Patents by Inventor Shafagh Kamkar
Shafagh Kamkar 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: 11621012Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: GrantFiled: July 26, 2021Date of Patent: April 4, 2023Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Dylan A. Hester, Bruce E. Duewer
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Publication number: 20210358509Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: ApplicationFiled: July 26, 2021Publication date: November 18, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Dylan A. Hester, Bruce E. Duewer
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Patent number: 11107485Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: GrantFiled: August 2, 2019Date of Patent: August 31, 2021Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Dylan A. Hester, Bruce E. Duewer
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Patent number: 11050971Abstract: An encoding for data in an audio data stream may be indicated in the data stream using a footer stored in low-order bits of data frames in the audio data stream. When the audio data stream may include either Pulse Code Modulation (PCM) or Direct Stream Digital (DSD) data, PCM data may be marked with a footer to indicate the encoding as PCM. The footer may be a fixed value, an alternating fixed value, a predetermined sequence of values, or a value computed based on the PCM data. Examples of computed values for the footer marker may include an error code, an error correction code (ECC), and a scrambled code.Type: GrantFiled: November 25, 2019Date of Patent: June 29, 2021Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Bruce E. Duewer, Dylan A. Hester
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Publication number: 20210099667Abstract: An encoding for data in an audio data stream may be indicated in the data stream using a footer stored in low-order bits of data frames in the audio data stream. When the audio data stream may include either Pulse Code Modulation (PCM) or Direct Stream Digital (DSD) data, PCM data may be marked with a footer to indicate the encoding as PCM. The footer may be a fixed value, an alternating fixed value, a predetermined sequence of values, or a value computed based on the PCM data. Examples of computed values for the footer marker may include an error code, an error correction code (ECC), and a scrambled code.Type: ApplicationFiled: November 25, 2019Publication date: April 1, 2021Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Bruce E. Duewer, Dylan A. Hester
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Patent number: 10522155Abstract: An encoding for data in an audio data stream may be indicated in the data stream using a footer stored in low-order bits of data frames in the audio data stream. When the audio data stream may include either Pulse Code Modulation (PCM) or Direct Stream Digital (DSD) data, PCM data may be marked with a footer to indicate the encoding as PCM. The footer may be a fixed value, an alternating fixed value, a predetermined sequence of values, or a value computed based on the PCM data. Examples of computed values for the footer marker may include an error code, an error correction code (ECC), and a scrambled code.Type: GrantFiled: September 1, 2017Date of Patent: December 31, 2019Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Bruce E. Duewer, Dylan A. Hester
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Patent number: 10509624Abstract: Audio content in a single-bit audio stream can be reproduced at a transducer by mapping the single-bit audio stream to symbols in a multi-bit audio stream. Volume control may be implemented, in part, in the digital domain and, in part, in the analog domain. In the digital domain, when converting the single-bit audio stream to a plurality of symbols, the plurality of symbols is selected based, at least in part, on audio content of the single-bit audio stream and a desired volume level. In the analog domain, when converting an analog current signal output from a current-steering DAC processing the plurality of symbols to an analog voltage signal, an analog gain value may be selected based, at least in part, on the desired volume level.Type: GrantFiled: September 15, 2017Date of Patent: December 17, 2019Assignee: Cirrus Logic, Inc.Inventors: Bruce Duewer, Dylan Hester, Shafagh Kamkar
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Publication number: 20190355370Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: ApplicationFiled: August 2, 2019Publication date: November 21, 2019Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Dylan A. Hester, Bruce E. Duewer
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Patent number: 10424311Abstract: An audio processing circuit may have a first path for processing multi-bit audio signals in parallel with a second path for processing single-bit audio signals. The parallel paths may share a common input node for receiving audio data and a common output node for reproducing audio at a transducer. Each path may have a volume control for adjusting an output of the path. The audio processing circuit may determine a type of an audio signal received at the input. The path not corresponding to the detected type of the audio signal is muted, and the path corresponding to the detected type of audio signal is unmuted.Type: GrantFiled: September 15, 2017Date of Patent: September 24, 2019Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Bruce Duewer, Dylan Hester
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Patent number: 10418044Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: GrantFiled: September 15, 2017Date of Patent: September 17, 2019Assignee: Cirrus Logic, Inc.Inventors: Shafagh Kamkar, Dylan Hester, Bruce Duewer
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Patent number: 10074378Abstract: A data encoding may be determined by examining the data itself. By examining the data, such as by identifying characteristics of the data, the data encoding may be identified and the substantive information extracted from the data by decoding the data according to the identified data encoding. The data encoding may be identified without extra control or header information separate from the encoded data itself. The identification of data encoding may be determined by a plurality of detectors examining different characteristics of the data and determining an encoding of the data based on each of those individual characteristics. The output of the detectors may be collected and used to decide the encoding of the data. One example application involves determining if audio data is DSD- or PCM-encoded audio data by examining only the data itself.Type: GrantFiled: December 9, 2016Date of Patent: September 11, 2018Assignee: Cirrus Logic, Inc.Inventors: Bruce E. Duewer, Dylan A. Hester, Shafagh Kamkar
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Publication number: 20180240464Abstract: An encoding for data in an audio data stream may be indicated in the data stream using a footer stored in low-order bits of data frames in the audio data stream. When the audio data stream may include either Pulse Code Modulation (PCM) or Direct Stream Digital (DSD) data, PCM data may be marked with a footer to indicate the encoding as PCM. The footer may be a fixed value, an alternating fixed value, a predetermined sequence of values, or a value computed based on the PCM data. Examples of computed values for the footer marker may include an error code, an error correction code (ECC), and a scrambled code.Type: ApplicationFiled: September 1, 2017Publication date: August 23, 2018Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Bruce E. Duewer, Dylan A. Hester
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Publication number: 20180218744Abstract: An audio processing circuit may have a first path for processing multi-bit audio signals in parallel with a second path for processing single-bit audio signals. The parallel paths may share a common input node for receiving audio data and a common output node for reproducing audio at a transducer. Each path may have a volume control for adjusting an output of the path. The audio processing circuit may determine a type of an audio signal received at the input. The path not corresponding to the detected type of the audio signal is muted, and the path corresponding to the detected type of audio signal is unmuted.Type: ApplicationFiled: September 15, 2017Publication date: August 2, 2018Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Bruce Duewer, Dylan Hester
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Publication number: 20180217807Abstract: Audio content in a single-bit audio stream can be reproduced at a transducer by mapping the single-bit audio stream to symbols in a multi-bit audio stream. Volume control may be implemented, in part, in the digital domain and, in part, in the analog domain. In the digital domain, when converting the single-bit audio stream to a plurality of symbols, the plurality of symbols is selected based, at least in part, on audio content of the single-bit audio stream and a desired volume level. In the analog domain, when converting an analog current signal output from a current-steering DAC processing the plurality of symbols to an analog voltage signal, an analog gain value may be selected based, at least in part, on the desired volume level.Type: ApplicationFiled: September 15, 2017Publication date: August 2, 2018Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Bruce Duewer, Dylan Hester, Shafagh Kamkar
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Publication number: 20180218745Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.Type: ApplicationFiled: September 15, 2017Publication date: August 2, 2018Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Shafagh Kamkar, Dylan Hester, Bruce Duewer
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Publication number: 20180166088Abstract: A data encoding may be determined by examining the data itself. By examining the data, such as by identifying characteristics of the data, the data encoding may be identified and the substantive information extracted from the data by decoding the data according to the identified data encoding. The data encoding may be identified without extra control or header information separate from the encoded data itself. The identification of data encoding may be determined by a plurality of detectors examining different characteristics of the data and determining an encoding of the data based on each of those individual characteristics. The output of the detectors may be collected and used to decide the encoding of the data. One example application involves determining if audio data is DSD- or PCM-encoded audio data by examining only the data itself.Type: ApplicationFiled: December 9, 2016Publication date: June 14, 2018Inventors: Bruce E. Duewer, Dylan A. Hester, Shafagh Kamkar