Patents Examined by Douglas S. King
  • Patent number: 7333389
    Abstract: An improved method and device for column decoding for flash memory devices utilizes a burst page with a length greater than the length of a logical page. When a misalignment of an initial address occurs, valid reads across logical page boundaries are possible. The memory device enters the wait state only when a read crosses a burst page boundary. This minimizes the amount of time in which the memory device enters the wait state. In the preferred embodiment, this is achieved with a different management of the control signals that feed the third level of a three-level decoding stage column decoder. Changes to the architecture or in the number of column decoder selectors are not required. The memory access time during synchronous reads is thus improved.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: February 19, 2008
    Assignee: Atmel Corporation
    Inventors: Stefano Sivero, Simone Bartoli, Fabio Tassan Caser, Riccardo Riva Reggiori
  • Patent number: 7313023
    Abstract: The present invention that partitions a memory array in N segments by switchably partitioning the bit lines in the array. In the exemplary embodiment, a top set of sense amps control the even bit lines and a bottom set of sense amps control the odd bit lines. The segmentation transistors turn on or off depending on the selected word line location in the array. Since bit line capacitance is mainly from the metal bit line to bit line coupling to their immediate neighbors, the bit line neighbors in the partitioned array are floating in some segments of the bit lines. The overall bit line capacitance is significantly reduced with a negligible increase in die size, resulting in reduced sensing times and enhanced read and write performance.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: December 25, 2007
    Assignee: SanDisk Corporation
    Inventors: Yan Li, Farookh Moogat
  • Patent number: 7304874
    Abstract: Improved layouts of binary and ternary content addressable memory cells (BCAM and TCAM) are shown. A content addressable memory cell layout has a plurality of P+ diffusion areas and a plurality of N+ diffusion areas that do not enclose isolation regions and on which shallow trench isolation stress can exert minimal influence on the drive current of the memories. Further, all transistors in the content addressable memory cell layout are oriented in the same direction to avoid unintended variations in electrical performance. The CAM layouts are “process friendly” to accommodate requirements of advanced process technologies such as the 90 nm process.
    Type: Grant
    Filed: March 8, 2005
    Date of Patent: December 4, 2007
    Assignee: LSI Corporation
    Inventors: Ramnath Venkatraman, Ruggero Castagnetti, Joseph Eugene Glenn
  • Patent number: 7263010
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of memory blocks, a plurality of redundancy sections respectively provided for the plurality of memory blocks and configured to be substituted for defective memory cells, a test circuit that carries out a test on the memory cell array and outputs defective data, first and second memory circuit that temporarily store the defective data, a first write circuit that writes the defective data alternately in the first and second memory circuits, a first read circuit that reads the defective data alternately from the first and second memory circuits, a plurality of third memory circuits respectively provided for the plurality of memory blocks, that store the defective data, and a second write circuit that writes defective data read by the first read circuit in a third memory circuit corresponding to a memory block in which an error occurred.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: August 28, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwai, Shinji Miyano
  • Patent number: 7233526
    Abstract: A semiconductor memory device includes a memory cell array, word lines, select gate lines, and switch elements. The memory cell array includes a plurality of memory cells arranged in a matrix. Each of the memory cells includes a first MOS transistor having a charge accumulation layer and a control gate and a second MOS transistor which has a drain connected to a source of the first MOS transistor. Each of the word lines connects commonly the control gates of the first MOS transistors in a same row. Each of the select gate lines connects commonly the gates of the second MOS transistors in a same row. The switch elements, in an erase operation, electrically connect the select gate lines to a semiconductor substrate in which the memory cell array is formed.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: June 19, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Umezawa
  • Patent number: 7227772
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: June 5, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono