Patents Assigned to Hitachi Microcomputer Eng.
  • Patent number: 4831515
    Abstract: An information processing apparatus for executing instructions in parallel includes circuitry which, when a first instruction requesting reading of an operand from a certain address of the main storage or buffer storage has been decoded, detects among instructions in execution the presence of a second instruction requesting writing of an operand held by a register such as a general-purpose register into that address of the main storage without implementing an operation on the operand. If the second instruction has been detected, the invention reads out an operand from the register specified for operand reading by said second instruction before operand writing into the main storage by the second instruction is completed.
    Type: Grant
    Filed: February 10, 1986
    Date of Patent: May 16, 1989
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng.
    Inventors: Eiki Kamada, Yooichi Shintani, Tohru Shonai, Shigeo Takeuchi
  • Patent number: 4804940
    Abstract: A resistor is provided with a plurality of turn parts whose corners have an obtuse flexional angle in order to improve the relative resistance precision. A ladder resistor can be formed with a plurality of such resistors connected in series, and various electronic devices are formed employing the ladder resistor.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: February 14, 1989
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng.
    Inventors: Akira Takigawa, Shizuo Kondo, Masumi Kasahara, Toshinori Hirashima, Mikio Haijima, Setsuo Ogura, Osamu Takada, Yoshiki Akamatsu
  • Patent number: 4803616
    Abstract: In a buffer memory, a validity flag to be added to each data portion is stored in a tag array or address section at a location corresponding to each data portion. After determining whether each validity flag is to be used as a search object, based upon the data portion to be accessed during searching the tag array and an access mode, the address and its validity flag are simultaneously searched. The logical sum of each output of the search result on a word coincidence line becomes a hit judgement signal.
    Type: Grant
    Filed: September 30, 1985
    Date of Patent: February 7, 1989
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng. Ltd.
    Inventors: Kunio Uchiyama, Tadahiko Nishimukai, Atsushi Hasegawa
  • Patent number: 4760520
    Abstract: A buffer or a plurality of buffers are provided each for holding a write address and an address specifying a write position which are obtained as a result of an execution based on a predicted result. The execution of the instruction is continued up to the operation stage regadless of whether or not the instruction is being executed in the predicted state, the data and the write address are held in the buffer written. The data in the buffer is canceled if the prediction is found to be wrong when the predicted state is completed, and the data is utilized if the prediction is found to be correct.
    Type: Grant
    Filed: October 31, 1985
    Date of Patent: July 26, 1988
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng.
    Inventors: Yooichi Shintani, Tohru Shonai, Eiki Kamada, Shigeo Takeuchi
  • Patent number: 4760561
    Abstract: An MOS static type RAM has a memory cell array comprising a plurality of static type memory cells arranged in matrix, a plurality of data lines connected to the data input-output terminals of the respective memory cells and a plurality of word lines connected to the selection terminals of the respective memory cells. Data line load circuits are disposed between the power terminal of the circuit and the data lines. Each data line load circuit is kept at a relatively high impedance in the data write-in operation, and at a relatively low impedance in the data read-out operation. The use of the data line load circuits comprised of such variable impedance circuits can speed up the operating speed of the RAM and can accomplish lower power consumption.
    Type: Grant
    Filed: June 3, 1985
    Date of Patent: July 26, 1988
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng.
    Inventors: Sho Yamamoto, Osamu Minato, Makoto Saeki, Yasuo Yoshitomi, Hideaki Nakamura, Masaaki Kubotera
  • Patent number: 4759015
    Abstract: In a network system wherein a plurality of terminal devices communicates with each other via respective node devices over a ring transmission line, a transmitting node device can confirm whether a multicast information transmission has succeeded or failed. The transmitting node device send a response frame after a multicast information frame. A receiving node device relays the multicast information frame and a response frame from the upstream node device to the downstream one when the multicast information has been received successfully, or in case of a failure in receiving the multicast information, sends a response frame to the downstream node device by changing at least part of the response frame from the upstream node device. The transmitting node device can determine from a received response frame if there is one or more of the receiving node devices which cannot receive the multicast information.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: July 19, 1988
    Assignee: Hitachi, Ltd. and Hitachi Microcomputer Eng. Ltd.
    Inventors: Atsushi Takai, Kazunori Nakamura, Yoshihiro Takiyasu, Nagatoshi Usami, Mitsuhiro Yamaga
  • Patent number: 4752819
    Abstract: Herein disclosed is a DRAM which has such a carrier trapping region around a memory cell array as can trap minority carriers deep in a semiconductor substrate so that the minority carriers to be generated in the semiconductor substrate by alpha rays may be sufficiently trapped. The memory cell of the DRAM has a capacitor which is partially formed of the semiconductor substrate. The carrier trapping region is formed by making use of trenches or a well region.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: June 21, 1988
    Assignees: Hitachi Ltd., Hitachi Microcomputer Eng.
    Inventor: Yoshihisa Koyama
  • Patent number: 4737864
    Abstract: A still picture reproducing system for a magnetic recording and reproducing apparatus is disclosed. The system sends one frame in order to shift a reproduction mode from ordinary reproduction to reproduction of a still picture by use of so-called "fine slow", sends one more frame if a noise is detected on a picture at this time, and stops if no noise is detected.
    Type: Grant
    Filed: February 20, 1986
    Date of Patent: April 12, 1988
    Assignees: Hitachi Microcomputer Eng. Co., Hitachi Video Eng., Hitachi Ltd.
    Inventors: Masataka Sekiya, Hideo Nishijima, Kaneyuki Okamoto, Isao Fukushima, Fumiaki Fujii, Katsumi Sera, Takashi Furutani
  • Patent number: 4507759
    Abstract: In a MOS static RAM, data lines disposed in a memory array and common data lines to be coupled with the data lines through a data line selection circuit are supplied with bias voltages of a level lower than a power source voltage level through bias MOSFETs. Normally, where the stand-by period of the RAM is long, the bias voltages of the data lines and the common data lines are abnormally raised by the leakage currents or tailing currents of the bias MOSFETs. As a result, the data read-out speed of the RAM is lowered. Such abnormal potential increases of the data lines and the common data lines are prevented by connecting resistance elements of comparatively high resistances (such as made of polycrystalline silicon layers), between the respective data lines and common data lines and the ground point of the circuitry.
    Type: Grant
    Filed: January 28, 1982
    Date of Patent: March 26, 1985
    Assignees: Hitachi, Ltd, Hitachi Microcomputer Eng. Ltd.
    Inventors: Tokumasa Yasui, Hideaki Nakamura, Kiyofumi Uchibori, Nobuyoshi Tanimura, Osamu Minato