System and method for communicating audio information between a computer and a duplex speakerphone modem

• US 6,418,203 B1
• Filed: 01/11/2000
• Issued: 07/09/2002
• Est. Priority Date: 06/06/1997
• Status: Expired due to Fees

• Current Assignee: Data Race, Inc.
• Original Assignee: Data Race, Inc.
• Inventors: Marcie, Patrick
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Eng, George
• Application Number:
  US09/481,097
• Time in Patent Office: 910 Days
• Field of Search: 379/88.02, 379/88.07, 379/88.13, 379/90.01, 379/93.01, 379/93-5-, 379/93-4-, 379/93.23, 379/100.16, 379/110.01, 379/388-1-3, 379/420.01, 379/195, 370/352, 370/355, 370/435, 370/465, 370/260, 370/266, 340/825.25, 340/825.44, 455/556-557, 375/222, 375/246, 375/377, 704/200, 704/258, 361/686, 361/688, 439/638, 439/928.1, 710/101, 710/128, 348/15, 381/109, 381/306
• US Class Current: 379/90.01
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks
• CPC Class Codes: H04M 1/6033 for providing handsfree use or a loudspeaker mode in telephone sets arrangements for preventing acoustic echo H04M9/08

Abstract

A modem configurable to operate in a normal mode to perform data communications on the Public Switched Telephone Network (PSTN) additionally configurable to operate in a duplex speakerphone mode. Preferably, the modem is a Personal Computer Memory Card Industry Association (PCMCIA) card for insertion into a connector in a portable computer. The computer includes a sound system with associated microphone and speaker that is incorporated in or associated with the portable computer as the audio input and output for the speakerphone operation. The modem incorporates an interface which allows digitized audio samples from the coder portion of a voice coder-decoder (CODEC) on the modem to be communicated to the computer and digitized audio samples from the computer'"'"'s sound system to be communicated to the decoder portion of the modem'"'"'s CODEC. The interface is configured in a manner which is transparent to the modem'"'"'s normal data communications functions, i.e., which enables conventional modem software to operate the modem in the normal mode without requiring modification to the conventional modem software. Preferably, the modem includes a digital signal processor (DSP) which performs electrical and acoustic echo cancellation and automatic gain control on the audio samples. The interface appears to the DSP as a conventional audio CODEC.

Claims

1. A computer system configured for use as a speakerphone, comprising:

an expansion bus coupled to a processor;

a sound system operably coupled to said expansion bus;

a modem operably coupled to said expansion bus and operable for coupling to a telephone line;

wherein the processor is operable to place the modem in a speakerphone mode;

wherein said sound system is operable to support speakerphone functionality and to receive a first analog audio input signal from a microphone and convert said first analog audio input signal into first digital audio output samples during a real-time speakerphone operation;

wherein said first digital audio output samples are operable to be transferred from said sound system to said modem on said expansion bus during said speakerphone operation;

wherein, when said modem is in said speakerphone mode, said modem is operable to convert said first digital audio output samples into a first analog audio output signal for transmission on the telephone line;

wherein, when said modem is in said speakerphone mode, said modem is operable to receive a second analog audio input signal from the telephone line and convert said second analog audio input signal into second digital audio samples;

wherein said second digital audio samples are operable to be transferred from said modem on said expansion bus to said sound system during said real-time speakerphone operation;

wherein said sound system is operable to receive said second digital audio samples and convert said second digital audio samples into a second analog audio output signal for transmission to a speaker during said real-time speakerphone operation; and

a direct memory access controller (DMAC) operable during said real-time speakerphone operation to transfer said first digital audio output samples from said sound system to said modem on said expansion bus and to transfer said second digital audio output samples from said modem on said expansion bus to said sound system.

2. The computer system of claim 1, wherein said expansion bus conforms to the Personal Computer Memory Card International Association (PCMCIA) specification, wherein said modem includes an interface portion for interfacing to said PCMCIA bus, wherein said interface portion conforms to the PCMCIA specification.

3. The computer system of claim 1, wherein said expansion bus is a bus selected from one of the set of buses comprising a CardBus, an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an SBUS, and a NuBus.

4. The computer system of claim 1, wherein during said real-time speakerphone operation said processor is operable to transfer said first digital audio output samples from said sound system to said modem on said expansion bus and to transfer said second digital audio output samples from said modem on said expansion bus to said sound system.

5. The computer system of claim 1, wherein said modem comprises:

an interface device for operably coupling said modem to said expansion bus; and

a coder-decoder (CODEC) coupled to said interface device;

wherein, when said modem is in said speakerphone mode, said interface device is operable to receive said first digital audio output samples from said expansion bus and provide said first digital audio output samples to said CODEC;

wherein, when said modem is in said speakerphone mode, said CODEC is operable to receive said first digital audio output samples from said interface device and convert said first digital audio output samples into said first analog audio output signal for transmission on the telephone line;

wherein, when said modem is in said speakerphone mode, said CODEC is operable to receive said second analog audio input signal from the telephone line and convert said second analog audio input signal into said second digital audio samples;

wherein, when said modem is in said speakerphone mode, said interface device is operable to receive said second digital audio samples from said CODEC and provide said second digital audio samples to said expansion bus.

6. The computer system of claim 5, wherein said interface device comprises:

a parallel to serial converter configured to receive said first digital audio samples from said processor in a parallel format, to convert said first digital audio samples from a parallel format into a serial format, and to provide said first digital audio samples to said CODEC in said serial format; and

a serial to parallel converter configured to receive said second digital audio samples from said CODEC in a serial format, to convert said second digital audio samples from a serial format into a parallel format, and to provide said second digital audio samples to said processor in a parallel format.

7. The computer system of claim 6, wherein said interface device further comprises interrupt logic for generating an interrupt to said processor upon completion of a transfer of one or more of said first digital audio samples from said parallel to serial converter to said CODEC and upon completion of a transfer of one or more of said second digital audio samples from said CODEC to said serial to parallel converter.

8. The computer system of claim 5, wherein said modem further comprises a digital signal processor (DSP) coupled between said CODEC and said interface device, wherein, when said modem is in said speakerphone mode, said DSP is operable to control data communications between said computer system and a data communications device coupled to the telephone line, wherein, when said modem is in said speakerphone mode, said DSP is further operable to transfer said first and second digital audio samples between said CODEC and said interface device.

9. The computer system of claim 8, wherein said modem further comprises an audio CODEC bus coupling said DSP and said interface device for transferring said first and second digital audio samples between said CODEC and said interface device when said modem is in said speakerphone mode, wherein said modem further comprises a parallel data bus for transferring data associated with said data communications between said DSP and said interface device.

10. The computer system of claim 8, wherein said DSP is configured to perform echo cancellation on said first and second digital audio samples when said modem is in said speakerphone mode.

11. The computer system of claim 8, wherein said DSP is configured to perform automatic gain control on said first and second digital audio samples when said modem is in said speakerphone mode.

12. The computer system of claim 1, wherein said modem is further configurable to operate in a second mode, wherein when configured in said second mode said modem is operable to perform data communications between said computer system and a data communications device on the telephone line.

13. A computer system configured for use as a speakerphone, comprising:

an expansion bus coupled to a processor;

a sound system operably coupled to said expansion bus;

a modem operably coupled to said expansion bus and operable for coupling to a telephone line;

wherein the processor is operable to place the modem in a speakerphone mode;

wherein said sound system is operable to support speakerphone functionality and to receive a first analog audio input signal from a microphone and convert said first analog audio input signal into first digital audio output samples during a real-time speakerphone operation;

wherein said first digital audio output samples are operable to be transferred from said sound system to said modem on said expansion bus during said speakerphone operation;

wherein, when said modem is in said speakerphone mode, said modem is operable to convert said first digital audio output samples into a first analog audio output signal for transmission on the telephone line;

wherein, when said modem is in said speakerphone mode, said modem is operable to receive a second analog audio input signal from the telephone line and convert said second analog audio input signal into second digital audio samples;

wherein said second digital audio samples are operable to be transferred from said modem on said expansion bus to said sound system during said real-time speakerphone operation;

wherein said sound system is operable to receive said second digital audio samples and convert said second digital audio samples into a second analog audio output signal for transmission to a speaker during said real-time speakerphone operation; and

bus master logic, wherein, when said modem is in said speakerphone mode, said bus master logic is operable to become master of said expansion bus and to transfer said first digital audio output samples from said sound system to said modem on said expansion bus and to transfer said second digital audio output samples from said modem on said expansion bus to said sound system.

14. A modem configured to be placed in a speakerphone mode for speakerphone use, comprising:

an interface device for operably coupling said modem to an expansion bus of a computer system;

a coder-decoder (CODEC) coupled between said interface device and a telephone line;

wherein when said modem is in said speakerphone mode said interface device is operable to receive on the expansion bus first digital audio output samples from a sound system of the computer system and provide said first digital audio output samples to said CODEC for real-time speakerphone use;

wherein when said modem is in said speakerphone mode said CODEC is operable to receive said first digital audio output samples from said interface device and convert said first digital audio output samples into a first analog audio output signal for transmission on the telephone line;

wherein when said modem is in said speakerphone mode said CODEC is further operable to receive a second analog audio input signal from the telephone line and convert said second analog audio input signal into second digital audio samples for realtime speakerphone use;

wherein when said modem is in said speakerphone mode said interface device is further operable to receive said second digital audio samples from said CODEC and send said second digital audio samples on the expansion bus to the sound system of the computer system;

a digital signal processor (DSP) coupled between said CODEC and said interface device, wherein said DSP is operable to control data communications between a computer system and a data communications device coupled to the telephone line, wherein said DSP is further operable to transfer said first and second digital audio samples between said CODEC and said interface device; and

an audio CODEC bus coupling said DSP and said interface device for transferring said first and second digital audio samples between said CODEC and said interface device, wherein said modem further comprises a parallel data bus for transferring data associated with said data communications between said DSP and said interface device.

15. The modem of claim 14, wherein said expansion bus conforms to the PCMCIA specification.

16. The modem of claim 14, wherein said expansion bus is selected from one of the set of buses comprising a CardBus, an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an SBUS, and a NuBus.

17. The modem of claim 14, wherein said interface device comprises:

a parallel to serial converter configured to receive said first digital audio samples from the expansion bus in a parallel format, to convert said first digital audio samples from a parallel format into a serial format, and to provide said first digital audio samples to said CODEC in said serial format; and

a serial to parallel converter configured to receive said second digital audio samples from said CODEC in a serial format, to convert said second digital audio samples from a serial format into a parallel format, and to provide said second digital audio samples to the expansion bus in a parallel format.

18. The modem of claim 17, wherein said interface device further comprises interrupt logic for generating an interrupt to a system processor coupled to the expansion bus upon completion of a transfer of one or more of said first digital audio samples from said parallel to serial converter to said CODEC and upon completion of a transfer of one or more of said second digital audio samples from said CODEC to said serial to parallel converter.

19. The modem of claim 14, wherein said DSP is configured to perform echo cancellation on said first and second digital audio samples.

20. The modem of claim 14, wherein said DSP is configured to perform automatic gain control on said first and second digital audio samples.

21. The modem of claim 14, wherein said modem is configurable to operate in first and second modes, wherein when configured in said first mode said modem is operable for audio speakerphone use, wherein when configured in said second mode said modem is operable to perform data communications between a computer system and a data communications device on the telephone line.

22. The modem of claim 14, further comprising:

one or more memory buffers for storing said first and second digital audio samples; and

bus master logic coupled to said expansion bus, wherein said bus master logic is operable to become master of said expansion bus and to transfer said first digital audio output samples from said sound system to said memory buffers on said expansion bus and to transfer said second digital audio output samples from said memory buffers on said expansion bus to said sound system.

23. A method for operating a computer system as a speakerphone, wherein the computer system comprises an expansion bus, a sound system operably coupled to said expansion bus, and a modem operably coupled to said expansion bus and to a telephone line, the method comprising:

instructing said modem to enter a speakerphone mode;

said sound system receiving a first analog audio input signal from a microphone during a real-time speakerphone operation and converting said first analog audio input signal into first digital audio output samples;

transferring on said expansion bus said first digital audio output samples from said sound system to said modem in response to said sound system converting said first analog audio input signal into said first digital audio output samples during said real-time speakerphone operation;

said modem converting said first digital audio output samples from a parallel to a serial format and into a first analog audio output signal for transmission on the telephone line during said real-time speakerphone operation in response to said transferring said first digital audio output samples from said sound system to said modem;

said modem receiving a second analog audio input signal from the telephone line and converting said second analog audio input signal from a serial to a parallel format and into second digital audio samples during said real-time speakerphone operation;

generating a processor interrupt after said converting said second analog audio input signal from a serial to a parallel format;

transferring on said expansion bus said second digital audio samples from said modem to said sound system in response to said modem converting said second analog audio input signal into second digital audio samples during said real-time speakerphone operation;

said sound system receiving said second digital audio samples and converting said second digital audio samples into a second analog audio output signal for transmission to a speaker during said real-time speakerphone operation.

24. The method of claim 23, wherein said expansion bus conforms to the Personal Computer Memory Card International Association (PCMCIA) specification, wherein said modem includes an interface portion for interfacing to said PCMCIA bus, wherein said interface portion conforms to the PCMCIA specification, wherein said transferring said first digital audio output samples from said sound system to said modem and said transferring said second digital audio samples from said modem to said sound system comprises transfers performed in conformance with the PCMCIA specification.

25. The method of claim 23, wherein said transferring said first digital audio output samples from said sound system to said modem and said transferring said second digital audio samples from said modem to said sound system comprise a processor operably coupled to said expansion bus performing said transferring.

26. The method of claim 23, wherein said transferring said first digital audio output samples from said sound system to said modem and said transferring said second digital audio samples from said modem to said sound system comprise a direct memory access controller (DMAC) operably coupled to said expansion bus performing said transferring.

27. The method of claim 23, wherein said transferring said first digital audio output samples from said sound system to said modem and said transferring said second digital audio samples from said modem to said sound system comprise bus master logic included in said modem coupled to said expansion bus performing said transferring.

28. The method of claim 23, wherein said modem comprises an interface device for operably coupling said modem to said expansion bus and a coder-decoder (CODEC) coupled to said interface device, the method further comprising:

said interface device receiving said first digital audio output samples from said expansion bus and providing said first digital audio output samples to said CODEC;

said CODEC receiving said first digital audio output samples from said interface device and converting said first digital audio output samples into said first analog audio output signal for transmission on the telephone line;

said CODEC receiving said second analog audio input signal from the telephone line and converting said second analog audio input signal into said second digital audio samples;

said interface device receiving said second digital audio samples from said CODEC and providing said second digital audio samples to said expansion bus.

29. The method of claim 28, wherein said interface device comprises a parallel to serial converter and a serial to parallel converter, the method further comprising:

said parallel to serial converter receiving said first digital audio samples from said expansion bus in a parallel format, converting said first digital audio samples from a parallel format into a serial format, and providing said first digital audio samples to said CODEC in said serial format;

said serial to parallel converter receiving said second digital audio samples from said CODEC in a serial format, converting said second digital audio samples from a serial format into a parallel format, and providing said second digital audio samples to said expansion bus in a parallel format.

30. The method of claim 29, wherein said interface device further comprises interrupt logic, the method further comprising:

said interrupt logic generating an interrupt to a system processor operably coupled to said expansion bus upon completion of a transfer of one or more of said first digital audio samples from said parallel to serial converter to said CODEC;

said interrupt logic generating an interrupt to said processor upon completion of a transfer of one or more of said second digital audio samples from said CODEC to said serial to parallel converter.

31. The method of claim 28, wherein said modem further comprises a digital signal processor (DSP) coupled between said CODEC and said interface device, the method further comprising:

said DSP performing data communications between a data communications device coupled to the telephone line and a computer system during a first time period;

said DSP transferring said first and second digital audio samples between said CODEC and said interface device during a second time period.

32. The method of claim 31, further comprising said DSP performing echo cancellation on said first and second digital audio samples.

33. The method of claim 31, further comprising said DSP performing automatic gain control on said first and second digital audio samples.