Complementing/balancing Patents (Class 365/202)
  • Patent number: 7042754
    Abstract: A ferroelectric memory device equipped with a plate line control section that selects a specified plate line that is connected to a specified memory cell, thereby discharging a data accumulation charge to a specified bit line connected to the specified memory cell, and discharges a reference accumulation charge to the specified bit line when the specified bit line is discharged; a device that, by successively connecting the specified bit line to a first sense amplifier line and a second sense amplifier line based on a change in the potential on the specified plate line, retains at the first sense amplifier line a potential on the specified bit line when the data accumulation charge is discharged, and retains at the second sense amplifier line a potential on the specified bit line when the reference accumulation charge is discharged; and a sense amplifier that judges the predetermined data based on potentials on the first sense amplifier line and the second sense amplifier line.
    Type: Grant
    Filed: March 9, 2005
    Date of Patent: May 9, 2006
    Assignee: Seiko Epson Corporation
    Inventor: Fumiaki Mukaiyama
  • Patent number: 7043599
    Abstract: Described are dynamic memory systems that perform overlapping refresh and data-access (read or write) transactions that minimize the impact of the refresh transaction on memory performance. The memory systems support independent and simultaneous activate and precharge operations directed to different banks. Two sets of address registers enable the system to simultaneously specify different banks for refresh and data-access transactions.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: May 9, 2006
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Richard E. Perego
  • Patent number: 7042780
    Abstract: Provided are a semiconductor integrated circuit including a unit which detects soft defects in a pull-up circuit of a static memory cell, and a soft defect detection method and a testing method thereof. The semiconductor integrated circuit includes a static memory cell, a bit line connected to a first node of the static memory cell and a complementary bit line connected to a second node of the static memory cell, and an equalization circuit connected to the bit line and the complementary bit line to equalize the bit line and the complementary bit line in response to a test signal during a test mode. The semiconductor integrated circuit and the soft defect detection method can rapidly detect soft defects in the pull-up circuit of the static memory cell without a retention test. Furthermore, the testing method can rapidly detect soft defects in the pull-up circuit of the static memory cell, allowing the test time to be drastically reduced.
    Type: Grant
    Filed: June 2, 2004
    Date of Patent: May 9, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chan-ho Lee
  • Patent number: 7023720
    Abstract: A ferroelectric memory device having a function of preventing destruction of data stored in an unselected memory cell. The ferroelectric memory device includes a protection circuit for protecting data in the unselected memory cell. The protection circuit is provided on an unselected-bitline-voltage supply line and an unselected-wordline-voltage supply line.
    Type: Grant
    Filed: December 30, 2003
    Date of Patent: April 4, 2006
    Assignee: Seiko Epson Corporation
    Inventor: Akira Maruyama
  • Patent number: 6999361
    Abstract: A test circuit for a memory device having a pair of arrays each of which includes a plurality of memory cells arranged in rows and columns. A pair of complementary digit lines is provided for each column of each array. The digit lines are selectively coupled to a pair of I/O lines for each array which are, in turn, coupled to a pair of complementary data lines. The data lines are coupled to respective inputs of a DC sense amplifier, one of which is provided for each array. A multiplexer connects the pair of I/O lines for either one of the arrays to the data lines in a normal operating mode. Thus, in the normal operating mode, data are selectively coupled to the inputs of the DC sense amplifier from the complementary digit lines for an addressed column. In a test mode, the multiplexer connects the I/O lines for both arrays to the data lines to compress the data from the two arrays.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: February 14, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Brent Keeth
  • Patent number: 6992940
    Abstract: The invention relates to a semiconductor memory apparatus in which the connections of the connecting contacts can be varied. The invention also relates to a semiconductor apparatus which comprises at least two semiconductor memory apparatuses according to the invention.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: January 31, 2006
    Assignee: Infineon Technologies AG
    Inventor: Andreas Täuber
  • Patent number: 6992939
    Abstract: The disclosed embodiments relate to a method and apparatus for identifying short circuits in an integrated circuit device. The method may comprise the acts of programming a first memory cell associated with a first digit line to a first data value, programming a second memory cell associated with a second digit line to a second data value, the second data value being complementary with respect to the first data value, firing a first sense amplifier associated with the first digit line, firing a second sense amplifier associated with the second digit line after a time delay with respect to the act of firing the first sense amplifier associated with the first digit line, detecting a measured data value associated with the second digit line, and comparing the measured data value to the second data value to determine whether the first digit line is short circuited to the second digit line.
    Type: Grant
    Filed: January 26, 2004
    Date of Patent: January 31, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Stephen R. Porter
  • Patent number: 6987702
    Abstract: A test circuit for a memory device having a pair of arrays each of which includes a plurality of memory cells arranged in rows and columns. A pair of complementary digit lines is provided for each column of each array. The digit lines are selectively coupled to a pair of I/O lines for each array which are, in turn, coupled to a pair of complementary data lines. The data lines are coupled to respective inputs of a DC sense amplifier, one of which is provided for each array. A multiplexer connects the pair of I/O lines for either one of the arrays to the data lines in a normal operating mode. Thus, in the normal operating mode, data are selectively coupled to the inputs of the DC sense amplifier from the complementary digit lines for an addressed column. In a test mode, the multiplexer connects the I/O lines for both arrays to the data lines to compress the data from the two arrays.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: January 17, 2006
    Assignee: Mycron Technology, Inc.
    Inventor: Brent Keeth
  • Patent number: 6985393
    Abstract: A margin test on a Dynamic Random Access Memory (DRAM) in accordance with the invention begins with a supply voltage level being stored in all memory cells of the DRAM. Circuitry incorporated into each sense amplifier of the DRAM then isolates the digit line equilibrating circuitry in each sense amplifier from the cell plate voltage DVC2 or supply voltage VCC to which the equilibrating circuitry is normally connected and connects the equilibrating circuitry to ground instead.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: January 10, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Danial S. Dean
  • Patent number: 6982899
    Abstract: A dummy bit line is provided between a pair of bit lines. The pair of bit lines is set at a power supply voltage and the dummy bit line is set at a ground voltage, and then the pair of bit lines and the dummy bit line are equalized. When a word line is activated in subsequent read operation, the pair of bit lines is at an intermediate potential lower than the power supply voltage, so that an apparent current drive capability of an access transistor decreases, and the static noise margin of a memory cell increases.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: January 3, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Norihiko Sumitani, Shigeo Houmura, Youji Nakai, Hidenari Kanehara, Kazuki Tsujimura
  • Patent number: 6980472
    Abstract: The present invention relates to electronic memories, more particularly to an improved method and apparatus to read the content of compact 2-transistor flash memory cells. A method of reading a 2-transistor flash memory cell 1 is provided. The memory cell 1 comprises a storage transistor 2 with a storage gate 6 and a selecting transistor 3 with a select gate 7. The method comprises leaving the storage gate 6 floating while the select gate 7 is switched from a first voltage to a second voltage, whereby the first voltage is lower than the second voltage. A device according to the present invention comprises a switching circuit for leaving the storage gate 6 floating while the select gate 7 is switched from the first voltage to the second voltage, the first voltage being lower than the second voltage.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: December 27, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Anthonie Meindert Herman Ditewig, Franciscus Petrus Widdershoven, Roger Cuppens
  • Patent number: 6977856
    Abstract: Disclosed herein is a semiconductor integrated circuit device equipped with a memory circuit, which realizes the speeding up of its operation and low power consumption thereof in a simple configuration. At input/output nodes of a sense amplifier including a CMOS latch circuit for performing an amplifying operation in response to an operation timing signal, a pair of first precharge MOSFETs brought to an on state during a precharge period to thereby supply a precharge voltage, and select switch MOSFETs for connecting the input/output nodes and each complementary bit line pair in response to a select signal are provided. A second precharge MOSFET for short-circuiting the complementary bit line pair is provided between the complementary bit line pair. A memory array is provided which includes dynamic memory cells each comprising an address selecting MOSFET and a storage capacitor, each of which is provided between one of the complementary bit line pair and a word line intersecting it.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: December 20, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yousuke Tanaka, Tomofumi Hokari, Masatoshi Hasegawa
  • Patent number: 6965533
    Abstract: A write operation of a MRAM in which a current necessary for inverting magnetization of an MTJ element has to be passed through a data line and therefore current consumption is large. The write operation comprises: comparing input data DI with read data GO read from a memory cell array and encoding the input data DI to form write data GI by a data encoder WC; and decoding the read data GO by a data decoder RD to form output data DO. In a nonvolatile semiconductor memory in which the current is passed through the data line to write data into a memory cell, the number of bits to be written during the write operation is reduced, and the current consumption can be reduced. This can realize the MRAM including a low-power highly-integrated memory.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: November 15, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Sakata, Hideyuki Matsuoka
  • Patent number: 6956789
    Abstract: A self-clocking memory device comprises a memory array, a memory input circuit, and a memory control circuit. The memory input circuit is operable to receive an input clock signal and generate a memory operation initiation signal in response thereto, while the memory control circuit is operable to receive the memory operation initiation signal and generate one or more control signals to initiate a memory operation in response thereto. The memory control circuit is further operable to identify completion of the memory operation and generate a cycle ready strobe signal in response thereto. The memory input circuit receives the cycle ready strobe signal as an input and generates a next memory operation initiation signal in response thereto for initiation of a next memory operation.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: October 18, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Vikas K. Agrawal, Bryan D. Sheffield, Stephen W. Spriggs
  • Patent number: 6952375
    Abstract: A single bit line reference signal path or line is used for both voltage subtraction and self-timing of a second sense that is longer than a first sense in a dual-sense, single-read memory cell. The self-timing mechanism includes an analog circuit.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: October 4, 2005
    Assignee: Intel Corporation
    Inventor: Hans Ola Dahl
  • Patent number: 6950365
    Abstract: A semiconductor memory device having a bitline coupling scheme capable of preventing sensing speed from lowering due to variations in an external power supply is provided. The semiconductor memory device includes a memory cell array which includes a plurality of memory cells, a bitline and a complementary bitline which are connected to the memory cell array, a coupling capacitor one end of which is connected to either the bitline or the complementary bitline and the other end of which a control signal is applied to, a bitline sensing amplifier which senses and amplifies a difference in the voltage between the bitline and the complementary bitline, and a control circuit which generate the control signal. Here, an internal power supply generated by dropping an external power supply applied from the outside of the semiconductor memory device is used as a power supply of the control circuit.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: September 27, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-seong Jang, Sung-ho Choi
  • Patent number: 6950339
    Abstract: A circuit for generating a trim bit signal in a flash memory device, comprises a control unit selected by a trim bit select signal and including a programmable and erasable cell, and an output unit for outputting a High level signal or a Low level signal through the trim bit signal output terminal depending on the program cell of the control unit.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: September 27, 2005
    Assignee: Hynix Semiconductor Inc.
    Inventors: Jong Bae Jeong, In Sun Park
  • Patent number: 6941412
    Abstract: Methods and apparatus for transforming data into a format which may be efficiently stored in a non-volatile memory are disclosed. According to one aspect of the present invention, a method for storing information of a first data format in a memory system includes generating statistics associated with the first data format, and transforming the information from the first data format to a second data format using the statistics. Once the information is transformed into the second data format, the information is stored into a memory. Storing the information in the second data format in the memory includes storing an identifier that identifies a transformation used to transform the information to the second data format. In one embodiment, costs associated with storing the information in the second data format are less than or equal to costs associated with storing the information in the first data format.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: September 6, 2005
    Assignee: SanDisk Corporation
    Inventors: Geoffrey S. Gongwer, Stephen J. Gross
  • Patent number: 6934179
    Abstract: A semiconductor integrated circuit device includes a first transistor which has first source and drain and a first gate, a ferro-electric capacitor which is connected to one of the first source and drain, a bit line which is connected to the other of the first source and drain, at least one capacitor connected to the bit line, and a control circuit which electrically connects the capacitor to the bit line or electrically disconnects the capacitor from the bit line.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: August 23, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Shuto
  • Patent number: 6931560
    Abstract: An apparatus comprising a first plurality of parallel switches and a second plurality of parallel switches. The first plurality of parallel switches may be configured to control a voltage on a first output pin. The second plurality of parallel switches may be configured to control a voltage on a second output pin. The first and second pluralities of parallel switches may be configured to provide rise time control of a differential waveform and be driven by a phased data signal.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: August 16, 2005
    Assignee: LSI Logic Corporation
    Inventors: Edson W. Porter, Brian E. Burdick, Todd A. Randazzo, Kevin J. Bruno, Stephen R. Burnham, William K. Petty
  • Patent number: 6922368
    Abstract: A method and apparatus of reducing the time for enabling a dynamic random access memory (DRAM) upon initial application of power, comprises generating an internal RAS signal upon initial power up to generate internal voltages. The internal RAS pulse is asserted after a short time delay ends. After the internal RAS pulse is asserted, voltages on a digit line pair are amplified with a sense amplifier. Then, the amplified voltages on the digit line pair are equilibrated with an equilibration circuit. The equilibrated voltage is also coupled through the equilibration circuit to charge a common plate of a memory cell capacitor.
    Type: Grant
    Filed: April 8, 2004
    Date of Patent: July 26, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6917552
    Abstract: Disclosed is a sense amplifier arrangement that achieves high-speed access and shorter cycle time when array voltage is lowered in a DRAM. In a TG clocking sense system to separate data lines between the array side and the sense amplifier side in an early stage of a sensing period, a restore amplifier RAP is added, which amplifies data lines on the array side by referring to the data in the sense amplifier, and the restore amplifier is driven by a voltage VDH higher than the array voltage VDL. As a result, high-speed sense operation of the TG clocking system is made compatible with high-speed restore operation of overdrive system, and it is possible to achieve high-speed access operation and shorter cycle time.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: July 12, 2005
    Assignee: Renesas Technology Corporation
    Inventors: Riichiro Takemura, Tomonori Sekiguchi, Takeshi Sakata
  • Patent number: 6914830
    Abstract: An integrated circuit memory device is designed to perform high speed data write cycles. An address strobe signal is used to latch a first address. During a burst access cycle the address is incremented internal to the device with additional address strobe transitions. A new memory address is only required at the beginning of each burst access. Read/Write commands are issued once per burst access eliminating the need to toggle the Read/Write control line at the device cycle frequency. A transition of the Read/Write control line during a burst access is used to terminate the burst access and initialize the device for another burst access. Write cycle times are maximized to allow for increases in burst mode operating frequencies. Local logic gates near a nay sense amplifiers are used to control write is data drivers to provide for maximum write times without crossing current during input/output line equilibration periods.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: July 5, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Todd A. Merritt, Troy A. Manning
  • Patent number: 6909654
    Abstract: A bit line pre-charge circuit of a semiconductor memory device includes a pre-charge circuit connected between a pair of bit lines for pre-charging the pair of bit lines in response to a pre-charge control signal and a pre-charge voltage transmitting circuit for transmitting a pre-charge voltage to the pre-charge circuit in response to the pre-charge control signal. A voltage drop in a pre-charge voltage generation line may be prevented when a short circuit is formed between a word line and a pair of bit lines, and current consumption during a standby operation of the semiconductor memory device may also be reduced, by preventing current from flowing from the pair of bit lines to the pre-charge voltage generation line.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: June 21, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Hoon Joo, Jin-Seok Lee, Sang-Seok Kang, Kyu-Chan Lee, Byung-Heon Kwak, Byung-Chul Kim
  • Patent number: 6903959
    Abstract: A memory IC having improved sensing during reads is disclosed. The IC includes the use of first and second reference voltages for sensing to compensate for asymmetry that exists between cells on bitline true and bitline complement. The first reference voltage is used for sensing a cell on bitline true while the second reference voltage is used for sensing a cell on bitline complement.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: June 7, 2005
    Assignee: Infineon Technologies Aktiengesellschaft
    Inventors: Thomas Roehr, Hans-Oliver Joachim, Joerg Wohlfahrt, Norbert Rehm
  • Patent number: 6903987
    Abstract: A sensing circuit including a sense amplifier to resolve a data signal generated by a memory cell is disclosed herein. The sensing circuit includes a bit line to receive the data signal, a first pre-charge device coupled to the bit line and configured to pre-charge the bit line, a device for providing a bias coupled to the bit line and configured to provide a bias to the bit line, and a reference node configured to be at least one pre-determined level. In one embodiment the pre-determined level is equal to a low potential such as ground and in another embodiment equal to a high potential such as VDD. One or more switching devices allows for the activation or deactivation of the pre-charge device allowing to pre-charge the bit line to a certain potential and the sensing circuit quickly and accurately determines whether a logical state of ‘1’ or ‘0’ is being applied to the bit line.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: June 7, 2005
    Assignee: T-Ram, Inc.
    Inventors: Sei-Seung Yoon, Jin-Man Han, Seong-Ook Jung
  • Patent number: 6903988
    Abstract: The present invention relates to a semiconductor memory device. A voltage generator for supplying a sense amplifier I/O voltage (VSIO) and a voltage generator for supplying a bit line precharge voltage (VBLP) are independently separated. It is possible to prevent the bit line precharge voltage (VBLP) from increasing when the sense amplifier I/O voltage (VSIO) is increased due to the introduction of a column reset voltage (VCORE).
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: June 7, 2005
    Assignee: Hynix Semiconductor Inc.
    Inventor: Ihl Ho Lee
  • Patent number: 6901014
    Abstract: Circuits and methods that enable screening for defective or weak memory cells in a semiconductor memory device. In one aspect, a semiconductor memory device comprises first and second drivers for a SRAM cell. The first driver is connected between a power supply voltage and the cell, which supplies the power supply voltage into the cell in response to a cell power control signal. The second driver is connected between the power supply signal and the cell, which supplies a voltage lower than the power supply voltage into the cell in response to the cell power down signal.
    Type: Grant
    Filed: May 27, 2003
    Date of Patent: May 31, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-Jae Son, Uk-Rae Cho, Kwang-Jin Lee
  • Patent number: 6888768
    Abstract: A semiconductor integrated device which comprises a memory cell 20 holding bit information; a pair of bit lines connected to the memory cell via which the bit information is input and output in predetermined cycles; and an output section 100 that latches an output from the memory cell via one bit line of the pair and the other bit line and outputs the bit information acquired from the one bit line as a result of reading from the memory cell, and which pre-charges the pair of bit lines before access to the memory cell. The memory cell 20 has a cutoff circuit (N24) that cuts off the other bit line to hold voltage thereof produced by pre-charging when the bit information held in the memory cell is read out.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: May 3, 2005
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kenichiro Sugio
  • Patent number: 6873558
    Abstract: An integrated circuit having first connections, a first memory cell, first and second prechargers, and first and second data transmission devices. The first connections have a dual-rail signal applied thereto. The first memory cell is connected to the first connections and buffer-stores the dual-rail signal applied to the first connections. The first precharger precharges first lines, which are connected to the first connections. The first data transmission device, which forwards the dual-rail signal stored in the first memory cell to second connections, which are connected to a second memory cell which transmits the dual-rail signal to the first connections again using the second data transmission device. The second precharger precharges second lines, which are connected to the second connections.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: March 29, 2005
    Assignee: Infineon Technologies AG
    Inventors: Thomas Kunemund, Andreas Wenzel
  • Patent number: 6870785
    Abstract: A nonvolatile ferroelectric memory device having a multi-bit control function can store and sense multi-bit data in a ferroelectric memory cell. In the memory device, a plurality of cell array blocks generates a plurality of different sensing critical voltages in a reference timing strobe interval. As a result, in different time intervals, the plurality of sensing critical voltages are compared with a plurality of cell data sensing voltages applied from a main bitline. A data register array unit stores a plurality of cell data applied from the plurality of cell array blocks in response to a plurality of read lock signals activated at different timings in different time intervals, respectively. Therefore, the plurality of data bits can be stored in a cell.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: March 22, 2005
    Assignee: Hynix Semiconductor Inc.
    Inventor: Hee Bok Kang
  • Patent number: 6865705
    Abstract: A semiconductor integrated circuit device comprises a control unit for switching a mode about the trimming or estimation in an internal circuit, the control unit including a controller capable of realizing the mode switching control about the trimming or estimation by the JTAG method. The controller includes an instruction decoder for decoding an input instruction, a shift scan register circuit for enabling a boundary scan based on the decoded result of the instruction decoder, and an operation controller for controlling the operations of the instruction decoder and the shift scan register circuit. Therefore, the trimming becomes possible after sealing a semiconductor chip into a package.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: March 8, 2005
    Assignees: Hitachi, Ltd., Hitachi Ulsi Systems Co., Ltd.
    Inventors: Masahiko Tomizawa, Masahiko Nishiyama
  • Patent number: 6862205
    Abstract: The semiconductor memory device includes: a memory cell including a capacitor having a charge storage node and a first MIS transistor and a second MIS transistor each having a source connected to the charge storage node; a first word line and a first bit line respectively connected to the gate and the drain of the first MIS transistor; a second word line and a second bit line respectively connected to the gate and the drain of the second MIS transistor; and a timer circuit for generating a periodic signal having a predetermined period. The first word line or the second word line is activated in response to the periodic signal.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: March 1, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masashi Agata, Kazunari Takahashi
  • Patent number: 6862233
    Abstract: A dynamic random access memory (DRAM) includes a bit line pair, including a first bit line and a second bit line. Memory cells and a sense amplifier are coupled to the bit lines. A first characterization cell is coupled between the first bit line and a first reference supply line. The first characterization cell includes a capacitor. Similarly, a second characterization cell is coupled between the first bit line and the first reference supply line. The second characterization cell also includes a capacitor but preferably with a different capacitance. In the preferred embodiment, similar characterization cells are coupled to the second bit line.
    Type: Grant
    Filed: September 8, 2003
    Date of Patent: March 1, 2005
    Assignee: STMicroelectronics, Inc.
    Inventor: Duane Giles Laurent
  • Patent number: 6862235
    Abstract: There is disclosed a write operation of a MRAM in which a current necessary for inverting magnetization of an MTJ element has to be passed through a data line and therefore current consumption is large. The write operation comprises: comparing input data DI with read data GO read from a memory cell array and encoding the input data DI to form write data GI by a data encoder WC; and decoding the read data GO by a data decoder RD to form output data DO. In a nonvolatile semiconductor memory in which the current is passed through the data line to write data into a memory cell, the number of bits to be written during the write operation is reduced, and the current consumption can be reduced. This can realize the MRAM including a low-power highly-integrated memory.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: March 1, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Sakata, Hideyuki Matsuoka
  • Patent number: 6862236
    Abstract: A ferroelectric memory device has a function of protecting data held in memory cells from an unexpected unstable power supply voltage generated when the power is turned on or off, or when reading or writing data, and a function of reducing power consumption during reading or writing of data. The ferroelectric memory device includes a short circuit which is operated when the power is turned on or off, or after reading or writing of data occurs. The short circuit short-circuits all of a voltage supply line for a selected word line, a voltage supply line for an unselected word line, a voltage supply line for a selected bit line and a voltage supply line for an unselected bit line, or short-circuits the voltage supply line for the unselected word line and the voltage supply line for the unselected bit line.
    Type: Grant
    Filed: December 30, 2003
    Date of Patent: March 1, 2005
    Assignee: Seiko Epson Corporation
    Inventor: Akira Maruyama
  • Publication number: 20040264272
    Abstract: A circuit is provided for equalizing a signal between a pair of data lines. The circuit comprises a fist equalizing element that is operatively coupled between the pair of data lines for equalizing the signal, the first equalizing element being located proximate a first end of the pair of data lines. The circuit further comprises a precharging element that is operatively coupled between the pair of data lines for precharging the pair of data lines to a precharge voltage, the precharging element being located proximate to the first equalizing element. The circuit also comprises a second equalizing element that is operatively coupled between the pair of data lines for equalizing the signal, and located at a predetermined position along the data lines. As a result of having multiple equalizing elements located along pairs of bit lines, the precharge and equalize function is performed faster than in conventional approaches.
    Type: Application
    Filed: May 28, 2004
    Publication date: December 30, 2004
    Inventor: Paul Demone
  • Publication number: 20040264274
    Abstract: A SRAM of complete CMOS type having its memory cell composed of six MISFETs, in which a pair of local wiring lines for connecting the input/output terminals of CMOS inverters are formed of a refractory metal silicide layer formed over a first conducting layer constituting the individual gate electrodes of the drive MISFETs, the transfer MISFETs and the load MISFETs of the memory cell and in which a reference voltage line formed over the local wiring lines is arranged to be superposed over the local wiring lines to form a capacity element.
    Type: Application
    Filed: June 15, 2004
    Publication date: December 30, 2004
    Inventors: Shuji Ikeda, Toshiaki Yamanaka, Kenichi Kikushima, Shinichiro Mitani, Kazushige Sato, Akira Fukami, Masaya Iida, Akihiro Shimizu
  • Publication number: 20040264273
    Abstract: A circuit arrangement in which two parallel subcircuits having a same functionality have a same input signal applied to them, and their output signals are compared in a common comparison arrangement. The two subcircuits are designed differently in terms of sensitivity to changes in environmental or operating parameters. Impermissible environmental parameters are indicated if the output signals differ from one another, and an alarm is generated.
    Type: Application
    Filed: June 10, 2004
    Publication date: December 30, 2004
    Applicant: Infineon Technologies AG
    Inventor: Wolfgang Pockrandt
  • Publication number: 20040257894
    Abstract: Magnetoresistive devices with increased response sensitivity to external magnetic fields and an increased magnetoresistive ratio (MR ratio) to cope with rapid advances made in a high-density magnetic recording device. A patterned dielectric layer is laminated in a flat shape on a substrate capable of being doped with carriers (holes) in an electric field, and an FET structure with gate electrodes is then fabricated on that dielectric layer, and the substrate spatially modulated by applying a non-uniform electrical field to induce a first ferromagnetic domain, a nonmagnetic domain and a second ferromagnetic domain.
    Type: Application
    Filed: June 8, 2004
    Publication date: December 23, 2004
    Inventors: Toshiyuki Onogi, Masahiko Ichimura, Tomihiro Hashizume
  • Publication number: 20040252567
    Abstract: Provided is a nonvolatile memory that realizes a high-speed verify operation. During verify writing/erasing, the writing/erasing and reading are performed at the same time. As to a circuit that performs a verify operation, for instance, there is obtained a construction where the output from a sense amplifier (102) that performs reading is connected to a switch which switches an operation voltage applied to a memory cell in accordance with a verify signal Sv, and the verify operation is finished concurrently with having the verify signal Sv switched. By obtaining such circuit construction and simultaneously performing writing/erasing and reading, it becomes possible to perform high-speed verify writing/erasing.
    Type: Application
    Filed: April 12, 2004
    Publication date: December 16, 2004
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Kiyoshi Kato
  • Publication number: 20040252565
    Abstract: A light emitting device comprising a light emitting element and a first transistor and a second transistor controlling current to be supplied to the light emitting element in a pixel; the first transistor is normally-on; the second transistor is normally-off; a channel length of the first transistor is longer than a channel width thereof; a channel length of the second transistor is equal to or shorter than a channel length thereof; gate electrodes of the first transistor and the second transistor are connected to each other; the first transistor and the second transistor have the same polarity; and the light emitting element, the first transistor and the second transistor are all connected in series.
    Type: Application
    Filed: March 18, 2004
    Publication date: December 16, 2004
    Inventors: Shunpei Yamazaki, Masayuki Sakakura, Mitsuaki Osame, Takashi Hamada, Tamae Takano, Yu Yamazaki, Aya Anzai
  • Publication number: 20040252566
    Abstract: A memory card having a plurality of different interfaces is disclosed. The memory card comprises a function module, a controller coupled to the function module for accessing, a first buffer coupled to the controller for sending a first control signal, and a second buffer coupled to the controller for sending a second control signal. The memory card activates one interface for detecting a first voltage level of the first buffer when the memory card is inserted into a first card reader, and the first buffer is activated to send the first control signal if the detection is positive. Alternatively, the memory card activates the other interface for detecting a second voltage level of the second buffer when the memory card is inserted into a second card reader, and the second buffer is activated to send the second control signal if the detection is positive.
    Type: Application
    Filed: March 30, 2004
    Publication date: December 16, 2004
    Applicants: C-One Technology Corporation, Pretec Electronics Corporation
    Inventors: Jung Ta Chang, Ping-Chang Liu, Gordon Yu
  • Publication number: 20040246798
    Abstract: Maximized multi-state compaction and more tolerance in memory state behavior is achieved through a flexible, self-consistent and self-adapting mode of detection, covering a wide dynamic range. For high density multi-state encoding, this approach borders on full analog treatment, dictating analog techniques including A to D type conversion to reconstruct and process the data. In accordance with the teachings of this invention, the memory array is read with high fidelity, not to provide actual final digital data, but rather to provide raw data accurately reflecting the analog storage state, which information is sent to a memory controller for analysis and detection of the actual final digital data.
    Type: Application
    Filed: March 24, 2004
    Publication date: December 9, 2004
    Inventors: Daniel C. Guterman, Yupin Kawing Fong
  • Patent number: 6829156
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: December 7, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6829182
    Abstract: A margin test on a Dynamic Random Access Memory (DRAM) in accordance with the invention begins with a supply voltage level being stored in all memory cells of the DRAM. Circuitry incorporated into each sense amplifier of the DRAM then isolates the digit line equilibrating circuitry in each sense amplifier from the cell plate voltage DVC2 or supply voltage VCC to which the equilibrating circuitry is normally connected and connects the equilibrating circuitry to ground instead.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: December 7, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Danial S. Dean
  • Publication number: 20040240288
    Abstract: A semiconductor memory device that does not delay read/write access due to a refresh and can be interface compatible with a high-speed SRAM such as a QDR SRAM, comprises a plurality of subarrays each having a plurality of dynamic memory cells; at least one cache memory for the plurality of subarrays; a circuit to check whether data read from the subarray selected by a read address is present in the cache memory or not; and a circuit performing control so that the check result indicates that the data is present in the cache memory, the data is read from the cache memory and refreshing of the subarray is performed concurrently with a read cycle.
    Type: Application
    Filed: May 21, 2004
    Publication date: December 2, 2004
    Applicant: NEC Electronics Corporation
    Inventor: Hiroyuki Takahashi
  • Publication number: 20040240287
    Abstract: Random-access memory device (20) comprising select lines (27; 47), bit lines (21.1-21.3), and several RAM cells (22.1-22.3), each RAM cell (22.1-22.3) being connected to a corresponding one of said select lines (27; 47) and to a corresponding one of said bit lines (21.1-21.3). The random-access memory device (20) further comprises select buffers (26; 46) for selecting the read-out of one out of the select lines (27; 47) when receiving a selection signal. Each of the select buffers (26; 46) comprises an inverter (29) serving as driver. The inverter (29) is being followed by a diode (30) for limiting output voltage swings at the respective select line (27; 47).
    Type: Application
    Filed: February 6, 2004
    Publication date: December 2, 2004
    Inventor: Nikola Stojanov
  • Publication number: 20040233750
    Abstract: The present invention presents a non-volatile memory having a plurality of erase units or blocks, where each block is divided into a plurality of parts sharing the same word lines to save on the row decoder area, but which can be read or programmed independently. An exemplary embodiment is a Flash EEPROM memory with a NAND architecture that has blocks composed of a left half and a right half, where each part will accommodate one or more standard page (data transfer unit) sizes of 512 bytes of data. In the exemplary embodiment, the left and right portions of a block each have separate source lines, and separate sets of source and drain select lines. During the programming or reading of the left side, as an example, the right side can be biased to produce channel boosting to reduce data disturbs. In an alternate set of embodiments, the parts can have separate well structures.
    Type: Application
    Filed: June 14, 2004
    Publication date: November 25, 2004
    Inventors: Yan Li, Jian Chen, Raul-Adrian Cernea
  • Publication number: 20040233746
    Abstract: Disclosed herein are a magnetic memory device and method for storing and retrieving data. The magnetic memory device includes a read disk and a storage disk. The read disk comprises of an array of read heads wherein the individual read head corresponds to a storage element on the storage disk.
    Type: Application
    Filed: December 2, 2003
    Publication date: November 25, 2004
    Inventors: Santosh Kumar, Subodh Kumar, Divyanshu Verma