Patents by Inventor Shree Kant

Shree Kant 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).

  • Patent number: 8482316
    Abstract: Circuits, methods, and systems are presented for managing current leakage in an electronic circuit. One circuit includes a keeper circuit, and a controller. The keeper circuit supplies current to a leaker circuit, which is experiencing current leakage, to compensate for the current leakage. Further, the controller provides to the keeper circuit a control signal that is based on the current leakage. The control signal has a cycle equal to the cycle of a clock signal, and the control signal is a pulse having a first value during a first period, and a second value during a second period of the pulse. The keeper circuit provides a current to the leaker circuit during the first period and the keeper circuit withholds the current to the leaker circuit during the second period, where the durations of the first period and the second period are based on the current leakage.
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: July 9, 2013
    Assignee: Oracle International Corporation
    Inventors: Zhen Wu Liu, Shree Kant, Heechoul Park
  • Patent number: 7484061
    Abstract: A method and apparatus is provided to enable provision of requested data within two clock cycles when performing a swap operation between an accessible memory cell and a background memory in a computer. In a first clock cycle, memory addresses to be used in the swap operation are decoded. In a high phase of a second clock cycle, requested data is restored from the background memory to an accessible memory cell. Because the data previously stored in the accessible memory cell is duplicated in a shadow memory cell, the restoration of data to the accessible memory cell is performed without data loss. In a low phase of the second clock cycle, the requested data is available for reading. During a third cycle, data is saved from the shadow memory cell to the background memory, and the shadow memory cell is made consistent with the accessible memory cell.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: January 27, 2009
    Assignee: Sun Microsystems, Inc.
    Inventors: Zhen Wu Liu, Shree Kant, Kenway W. Tam
  • Patent number: 7337305
    Abstract: A system and method of processing multiple swap requests including receiving a first swap request in a pipeline and executing the first swap request. A second swap request is also received in the pipeline immediately following the first swap request. The first swap request and the second swap request are examined to determine if the first swap request and the second swap request swap a same register.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: February 26, 2008
    Assignee: Sun Microsystems, Inc.
    Inventors: Kenway W. Tam, Shree Kant
  • Patent number: 7203100
    Abstract: A multi-threaded memory system including a plurality of entries, each one of the plurality of entries including a plurality of threads, each one of the plurality of threads including an active cell and a shared read cell. The shared read cell has an output coupled to a read bit line and a corresponding plurality of inputs coupled to an output of the corresponding active cells in each one of the plurality of threads. A multi-threaded memory system is also described.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: April 10, 2007
    Assignee: Sun Mircosystems, Inc.
    Inventors: Shree Kant, Kathirgamar Aingaran, Yuan-Jung D Lin, Kenway Tam
  • Patent number: 7136308
    Abstract: A memory system includes an active storage circuit and at least one base storage circuit. The at least one base storage circuit is coupled to the active storage circuit though at least one pass gate, at least one driver and a bit line. The at least one pass gate and the at least one driver have a device size substantially similar to a device size of each one of the devices in the active storage circuit and the at least one base storage circuit. A method of swapping data between two storage circuits is also described.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: November 14, 2006
    Assignee: Sun Microsystems, Inc.
    Inventors: Shree Kant, Kenway Tam, Poonacha P. Kongetira, Yuan-Jung D Lin, Zhen W. Liu, Kathirgamar Aingaran
  • Publication number: 20060092711
    Abstract: A multi-threaded memory system including a plurality of entries, each one of the plurality of entries including a plurality of threads, each one of the plurality of threads including an active cell and a shared read cell. The shared read cell has an output coupled to a read bit line and a corresponding plurality of inputs coupled to an output of the corresponding active cells in each one of the plurality of threads. A multi-threaded memory system is also described.
    Type: Application
    Filed: January 21, 2005
    Publication date: May 4, 2006
    Applicant: Sun Microsystems, Inc
    Inventors: Shree Kant, Kathirgamar Aingaran, Yuan-Jung Lin, Kenway Tam
  • Publication number: 20060092710
    Abstract: A memory system includes an active storage circuit and at least one base storage circuit. The at least one base storage circuit is coupled to the active storage circuit though at least one pass gate, at least one driver and a bit line. The at least one pass gate and the at least one driver have a device size substantially similar to a device size of each one of the devices in the active storage circuit and the at least one base storage circuit. A method of swapping data between two storage circuits is also described.
    Type: Application
    Filed: November 1, 2004
    Publication date: May 4, 2006
    Applicant: Sun Microsystems, Inc
    Inventors: Shree Kant, Kenway Tam, Poonacha Kongetira, Yuang-Jung Lin, Zhen Liu, Kathirgamar Aingaran
  • Patent number: 6940771
    Abstract: A memory array design is provided. Memory cells are defined an intersections of rows and columns. A pair of bitline segments are defined for each column. A connecting load device of each memory cell is connected to either a first or a second of the pair of bitline segments. An equal number of load devices in each column couple to each of the pair of bitlines.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: September 6, 2005
    Assignee: Sun Microsystems, Inc.
    Inventors: Shree Kant, Aparna Ramachandran, Ranjan Vaish
  • Patent number: 6900668
    Abstract: A first sense amp circuit includes a pre-charge circuit, a keeper circuit, a select device and a driver device. The pre-charge circuit coupled to an input data line, the input data line being coupled to an input of a first inverter. The keeper circuit coupled in parallel with the first inverter. The select device coupled to a discharge path of the first inverter. The driver device coupled in parallel to an output data line of the first inverter.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: May 31, 2005
    Assignee: Sun Microsystems Inc.
    Inventors: Kenway W. Tam, Shree Kant
  • Publication number: 20050110527
    Abstract: A first sense amp circuit includes a pre-charge circuit, a keeper circuit, a select device and a driver device. The pre-charge circuit coupled to an input data line, the input data line being coupled to an input of a first inverter. The keeper circuit coupled in parallel with the first inverter. The select device coupled to a discharge path of the first inverter. The driver device coupled in parallel to an output data line of the first inverter.
    Type: Application
    Filed: November 24, 2003
    Publication date: May 26, 2005
    Applicant: Sun Microsystems, Inc
    Inventors: Kenway Tam, Shree Kant
  • Publication number: 20050114634
    Abstract: A system and method of processing multiple swap requests including receiving a first swap request in a pipeline and executing the first swap request. A second swap request is also received in the pipeline immediately following the first swap request. The first swap request and the second swap request are examined to determine if the first swap request and the second swap request swap a same register.
    Type: Application
    Filed: November 24, 2003
    Publication date: May 26, 2005
    Applicant: Sun Microsystems, Inc.
    Inventors: Kenway Tam, Shree Kant
  • Publication number: 20040151044
    Abstract: A memory array design is provided. Memory cells are defined an intersections of rows and columns. A pair of bitline segments are defined for each column. A connecting load device of each memory cell is connected to either a first or a second of the pair of bitline segments. An equal number of load devices in each column couple to each of the pair of bitlines.
    Type: Application
    Filed: January 30, 2003
    Publication date: August 5, 2004
    Applicant: Sun Microsystems, Inc.
    Inventors: Shree Kant, Aparna Ramachandran, Ranjan Vaish
  • Patent number: 6707721
    Abstract: A register file design having an asymmetric bit line driver is provided. More specifically, the register file design uses a memory element that has a footer device that facilitates the discharge/charging of a bit line through a pass device, where a width of the footer device is greater than a width of the pass device. Further, a method for performing low power memory operations using asymmetric bit line drivers is provided.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: March 16, 2004
    Assignee: Sun Microsystems, Inc.
    Inventors: Gajendra Singh, Aparna Ramachandran, Miao Rao, Shree Kant
  • Patent number: 6646951
    Abstract: An address decoder having pre-decode logic circuitry positioned in between ends of final decode logic circuitry is provided. Such an address decoder yields less wire load, less gate load, less power consumption, and increased speed due to the pre-decode logic circuitry having to be capable of only driving a signal over half the length of a final decoder. Further, a method to select memory elements from a memory array using centrally positioned pre-decode logic circuitry is provided.
    Type: Grant
    Filed: October 23, 2001
    Date of Patent: November 11, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Shree Kant, Aparna Ramachandran
  • Publication number: 20030174535
    Abstract: A register file design having an asymmetric bit line driver is provided. More specifically, the register file design uses a memory element that has a footer device that facilitates the discharge/charging of a bit line through a pass device, where a width of the footer device is greater than a width of the pass device. Further, a method for performing low power memory operations using asymmetric bit line drivers is provided.
    Type: Application
    Filed: March 13, 2002
    Publication date: September 18, 2003
    Inventors: Gajendra Singh, Aparna Ramachandran, Miao Rao, Shree Kant
  • Publication number: 20030076732
    Abstract: An address decoder having pre-decode logic circuitry positioned in between ends of final decode logic circuitry is provided. Such an address decoder yields less wire load, less gate load, less power consumption, and increased speed due to the pre-decode logic circuitry having to be capable of only driving a signal over half the length of a final decoder. Further, a method to select memory elements from a memory array using centrally positioned pre-decode logic circuitry is provided.
    Type: Application
    Filed: October 23, 2001
    Publication date: April 24, 2003
    Inventors: Shree Kant, Aparna Ramachandran
  • Patent number: 6442099
    Abstract: A method and apparatus for consuming low power when accessing data from a memory array is provided. Further, a method and apparatus for consuming low power when accessing data from a segmented bit line structure in a register file is provided by using transistors having progressively smaller widths as the storage cells or segments they are in get closer to an output of the segmented bit line structure. Further, a method and apparatus for consuming low power when accessing data from a differential bit line structure in a register file is provided by using transistors having progressively smaller widths as the storage cells they are in get closer to an output of the differential bit line structure.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: August 27, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Shree Kant, Gajendra P. Singh
  • Patent number: 6320813
    Abstract: Decoding of addresses in a register file is simplified by reducing the number of bits used for addressing by one. Bits are read from even/odd cell combinations simultaneously, and a reserved address line is driven high. The reserved address line is coupled to each driver corresponding to a storage cell. Individual even cells may also be read. Writing to even/odd cell combinations may be performed in a similar manner. However, when writing, an even write enable line and an odd write enable line are provided to indicate whether an even cell, an odd cell, or an even/odd cell combination should be written to simultaneously. By simplifying the decoding stage, performance of reading and writing tasks may be performed much faster and use less resources.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: November 20, 2001
    Assignee: Sun Microsystems, Inc.
    Inventor: Shree Kant
  • Patent number: 6316301
    Abstract: In a logic circuit having PMOS pull-up devices and NMOS pull-down devices, the PMOS pull-up devices are sized relative to the NMOS pull-down devices according to the number of transistors that simultaneously turn on. In one embodiment, the PMOS transistor width is determined by multiplying the effective NMOS transistor width by a predetermined factor indicative of a current carrying ratio between one of the PMOS pull-up transistors and one of the NMOS pull-down transistors and dividing by the number of PMOS pull-up transistors that simultaneously turn on to charge the output node high. Where the PMOS pull-up devices are parallel-connected, the NMOS transistor width is divided by the number of NMOS transistors.
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: November 13, 2001
    Assignee: Sun Microsystems, Inc.
    Inventor: Shree Kant
  • Patent number: 6038193
    Abstract: A read system for a multi-ported register file includes a segmented bit line coupled to a global bit line. Each local bit line segment is coupled to a sub-set of the register files in a column to reduce device load and connection load. The local bit line segments are each coupled in series by local sense amps with the local bit line segment coupled to the input of a global sense amplifier. The number of cells coupled to the last bit line segment is more than the number of cells coupled to a bit line segment farthest from the global sense amplifier to balance device and interconnect load and provide for uniform read timing. Both the local bit line segments and global bit line are precharged prior to sensing a bit so that the local sense amplifiers do not require output pull-up transistors. This scheme will not work if the local sense amp includes a pull-up PMOS transistor at its output.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: March 14, 2000
    Assignee: Sun Microsystems, Inc.
    Inventors: Yong Wang, Shree Kant