Host signal processor modem and telephone
DCFirst Claim
1. A communication system comprising:
- a host computer which includes native audio hardware capable of generating audible output from the host computer, wherein the audio hardware processes digital samples according to a first sampling clock;
a communication device comprising;
an interface coupled to the host computer; and
an analog-to-digital converter coupled to the interface, the analog-to-digital converter converting an analog signal from an input line to digital samples accessible by the host computer through the interface, wherein the communication device processes digital samples according to a second sampling clock which is asynchronous to the first sampling clock; and
software executed by the host computer, the software transferring the digital samples from the communication device to the native audio hardware which plays the digital samples, the software comprising a procedure which transfers digital samples from the communication device to a buffer in a memory of the host computer, wherein the procedure duplicates or deletes samples to equalize a data transfer rate from the communication device and a data transfer rate to the audio hardware, wherein;
samples from the communication device are transferred to a location the buffer, indicated by a first index;
samples are transferred to the audio hardware from a location in the buffer, indicated by a second index; and
the procedure compares the first index to the second index and determines from a difference between the first and second indices whether to duplicate or delete samples being transferred to the buffer.
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Accused Products
Abstract
A host signal processor (HSP) modem has a software interface between HSP modem hardware and native audio hardware in a host computer. No hard wire connections between modem hardware and audio hardware are required for synchronization. Instead, a software clock recovery system matches a transfer rate of the HSP modem hardware and a transfer rate of the audio hardware by duplicating or deleting samples. The software interface allows the native audio hardware to make audible the handshaking sequence during modem connections which eliminates the need for a speaker and speaker drivers in the modem hardware. The combination of HSP modem hardware, audio hardware, and software executed by the host computer also allows the HSP modem to perform voice communication such as telephone or speakerphone functions.
78 Citations
19 Claims
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1. A communication system comprising:
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a host computer which includes native audio hardware capable of generating audible output from the host computer, wherein the audio hardware processes digital samples according to a first sampling clock; a communication device comprising;
an interface coupled to the host computer; and
an analog-to-digital converter coupled to the interface, the analog-to-digital converter converting an analog signal from an input line to digital samples accessible by the host computer through the interface, wherein the communication device processes digital samples according to a second sampling clock which is asynchronous to the first sampling clock; andsoftware executed by the host computer, the software transferring the digital samples from the communication device to the native audio hardware which plays the digital samples, the software comprising a procedure which transfers digital samples from the communication device to a buffer in a memory of the host computer, wherein the procedure duplicates or deletes samples to equalize a data transfer rate from the communication device and a data transfer rate to the audio hardware, wherein; samples from the communication device are transferred to a location the buffer, indicated by a first index; samples are transferred to the audio hardware from a location in the buffer, indicated by a second index; and the procedure compares the first index to the second index and determines from a difference between the first and second indices whether to duplicate or delete samples being transferred to the buffer. - View Dependent Claims (2, 3, 4, 5)
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6. A host signal processor modem comprising:
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a communication device comprising an interface for connection to a host computer, and an analog-to-digital converter which converts analog signals from an input line to digital samples accessible to the host computer through the interface; and software executed by the host computer, the software including a procedure which during a handshake sequence for the host signal processor modem, transfers digital samples from the communication device to audio hardware native to the host computer, the audio hardware playing the digital samples to allow user monitoring of the handshake sequence, wherein; samples from the communication device are transferred to a location in a buffer, indicated by a first index; samples are transferred to the audio hardware from a location in the buffer, indicated by a second index; and the procedure compares the first index to the second index and determines from a difference between the first and second indices whether to delete or duplicate samples being transferred to the buffer, whereby the software deletes or duplicates digital samples being transferred, as necessary to equalize a transfer rate from the communication device and a transfer rate to the audio hardware. - View Dependent Claims (7, 8, 9, 10)
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11. A host signal processor modem comprising:
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a communication device comprising an interface for connection to a host computer, and an analog-to-digital converter which converts analog signals from an input line to digital samples accessible to the host computer through the interface; software executed by the host computer, the software including a procedure which during a handshake sequence for the host signal processor modem, transfers digital samples from the communication device to audio hardware native to the host computer, the audio hardware playing the digital samples to allow user monitoring of the handshake sequence; and a buffer in a memory of the host computer, wherein samples from the communication device are transferred from the communication device to a location in the buffer, indicated by a first index and samples are transferred to the audio hardware from a location in the buffer, indicated by a second index, wherein; the audio hardware processes digital samples according to a first sampling clock; the communication device processes digital samples according to a second sampling clock which is asynchronous to the first sampling clock; and the software comprises a procedure that compares the first index to the second index and determines from a difference between the first and second indices whether to duplicate or delete digital samples. - View Dependent Claims (12, 13, 14, 15)
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16. A method for operating a host signal processor modem, comprising:
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transferring digital samples from an analog-to-digital converter in a hardware portion of the host signal processor modem to a buffer in a host computer which executes a software portion of the host signal processor modem; and using audio hardware native to the host computer to play the digital samples from the buffer, wherein transferring the digital samples comprises; transferring samples from the hardware portion of the host signal processor modem to a location in the buffer, indicated by a first index; transferring samples to the audio hardware from a location in the buffer, indicated by a second index; and determining from a difference between the first and second indices whether to duplicate samples being transferred; and duplicating digital samples from the hardware portion of the host signal processor modem to increase a data transfer rate to the buffer and match a rate at which the audio hardware plays the digital samples from the buffer. - View Dependent Claims (17)
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18. A method for operating a host signal processor modem, comprising:
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transferring digital samples from an analog-to-digital converter in a hardware portion of the host signal processor modem to a buffer in a host computer which executes a software portion of the host signal processor modem; and using audio hardware native to the host computer to play the digital samples from the buffer, wherein transferring the digital samples comprises; transferring samples from the hardware portion of the host signal processor modem to a location in the buffer, indicated by a first index; transferring samples to the audio hardware from a location in the buffer, indicated by a second index; and determining from a difference between the first and second indices whether to skip transfer of some digital samples; and skipping transfer of some digital samples from the hardware portion of the host signal processor modem to decrease a data transfer rate to the buffer and match a rate at which the audio hardware plays the digital samples from the buffer. - View Dependent Claims (19)
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Specification