Patents Examined by Terrell W. Fears
  • Patent number: 6353569
    Abstract: A memory structure/circuit has at least two memory cell arrays connected to each other in a hierarchy. The bit lines of the two or more memory cell arrays are connected by hierarchy switches. The memory cells of one of the arrays can be read out faster than the others by using the hierarchy switches to select one array without selecting the other arrays. So the data that is read with higher frequency can be selectively read out faster if it is stored in the faster access memory array. If the data in the faster access memory cell array includes a copy of the data in the other array, it can be used as a cache memory. A tag array and data array in combination that are connected to another tag array and data array in combination through hierarchy switch connections can provide a cache memory that is direct mapped or set associative, and also full associative.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: March 5, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Mizuno, Suguru Tachibana, Koichiro Ishibashi, Kenichi Osada
  • Patent number: 6349058
    Abstract: An electronic circuit includes a non-volatile memory that has several memory cells. The output of the non-volatile memory is connected to the inputs of several latches. Each latch has an output adapted to be read independently. A refresh circuit is connected to address lines of the non-volatile memory and to the write pins of each of the latches. The data contained in the memory cells of the non-volatile memory is represented by the data contained in the latches.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: February 19, 2002
    Assignee: Microchip Technology Incorporated
    Inventor: Joseph A. Thomsen
  • Patent number: 6344998
    Abstract: An electrically alterable, non-volatile memory cell has more than two memory states that can be programmed selectively. Programming of the cell is conducted by applying a plurality of programming signals having different characteristics to the cell. The programming signals include at least a first programming signal which programs the cell by a first increment and a subsequent programming signal which programs the cell by a second increment smaller than the first increment. As the cell is being programmed to a selected state, its programming status is verified independently of reference values bounding the memory states. For this purpose, a signal indicative of the programming status (e.g., the cell's bit line signal) is compared with a reference signal corresponding to the selected state but having a value different from the reference value or values bounding the selected state. The programming operation can thus be controlled without actually reading the memory state of the cell.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: February 5, 2002
    Assignee: BTG International Inc.
    Inventor: Gerald J. Banks
  • Patent number: 6343034
    Abstract: An electrically alterable, non-volatile memory cell has more than two memory states that can be programmed selectively. Programming of the cell is conducted by applying a plurality of programming signals having different characteristics to the cell. The programming signals include at least a first programming signal which programs the cell by a first increment and a subsequent programming signal which programs the cell by a second increment smaller than the first increment. As the cell is being programmed to a selected state, its programming status is verified independently of reference values bounding the memory states. For this purpose, a signal indicative of the programming status (e.g., the cell's bit line signal) is compared with a reference signal corresponding to the selected state but having a value different from the reference value or values bounding the selected state. The programming operation can thus be controlled without reading out the cell.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: January 29, 2002
    Assignee: BTG International Inc.
    Inventor: Gerald J. Banks
  • Patent number: 6341095
    Abstract: An apparatus for increasing pulldown rate of a bitline in a memory device during a read operation is disclosed. The memory device includes a pair of complementary differential bitlines, and each of the complementary differential bitlines has a precharge transistor. The memory device also includes multiple storage cells coupled between the complementary differential bitlines. Furthermore, each of the complementary differential bitlines has a discharge transistor for increasing the pulldown rate of a respective bitline during a read operation.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: January 22, 2002
    Assignee: International Business Machines Corporation
    Inventors: Michael Ju Hyeok Lee, Jose Angel Paredes
  • Patent number: 6339545
    Abstract: An electrically alterable, non-volatile memory cell has more than two memory states that can be programmed selectively. Programming of the cell is conducted by applying a plurality of programming signals having different characteristics to the cell. The programming signals include at least a first programming signal which programs the cell by a first increment and a subsequent programming signal which programs the cell by a second increment smaller than the first increment. As the cell is being programmed to a selected state, its programming status is verified independently of reference values bounding the memory states. For this purpose, a signal indicative of the programming status (e.g., the cell's bit line signal) is compared with a reference signal corresponding to the selected state but having a value different from the reference value or values bounding the selected state. The programming operation can thus be controlled without actually reading the memory state of the cell.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: January 15, 2002
    Assignee: BTG International Inc.
    Inventor: Gerald J. Banks
  • Patent number: 6339544
    Abstract: An apparatus including a contact on a substrate, a dielectric material overlying the contact, a phase change element overlying the dielectric material on a substrate, and a heater element disposed in the dielectric material and coupled to the contact and the phase change element, wherein a portion of the dielectric material comprises a thermal conductivity less than silicon dioxide. A method including introducing over a contact formed on a substrate, a dielectric material, a portion of which comprises a thermal conductivity less than silicon dioxide, introducing a heater element through the dielectric material to the contact, and introducing a phase change material over the dielectric material and the heater element.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: January 15, 2002
    Assignee: Intel Corporation
    Inventors: Chien Chiang, Guy C. Wicker
  • Patent number: 6335884
    Abstract: Herein disclosed is a semiconductor memory device, in which peripheral circuits are arranged in a cross area of a semiconductor chip composed of the longitudinal center portions and the transverse center portions, and in which memory arrays are arranged in the four regions which are divided by the cross area. Thanks to this structure in which the peripheral circuits are arranged at the center portion of the chip, the longest signal transmission paths can be shortened to about one half of the chip size to speed up the DRAM which is intended to have a large storage capacity.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: January 1, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiko Kajigaya, Kazuyuki Miyazawa, Manabu Tsunozaki, Kazuyoshi Oshima, Takashi Yamazaki, Yuji Sakai, Jiro Sawada, Yasunori Yamaguchi, Tetsurou Matsumoto, Shinji Udo, Hiroshi Yoshioka, Hirokazu Saito, Mitsuhiro Takano, Makoto Morino, Sinichi Miyatake, Eiji Miyamoto, Yasuhiro Kasama, Akira Endo, Ryoichi Hori, Jun Etoh, Masashi Horiguchi, Shinichi Ikenaga, Atsushi Kumata
  • Patent number: 6335896
    Abstract: A capacitor memory data storage system of reading, writing and refreshing which uses short bit line segments separated by pass transistors to allow smaller capacitors and faster speeds than the prior art.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: January 1, 2002
    Assignee: Altera Corporation
    Inventor: Sven E. Wahlstrom
  • Patent number: 6331942
    Abstract: A CAM cell design methodology and a method of pre-charge and comparison timing is disclosed. A CAM cell utilizing this design methodology includes grounding circuitry and a P-channel transistor configured to communicate a comparison result to a match line using the Miller effect. In one embodiment, the CAM cell further includes a positive comparison bit line, a negative comparison bit line, a first dual-ended CAM memory core cell configured to store data, a second dual-ended CAM memory core cell configured to store masking data, comparison circuitry, and a second P-channel transistor configured to communicate a masked state to the match line.
    Type: Grant
    Filed: September 9, 2000
    Date of Patent: December 18, 2001
    Assignee: Tality, L.P.
    Inventor: LuVerne R. Peterson
  • Patent number: 6331953
    Abstract: A method of erasing a memory cell that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. The method includes: applying a voltage across the gate and the first region in accordance with a coarse erase sequence of voltages so that a portion of the first amount of charge is removed from the charge trapping region; and applying a voltage across the gate and the first region in accordance with a fine erase sequence of voltages so that a portion of the first amount of charge is removed from the charge trapping region.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: December 18, 2001
    Assignee: Advanced Micro Devices
    Inventors: Janet S. Y. Wang, Narbeh Derhacobian, Daniel Sobek
  • Patent number: 6331960
    Abstract: A nonvolatile semiconductor memory device includes nonvolatile memory cells (C), constant voltage circuits for applying one of different verify voltages to control gates of the nonvolatile memory cells C in response to control data introduced into the memory device from the exterior, and writing and sensing circuit circuits for applying a potential to drains of the nonvolatile memory cells C in response to write data introduced into the memory device and for detecting and amplifying currents between drains and sources of the nonvolatile memory cells. By dividing the memory cell array 501 and a serial register 502 into some parts and by connecting an external SRAM 503 so as to progress the transfer of data from the memory cell array 501 to the serial register 502 and the transfer of data from the serial register 502 to the external SRAM 503 in parallel, the read speed is increased.
    Type: Grant
    Filed: August 21, 2000
    Date of Patent: December 18, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Junichi Miyamoto
  • Patent number: 6330205
    Abstract: The present invention provides a semiconductor memory device comprising: memory cells; main decoders decoding address signals sense amplifiers for reading out informations from the memory cells; and word drivers for driving the memory cells, wherein a row address controlled by a single main word line in a basic cell in the word driver, and two of the main word line of the row address are made correspond to a half of lower-order 2-bits of the row address, and a word driver signal is placed inside of the basic cell of the word driver to prevent the word driver signal from being commonly used to adjacent two of the basic cell.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: December 11, 2001
    Assignee: NEC Corporation
    Inventors: Yoshiaki Shimizu, Kazuhiko Matsuki
  • Patent number: 6330203
    Abstract: Described is a method for verification of proper address generation in packet based memory protocol (Direct RDRAM) devices during the auto-refresh or self-refresh cycle that does not require changes to the interface logic or core signal generation. The method requires minimal additional logic while using the core control signals that function similarly to the RAS, CAS, and WE signals in a standard DRAM. Initially, high level (1) data are written to all of the memory cells of one bit line. The signals are manipulated, and a refresh is performed. As each memory cell is addressed during the refresh, the data are changed to a low level (0). Addressing is then verified by observing the data stored in the memory cells and confirming that a low level (0) is now stored. The method may be extended to standard DRAM devices.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: December 11, 2001
    Assignee: Vanguard International Semiconductor Corporation
    Inventor: Jeffrey S. Earl
  • Patent number: 6327204
    Abstract: A method of storing information in a memory cell. The method writes information via only the bit-line that is connected to a memory cell with respect to a word-line, and thus reduces the overall power consumption in the memory by reducing the unnecessary power consumption occurring from the change of voltage level in the bit-line that is not connected to a memory cell. To this end, a method of storing information in a memory cell having a sense amplifier which differentially amplifies a difference in voltage level between a pair of bit-lines is provided, the method comprising the steps of activating a word-line connected to the memory cell to be accessed, differentially amplifying the difference in voltage level between the pair of bit-lines coupled to the memory cell to be accessed, and selecting only one bit-line that is connected to the memory cell among the pair of bit-lines and rewriting the information via the one bit-line.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: December 4, 2001
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: Jeong Hoon Kook, Hoi Jun Yoo
  • Patent number: 6327193
    Abstract: Vertical rate deflection signals are generated using a combination of digital and analog techniques. A signal is generated by a switched capacitor type accumulator circuit, a wave shape control circuit, and a DC signal centering circuit. The signal is periodically reset by initializing a first storage circuit in the accumulator circuit to an initial start voltage. A buffer couples the first storage circuit to a first signal output. A second signal output is produced by generating a controlled offset from the first signal output. The second signal output is sampled by a second storage circuit, and subsequently coupled to the first storage circuit. The amplitude and slope of the signal are determined by the controlled offset level. The wave shape control circuit dynamically controls the offset level. By varying the offset level, the waveform shape is adjusted to provide a linear ramp, S corrected ramp, EWPCC parabolic signal or the like.
    Type: Grant
    Filed: September 25, 2000
    Date of Patent: December 4, 2001
    Assignee: National Semiconductor Corporation
    Inventor: Andy Morrish
  • Patent number: 6327188
    Abstract: An internal address signal corresponding to data to be written into a memory cell is held in a latch circuit. The held internal address signal is selected by a multiplexer in the next writing operation and applied to a decoder. Write data is taken in and held by the latch circuit during the period in which data is not being read out from the memory cell array. A comparator compares the held internal address signal and an internal address signal for reading data. If a matching is found between them, the multiplexer outputs data from the latch circuit for external output. Accordingly, delay of a writing operation following a reading operation can be eliminated without increasing chip cost, package cost, and system cost, as a result high speed operation of cache memories is achieved and the speed performance of computers of various levels such as supercomputers, large size calculators, work stations and personal computers can be improved.
    Type: Grant
    Filed: January 4, 2000
    Date of Patent: December 4, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Tomohisa Wada
  • Patent number: 6327179
    Abstract: There is provided a semiconductor memory device using a three-layer gate electrode material film to improve yields and reliability, and a method for producing the same. A floating gate 4 of a memory transistor MT is formed of a first-layer gate electrode material film L1, and a control gate 6 is formed of a laminated film of second-layer and third-layer gate electrode material films L2 and L3. A gate electrode 8 of a selecting gate transistor ST is formed of the first-layer gate electrode material film L1, and the second-layer and third-layer gate electrode material films L2 and L3 which are stacked thereon via an interlayer dielectric film 5. The third-layer gate electrode material film L3 contacts the first-layer gate electrode material film L1 via an opening 9. A gate electrode 12 of a peripheral circuit transistor Q is formed of the laminated film of the second-layer and third-layer gate electrode material films L2 and L3.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: December 4, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kanji Osari
  • Patent number: 6327189
    Abstract: An electrically alterable, non-volatile memory cell has more than two memory states that can be programmed selectively. Programming of the cell is conducted by applying a plurality of programming signals having different characteristics to the cell. The programming signals include at least a first programming signal which programs the cell by a first increment and a subsequent programming signal which programs the cell by a second increment smaller than the first increment. As the cell is being programmed to a selected state, its programming status is verified independently of reference values bounding the memory states. For this purpose, a signal indicative of the programming status (e.g., the cell's bit line signal) is compared with a reference signal corresponding to the selected state but having a value different from the reference value or values bounding the selected state. The programming operation can thus be controlled without actually reading the memory state of the cell.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: December 4, 2001
    Assignee: BTG International Inc.
    Inventor: Gerald J. Banks
  • Patent number: 6324121
    Abstract: An electrically alterable, non-volatile memory cell has more than two memory states that can be programmed selectively. Programming of the cell is conducted by applying a plurality of programming signals having different characteristics to the cell. The programming signals include at least a first programming signal which programs the cell by a first increment and a subsequent programming signal which programs the cell by a second increment smaller than the first increment. As the cell is being programmed to a selected state, its programming status is verified independently of reference values bounding the memory states. For this purpose, a signal indicative of the programming status (e.g., the cell's bit line signal) is compared with a reference signal corresponding to the selected state but having a value different from the reference value or values bounding the selected state. The programming operation can thus be controlled without actually reading the memory state of the cell.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: November 27, 2001
    Assignee: BTG International Inc.
    Inventor: Gerald J. Banks