Patents by Inventor Akio Makimoto

Akio Makimoto 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).

  • Patent number: 6977941
    Abstract: A packet switch having a structure of writing a variable length packet received from each of input lines into a shared buffer memory on a fixed length data block unit basis, wherein a buffer controller forms an input queue for each input line and, when the last data block of a variable length packet is registered in the input queue, links a linked address list for the input queue to one or a plurality of output queues corresponding to one or a plurality of packet destination output lines.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: December 20, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Masami Takahashi, Akio Makimoto, Takahiko Kozaki, Takayuki Kanno, Yasuo Oginuma, Kaori Nakayama, Mitsuhiro Wada, Norihiko Moriwaki, Masumi Fukano, Yusho Futami
  • Patent number: 6463066
    Abstract: Provided is a high-throughput large-capacity ATM switch in which variation in memory access time and data output delay time generated in the case where a DRAM is used as a cell buffer of the ATM switch is absorbed. To realize this, the ATM switch comprises a first memory using a DRAM for storing cells, a second memory using an SRAM for switching and temporarily storing the cells before transferring the cells to the first memory, and a controller for generating write/read address and timing signals for the first and second memories. The controller generates read address and timing signals for the second memory and write address and timing signals for the first memory taking variation in access time or delay time based on access address of the first memory into account, so that the cells are output on destination output lines after the cells are switched and stored in the second memory and then stored in the first memory.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: October 8, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Norihiko Moriwaki, Kenichi Sakamoto, Akihiko Takase, Akio Makimoto, Kazumasa Yanagisawa
  • Publication number: 20020054602
    Abstract: A packet switch having a structure of writing a variable length packet received from each of input lines into a shared buffer memory on a fixed length data block unit basis, wherein a buffer controller forms an input queue for each input line and, when the last data block of a variable length packet is registered in the input queue, links a linked address list for the input queue to one or a plurality of output queues corresponding to one or a plurality of packet destination output lines.
    Type: Application
    Filed: February 26, 2001
    Publication date: May 9, 2002
    Inventors: Masami Takahashi, Akio Makimoto, Takahiko Kozaki, Takayuki Kanno, Yasuo Oginuma, Kaori Nakayama, Mitsuhiro Wada, Norihiko Moriwaki, Masumi Fukano, Yusho Futami
  • Publication number: 20010009551
    Abstract: Provided is a high-throughput large-capacity ATM switch in which variation in memory access time and data output delay time generated in the case where a DRAM is used as a cell buffer of the ATM switch is absorbed. To realize this, the ATM switch comprises a first memory using a DRAM for storing cells, a second memory using an SRAM for switching and temporarily storing the cells before transferring the cells to the first memory, and a controller for generating write/read address and timing signals for the first and second memories. The controller generates read address and timing signals for the second memory and write address and timing signals for the first memory taking variation in access time or delay time based on access address of the first memory into account, so that the cells are output on destination output lines after the cells are switched and stored in the second memory and then stored in the first memory.
    Type: Application
    Filed: March 5, 2001
    Publication date: July 26, 2001
    Inventors: Norihiko Moriwaki, Kenichi Sakamoto, Akihiko Takase, Akio Makimoto, Kazumasa Yanagisawa
  • Patent number: 6249524
    Abstract: Provided is a high-throughput large-capacity ATM switch in which variation in memory access time and data output delay time generated in the case where a DRAM is used as a cell buffer of the ATM switch is absorbed. To realize this, the ATM switch comprises a first memory using a DRAM for storing cells, a second memory using an SRAM for switching and temporarily storing the cells before transferring the cells to the first memory, and a controller for generating write/read address and timing signals for the first and second memories. The controller generates read address and timing signals for the second memory and write address and timing signals for the first memory taking variation in access time or delay time based on access address of the first memory into account, so that the cells are output on destination output lines after the cells are switched and stored in the second memory and then stored in the first memory.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: June 19, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Norihiko Moriwaki, Kenichi Sakamoto, Akihiko Takase, Akio Makimoto, Kazumasa Yanagisawa
  • Patent number: 6185212
    Abstract: An ATM cell processing apparatus including a DRAM for a frame producing buffer of a frame producing unit. In order to absorb the anisotropy of the access rate of the DRAM access, the random access mode of the DRAM access is always used. To compensate a drop in access rate in this case, the DRAM is arranged is an array form and each cell is divided. Resultant partial cell data are written into and read from respective DRAM banks in order. As a result, a fast cell buffer having a large capacity can be formed. The present cell buffer can be applied to a FIFO and the like as well.
    Type: Grant
    Filed: April 8, 1998
    Date of Patent: February 6, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Sakamoto, Akio Makimoto, Akihiko Takase, Norihiko Moriwaki, Atsushi Kiuchi