Patents by Inventor Takayuki Kawahara

Takayuki Kawahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060062055
    Abstract: A DRAM adopting a single-intersection memory cell array having randomly accessible data registers accessed whenever the chip is accessed externally. When data items recorded in the data registers are simultaneously written in the memory cell array, the data items are encoded. When data items are read from the memory cell array into the data registers, the data items are decoded. The margin is enhanced because array noise derived from reading is reduced. In addition, the access time of the DRAM is also reduced.
    Type: Application
    Filed: November 8, 2005
    Publication date: March 23, 2006
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Takeshi Sakata, Kazushige Ayukawa, Takayuki Kawahara
  • Patent number: 7002856
    Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.
    Type: Grant
    Filed: May 20, 2005
    Date of Patent: February 21, 2006
    Assignee: Renesas Technology Corporation
    Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
  • Publication number: 20060028853
    Abstract: According to one aspect of the present invention, there is provided a semiconductor device comprising a plurality of memory cells, and an error-correction circuit, wherein write operation is performed by a late-write method, and ECC processing is executed in parallel with writing, and thereby cycle time is shortened. Moreover, it is better that when a memory cell is power supplied through a well tap, the same address is not assigned while the memory cell is power supplied through the well tap.
    Type: Application
    Filed: October 4, 2005
    Publication date: February 9, 2006
    Inventors: Kenichi Osada, Takayuki Kawahara, Ken Yamaguchi, Yoshikazu Saito, Naoki Kitai
  • Patent number: 6990037
    Abstract: A DRAM adopting a single-intersection memory cell array having randomly accessible data registers accessed whenever the chip is accessed externally. When data items recorded in the data registers are simultaneously written in the memory cell array, the data items are encoded. When data items are read from the memory cell array into the data registers, the data items are decoded. The margin is enhanced because array noise derived from reading is reduced. In addition, the access time of the DRAM is also reduced.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: January 24, 2006
    Assignee: Renesas Technology Corporation
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Takeshi Sakata, Kazushige Ayukawa, Takayuki Kawahara
  • Publication number: 20060013032
    Abstract: A nonvolatile memory device of the present invention performs a programming operation by accumulating a charge in certain capacitance which is provided for each programming memory cell and injecting hot electrons generated when the charge is discharged via the memory cell into a floating gate. Thus, a variation in a programming characteristic of the nonvolatile semiconductor memory device is reduced, thereby realizing high-speed programming operation.
    Type: Application
    Filed: September 19, 2005
    Publication date: January 19, 2006
    Inventors: Hideaki Kurata, Naoki Kobayashi, Shunichi Saeki, Takashi Kobayashi, Takayuki Kawahara, Yoshinori Takase, Keiichi Yoshida, Michitaro Kanamitsu, Shoji Kubono, Atsushi Nozoe
  • Patent number: 6977858
    Abstract: A semiconductor device comprises, a plurality of memory cells, and an error-correction circuit, wherein write operation is performed by a late-write method, and ECC processing is executed in parallel with writing, and thereby cycle time is shortened. Moreover, it is better that when a memory cell is power supplied through a well tap, the same address is not assigned while the memory cell is power supplied through the well tap.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: December 20, 2005
    Assignees: Renesas Technology Corp., Hitachi Ulsi Systems Co., Ltd.
    Inventors: Kenichi Osada, Takayuki Kawahara, Ken Yamaguchi, Yoshikazu Saito, Naoki Kitai
  • Publication number: 20050276094
    Abstract: A SRAM memory is composed of FD-SOI transistors, and performance of the memory cell is improved by controlling an electric potential of a layer under a buried oxide film of a SOI transistor constituting a driver transistor. Performance of the SRAM circuit in the low power voltage state is improved. In the SRAM memory cell composed of the FD-SOI transistor, an electric potential of a well under a BOX layer is controlled to control a threshold voltage Vth, thereby increasing a current. Thus, the operations of the memory cell can be stabilized.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 15, 2005
    Inventors: Masanao Yamaoka, Kenichi Osada, Kiyoo Itoh, Takayuki Kawahara
  • Patent number: 6970391
    Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: November 29, 2005
    Assignee: Renesas Technology Corporation
    Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
  • Patent number: 6970019
    Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with MOS transistors. The semiconductor integrated circuit device includes a current control device. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors, that have both an operation mode and a low power back-up or sleep mode used for power reduction.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: November 29, 2005
    Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
  • Publication number: 20050237805
    Abstract: A semiconductor non-volatile storage device of the present invention which lets a memory cell directly drive up to a local bit line, wherein the output of the local bit line is received by a gate electrode of a separately-provided signal amplifying transistor, and the signal amplifying transistor is used to drive a global bit line having a large load capacity. Since an amplifying transistor having a drive power higher than a memory cell drives the parasitic capacity of a global bit line, information stored in a memory cell can be read out at high speed. Therefore, the storage device is used for storing program codes for controlling microcomputers or the like to thereby enhance a system performance.
    Type: Application
    Filed: June 21, 2005
    Publication date: October 27, 2005
    Inventors: Nozomu Matsuzaki, Hideaki Kurata, Takayuki Kawahara
  • Publication number: 20050232044
    Abstract: Due to the further scaling down, the offset of the sense amplifier is increased and the malfunction occurs in the read operation, and thus, the yield of the chip is degraded. For its prevention, a plurality of pull-down circuits and one pull-up circuit are used to constitute the sense amplifier circuit. Also, the transistor in one of the plurality of pull-down circuits has a constant such as a channel length or a channel width larger than that of the transistor in the other pull-down circuit. Further, the pull-down circuit with a larger constant of the transistor is first activated, and then, the other pull-down circuit and the pull-up circuit are activated to perform the read operation.
    Type: Application
    Filed: March 4, 2005
    Publication date: October 20, 2005
    Inventors: Satoru Akiyama, Riichiro Takemura, Takayuki Kawahara, Tomonori Sekiguchi
  • Publication number: 20050219935
    Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.
    Type: Application
    Filed: May 20, 2005
    Publication date: October 6, 2005
    Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
  • Publication number: 20050213414
    Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.
    Type: Application
    Filed: May 18, 2005
    Publication date: September 29, 2005
    Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
  • Patent number: 6950347
    Abstract: A nonvolatile memory device of the present invention performs a programming operation by accumulating a charge in certain capacitance which is provided for each programming memory cell and injecting hot electrons generated when the charge is discharged via the memory cell into a floating gate. Thus, a variation in a programming characteristic of the nonvolatile semiconductor memory device is reduced, thereby realizing high-speed programming operation.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: September 27, 2005
    Assignees: Renesas Technology Corp., Hitachi, ULSI System Co., Ltd., Hitachi Device Engineering Co.
    Inventors: Hideaki Kurata, Naoki Kobayashi, Shunichi Saeki, Takashi Kobayashi, Takayuki Kawahara, Yoshinori Takase
  • Patent number: 6944056
    Abstract: A semiconductor non-volatile storage device of the present invention which lets a memory cell directly drive up to a local bit line, wherein the output of the local bit line is received by a gate electrode of a separately-provided signal amplifying transistor, and the signal amplifying transistor is used to drive a global bit line having a large load capacity. Since an amplifying transistor having a drive power higher than a memory cell drives the parasitic capacity of a global bit line, information stored in a memory cell can be read out at high speed. Therefore, the storage device is used for storing program codes for controlling microcomputers or the like to thereby enhance a system performance.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: September 13, 2005
    Assignee: Renesas Technology Corp.
    Inventors: Nozomu Matsuzaki, Hideaki Kurata, Takayuki Kawahara
  • Publication number: 20050185445
    Abstract: A semiconductor device comprises a plurality of memory cells, a central processing unit, a timer circuit which times a RESET time, and a timer circuit which times a SET time. A threshold voltage of an NMOS transistor of each memory cell is lower than that of the peripheral circuit, thereby easily executing a RESET operation. The direction of a flowing current is changed across the RESET operation and the SET operation, and the bit lines are activated at high speed, thus preventing system malfunctions. Further, the semiconductor device can overcome such problems as a wrong write operation and data destruction, resulting from the variation in the CMOS transistors when operating phase change elements with minimum size CMOS transistors at a core voltage (e.g. 1.2 V). According to the present invention, stable operations can be realized at a low voltage, using minimum-size cell transistors.
    Type: Application
    Filed: February 15, 2005
    Publication date: August 25, 2005
    Inventors: Kenichi Osada, Riichiro Takemura, Norikatsu Takaura, Nozomu Matsuzaki, Takayuki Kawahara
  • Publication number: 20050146960
    Abstract: A DRAM adopting a single-intersection memory cell array having randomly accessible data registers accessed whenever the chip is accessed externally. When data items recorded in the data registers are simultaneously written in the memory cell array, the data items are encoded. When data items are read from the memory cell array into the data registers, the data items are decoded. The margin is enhanced because array noise derived from reading is reduced. In addition, the access time of the DRAM is also reduced.
    Type: Application
    Filed: February 3, 2005
    Publication date: July 7, 2005
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Takeshi Sakata, Kazushige Ayukawa, Takayuki Kawahara
  • Publication number: 20050104621
    Abstract: The present invention relates to an LSI in which functions can be changed, and realizes, particularly, a system LSI in which functions are changed by changing connections of the circuit by use of MEMS switches. A bistable MEMS switch which can maintain states, and exhibits optimal stitching property, i.e., the switch has a very small resistance of several ? or less in an on-state, and has an infinite resistance in an off-state; is employed. An element in which functions can be changed during operation, is produced by utilizing a wiring layer of a CMOS semiconductor to form the MEMS switch. A semiconductor device exhibiting high-degree of freedom for changing functions, high-speed, and having small area, is realized.
    Type: Application
    Filed: September 3, 2004
    Publication date: May 19, 2005
    Inventors: Takayuki Kawahara, Masayuki Miyazaki, Yasushi Goto, Natsuki Yokoyama, Takahiro Onai
  • Patent number: 6894912
    Abstract: A DRAM adopting a single-intersection memory cell array having randomly accessible data registers accessed whenever the chip is accessed externally. When data items recorded in the data registers are simultaneously written in the memory cell array, the data items are encoded. When data items are read from the memory cell array into the data registers, the data items are decoded. The margin is enhanced because array noise derived from reading is reduced. In addition, the access time of the DRAM is also reduced.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: May 17, 2005
    Assignee: Renesas Technology Corporation
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Takeshi Sakata, Kazushige Ayukawa, Takayuki Kawahara
  • Patent number: 6862220
    Abstract: A semiconductor device including a nonvolatile memory unit and a variable logic unit mounted on a chip is configured to achieve higher speed operation at a lower voltage. The semiconductor device includes a nonvolatile memory unit comprising a plurality of rewritable nonvolatile memory cells and a variable logic unit whose logical functions are determined, according to logic constitution definition data to be loaded into storage cells thereof. A nonvolatile memory cell essentially has a split gate structure composed of a selecting MOS transistor and a memory MOS transistor and constructed such that the dielectric withstand voltage of the gate of the selecting MOS transistor is lower than that of the memory MOS transistor or the gate insulation layer of the selecting MOS transistor is thinner than that of a high-voltage-tolerant MOS transistor. Because the selecting MOS transistor has a high Gm, a sufficiently great current for reading can be obtained.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: March 1, 2005
    Assignee: Renesas Technology Corporation
    Inventors: Takayuki Kawahara, Nozomu Matsuzaki, Terumi Sawase, Masaharu Kubo