Pulse or digital communications – Transceivers – Modems
Reexamination Certificate
2000-01-10
2001-10-16
Pham, Chi (Department: 2631)
Pulse or digital communications
Transceivers
Modems
C379S093050
Reexamination Certificate
active
06304597
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to modem architecture for communication lines. More particularly, this invention relates to modem circuitry used in connection with isolation systems for connecting to phone lines.
BACKGROUND
New generations of consumer appliances like set-top boxes, payphones, vending machines and other systems often require or prefer low-speed data modems. Such modems allow remote hosts to handle billing or other housekeeping functions, or permit “smart” vending machines to call for more supplies. Although typical microprocessor and digital-signal-processor (DSP)-based multimedia chips employed in set-top boxes and other systems are capable of implementing a low-speed modem, they would do so at an undesirable manufacturing complexity and expense.
Prior modem architectures typically included multiple integrated circuits for handling modem processing and communication line termination. In particular, one or more digital-signal-processor chips have been coupled to analog-front-end circuitry, which in turn has been connected to line termination circuitry across a transformer isolation barrier. Such modem architectures suffer from numerous disadvantages.
SUMMARY OF THE INVENTION
The present invention provides an improved modem architecture and associated method that integrate modem functionality and line-side isolation functionality while allowing control of modem processing so that it may be bypassed if raw data, such as raw pulse-code-modulated (PCM) data, is desired to be transmitted or received.
In one embodiment, the integrated modem and line-isolation circuit having selective modem processing including system-side line-isolation circuitry capable of being coupled to an isolation barrier to communicate digital information through the communication line, digital signal processing (DSP) circuitry coupled to the system-side line-isolation circuitry, selection circuitry coupled to an output from the modem processor and a separate data path; and a control signal coupled to the selection circuitry. The DSP circuitry has a modem processor for modem data and a digital processor for system-side circuitry, and the control signal determines whether the output from the modem processor or the separate data path is output from the selection circuitry. In a more particular embodiment, the modem processor receives pulse-code-modulated (PCM) data as an input, the separate data path comprises PCM data, and the selection circuitry outputs either modem data from the modem processor or PCM data from the separate data path depending upon the control signal. Still further, the PCM data may be received across an isolation barrier from a communication line.
In further more detailed embodiments, the modem processor may receive modem data as an input, and the selection circuitry may output processed modem data from the modem processor. Also, this processed modem data is transmitted across an isolation barrier to a communication line and may be received from an external system-side integrated circuit. Still further, the separate data path may be pulse-code-modulated (PCM) data, and the selection circuitry may output PCM data. Also, this PCM data may transmitted across an isolation barrier to a communication line and may be received from an external system-side integrated circuit. In a still further embodiment, the DSP may include digital filters for digital data received across the isolation barrier from the communication line and a digital modulator for digital data transmitted across the isolation barrier to the communication line.
In another embodiment, the present invention is digital-signal-processor (DSP) circuitry within an integrated modem and line-isolation circuit having selective modem processing including a modem processor, selection circuitry coupled to an output from the modem processor and a separate data path, and a control signal coupled to the selection circuitry, wherein the control signal determines whether the output from the modem processor or the separate data path is output from the selection circuitry. In a more particular embodiment, the modem processor may receive pulse-code-modulated (PCM) data as an input, the separate data path may be PCM data, and the selection circuitry may output either modem data from the modem processor or PCM data from the separate data path depending upon the control signal.
In still a further embodiment, the present invention is a method for selectively utilizing a modem processor in an integrated modem and line-isolation circuit including providing a system-side line-isolation integrated circuit capable of being coupled to an isolation barrier, where the system-side line-isolation integrated circuit including digital-signal-processing (DSP) circuitry having a modem processor for modem data and a digital processor for system-side circuitry, and generating an output for the DSP circuitry by selecting either an output from the modem processor or a signal from a separate data path. In a more particular embodiment, the modem processor may receive pulse-code-modulated (PCM) data as an input, the separate data path comprises PCM data, and the generating step may select either modem data from the modem processor or PCM data from the separate data path.
REFERENCES:
patent: 4395590 (1983-07-01), Pierce et al.
patent: 4417099 (1983-11-01), Pierce
patent: 5369666 (1994-11-01), Folwell et al.
patent: 5369687 (1994-11-01), Farkas
patent: 5655010 (1997-08-01), Bingel
patent: 5687194 (1997-11-01), Paneth et al.
patent: 5870046 (1999-02-01), Scott et al.
patent: 6081586 (2000-06-01), Rahamim et al.
patent: WO98/48541 (1998-10-01), None
Silicon Systems, SSI 73D2950/2950T Low Power FAX/Data Modem Chip Set Advance Information, pp. 4-75-4-105, Dec. 1993.
Krypton, “K2930G Functional and Electrical Descriptions”, 10 pages (1997).
Information Sheet—Siemens, DAA2000 Optical DAA Kit—Preliminary, pp. 1-21; Jun. 13, 1997.
Siemens Press Release, Siemens Pioneers Programmable Front End For Analog Modems Single Design For Worldwide Standards, Aug. 6, 1997.
Information Sheet—Siemens, ICs for Communications, ALIS Reference Board, SIPB 4595 Version 1.0, Technical Description 06.97, Q67220-H1014, Jun. 1997.
Information Sheet—Siemens, ICs for Communications, ALIS Evaluation Board, SIPB 45900 Version 1.1, Technical Description 06.97, Q67220-H1047, Jun. 1997.
Data Sheet SmartMC™Modem Codec, Host-Processed, V.90/K56flex™Modem Codec (MC) Device Set with SmartDAA™Technology for AC-link (AC'97 2.1) Applications, Mar. 1999.
Rockwell Semiconductor Systems, RC96V24DP, Single Device Data/Fax Modem Data Pump, Sep. 1998.
CP Clare CPC2400 Preliminary Specifications, Oct. 1998.
TDK Semiconductor Corp., 73K224BL V.22bis/V.22/V.21/Bell 212A/103 Single-Chip Modem w/Integrated Hybrid, Nov. 1997.
Zilog Preliminary Product Spefication DS97FMO0201 Z02201 V.22bis Modem Data Pump with Integrated AFE, 1998.
Silicon Laboratories, Si3032 Direct Digital Access Arrangement (DDAA), Nov. 1997.
DuPuis Timothy J.
Krone Andrew W.
Reid Mitchell
O'Keefe, Egan & Peterman
Pham Chi
Phu Phuong
Silicon Laboratories Inc.
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