Patents Examined by Thong Le
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Patent number: 6678191Abstract: Disclosed is a nonvolatile semiconductor memory device having a memory cell array by which random access can be performed. The memory cell array structure of the nonvolatile semiconductor memory device having a main memory cell array formed of a plurality of NAND cell strings includes a sub memory cell array having a plurality of NAND cell strings that is provided therein with memory cell transistors. The number of the memory cell transistors in the sub memory cell array is less than that of the memory cell transistors in the NAND cell strings of the main memory cell arrays. The sub memory cell array is operationally connected to main bit lines of the main memory cell array during program and erase operations and is electrically disconnected with the main bit lines during read operation, thereby having a separate read path that is independent from the read path of the main memory cell array.Type: GrantFiled: June 6, 2002Date of Patent: January 13, 2004Assignee: Samsung Electronics Co., Ltd.Inventors: Seung-Jae Lee, Young-Ho Lim
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Patent number: 6667915Abstract: Redundancy decoders corresponding to a plurality of redundancy circuits, each of which is for relieving a defective memory cell, are classified into a high-priority redundancy decoder used with a higher priority and the other low-priority decoders. When a defective address stored inside is designated as an accessing object, each of the low-priority decoders activates a corresponding redundancy circuit, except for the case where a defective address stored in the high-priority redundancy decoder agrees with an address signal.Type: GrantFiled: August 22, 2002Date of Patent: December 23, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Toshiaki Yonezu, Yoshinori Fujiwara
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Patent number: 6668364Abstract: Methods and apparatuses for designing a plurality of integrated circuits (ICs) from a language representation of hardware. In one example of a method, a technology independent RTL (register transfer level) netlist is partitioned between representations of a plurality of ICs. In a typical example of the method, a hardware description language (HDL) code is written and compiled without regard to splitting the design among multiple ICs. After compilation, a partition of the technology independent RTL netlist, obtained from the compilation, is performed among the multiple ICs. After a partition, the technology independent RTh netlist is mapped to a particular target technology (e.g. a particular IC vendor's architecture for implementing logic circuitry), and place and route tools may be used to create the design in multiple ICs (e.g. field programmable gate arrays). Other examples of methods and apparatuses are described.Type: GrantFiled: June 3, 2002Date of Patent: December 23, 2003Assignee: Synplicity, Inc.Inventors: Kenneth S. McElvain, Robert Erickson
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Patent number: 6667922Abstract: A method of transferring data to a memory storage cell that is attached to a first bitline. The method includes passing a charge representative of data from a memory storage cell to a first bitline that is connected to the memory storage cell and detecting that the charge is on the first bitline. Upon detecting the charge is on the first bitline, preventing a portion of a second bitline that is complementary to the first bitline from being driven to a full voltage state.Type: GrantFiled: August 21, 2002Date of Patent: December 23, 2003Assignee: Infineon Technologies AGInventors: Stephen Michael Camacho, Paul Edward Brucke
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Patent number: 6665225Abstract: In a semiconductor integrated circuit having a DRAM, a DWL driver circuit has a bias function unit (42, 43) for supplying, as a potential of a word line, a sub decode signal of an H level in an active state and an L level signal of a ground potential in a standby state, and switching the potential of the word line to a low potential for self refresh which is higher than the ground potential only by a very small value (+&agr;volts) in a self refresh mode. Thus, a refresh cycle is extended to thereby reduce a self refresh current.Type: GrantFiled: June 3, 2002Date of Patent: December 16, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Mitsunori Tsujino
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Patent number: 6665224Abstract: A semiconductor dynamic random access memory (DRAM) 300 with a programmable memory refresh counter 345 is presented. The counter 345 permits the specification of portions of the DRAM 300 to be refreshed, saving power and time over DRAMs that refresh the entire memory. The counter 345 may be programmed with a wordline address at the beginning of a block of memory and subsequent refresh operations automatically increment or decrement the value in the counter. Additionally, blocks of the memory not being refreshed can be accessed (written or read), improving the utilization of the memory device.Type: GrantFiled: May 22, 2002Date of Patent: December 16, 2003Assignee: Infineon Technologies AGInventors: Gunther Lehmann, Manfred Menke
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Patent number: 6665216Abstract: A system for reading data in a memory cell includes three comparators, each of which has two inputs. A first reference cell having a low reference voltage is coupled to one input of the first comparator. A second reference cell having a high reference voltage is coupled to one input of the second comparator. A memory cell having a memory cell voltage is coupled to the other input of the first and second comparators. One input of the third comparator is coupled to the first comparator's output signal, which includes a difference voltage between the memory cell voltage and the low reference voltage. The other input of the third comparator is coupled to the second comparator's output signal, which includes a difference voltage between the memory cell voltage and the high reference voltage. A method and apparatus for reading data in a memory cell also are described.Type: GrantFiled: July 23, 2002Date of Patent: December 16, 2003Assignee: Macronix International Co., Ltd.Inventors: Hsin-Yi Ho, Nai-Ping Kuo, Chun-Hsiung Hung, Gin-Laing Chen, Wen-Chiao Ho, Ho-Chun Liou
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Patent number: 6661710Abstract: A flash memory device is provided, which may perform a read operation by itself without receipt of any command and/or address. The flash memory device may be used as a boot-up memory in a system. Additionally, it may be operable to also carry out normal write/read operations that may require command, address and control data from sources external the flash memory. During a system power-up, as the supply voltage increases, the flash memory device detects whether it is to be used as a boot-up memory in a system. The flash memory may then enter suitable operation modes in accordance with the detected results.Type: GrantFiled: May 21, 2002Date of Patent: December 9, 2003Assignee: Samsung Electronics Co., Ltd.Inventor: Suk-Chun Kwon
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Patent number: 6661716Abstract: According to one embodiment, the write circuitry of a content addressable memory (CAM) can include periphery circuits (102) that generate data signals (112) and write control signals (118) that connect over some distance to CAM core circuits (104). CAM core circuits (104) may include bitline write driver circuits (106), a write control circuit (108), and CAM cells (110). Write control signals (118) may include a signal surrounded by its complements and be positioned such that a routing of the write control signal is as long as the longest of the data signals (112).Type: GrantFiled: February 21, 2002Date of Patent: December 9, 2003Assignee: Cypress Semiconductor CorporationInventor: Stefan P. Sywyk
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Patent number: 6661711Abstract: Methods and apparatus for tightening an erased bit threshold voltage distribution are disclosed. According to one aspect of the present invention, a method for processing erased bits associated with an erased bit distribution which includes an over-erased bit which has a first value that is less than a first threshold voltage value and a bit that has a second value that substantially exceeds a second threshold voltage value includes inhibiting the fast bit. The method also includes applying a soft program pulse to the erased bits such that inhibiting the fast bit substantially prevents the second value from changing and applying the soft program pulse to the over-erased bit substantially causes the first value to increase. In one embodiment, applying the soft program pulse to the over-erased bit substantially causes the first value to increase to a value that is greater than or equal to the first threshold voltage value.Type: GrantFiled: February 6, 2002Date of Patent: December 9, 2003Assignee: Sandisk CorporationInventors: Feng Pan, Tat-Kwan Edgar Yu
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Patent number: 6657914Abstract: A first semiconductor chip is provided. The first semiconductor chip is operable to be incorporated along with at least a second semiconductor chip of the same type into an integrated circuit device within in a single package. The integrated circuit device has a common address path for the first and second semiconductor chips. The first semiconductor chip includes a configurable addressing circuit operable to be configured so that the first semiconductor chip responds to a predetermined range of addresses in the common address path of the integrated circuit device, to decode an address conveyed in the common address path of the integrated circuit device, and to generate a selection signal if the address conveyed in the common address path falls within the predetermined range of addresses.Type: GrantFiled: July 19, 2001Date of Patent: December 2, 2003Assignee: Inapac Technology, Inc.Inventors: Adrian E. Ong, Fan Ho
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Patent number: 6657902Abstract: A semiconductor memory device includes: at least one memory cell block including multiple dynamic memory cells arrayed in a matrix; a row address decoder and a column address decoder that select a memory cell in the memory cell block, which is specified by an address including a row address and a column address; an output buffer that causes data to be output from the selected memory cell specified by the address; a preset circuit that presets an output level of the output buffer; and a preset control module that controls an operation of the preset circuit. At every time of outputting data from the memory cell selected by the column address decoder, the output level of the output buffer is preset, prior to output of the data from the selected memory cell by means of the output buffer. This arrangement effectively prevents the potential noise in a power source of the semiconductor memory device.Type: GrantFiled: April 11, 2002Date of Patent: December 2, 2003Assignee: Seiko Epson CorporationInventor: Koichi Mizugaki
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Patent number: 6657878Abstract: Content addressable memory (CAM) devices provide improved reliability by inhibiting disabled CAM cells within defective (or unused redundant columns) from contributing to either sustained or intermittent look-up errors when the CAM device is operated in an intended application. The improved reliability may be achieved in volatile CAM devices by configuring (e.g., programming) each column driver that is associated with a CAM array having a defective column therein to preserve intentionally written data and/or mask values of the disabled CAM cells across repeated power reset events.Type: GrantFiled: February 27, 2002Date of Patent: December 2, 2003Assignee: Integrated Device Technology, Inc.Inventors: Chuen-Der Lien, Chau-Chin Wu
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Patent number: 6657907Abstract: A column repair circuit of a semiconductor memory is disclosed, in which a column repair efficiency is increased in a row flexible redundancy structure. A repair circuit for a memory divided into arrays and arranged by row lines and column lines crossing each other, the circuit includes a plurality of column fuse boxes for outputting a redundant column enable signal for repairing a defective line, and an array address inverter corresponding to one of the column fuse boxes for inverting a self-pair signal input thereto and a corresponding array address input thereto, the self-pair signal indicating whether a row repair is performed in a corresponding array or in another array, and for selectively outputting the inverted array address according to the self-pair signal.Type: GrantFiled: May 15, 2002Date of Patent: December 2, 2003Assignee: Hynix Semiconductor Inc.Inventor: Hyung Dong Lee
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Patent number: 6654297Abstract: An apparatus and method of operating an open digit line and a folded digit line DRAM memory array having a plurality of memory cells wherein, in a plan view, each memory cell, in one embodiment, has an area of 6F2. One method comprises, storing a first bit in a first memory cell and storing a second bit that is complementary to the first bit in a second memory cell. The first bit and the second bit form a data bit. The data bit is read by comparing a voltage difference between the first memory cell and the second memory cell.Type: GrantFiled: October 24, 2002Date of Patent: November 25, 2003Assignee: Micron Technology, Inc.Inventor: David L. Pinney
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Patent number: 6650592Abstract: A system, method, and computer program product are disclosed for automatically performing timing checks on a memory cell. A static timing tool is provided that includes multiple, different standard timing elements. Each standard timing element is associated with one or more standard timing checks. The memory cell is represented using one or more of the standard timing elements. Standard timing checks associated with the timing elements used to represent the memory cell are used to verify timing in the memory cell.Type: GrantFiled: November 29, 2001Date of Patent: November 18, 2003Assignee: International Business Machines CorporationInventors: Matthew J. Amatangelo, Christopher M. Durham, Peter Juergen Klim
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Patent number: 6650590Abstract: One (first level shift circuit) of first and second level shift circuits is provided in a local word-drive-line driving circuit located near memory cell arrays. The second level shift circuit is provided in a global word-drive-line driving circuit located remote from the memory cell arrays.Type: GrantFiled: March 22, 2002Date of Patent: November 18, 2003Assignees: Kabushiki Kaisha Toshiba, Fujitsu LimitedInventors: Tsuneo Inaba, Fumihiro Kohno, Kenji Tsuchida, Toshimi Ikeda
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Patent number: 6650566Abstract: The invention provides a method of programming in a nonvolatile semiconductor memory device, having a plurality of memory cell strings connected to a plurality of bitlines and constructed of a plurality of memory cell transistors whose gates are coupled to a plurality of wordlines, and a plurality of registers corresponding to the bitlines. The method involves applying a first voltage to a first one of the bitlines and applying a second voltage to a second one of the bitline, the first bitline being adjacent to the second bitline, the first and second voltages being supplied from the registers; electrically isolating the first and second bitlines from their corresponding registers; charging the first bitline up to a third voltage higher than the first voltage and lower than the second voltage; and applying a fourth voltage to a wordline after cutting off current paths into the first and second bitlines.Type: GrantFiled: December 12, 2001Date of Patent: November 18, 2003Assignee: Samsung Electronics Co., Ltd.Inventors: Jae-Yong Jeong, Sung-Soo Lee
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Patent number: 6650594Abstract: A semiconductor integrated circuit and a memory device capable of selecting power-down exit speed and power-save modes and method thereof are provided. The memory device includes a command decoder for generating a power-down signal in response to a power-down command, a mode register (MRS) for storing power-down exit information, a clock synchronization circuit such as a DLL or PLL circuit for generating an internal clock signal synchronized with an external clock signal, and a controller for controlling the DLL or PLL circuit. At power-down exit of the memory device, the power-down exit information can be selected between a fast wakeup time and a slow wakeup time.Type: GrantFiled: October 28, 2002Date of Patent: November 18, 2003Assignee: Samsung Electronics Co., Ltd.Inventors: Jung-Bae Lee, Dong-Yang Lee
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Patent number: 6646935Abstract: A memory device is provided for reducing the test time and the complexity of the test pattern. The memory device is composed of a memory cell array including a plurality of memory cells, an I/O buffer, a command providing unit, an address providing unit, and an address decoder. The command providing unit is responsive to a test mode signal for providing a command that controls an access to the memory cell array. The address providing unit provides an address in response to the command. The address decoder allows the memory cell array to be accessed in response to the address. The command providing unit sets the command to be a predetermined internal command when the test mode signal is activated. The command providing unit, when the test mode signal is not activated, receives an external command through the I/O buffer and sets the command to be the external command.Type: GrantFiled: January 17, 2002Date of Patent: November 11, 2003Assignee: NEC Electronics CorporationInventor: Toshiaki Akioka