Patents by Inventor Hisashi Iwamoto
Hisashi Iwamoto 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).
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Patent number: 5815462Abstract: A first clock signal for controlling the inputting of an external signal and for controlling internal operation and a second clock signal for controlling data output are applied to separate clock input nodes, respectively. Data output timing with respect to the first clock signal can be adjusted and thus clock access time and data hold time can be adjusted. Internal data read path is pipelined to include a first transfer gate responsive to the first clock signal for transferring internal read data and a second transfer gate responsive to the second clock signal for transferring the internal read data from the first transfer gate for external outputting through an output buffer. A synchronous semiconductor memory device is provided capable of setting clock access time and data hold time at the optimal values depending on the application and of reducing the clock access time.Type: GrantFiled: February 12, 1997Date of Patent: September 29, 1998Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Yasuhiro Konishi, Hisashi Iwamoto, Takashi Araki, Yasumitsu Murai, Seiji Sawada
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Patent number: 5805603Abstract: A synchronous semiconductor memory device is provided with a delay circuit between an input latch circuit and a pad. The synchronous semiconductor memory device can operate at a higher speed since respective external input signals supplied to a plurality of pads are delayed such that the time required for transmission from respective pads to the input latch circuit is equal, and that skew is eliminated.Type: GrantFiled: January 7, 1997Date of Patent: September 8, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takashi Araki, Yasuhiro Konishi, Hisashi Iwamoto
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Patent number: 5796669Abstract: Switches (11, 12) select either of refresh address counters (6a, 6b) in accordance with a refresh bank set signal (.phi.REFADD) when a bank refresh signal (.phi.BANKREF) is activated. An internal bank address (int.BA) serves as the refresh bank set signal (.phi.REFADD) to control the switch (12) and the refresh address counter (6a or 6b) designated by the internal bank address (int.BA) performs a count operation in synchronization with a refresh clock (.phi.REFCLK). The switch (11) outputs either of refresh addresses (Ref.Add.sub.-- A<0:10>, Ref.Add.sub.-- B<0:10>) which is updated. With this configuration provided is an SDRAM which allows access to data during a refresh operation.Type: GrantFiled: July 25, 1997Date of Patent: August 18, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takashi Araki, Hisashi Iwamoto, Yasuhiro Konishi
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Patent number: 5764590Abstract: A synchronous DRAM includes a selector which supplies 2 bits of serial data signals from one data input/output terminal to two input/output line pairs as parallel data signals in x8 configuration mode, and supplies 2 bits of parallel data signals from both data input/output terminals directly to two input/output line pairs in x16 configuration mode. Therefore, the synchronous DRAM allows switching of bit configuration, and it takes 2-bits prefetch configuration in x8 configuration mode, and signal pipeline configuration in x16 configuration mode.Type: GrantFiled: October 22, 1996Date of Patent: June 9, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hisashi Iwamoto, Yasuhiro Konishi
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Patent number: 5731727Abstract: A control transistor is connected in parallel with an input transistor of a bias generation circuit in a voltage control delay circuit. A power supply potential Vcc is divided by voltage divider resistors to be applied to the gate of the control transistor. Reduction in the power supply potential Vcc causes reduction in a current Ib flowing to the control transistor, and a current Ic=Ia+Ib flowing to a delay time variable element. When the power supply potential Vcc is reduced, the factor of a delay time period of delay time variable elements becoming shorter due to a smaller amplitude of a clock signal is canceled with the factor of the delay time period of the delay time variable elements become longer due to a smaller current Ic flowing thereto. Therefore, variation in the delay time period can be suppressed to a low level.Type: GrantFiled: September 14, 1995Date of Patent: March 24, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hisashi Iwamoto, Yasuhiro Konishi
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Patent number: 5708611Abstract: A refresh control circuit of a DLL circuit responds to an auto refresh detection signal AR and a self refresh detection signal SR to inhibit input of clock signals ECLK and RCLK to a phase comparator and to a voltage control delay circuit. The DLL circuit can be stopped in a mode where an internal clock signal is not required to reduce power consumption.Type: GrantFiled: February 18, 1997Date of Patent: January 13, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hisashi Iwamoto, Yasuhiro Konishi
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Patent number: 5652723Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: April 15, 1992Date of Patent: July 29, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5650968Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: May 21, 1996Date of Patent: July 22, 1997Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5629895Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: April 30, 1996Date of Patent: May 13, 1997Assignees: Mitsubishi Electric Engineering Co., Ltd., Mitsubishi Denki Kabushiki KaishaInventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5629897Abstract: A refresh control circuit of a DLL circuit responds to an auto refresh detection signal AR and a self refresh detection signal SR to inhibit input of clock signals ECLK and RCLK to a phase comparator and to a voltage control delay circuit. The DLL circuit can be stopped in a mode where an internal clock signal is not required to reduce power consumption.Type: GrantFiled: September 8, 1995Date of Patent: May 13, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hisashi Iwamoto, Yasuhiro Konishi
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Patent number: 5623454Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: February 9, 1996Date of Patent: April 22, 1997Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5603009Abstract: A semiconductor memory device containing a cache includes a static random access memory (SRAM) as a cache memory, and a dynamic random access memory (DRAM) as a main memory. Collective transfer of data blocks is possible between the DRAM and the SRAM through a bi-directional data transfer gate circuit and through an internal data line. A DRAM row decoder and a DRAM column decoder are provided in the DRAM. A SRAM row decoder and an SRAM column decoder are provided in the SRAM. Addresses of the SRAM and DRAM can be independently applied. The data transfer gate includes a latch circuit for latching data from the SRAM, which serves as a high speed memory, an amplifier circuit and a gate circuit for amplifying data from the DRAM, which serves as a large capacity memory, and for transmitting the amplified data to the SRAM, and a gate circuit, responsive to a DRAM write enable signal for transmitting write data to corresponding memory cells of the DRAM.Type: GrantFiled: December 14, 1994Date of Patent: February 11, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Konishi, Katsumi Dosaka, Kouji Hayano, Masaki Kumanoya, Akira Yamazaki, Hisashi Iwamoto
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Patent number: 5594704Abstract: Memory arrays are divided into banks which can be operated independent from each other. Read data storing registers and write data storing registers operating independent from each other are provided for the banks. The memory array is divided into a plurality of small array blocks, local IO lines are arranged corresponding to each array block, and the local IO lines are connected to global IO lines. The global IO lines are connected to preamplifier groups and to write buffer groups. By control signal generating circuits and by a register control circuit, inhibition of writing of a desired bit only during successive writing operation can be done, data can be collectively written to the selected memory cells when the final data is input if the data writing should be stopped before reaching the wrap length in successive writing, and the timing for activating the memory array when the write cycle should be repeatedly carried out can be delayed.Type: GrantFiled: April 10, 1995Date of Patent: January 14, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Konishi, Takayuki Miyamoto, Takeshi Kajimoto, Hisashi Iwamoto
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Patent number: 5592434Abstract: To one memory array, global signal input/output line pairs in two systems, a switch for connecting the global IO line pairs to a write buffer group alternately on a clock cycle basis, and another switch for connecting the global IO line pairs to an equalize circuit alternately on a clock cycle basis are provided. During one clock cycle, writing of data through one global IO line pair and equalization of the other global IO line pair can be carried out in parallel. Therefore, data can be written easily at a high frequency.Type: GrantFiled: October 25, 1995Date of Patent: January 7, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hisashi Iwamoto, Yasuhiro Konishi, Katsumi Dosaka, Yasumitsu Murai
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Patent number: 5583813Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: June 5, 1995Date of Patent: December 10, 1996Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5559750Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: June 5, 1995Date of Patent: September 24, 1996Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5544121Abstract: A semiconductor memory device includes a DRAM, an SRAM and a bi-direction transfer gate circuit provided between SRAM and DRAM. SRAM array includes a plurality of sets of word lines. Each set is provided in each row of SRAM array and each word line in each set is connected to a different group of memory cells of an associated row. An address signal for the SRAM and an address signal for the DRAM are separately applied to an address buffer. The semiconductor memory device further includes an additional function control circuit for realizing a burst mode and a sleep mode. A data transfer path from DRAM to the SRAM and a data transfer path from the SRAM to the DRAM are separately provided in the bi-directional transfer gate circuit. Data writing paths and data reading paths are separately provided in the DRAM array. By the above described structure, operation of the buffer circuit is stopped in the sleep mode, reducing power consumption.Type: GrantFiled: June 5, 1995Date of Patent: August 6, 1996Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Katsumi Dosaka, Masaki Kumanoya, Kouji Hayano, Akira Yamazaki, Hisashi Iwamoto, Hideaki Abe, Yasuhiro Konishi, Katsumitsu Himukashi, Yasuhiro Ishizuka, Tsukasa Saiki
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Patent number: 5530379Abstract: First and second transistors are connected via a first switch. Second and third transistors are connected in parallel via a second switch. Either an input signal or an output ground voltage is applied to the gate of a third transistor via a third switch. In a LVTTL version, the first switch is on and the second switch is off. By the third switch, the output ground voltage is applied to the gate of the third transistor. As a result, first and second, transistors are arranged in series between the output power supply voltage and the output ground voltage, resulting in an output buffer circuit corresponding to a LVTTL. In a GTL version, the first switch is off and the second switch is on. An input signal is applied to the gate of the third transistor by the third switch. As a result, second and third transistors are arranged in parallel to form an open drain. This can be used as an output buffer circuit corresponding to a GTL.Type: GrantFiled: April 21, 1995Date of Patent: June 25, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Konishi, Takashi Araki, Hisashi Iwamoto
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Patent number: 5521463Abstract: Image rotation of a cathode ray tube caused by the influence of earth magnetism can be suppressed. An image rotation correcting coil for generating a magnetic field of the direction opposite to that of a horizontal earth magnetism component of the direction vertical to the picture tube is disposed between a deflection yoke formed at the outside of a tube envelope of a cathode ray tube and an anode button.Type: GrantFiled: August 4, 1995Date of Patent: May 28, 1996Assignee: Sony CorporationInventors: Junichi Ogawa, Satoru Nakanishi, Hisashi Iwamoto, Kenji Ebe
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Patent number: 5517462Abstract: In a synchronous semiconductor memory device, memory arrays (MA) forming activation units each are divided into a plurality of small memory arrays (MK). There are provided local I/O line pairs (LIO) each for two small memory arrays. The global I/O line pairs (GIO) crossing word lines are arranged in word line shunt regions (WS). The connection switches (BS) are arranged in the crossing between the local I/O line pairs and global I/O line pairs. Each small memory array in the activated memory array is connected to the corresponding global I/O line pair through the local I/O line pair. Thereby, a plurality of bits can be simultaneously read without increasing an area occupied by interconnections. The control of connection switch is made using a sense amplifier activation signal. Global I/O lines are precharged/equalized after data are transferred to read data registers provided for data output terminal for sequential data output or into selected memory cells.Type: GrantFiled: January 31, 1995Date of Patent: May 14, 1996Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Hisashi Iwamoto, Yasumitsu Murai, Yasuhiro Konishi, Naoya Watanabe, Seiji Sawada