Patents by Inventor Takashi Kurafuji
Takashi Kurafuji 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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Publication number: 20240126472Abstract: A semiconductor device includes a logic circuit, a memory, and a storage device. The storage device has a first special information storage region into which special information is written before a solder reflow process, a second special information storage region into which special information for updating is written after the solder reflow process, and a data storage region. The first special information storage region is constituted by a memory cell having a high reflow resistance and in which data is retained even after the solder reflow process. The second special information storage region and the data storage region are constituted by memory cells having a low reflow resistance and in which data may not be retained during the solder reflow process.Type: ApplicationFiled: December 27, 2023Publication date: April 18, 2024Inventors: Ken MATSUBARA, Takashi ITO, Takashi KURAFUJI, Yasuhiko TAITO, Tomoya SAITO, Akihiko KANDA
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Publication number: 20220382483Abstract: A semiconductor device includes a logic circuit, a memory, and a storage device. The storage device has a first special information storage region into which special information is written before a solder reflow process, a second special information storage region into which special information for updating is written after the solder reflow process, and a data storage region. The first special information storage region is constituted by a memory cell having a high reflow resistance and in which data is retained even after the solder reflow process. The second special information storage region and the data storage region are constituted by memory cells having a low reflow resistance and in which data may not be retained during the solder reflow process.Type: ApplicationFiled: May 17, 2022Publication date: December 1, 2022Inventors: Ken MATSUBARA, Takashi ITO, Takashi KURAFUJI, Yasuhiko TAITO, Tomoya SAITO, Akihiko KANDA
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Patent number: 11137937Abstract: A master issues the valid data is specified when the data update processing is interrupted. The control unit 3 stores in the storage unit 2 the second update status flag 8_2, which indicates the update status of the first update status flag 8_1 and the second data 6_2, which indicate the update status of the first data 6_1, and the third update status flag 8_3, which indicates the update status of the valid indication flag 7. When the determination based on the valid instruction flag 7 is impossible, the usage data determination unit 4 determines which of the first data 6_1 and the second data 6_2 is valid based on the values of the first update status flag 8_1, the second update status flag 8_2, and the third update status flag 8_3.Type: GrantFiled: June 24, 2019Date of Patent: October 5, 2021Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Takashi Kurafuji, Satoshi Yamamoto
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Patent number: 10719615Abstract: To provide an information processing apparatus, a reading control method, and a computer readable storage medium that can improve the secrecy of information written in a secret area compared with the case of controlling access only by authentication, the information processing apparatus includes a nonvolatile memory that has a secret area where secret information is stored, an authentication controller that authenticates access to the nonvolatile memory, a flag information storage unit that stores flag information, and a memory controller that controls access to the nonvolatile memory by using the flag information stored in the flag information storage unit. The memory controller allows reading of the secret information from the secret area when a value of the flag information is a specified value and validity of access is authenticated by the authentication controller.Type: GrantFiled: May 1, 2017Date of Patent: July 21, 2020Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Yoshihiko Asai, Takashi Kurafuji, Yoko Kimura
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Patent number: 10599589Abstract: According to one embodiment, a memory controller is configured so that when the memory controller controls a writing/erasing process for a flash memory performed by a first or second master, the memory controller can prohibit, while the first master is performing the writing/erasing process for the flash memory, an interruption of the writing/erasing process in execution, the interruption resulting from access to the flash memory by the second master.Type: GrantFiled: May 3, 2018Date of Patent: March 24, 2020Assignee: RENESAS ELECTRONICS CORPORATIONInventor: Takashi Kurafuji
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Publication number: 20200019341Abstract: A master issues the valid data is specified when the data update processing is interrupted. The control unit 3 stores in the storage unit 2 the second update status flag 8_2, which indicates the update status of the first update status flag 8_1 and the second data 6_2, which indicate the update status of the first data 6_1, and the third update status flag 8_3, which indicates the update status of the valid indication flag 7. When the determination based on the valid instruction flag 7 is impossible, the usage data determination unit 4 determines which of the first data 6_1 and the second data 6_2 is valid based on the values of the first update status flag 8_1, the second update status flag 8_2, and the third update status flag 8_3.Type: ApplicationFiled: June 24, 2019Publication date: January 16, 2020Inventors: Takashi KURAFUJI, Satoshi YAMAMOTO
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Patent number: 10366758Abstract: A storage device includes a data memory unit and a status memory unit. The data memory unit includes a pair of flash memory cells to be read by a complementary read mode, and 1-bit data is stored therein by the pair of flash memory cells. The status memory unit includes a flash memory cell to be read by a reference read mode, and a status flag is stored therein by the flash memory cell.Type: GrantFiled: February 20, 2018Date of Patent: July 30, 2019Assignee: RENESAS ELECTRONICS CORPORATIONInventors: Takashi Kurafuji, Tomoya Ogawa, Yasuhiko Taito
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Publication number: 20180373651Abstract: According to one embodiment, a memory controller is configured so that when the memory controller controls a writing/erasing process for a flash memory performed by a first or second master, the memory controller can prohibit, while the first master is performing the writing/erasing process for the flash memory, an interruption of the writing/erasing process in execution, the interruption resulting from access to the flash memory by the second master.Type: ApplicationFiled: May 3, 2018Publication date: December 27, 2018Inventor: Takashi KURAFUJI
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Patent number: 10127989Abstract: An object of the present disclosure is to provide a semiconductor having high security. A semiconductor device includes: a memory region having a plurality of memory cells capable of storing data; a read circuit capable of switching a reference current reading method of reading data by comparing current flowing a memory cell to be read in the memory region with a reference current, and a complementary reading method of reading data by comparing currents flowing in first and second memory cells in which complementary data to be read in the memory region is stored; a register setting a security state; a mode controller setting a mode; and a control circuit controlling the reference current reading method and the complementary reading method of reading the data in the read circuit on the basis of a signal of setting a mode from the mode controller and a value of the register.Type: GrantFiled: April 18, 2018Date of Patent: November 13, 2018Assignee: Renesas Electronics CorporationInventor: Takashi Kurafuji
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Publication number: 20180277214Abstract: A storage device includes a data memory unit and a status memory unit. The data memory unit includes a pair of flash memory cells to be read by a complementary read mode, and 1-bit data is stored therein by the pair of flash memory cells. The status memory unit includes a flash memory cell to be read by a reference read mode, and a status flag is stored therein by the flash memory cell.Type: ApplicationFiled: February 20, 2018Publication date: September 27, 2018Inventors: Takashi KURAFUJI, Tomoya OGAWA, Yasuhiko TAITO
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Publication number: 20180240524Abstract: An object of the present disclosure is to provide a semiconductor having high security. A semiconductor device includes: a memory region having a plurality of memory cells capable of storing data; a read circuit capable of switching a reference current reading method of reading data by comparing current flowing a memory cell to be read in the memory region with a reference current, and a complementary reading method of reading data by comparing currents flowing in first and second memory cells in which complementary data to be read in the memory region is stored; a register setting a security state; a mode controller setting a mode; and a control circuit controlling the reference current reading method and the complementary reading method of reading the data in the read circuit on the basis of a signal of setting a mode from the mode controller and a value of the register.Type: ApplicationFiled: April 18, 2018Publication date: August 23, 2018Inventor: Takashi KURAFUJI
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Patent number: 9978455Abstract: An object of the present disclosure is to provide a semiconductor having high security. A semiconductor device includes: a memory region having a plurality of memory cells capable of storing data; a read circuit capable of switching a reference current reading method of reading data by comparing current flowing a memory cell to be read in the memory region with a reference current, and a complementary reading method of reading data by comparing currents flowing in first and second memory cells in which complementary data to be read in the memory region is stored; a register setting a security state; a mode controller setting a mode; and a control circuit controlling the reference current reading method and the complementary reading method of reading the data in the read circuit on the basis of a signal of setting a mode from the mode controller and a value of the register.Type: GrantFiled: March 22, 2017Date of Patent: May 22, 2018Assignee: RENESAS ELECTRONICS CORPORATIONInventor: Takashi Kurafuji
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Publication number: 20170357821Abstract: To provide an information processing apparatus, a reading control method, and a computer readable storage medium that can improve the secrecy of information written in a secret area compared with the case of controlling access only by authentication, the information processing apparatus includes a nonvolatile memory (2) that has a secret area (6) where secret information is stored, an authentication controller (4) that authenticates access to the nonvolatile memory (2), a flag information storage unit (3) that stores flag information, and a memory controller (5) that controls access to the nonvolatile memory (2) by using the flag information stored in the flag information storage unit (3). The memory controller (5) allows reading of the secret information from the secret area (6) when a value of the flag information is a specified value and validity of access is authenticated by the authentication controller (4).Type: ApplicationFiled: May 1, 2017Publication date: December 14, 2017Applicant: Renesas Electronics CorporationInventors: Yoshihiko ASAI, Takashi KURAFUJI, Yoko KIMURA
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Publication number: 20170278575Abstract: An object of the present disclosure is to provide a semiconductor having high security. A semiconductor device includes: a memory region having a plurality of memory cells capable of storing data; a read circuit capable of switching a reference current reading method of reading data by comparing current flowing a memory cell to be read in the memory region with a reference current, and a complementary reading method of reading data by comparing currents flowing in first and second memory cells in which complementary data to be read in the memory region is stored; a register setting a security state; a mode controller setting a mode; and a control circuit controlling the reference current reading method and the complementary reading method of reading the data in the read circuit on the basis of a signal of setting a mode from the mode controller and a value of the register.Type: ApplicationFiled: March 22, 2017Publication date: September 28, 2017Inventor: Takashi KURAFUJI
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Publication number: 20160210070Abstract: An information processing apparatus according to the present invention includes: at least one flash memory including a data storage region that stores data and an erase count storage region that stores erase count data indicating the number of times that the data is erased in the data storage region; and a control circuit that is connected between a processor and the at least one flash memory. The control circuit allows changes of data stored in the data storage region by the processor and suppresses changes of the erase count data stored in the erase count storage region by the processor.Type: ApplicationFiled: January 7, 2016Publication date: July 21, 2016Inventors: Takashi KURAFUJI, Akira AWATANI
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Patent number: 8144518Abstract: The semiconductor device includes a nonvolatile memory, having a memory array containing 1-bit twin cells, each composed of electrically rewritable first and second storage devices, the first and second storage devices holding binary data according to difference of their threshold voltages, and having different retention characteristics depending on difference of the binary data thereof; a read circuit for differentially amplifying complementary data output from the first and second storage devices of the twin cell selected for read, and judging information stored in the twin cell; and a control circuit. Two memory cells constituting a twin cell are arranged to hold different data. Therefore, even when the retention performance of one memory cell deteriorates, the difference between data held by the two memory cells can be maintained. Hence, differential amplification of such difference enables acquisition of proper stored information.Type: GrantFiled: May 3, 2011Date of Patent: March 27, 2012Assignee: Renesas Electronics CorporationInventors: Masamichi Fujito, Makoto Mizuno, Takahiro Yokoyama, Kenji Kawada, Takashi Iwase, Yasunobu Aoki, Takashi Kurafuji, Tomohiro Uchiyama, Shuichi Sato, Yuji Uji
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Publication number: 20110208904Abstract: The semiconductor device includes a nonvolatile memory, having a memory array containing 1-bit twin cells, each composed of electrically rewritable first and second storage devices, the first and second storage devices holding binary data according to difference of their threshold voltages, and having different retention characteristics depending on difference of the binary data thereof; a read circuit for differentially amplifying complementary data output from the first and second storage devices of the twin cell selected for read, and judging information stored in the twin cell; and a control circuit. Two memory cells constituting a twin cell are arranged to hold different data. Therefore, even when the retention performance of one memory cell deteriorates, the difference between data held by the two memory cells can be maintained. Hence, differential amplification of such difference enables acquisition of proper stored information.Type: ApplicationFiled: May 3, 2011Publication date: August 25, 2011Applicant: RENESAS ELECTRONICS CORPORATIONInventors: Masamichi Fujito, Makoto Mizuno, Takahiro Yokoyama, Kenji Kawada, Takashi Iwase, Yasunobu Aoki, Takashi Kurafuji, Tomohiro Uchiyama, Shuichi Sato, Yuji Uji
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Patent number: 7957195Abstract: The semiconductor device includes a nonvolatile memory, having a memory array containing 1-bit twin cells, each composed of electrically rewritable first and second storage devices, the first and second storage devices holding binary data according to difference of their threshold voltages, and having different retention characteristics depending on difference of the binary data thereof; a read circuit for differentially amplifying complementary data output from the first and second storage devices of the twin cell selected for read, and judging information stored in the twin cell; and a control circuit. Two memory cells constituting a twin cell are arranged to hold different data. Therefore, even when the retention performance of one memory cell deteriorates, the difference between data held by the two memory cells can be maintained. Hence, differential amplification of such difference enables acquisition of proper stored information.Type: GrantFiled: December 3, 2009Date of Patent: June 7, 2011Assignee: Renesas Electronics CorporationInventors: Masamichi Fujito, Makoto Mizuno, Takahiro Yokoyama, Kenji Kawada, Takashi Iwase, Yasunobu Aoki, Takashi Kurafuji, Tomohiro Uchiyama, Shuichi Sato, Yuji Uji
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Publication number: 20100080058Abstract: The semiconductor device includes a nonvolatile memory, having a memory array containing 1-bit twin cells, each composed of electrically rewritable first and second storage devices, the first and second storage devices holding binary data according to difference of their threshold voltages, and having different retention characteristics depending on difference of the binary data thereof; a read circuit for differentially amplifying complementary data output from the first and second storage devices of the twin cell selected for read, and judging information stored in the twin cell; and a control circuit. Two memory cells constituting a twin cell are arranged to hold different data. Therefore, even when the retention performance of one memory cell deteriorates, the difference between data held by the two memory cells can be maintained. Hence, differential amplification of such difference enables acquisition of proper stored information.Type: ApplicationFiled: December 3, 2009Publication date: April 1, 2010Applicant: RENESAS TECHNOLOGY CORP.Inventors: Masamichi Fujito, Makoto Mizuno, Takahiro Yokoyama, Kenji Kawada, Takashi Iwase, Yasunobu Aoki, Takashi Kurafuji, Tomohiro Uchiyama, Shuichi Sato, Yuji Uji
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Patent number: 7646642Abstract: The semiconductor device includes a nonvolatile memory, having a memory array containing 1-bit twin cells, each composed of electrically rewritable first and second storage devices, the first and second storage devices holding binary data according to difference of their threshold voltages, and having different retention characteristics depending on difference of the binary data thereof; a read circuit for differentially amplifying complementary data output from the first and second storage devices of the twin cell selected for read, and judging information stored in the twin cell; and a control circuit. Two memory cells constituting a twin cell are arranged to hold different data. Therefore, even when the retention performance of one memory cell deteriorates, the difference between data held by the two memory cells can be maintained. Hence, differential amplification of such difference enables acquisition of proper stored information.Type: GrantFiled: October 9, 2007Date of Patent: January 12, 2010Assignee: Renesas Technology Corp.Inventors: Masamichi Fujito, Makoto Mizuno, Takahiro Yokoyama, Kenji Kawada, Takashi Iwase, Yasunobu Aoki, Takashi Kurafuji, Tomohiro Uchiyama, Shuichi Sato, Yuji Uji