Patents by Inventor Shahin Hedayat
Shahin Hedayat has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6434395Abstract: A portable radio telephone handset includes the capability of operating as a data transfer terminal as well as an analog cellular telephone subscriber station. Two modes of operation are available in the handset, an analog cellular communication mode and a Cellular Digital Packet Data (CDPD) mode. A paging function for incoming analog cellular communication is carried out on a CDPD channel. The handset distinguishes between paging signals identifying CDPD mode communications and paging signals identifying analog cellular communications. The handset automatically preempts CDPD communications in favor of analog cellular communications such as those carried out in an AMPS configuration.Type: GrantFiled: December 18, 1996Date of Patent: August 13, 2002Assignee: Pacific Communications Sciences, Inc.Inventors: Michael L. Lubin, Seton P. Kasmir, Kathryn A. Kubasak, Gregory A. Hein, Surendra B. Mandava, Chanchai Poonpol, Shahin Hedayat, Donald W. Burtis
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Patent number: 6327648Abstract: A novel multi-DSP system allows a main DSP to operate concurrently with an auxiliary DSP for implementing a filter algorithm. The main DSP and auxiliary DSP have separate program memories but share the same data memory. The auxiliary DSP program memory is mapped to the main DSP program memory to allow the main DSP to download filter process instructions from its program memory into the auxiliary DSP program memory. The auxiliary DSP fetches the instructions from its program memory to execute them. The auxiliary DSP is prevented from access to the shared data its program memory when this memory is occupied by the main DSP. An arbitration mechanism gives the auxiliary DSP access to the data memory only when the main DSP is not using this memory.Type: GrantFiled: May 7, 1997Date of Patent: December 4, 2001Assignee: Cirrus Logic, Inc.Inventors: Shahin Hedayat, Surendra Mandava
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Patent number: 6135651Abstract: A software patch method and apparatus using a content addressable memory (CAM) to produce a code change enable signal when a program memory address matches a patch memory address, to cause program execution of modem operation to be diverted to the patch code when an address comparison hit is achieved. The patching apparatus includes a program memory for applying program instructions onto a data bus for execution, unless an address comparison of a program address and a patch address causes application of a substitute address onto the data bus.Type: GrantFiled: May 29, 1997Date of Patent: October 24, 2000Assignee: Cirrus Logic, Inc.Inventors: Karl Thomas Leinfelder, Wesley Hamilton Smith, Sanjay Gupta, Navin Jaffer, Shahin Hedayat, Babu Mandava
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Patent number: 5892972Abstract: A system of ISA bus cards compatible with plug and play protocol stores common resource data in a plurality of programmable read only memories which are each installed on the individual bus cards. A random access memory is also provided on each one of the bus cards. In order to comply with the plug and play protocol, each of the random access memories is programmed independently from the read only memories with a unique identification that identifies the individual bus card. The separation of the storage location of the unique identification from the resource data common to all of the bus cards allows for mass production and programming of the read only memories, while still providing the unique identification for each bus card that is required by the plug and play protocol.Type: GrantFiled: June 17, 1997Date of Patent: April 6, 1999Assignee: Cirrus Logic, Inc.Inventors: Sharath C. Narahari, Nagesh Sreedhara, Ramchandra Nadkarni, Shahin Hedayat
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Patent number: 5889856Abstract: An integrated line-card terminates an asymmetric digital-subscriber line (ADSL) copper-pair at a single point in a central office. The line card contains analog line circuitry such as a ring generator, off-hook detector, D.C. current feed, and a single analog-digital (A/D) converter. The phone line carries a composite signal of both the high-frequency ADSL data and the low-frequency voice or plain-old-telephone-service (POTS) signal. Instead of using an analog frequency-splitter with bulky, expensive inductor coils, a digital splitter is used. A digital-signal processor (DSP) can be used to perform the digital splitting of ADSL and POTS. The waveforms from the analog phone line are first converted to digital values by the A/D converter, and then a digital splitter separates the low-frequency POTS from the high-frequency ADSL.Type: GrantFiled: May 22, 1997Date of Patent: March 30, 1999Assignee: Centillium Technology Corp.Inventors: Anthony J. P. O'Toole, Shahin Hedayat, Surendra Babu Mandava
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Patent number: 5642516Abstract: Interrupts are prioritized such that selected interrupts use shadow registers to save the current state of the machine, whereas other interrupts use a software implemented interrupt service routine (ISR) to save and restore the current machine state. Hence, the number of nested interrupts that can be serviced will not be limited to the depth of register shadowing.Type: GrantFiled: October 14, 1994Date of Patent: June 24, 1997Assignee: Cirrus Logic, Inc.Inventors: Shahin Hedayat, Surendra Mandava
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Patent number: 5533105Abstract: An emulator circuit is provided for allowing a data/fax/voice modem, a host computer, and a telephone headset to emulate the functions of a telephone. For voice communication, the emulator circuit connects the telephone headset to the telephone line. For automated data/fax/voice communications, the emulator circuit connects the modem to the telephone line. Two specific embodiments of the emulator circuit are described. In one, the emulator circuit is configured from analog circuit components connected to the modem. In the other, the emulator circuit is an integrated circuit component of the modem. In both embodiments, the provision of the emulator circuit obviates the need to provide a separate telephone for handling voice telephone conversations.Type: GrantFiled: September 15, 1993Date of Patent: July 2, 1996Assignee: Cirrus Logic, Inc.Inventors: Paul M. Brown, Shahin Hedayat, George V. Urbani
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Patent number: 5524047Abstract: An emulator circuit is provided for allowing a data/fax/voice modem, a host computer, and a telephone headset to emulate the functions of a telephone. For voice communications, the emulator circuit connects the telephone headset to a communication device such as a telephone line or cellular radio. For automated data/fax/voice communications, the emulator circuit connects the modem to the communication device. Two specific embodiments of the emulator circuit are described. In one, the emulator circuit is configured from analog circuit components connected to the modem. In the other, the emulator circuit is an integrated circuit component of the modem. In both embodiments, the provision of the emulator circuit obviates the need to provide a separate telephone for handling voice telephone conversations and other communications through said telephone line, cellular radio.Type: GrantFiled: December 27, 1993Date of Patent: June 4, 1996Assignee: Cirrus Logic, Inc.Inventors: Paul M. Brown, Shahin Hedayat, George V. Urbani
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Patent number: 4975828Abstract: This invention provides a flexible, general-purpose, engine-based architecture for a multi-channel data communications controller. It can be customized to handle a wide range of protocols and other host system requirements with minimal reliance on the host's processing power. The always present time-critical tasks of transmitting and receiving serial data, as well as transmitting and receiving characters to/from the host, are handled quickly and efficiently by utilizing dedicated interface processors. This leaves the general purpose main engine less burdened with these time cricital tasks, enabling it to perform the relatively more complex (though less time critical) tasks of assembling and disassembling characters, as well as maintaining RAM-based data FIFOs and performing error-checking and other protocol-related tasks. Custon protocols can be implemented merely by re-microcoding the machine, without requiring modifications to the basic architecture of the chip, substantially reducing design time.Type: GrantFiled: August 5, 1987Date of Patent: December 4, 1990Assignee: Cirrus Logic, Inc.Inventors: John Wishneusky, Cecil Kaplinsky, Anthony O'Toole, Shahin Hedayat, Shrikant Acharya