software and a software routine that detects the CONNECT_TO_LINE command and accordingly instructs the modem  58  to connect the telephone  3  to the telephone line  6 . 
     Also coupled to the local bus  86  are a level two (L 2 ) cache, a host bridge/system controller circuit  90 , and a system memory  88 . The circuit  90  controls access to the system memory  88  and interfaces the local bus  86  to a primary Peripheral Component Interconnect (PCI) bus  80 . 
     A PCI-Industry Standard Architecture (ISA) bridge  92  interfaces the primary PCI bus  80  to an ISA bus  94 . Coupled to the ISA bus  94  are an I/O circuit  104  (controlling a floppy disk drive  106 , a keyboard  100  and a mouse  102 ) and an Intelligent Device Electronics (IDE) controller which controls a hard disk drive  98 . 
     A PCI-PCI bridge  78  interfaces the primary PCI bus  80  to a secondary PCI bus  76 . Coupled to the bus  76  are the analog interface port  52  and a multimedia accelerator  66 . The multimedia accelerator  66  controls data paths going from the bus  76  to a display  68 , speakers  70  and a serial interface called an AC link  62 . The AC link  62  functions as a two serial link between an I/O interface  60  and the accelerator  66 . The I/O interface  60  provides registers, decode logic and other functions for the modem  58 . 
     As examples of the commands entered via the key pad  3   a , in some arrangements, the key “#” is pressed to indicate the CONNECT_TO_PORT command, and the key “*” is pressed to indicate the CONNECT_TO_LINE command. In other arrangements, other keys are used to enter the commands. Also, in some arrangements, the same key is used to enter both the CONNECT_TO_PORT and CONNECT_TO_LINE commands. In some arrangements, the command is formed by pressing a predetermined sequence of keys. An example, the CONNECT_TO_LINE command might be formed by pressing the key “*” and then pressing the key “#.” 
     Referring to FIG. 7, in other arrangements, the commands may be generated by a user&#39;s voice. In this manner, the user speaks into the telephone  3  to deliver commands to a modem  200 . For example, if the user takes the telephone  3  off-hook and says “connect to port” into the telephone  3 , the modem  200  is constructed to respond to the voice command and connect the telephone  3  to the analog interface port  52 . 
     The modem  200  has a similar design to the modem  58 , with the differences being that the modem  200  has a voice DSP engine  204  and a controller  201  replaces the controller  16 . The controller  201  has a similar design to the controller  16  except that the controller  201  has a voice recognition routine  202 . The controller  201  uses the voice recognition routine  202  to interact with the voice DSP engine  204  to interpret speech from the telephone  3 . The voice recognition routine  202  is activated when the modem  200  detects the telephone  3  has been taken off-hook. The voice DSP engine  204  is coupled to the DSP engine  18 . 
     Other techniques and structures may be used to decode the voice commands. For example, in some arrangements, software executed by the CPU  82  is used to decode the voice commands. 
     Other embodiments are within the scope of the following claims. For example, a software modem may be used where the functions of the controller  16  are implemented in software executed by the CPU  82 .