Patents Examined by Joseph Popek
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Patent number: 5691943Abstract: The present invention discloses provides a page mode mask ROM capable of decreasing sense amplifiers by latching data using a two-stage latch circuit. Accordingly, the present invention provides a method for decreasing the number of amplifiers in memory device including an Y-predecoder, an Y-decoder, amplifiers and a cell array, said method comprising of the steps of: generating clock signals according to an address transition pulse; generating enable signal for driving said Y-predecoder and said amplifiers in response to said clock signals and said address transition pulse; amplifying data stored in said cell array in response to the output from said Y-decoder; latching the amplified data in a latch means; and transferring the latched data in said latch means to another latch means under the control of an address transition pulse generated whenever address transition occurs.Type: GrantFiled: June 7, 1996Date of Patent: November 25, 1997Assignee: Hyundai Electronics Industries Co., Ltd.Inventor: Chan Soo Yun
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Patent number: 5689463Abstract: A NAND type EEPROM includes block selecting circuits (BSC1 to BSC6) configured to keep a defective block non-selected in the mode for simultaneous writing and simultaneous erasure of all blocks (BLK1-BLK4) to test the device, after the defective block is replaced by a redundant block (SBLK1, SBLK2). This prohibitor a high voltage boosted by a booster circuit for simultaneous writing and simultaneous erasure of all blocks from being applied to the defective block. The block selecting circuits output a "NON-SELECT" signal when a signal instructing simultaneous writing or simultaneous erasure of all blocks is supplied after corresponding fuses (fa-fh)are blown or cut off. Therefore, once a defective block is replaced by a redundant block, there never occurs a voltage drop which may otherwise be caused by leakage of current from the defective block, and the device can be used as a non-defective NAND type EEPROM in all modes including the test mode.Type: GrantFiled: October 4, 1995Date of Patent: November 18, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Hiroaki Murakami, Yoshiyuki Tanaka
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Patent number: 5686730Abstract: A high memory capacity DIMM for use in a directory-based, distributed shared memory multiprocessor computer system includes a data memory for storing data and a state memory for storing state or directory information corresponding to at least a portion of the data. The DIMM allows the data and the state information to be accessed independently. The DIMM is configured for use in a DIMM pair. In the DIMM pair, a first DIMM includes a first data memory having first and second memory bank portions for storing data, and a first state memory configured to store state information corresponding to data stored in a first memory bank. A second DIMM includes a second data memory having third and fourth memory bank portions for storing data, and a second state memory configured to store state information corresponding to data stored in a second memory bank. The first memory bank is formed from the first memory bank portion and the third memory bank portion.Type: GrantFiled: November 12, 1996Date of Patent: November 11, 1997Assignee: Silicon Graphics, Inc.Inventors: James P. Laudon, Daniel E. Lenoski, John Manton
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Patent number: 5687112Abstract: An electrically operated, directly overwritable, multibit, single-cell chalcogenide memory element with multibit storage capabilities and having at least one contact for supplying electrical input signals to set the memory element to a selected resistance value, the second contact tapering to a peak adjacent to the memory element. In this manner the tapered contact helps define the size and position of a conduction path through the memory element.Type: GrantFiled: April 19, 1996Date of Patent: November 11, 1997Assignee: Energy Conversion Devices, Inc.Inventor: Stanford R. Ovshinsky
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Patent number: 5684753Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data ports (22) thereof to permit asynchronious read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36) which stores a random access address and an address sequencer (40) which provides a stream of addresses to the memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: November 4, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5682344Abstract: A ferroelectric random access memory (RAM) is described which uses ferroelectric memory cells to store data. The ferroelectric memory is a static memory in which data stored in the ferroelectric memory cells can be destroyed during read operations. The memory includes circuitry which latches a current memory address during an access operation and prohibits the memory from moving to a new memory address until the destroyed data has been replaced. The memory also includes circuitry which can detect a transition in address data provided on address inputs.Type: GrantFiled: September 11, 1995Date of Patent: October 28, 1997Assignee: Micron Technology, Inc.Inventor: Mirmajid Seyyedy
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Patent number: 5680370Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data ports (22) thereof to permit asynchronous read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36) which stores a random access address and an address sequencer (40) which provides a stream of addresses to the memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: October 21, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5680358Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data ports (22) thereof to permit asynchronious read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36), which stores a random access address and an address sequencer (40) which provides a stream of addresses to the memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: October 21, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5680367Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data ports (22) thereof to permit asynchronous read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36) which stores a random access address and an address sequencer (40) which provides a stream of addresses to the memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: October 21, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5680350Abstract: This invention constitutes a method for narrowing threshold voltage distribution among the individual cells of a block erased flash memory array by firstly, preprogramming cells within the block be erased to a level of saturation using hot electron injection to drive a surplus of electrons into the floating gate of each cell; secondly, subjecting all cells with the block to a first erase pulse which causes the surplus electrons within the floating gate of each cell to be driven into the cell's source region via Fowler-Nordheim tunneling, with the erase pulse being of sufficient length to erase every cell within the block; thirdly, subjecting all cells within the block to a word line stress step or a soft programming step, by means of which some electrons are driven back into the floating gate of each cell via Fowler-Nordheim tunneling or hot electron injection, respectively; and, fourthly, subjecting all cells within the block to a second erase pulse, the second erase pulse being at least an order of magnitudType: GrantFiled: December 14, 1994Date of Patent: October 21, 1997Assignee: Micron Technology, Inc.Inventor: Roger R. Lee
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Patent number: 5680369Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data parts (22) thereof to permit asynchronous read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36) which stores a random access address and an address sequencer (40) which provides a stream of addresses to the memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: October 21, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5680368Abstract: A memory circuit (14) having features specifically adapted to permit the memory circuit (14) to serve as a video frame memory is disclosed. The memory circuit (14) contains a dynamic random access memory array (24) with buffers (18, 20) on input and output data ports (22) thereof to permit asynchronious read, write and refresh accesses to the memory array (24). The memory circuit (14) is accessed both serially and randomly. An address generator (28) contains an address buffer register (36) which stores a random access address and an address sequencer (40) which provides a stream of addresses memory array (24). An initial address for the stream of addresses is the random access address stored in the address buffer register (36).Type: GrantFiled: June 7, 1995Date of Patent: October 21, 1997Assignee: Texas Instruments IncorporatedInventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
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Patent number: 5680344Abstract: A static ferroelectric memory circuit is described which has an array of ferroelectric memory cells fabricated as single capacitors using a ferroelectric dielectric and arranged as a static random access memory (SRAM). Data can be stored in a non-volatile manner on the memory cells by controlling the voltage placed upon the plates of the cell. A method is described for operating the ferroelectric memory as a dynamic random access memory (DRAM). Test methods are described for testing the memory cells and identifying whether a defect is result of a ferroelectric material defect or a physical defect, such as a short, open or high leakage.Type: GrantFiled: September 11, 1995Date of Patent: October 21, 1997Assignee: Micron Technology, Inc.Inventor: Mirmajid Seyyedy
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Patent number: 5680352Abstract: A circuit which responds to an external standby command (a transition in a chip enable signal from an external device) by generating a delayed internal standby signal. The internal standby signal functions by switching selected components of the circuit (such as address buffers) from an active mode to a standby mode. In preferred embodiments, the circuit is a memory circuit implemented as an integrated circuit. The amount of the delay in generating the delayed internal standby signal is selected to achieve a desired decreased average response time to a sequence of commands (such as memory access commands) without excessive power consumption. In embodiments in which the circuit is a memory chip (such as a flash memory chip) having address access time in the range from 60 ns to 80 ns, the delay typically is from about 100 ns to about 200 ns.Type: GrantFiled: June 3, 1996Date of Patent: October 21, 1997Assignee: Micron Quantum Devices, Inc.Inventor: Fariborz F. Roohparvar
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Patent number: 5677865Abstract: A random access memory circuit is described which uses single ferroelectric memory cells to store data. The ferroelectric memory cells can be selectively read using a reference voltage which is compared to a voltage representative of data stored on the memory cell using a multiplexed sense amplifier. The reference voltage is generated using a non-remnant capacitor circuit coupled to a bit line. In using a non-remnant capacitor circuit, a single-ended reference voltage can be generated on the bit line. The capacitance of the bit line is substantially greater than the capacitance of the non-remnant capacitor, therefore, the resultant reference voltage on the bit line remains relatively constant with fluctuations in supply voltage. A ferroelectric memory cell can then be read by comparing the voltage on its corresponding bit line to the reference voltage using the sense amplifier.Type: GrantFiled: September 11, 1995Date of Patent: October 14, 1997Assignee: Micron Technology, Inc.Inventor: Mirmajid Seyyedy
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Patent number: 5677889Abstract: An SRAM includes a memory cell array, a peripheral circuitry including a bit line load connected to the memory cell array, a multiplexer and the like, and a voltage lowering circuit. The voltage lowering circuit receives a power supply potential Vcc and outputs a potential Vin which is lower. The potential Vin is applied to the peripheral circuitry except the memory cell array, and the power supply potential Vcc is directly applied to the memory cell array. Therefore, operational potential of the memory cell array is made relatively higher with respect to the peripheral circuitry. As a result, a static semiconductor memory device which can operation at low voltage and consumes less power can be provided.Type: GrantFiled: August 18, 1995Date of Patent: October 14, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshiyuki Haraguchi, Tadato Yamagata
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Patent number: 5677869Abstract: A method for programming an array of memory cells wherein each cell may be placed in more than two states. The method comprises the steps of 1) selecting a plurality of different programming voltage levels wherein each programming voltage level is associated with a corresponding one of a plurality of states, and 2) applying a plurality of programming pulses to selected subsets of the array of memory cells, wherein each programming pulse has one of the programming voltage levels and one of a corresponding plurality of pulse widths such that each of the memory cells of a corresponding one of the selected subsets are programmed directly to a corresponding one of the plurality of states by a corresponding programming pulse.Type: GrantFiled: December 14, 1995Date of Patent: October 14, 1997Assignee: Intel CorporationInventors: Albert Fazio, Gregory E. Atwood, James Q. Mi, Paul Ruby
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Patent number: 5675536Abstract: The present invention discloses a flash memory cell which can prevent an over programming in a way that uses a cross coupled latch circuit and peripheral circuits upon a byte programming into a flash memory cell programmed by hot electron injection.Type: GrantFiled: December 21, 1995Date of Patent: October 7, 1997Assignee: Hyundai Electronics Industries Co., Ltd.Inventor: Hyun Soo Sim
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Patent number: 5675535Abstract: In a sense amplifier for use in a semiconductor memory having a plurality of memory cells, comprising first and differential amplifiers receiving a potential signal read out from a selected memory cell and a reference potential, and having an output for respectively outputting first and second outputs differentially amplified in a phase opposite to each other, a CMOS inverter circuit is composed of a PMOS transistor and a NMOS transistor having their gate connected in common to receive the output of second differential amplifier. The CMOS inverter circuit has a threshold level corresponding to an intermediate level between a high logic level and a low logic level of binary information.Type: GrantFiled: January 23, 1996Date of Patent: October 7, 1997Assignee: NEC CorporationInventor: Toshikatsu Jinbo
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Patent number: 5673221Abstract: A sensing circuit for serial dichotomic sensing of multiple-level memory cells which can take one programming level among a plurality of m=2.sup.n (n>=2) different programming levels, comprises biasing means for biasing a memory cell to be sensed in a predetermined condition, so that the memory cell sinks a cell current with a value belonging to a plurality of m distinct cell current values, each cell current value corresponding to one of the programming levels, a current comparator for comparing the cell current with a reference current generated by a variable reference current generator, and a successive approximation register supplied with an output signal of the current comparator and controlling the variable reference current generator.Type: GrantFiled: January 29, 1996Date of Patent: September 30, 1997Assignee: SGS-Thomson Microelectronics S.r.l.Inventors: Cristiano Calligaro, Vincenzo Daniele, Roberto Gastaldi, Alessandro Manstretta, Nicola Telecco, Guido Torelli