Patents by Inventor Shayan Zhang
Shayan Zhang 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: 8059482Abstract: A memory has a method of operating that includes performing operations of a first type and a second type. A first voltage is coupled to a power supply node of a first memory cell of a memory array during a first operation of the first type. The first voltage is decoupled from the power supply node in response to terminating the first operation of the first type so as to allow the power supply node to drift. If the power supply node drifts to a second voltage, a power supply source is coupled to the power supply node. This is useful in reducing power in the circuit that produces the first voltage.Type: GrantFiled: June 19, 2009Date of Patent: November 15, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Andrew C. Russell, Prashant U. Kenkare, Shayan Zhang
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Publication number: 20110255361Abstract: A multi-port memory is operated according to a method. Data is written, in a first mode, to a storage node of a memory cell from a first port through a first conductance. The first mode is characterized by a power supply voltage being applied at a power node at a first level. Data is written, in a second mode, to the storage node of the memory cell simultaneously from the first port through the first conductance and a second port through a second conductance. The second mode is characterized by the power supply voltage being applied at the power node at a second level different from the first level.Type: ApplicationFiled: April 14, 2010Publication date: October 20, 2011Inventors: Andrew C. Russell, Shayan Zhang
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Patent number: 8009489Abstract: A memory has a first bit line, a second bit line, and a word line. A memory cell is coupled to the word line and the first and second bit lines. A sense amplifier has a first input, a second input, a first output, and a second output. A pair of coupling transistors includes a first transistor and a second transistor. In one embodiment, the first transistor is coupled between the first bit line and the first input of the sense amplifier and the second transistor is coupled between the second bit line and the second input of the sense amplifier. A write back circuit is coupled to an output of the sense amplifier. The write back circuit writes back to the memory cell a value read from the memory cell during a read cycle.Type: GrantFiled: May 28, 2009Date of Patent: August 30, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Shayan Zhang, Jack M. Higman, Prashant U. Kenkare, Pelley H. Perry, Andrew C. Russell
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Patent number: 8004907Abstract: A memory includes an SRAM bitcell including a pair of cross-coupled inverters, wherein a first inverter of the pair includes a first device having a body and a second inverter of the pair includes a second device having a body. A first selection circuit has a first input coupled to a first supply voltage terminal, a second input coupled to a second supply voltage terminal, and an output coupled to a first current electrode of the first device and to a first current electrode of the second device. A second selection circuit has a first input coupled to the first supply voltage terminal, a second input coupled to the second supply voltage terminal, and an output coupled to the body of each of the first and second devices. A word line coupled to the SRAM bitcell is driven by a word line driver coupled to the first supply voltage terminal.Type: GrantFiled: June 5, 2009Date of Patent: August 23, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Andrew C. Russell, Troy L. Cooper, Prashant U. Kenkare, Shayan Zhang
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Publication number: 20110099402Abstract: A selected thread is scheduled to run on a corresponding master of a multiple threaded processing system. When the priority of the selected thread is high, the selected thread is run on the corresponding master. When the priority of the selected thread is low and the corresponding master is in an operational mode, the selected thread is run on the corresponding master. When the priority of the selected thread is low and the corresponding master is in a low power mode, the selected thread is selectively run on the corresponding master based on an amount of time that the corresponding master has been in the low power mode since its most recent entrance into the low power mode.Type: ApplicationFiled: October 28, 2009Publication date: April 28, 2011Inventors: Shayan Zhang, William C. Moyer
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Patent number: 7903483Abstract: An integrated circuit having a memory and a method for operating the memory are provided. The method for operating the memory comprises: accessing a first portion of the memory, the first portion having a first access margin; detecting an error in the first portion of the memory; changing the first access margin to a second access margin, the second access margin being different than the first access margin; determining that the error is corrected with the first portion having the second access margin; and storing an access assist bit in a first storage element, the access assist bit corresponding to the first portion, wherein the assist bit, when set, indicates that subsequent accesses to the first portion are accomplished at the second access margin.Type: GrantFiled: November 21, 2008Date of Patent: March 8, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Andrew C. Russell, Shayan Zhang
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Patent number: 7863963Abstract: A circuit comprises first and second inverters, first, second, third, and fourth transistors, and an enabling circuit. The first and second inverters each have an input terminal for receiving one of the first or second input signals, an output terminal, and first and second supply terminals. The first transistor is coupled to a first power supply terminal, to the output terminal of the second inverter, and to the first inverter. The second transistor is coupled to the first power supply terminal, to the output terminal of the first inverter, and to the first supply terminal of the second inverter. The third and fourth transistor are coupled to the second supply terminals of the first and second inverters, respectively, and each includes a control electrode and a second current electrode. The enabling circuit is for controlling the third and fourth transistors to reduce a leakage current in the circuit.Type: GrantFiled: January 23, 2009Date of Patent: January 4, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Shayan Zhang, Andrew C. Russell, Hector Sanchez
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Publication number: 20100322027Abstract: A memory has a method of operating that includes performing operations of a first type and a second type. A first voltage is coupled to a power supply node of a first memory cell of a memory array during a first operation of the first type. The first voltage is decoupled from the power supply node in response to terminating the first operation of the first type so as to allow the power supply node to drift. If the power supply node drifts to a second voltage, a power supply source is coupled to the power supply node. This is useful in reducing power in the circuit that produces the first voltage.Type: ApplicationFiled: June 19, 2009Publication date: December 23, 2010Inventors: Andrew C. Russell, Prashant U. Kenkare, Shayan Zhang
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Patent number: 7852692Abstract: Test circuitry for determining whether a memory can operate at a lower operating voltage. The test circuitry includes a sense circuit having a delayed sensing characteristic as compared to other sense amplifier circuits of the memory. With this circuitry, the test circuitry can determine if the sense circuit can provide valid data under more severe sensing conditions. In one example, the sense circuit includes a delay circuit in the sense enable signal path. If sense circuit can provide data at more server operating conditions, then the memory operating voltage can be lowered.Type: GrantFiled: June 30, 2008Date of Patent: December 14, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Shayan Zhang, Jack M. Higman, Michael D. Snyder
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Publication number: 20100309736Abstract: A memory includes an SRAM bitcell including a pair of cross-coupled inverters, wherein a first inverter of the pair includes a first device having a body and a second inverter of the pair includes a second device having a body. A first selection circuit has a first input coupled to a first supply voltage terminal, a second input coupled to a second supply voltage terminal, and an output coupled to a first current electrode of the first device and to a first current electrode of the second device. A second selection circuit has a first input coupled to the first supply voltage terminal, a second input coupled to the second supply voltage terminal, and an output coupled to the body of each of the first and second devices. A word line coupled to the SRAM bitcell is driven by a word line driver coupled to the first supply voltage terminal.Type: ApplicationFiled: June 5, 2009Publication date: December 9, 2010Inventors: Andrew C. Russell, Troy L. Cooper, Prashant U. Kenkare, Shayan Zhang
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Publication number: 20100302837Abstract: A memory has a first bit line, a second bit line, and a word line. A memory cell is coupled to the word line and the first and second bit lines. A sense amplifier has a first input, a second input, a first output, and a second output. A pair of coupling transistors includes a first transistor and a second transistor. In one embodiment, the first transistor is coupled between the first bit line and the first input of the sense amplifier and the second transistor is coupled between the second bit line and the second input of the sense amplifier. A write back circuit is coupled to an output of the sense amplifier. The write back circuit writes back to the memory cell a value read from the memory cell during a read cycle.Type: ApplicationFiled: May 28, 2009Publication date: December 2, 2010Inventors: Shayan Zhang, Jack M. Higman, Prashant U. Kenkare, Pelley H. Perry, Andrew C. Russell
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Publication number: 20100277990Abstract: A storage unit on an integrated circuit stores information that identifies a circuit on the integrated circuit, a selected operating condition, and a required operating configuration for the circuit for the selected operating condition. The manner of operating the circuit is changed to the required operating configuration in response to an operating condition of the circuit changing to the selected operating condition. This allows for efficiently identifying the few circuits that do not meet specified requirements based on a reduction in, for example, operating voltage, and altering their operation in order to meet the specified requirements relative to the reduced operating voltage without having to do so for the vast majority of the circuits that are able to meet the requirements at the lowered operating voltage.Type: ApplicationFiled: April 30, 2009Publication date: November 4, 2010Inventors: Prashant U. Kenkare, Troy L. Cooper, Andrew C. Russell, Shayan Zhang
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Publication number: 20100246297Abstract: A memory system has a first memory having an array of memory cells that includes a redundant column. The redundant column substitutes for a first column in the array. The first column includes a test memory cell. The array receives a power supply voltage. The test memory cell becomes non-functional at a higher power supply voltage than the memory cells of the array. A memory controller is coupled to the first memory and is for determining if the test memory cell is functional at a first value for the power supply voltage. This is useful in making decisions concerning the value of the power supply voltage applied to the array.Type: ApplicationFiled: March 31, 2009Publication date: September 30, 2010Inventors: Shayan Zhang, James D. Burnett, Kent P. Fancher, Andrew C. Russell, Michael D. Snyder
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Publication number: 20100246298Abstract: A memory and method for access the memory are provided. A first test is used to test memory elements to determine a lowest power supply voltage at which all the memory elements will operate to determine a weak memory element. Redundancy is used to substitute a redundant memory element for the weak memory element. The weak memory element is designated as a test element. In response to receiving a request to change a power supply voltage provided to the memory elements, a second test is used to test the test element to determine if the test element will function correctly at a new power supply voltage. If the test element passes the second test, the memory elements are accessed at the new power supply voltage. If the test element fails the second test, the memory elements are accessed using an access assist operation.Type: ApplicationFiled: March 31, 2009Publication date: September 30, 2010Inventors: Shayan Zhang, Troy L. Cooper, Jack M. Higman, Prashant U. Kenkare, Andrew C. Russell
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Patent number: 7800974Abstract: A technique for operating a memory circuit that improves performance of the memory circuit and/or power consumption for at least some operating points of the memory circuit includes adjusting a number of operational pipeline stages at least partially based on an operating point of the memory. In at least one embodiment of the invention, a method for operating a memory circuit includes selecting a mode of operating the memory circuit at least partially based on a feedback signal generated by the memory circuit. The technique includes operating the memory circuit using a number of pipeline stages based on the selected mode of operation of the memory circuit. In at least one embodiment of the invention, the technique includes sensing a timing margin associated with an individual pipeline stage and generating the feedback signal based thereon.Type: GrantFiled: February 21, 2008Date of Patent: September 21, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Shayan Zhang, William C. Moyer, Huy B. Nguyen
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Patent number: 7793172Abstract: Methods and systems for configuring characteristics associated with at least one portion of a memory array comprising addressable units are provided. In one aspect, a method for controlling a power supply voltage for a memory array comprises detecting whether an error occurred in performing a read operation on an addressable unit of the memory array using a first power supply voltage coupled to the memory array. The method further comprises incrementing an error counter for tracking an error count associated with the memory array and switching the memory array to a second power supply voltage if the error count is equal to or exceeds an error threshold for the memory array. The method further comprises, based on at least one condition, switching the memory array to the first power supply voltage and resetting the error counter to an initial value.Type: GrantFiled: September 28, 2006Date of Patent: September 7, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Klas M. Bruce, Andrew C. Russell, Shayan Zhang, Bradford L. Hunter
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Publication number: 20100191990Abstract: A memory has bits that fail as power supply voltage is reduced to reduce power and/or increase endurance. The bits become properly functional when the power supply voltage is increased back to its original value. With the reduced voltage, portions of the memory that include non-functional bits are not used. Much of the memory may remain functional and use is retained. When the voltage is increased, the portions of the memory that were not used because of being non-functional due to the reduced power supply voltage may then be used again. This is particularly useful in a cache where the decrease in available memory due to power supply voltage reduction can be implemented as a reduction in the number of ways. Thus, for example an eight way cache can simply be reduced to a four way cache when the power is being reduced or endurance increased.Type: ApplicationFiled: January 27, 2009Publication date: July 29, 2010Inventors: Shayan Zhang, James D. Burnett, Prashant U. Kenkare, Hema Ramamurthy, Andrew C. Russell, Michael D. Snyder
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Publication number: 20100188131Abstract: A circuit comprises first and second inverters, first, second, third, and fourth transistors, and an enabling circuit. The first and second inverters each have an input terminal for receiving one of the first or second input signals, an output terminal, and first and second supply terminals. The first transistor is coupled to a first power supply terminal, to the output terminal of the second inverter, and to the first inverter. The second transistor is coupled to the first power supply terminal, to the output terminal of the first inverter, and to the first supply terminal of the second inverter. The third and fourth transistor are coupled to the second supply terminals of the first and second inverters, respectively, and each includes a control electrode and a second current electrode. The enabling circuit is for controlling the third and fourth transistors to reduce a leakage current in the circuit.Type: ApplicationFiled: January 23, 2009Publication date: July 29, 2010Inventors: Shayan Zhang, Andrew C. Russell, Hector Sanchez
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Publication number: 20100128541Abstract: An integrated circuit having a memory and a method for operating the memory are provided. The method for operating the memory comprises: accessing a first portion of the memory, the first portion having a first access margin; detecting an error in the first portion of the memory; changing the first access margin to a second access margin, the second access margin being different than the first access margin; determining that the error is corrected with the first portion having the second access margin; and storing an access assist bit in a first storage element, the access assist bit corresponding to the first portion, wherein the assist bit, when set, indicates that subsequent accesses to the first portion are accomplished at the second access margin.Type: ApplicationFiled: November 21, 2008Publication date: May 27, 2010Inventors: Andrew C. Russell, Shayan Zhang
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Patent number: 7688656Abstract: A method for dynamically controlling sense amplifier differential margin of a memory during operation, in an integrated circuit, including a plurality of addressable units, is provided. The method includes setting the sense amplifier differential margin corresponding to the plurality of addressable units to a first value. The method further includes if a read data error occurs when data is read from a set of the plurality of addressable units, then setting the sense amplifier differential margin corresponding to the plurality of addressable units to a second value, wherein the second value is greater than the first value.Type: GrantFiled: October 22, 2007Date of Patent: March 30, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Shayan Zhang, Hema Ramamurthy, Zheng Xu, Michael D. Snyder