Patents by Inventor Shigemasa Shiota

Shigemasa Shiota 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: 20040158778
    Abstract: The invention is directed to largely improve reliability by surely protecting data on the basis of an emergency stop request even during a data transfer process. The invention provides a data memory system taking the form of a memory card or the like. When an emergency stop signal requesting an emergency stop is received from an information processor of a host during a read/write data transfer process, a control circuit immediately stops the transfer process and notifies the information processor of end of the read data transfer. At this time, the end of read data transfer is notified irrespective of whether the transfer is finished normally or abnormally. Even when a read data transfer request is received again from the information processor after notifying the information processor of the end of read data transfer, without transferring data, a controller notifies the information processor of an untransferable state of read data.
    Type: Application
    Filed: January 9, 2004
    Publication date: August 12, 2004
    Applicant: Renesas Technology Corp.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara
  • Publication number: 20040156251
    Abstract: A memory system permitting a number of alternative memory blocks to be made ready in order to extend the rewritable life and thereby contributing to enhanced reliability of information storage is to be provided. The memory system is provided with a nonvolatile memory having a plurality of data blocks in predetermined physical address units and a controller for controlling the nonvolatile memory in response to an access request from outside. Each of the data blocks has areas for holding a rewrite count and error check information regarding each data area. The controller, in a read operation on the nonvolatile memory, checks for any error in the area subject to the read according to error check information and, when there is any error, if the rewrite count is greater than a predetermined value, will replace the pertinent data block with another data block or if it is not greater, correct data in the data block pertaining to the error.
    Type: Application
    Filed: January 14, 2004
    Publication date: August 12, 2004
    Applicant: Renesas Technology Corp.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara, Kinji Mitani
  • Patent number: 6744692
    Abstract: The present invention provides a memory system which contributes to improvement in efficiency of a data process accompanying a memory access. A memory system has a rewritable nonvolatile memory, a buffer memory, and a controller. The controller controls, in response to an access request from an external apparatus, first data transfer between the controller and the external apparatus, second data transfer between the controller and the nonvolatile memory, and third data transfer between the controller and the buffer memory, controls transfer from the controller to the buffer memory in the third data transfer and transfer from the buffer memory to the controller in a time sharing manner, and enables the first data transfer or the second data transfer to be performed in parallel with the transfer carried out in the time sharing manner.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: June 1, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara, Yasuhiro Nakamura
  • Patent number: 6728138
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: April 27, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito
  • Patent number: 6725322
    Abstract: Blocks and clusters are brought to correspondence thereby to erase blocks of memory area efficiently. A flash memory has its physical addresses partitioned from address 0h sequentially into blocks each having eight sectors. The data area of logical address starts at address 4Dh, which is set to the starting physical address 50h of the block which is close to the top of data area, and the data area is set sequentially to the following physical addresses. The remaining logical addresses 3D7Dh-3D7Fh are brought back to the top of physical address and set to physical addresses 0h-2h. Consequently, clusters (a cluster has 4 k bytes or 2 k bytes) of data sent from a host unit correspond to blocks of physical addresses, enabling block erasure of the flash memory, whereby the number of times of erasing operation at data writing can be reduced significantly.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: April 20, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Atsushi Shiraishi, Manabu Inoue, Shigemasa Shiota, Yosuke Yukawa, Yuichiro Onuki, Takeshi Suzuki, Kenzo Matsumura
  • Patent number: 6701471
    Abstract: High-speed memory access and transparent error detection and correction using a single error correcting means are obtained and processed by an external storage device of a host computer when sector data having an arbitrary byte width are accessed continuously according to a size of a sector unit. Consequently, the host computer always reads sector data, and at the same time, error detection and the error correction for a next sector data are simultaneously performed, thereby greatly reducing the time required for error detection and error correction, and high speed memory access can be obtained.
    Type: Grant
    Filed: January 2, 2001
    Date of Patent: March 2, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Tamura, Shigemasa Shiota, Kunihiro Katayama, Masashi Naito
  • Patent number: 6694460
    Abstract: The memory device has an electrically rewritable nonvolatile memory used as a storage medium. To promote even deterioration throughout the memory, the erasing time and writing time are measured, the influence of scatter of cells in the memory are eliminated on the basis of the resultant measurement values and a degree of deterioration is determined with a high accuracy, whereby a memory device of a high reliability and high efficiency is realized. In order to rewrite the nonvolatile memory, therefore, the memory measures erasing time and writing time, compares erasing time with stored reference time, compares the writing time from the comparison results, and determines the degree of deterioration from the correction results. Accordingly, control is possible such that, successively, the more heavily deteriorated part of the memory is used less frequently while the less deteriorated part is used more frequently.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: February 17, 2004
    Assignee: Renesas Technology Corporation
    Inventors: Kunihiro Katayama, Takayuki Tamura, Masashi Naito, Shigemasa Shiota
  • Publication number: 20040022249
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Application
    Filed: July 30, 2003
    Publication date: February 5, 2004
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito
  • Publication number: 20030202383
    Abstract: The present invention provides a memory system which contributes to improvement in efficiency of a data process accompanying a memory access. A memory system has a rewritable nonvolatile memory, a buffer memory, and a controller. The controller controls, in response to an access request from an external apparatus, first data transfer between the controller and the external apparatus, second data transfer between the controller and the nonvolatile memory, and third data transfer between the controller and the buffer memory, controls transfer from the controller to the buffer memory in the third data transfer and transfer from the buffer memory to the controller in a time sharing manner, and enables the first data transfer or the second data transfer to be performed in parallel with the transfer carried out in the time sharing manner.
    Type: Application
    Filed: April 2, 2003
    Publication date: October 30, 2003
    Applicants: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara, Yasuhiro Nakamura
  • Publication number: 20030149851
    Abstract: To prevent stored information from being changed even at the occurrence of an abnormal condition in an upstream side of a system due to uncontrollable run of an OS. A nonvolatile storage means having data storage areas and management areas for them in units of predetermined physical addresses has an access protect definition table TLB in a predetermined physical address, and the table has access attribute information defining whether to permit or not access to the data storage areas in association with the physical addresses. The memory system itself possesses access attribute information defining whether to permit or not a write to and a read from the data storage areas in association with addresses to implement an access protect function for write and read. Therefore, the access protect function is maintained even if an abnormal condition occurs in a host device that manages the memory system or controls it as a peripheral circuit.
    Type: Application
    Filed: January 7, 2003
    Publication date: August 7, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara, Yasuhiro Nakamura
  • Publication number: 20030147297
    Abstract: The present invention provides a memory system which contributes to improvement in efficiency of a data process accompanying a memory access. A memory system has a rewritable nonvolatile memory, a buffer memory, and a controller. The controller controls, in response to an access request from an external apparatus, first data transfer between the controller and the external apparatus, second data transfer between the controller and the nonvolatile memory, and third data transfer between the controller and the buffer memory, controls transfer from the controller to the buffer memory in the third data transfer and transfer from the buffer memory to the controller in a time sharing manner, and enables the first data transfer or the second data transfer to be performed in parallel with the transfer carried out in the time sharing manner.
    Type: Application
    Filed: January 14, 2003
    Publication date: August 7, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Shigemasa Shiota, Hiroyuki Goto, Hirofumi Shibuya, Fumio Hara, Yasuhiro Nakamura
  • Publication number: 20030128585
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Application
    Filed: February 27, 2003
    Publication date: July 10, 2003
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito
  • Patent number: 6542405
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: April 1, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito
  • Patent number: 6535422
    Abstract: The present invention provides a nonvolatile memory system whose storage capacity can be easily changed. The nonvolatile memory system comprises plural memory modules, a controller for controlling the operation of the plural memory modules according to access requests from the outside, and a module selecting decoder for selectively enabling the memory modules by decoding a selection signal outputted from the controller, wherein the memory modules are freely mounted or dismounted. With this arrangement, the storage capacity can be changed by increasing or decreasing the memory modules.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: March 18, 2003
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Hiroyuki Goto, Shigemasa Shiota, Takayuki Tamura, Hirofumi Shibuya, Yasuhiro Nakamura
  • Publication number: 20030033567
    Abstract: A memory card includes a non-volatile memory, a memory controller for controlling the operation of the memory card. The memory controller is capable of providing an interface with outside according to a predetermined protocol, and performs error detection and correction of the memory information at regular time intervals or at the timing of connection of electric power supply, independently of reading out the memory information according to external access request. Therefore, it is possible to improve reliability of data retention in the non-volatile memory without the host device reading out the memory information from the non-volatile memory of the memory card.
    Type: Application
    Filed: February 26, 2002
    Publication date: February 13, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takayuki Tamura, Hirofumi Shibuya, Hiroyuki Goto, Shigemasa Shiota, Yasuhiro Nakamura
  • Publication number: 20030033573
    Abstract: A memory card has a plurality of non-volatile memories and a main controller for controlling the operation of the non-volatile memories. The main controller performs an access control to the non-volatile memories in response to an external access instruction, and an alternate control for alternating an access error-related storage area of the non-volatile memory with other storage area. In the access control, the speeding up of the data transfer between flash memories is achieved by causing the plurality of non-volatile memories to parallel access operate. In the alternation control, the storage areas is made alternative for each non-volatile memory in which an access error occurs.
    Type: Application
    Filed: February 27, 2002
    Publication date: February 13, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takayuki Tamura, Hirofumi Shibuya, Hiroyuki Goto, Shigemasa Shiota
  • Publication number: 20020178338
    Abstract: This invention realizes separate control for each memory area. A memory unit is structured by including a semiconductor memory device capable of memorizing information, the aforementioned memory device is divided into plural memory areas logically and also management table, which is capable of controlling separately each aforementioned memory area for accessing from the outside, is tabled, control information, which prohibits accessing the prescribed memory area of the aforementioned plural memory areas, is provided in the aforementioned management information, and it is prohibited to access the specified memory area from the outside in accordance with control information.
    Type: Application
    Filed: February 25, 2002
    Publication date: November 28, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Hirofumi Shibuya, Takayuki Tamura, Hiroyuki Goto, Shigemasa Shiota, Yasuhiro Nakamura
  • Publication number: 20020097604
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Application
    Filed: March 26, 2002
    Publication date: July 25, 2002
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito
  • Publication number: 20020085418
    Abstract: The present invention provides a nonvolatile memory system whose storage capacity can be easily changed. The nonvolatile memory system comprises plural memory modules, a controller for controlling the operation of the plural memory modules according to access requests from the outside, and a module selecting decoder for selectively enabling the memory modules by decoding a selection signal outputted from the controller, wherein the memory modules are freely mounted or dismounted. With this arrangement, the storage capacity can be changed by increasing or decreasing the memory modules.
    Type: Application
    Filed: December 21, 2001
    Publication date: July 4, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Hiroyuki Goto, Shigemasa Shiota, Takayuki Tamura, Hirofumi Shibuya, Yasuhiro Nakamura
  • Patent number: 6388920
    Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: May 14, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiro Katayama, Takayuki Tamura, Satoshi Watatani, Kiyoshi Inoue, Shigemasa Shiota, Masashi Naito