Patents Assigned to Hitachi Computer Eng. Co.
  • Patent number: 5355461
    Abstract: A data processing system capable of accessing multiple virtual address spaces wherein a an access register translation is performed when obtaining an origin address (STO) of a translation table to be used for address translation of a logical address into a real address. If an access register designated by an instruction has a value equal to a predetermined value, another STO stored in a control register is used instead of the STO obtained by the access register translation. Registers are provided for storing results of detection as to whether or not each of the access registers has a value equal to the predetermined value and a sector is provided selecting either the STO in the control register or the STO obtained by the access register translation based on the stored results of detection, thus eliminating a process to discriminate the values of the access registers at each access to the virtual address spaces.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: October 11, 1994
    Assignees: Hitachi, Ltd., Hitachi Computer Eng. Co., Ltd.
    Inventors: Fujio Wakui, Masahiko Tagami
  • Patent number: 5351040
    Abstract: In a ring LAN system having a configuration control unit serially connected to a dual ring transmission line, the configuration control unit is provided with a transmission line reconfiguration control mechanism to disconnect a fault point upon detection of a transmission fault, such as a breaking of one of a twisted pair of cables, and after recovery of the fault, reconnect the disconnected point to restore the transmission line to its original state. The reconfiguration control mechanism suspends reconfiguration control if a reconfiguration operation counter counts more than a predetermined number of reconfiguration operations within a predetermined time period measured by a reconfiguration operation monitor timer, such as when a temporary fault occurs intermittently.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: September 27, 1994
    Assignees: Hitachi, Ltd., Hitachi Software Eng. Co. Ltd., Hitachitelecom Tech. Ltd., Hitachi Computer Eng. Co., Ltd.
    Inventors: Fumiaki Matsuura, Kazuhiro Ushijima, Hisashi Matsumura, Masahide Kouhei, Tsutomu Koita
  • Patent number: 4783783
    Abstract: A data processing system includes a multistage pipeline arithmetic/logic operation unit for implementing an arithmetic or logic operation for sets of element data sequentially and storing operational results sequentially in a memory using a single instruction. Check information indicative of the presence or absence of a fault occurring in each stage of the pipeline operation unit is moved in synchronism with the advancement of stages of the pipeline operation unit. A request control unit for storing the operational result in the memory suppresses the storing of the operational result in the memory if check information indicates a fault of the operational result which is being stored in the memory. The request control unit issues storage requests, which are counted by a counter. The counter indicates the number of elements stored normally in the memory.
    Type: Grant
    Filed: July 24, 1986
    Date of Patent: November 8, 1988
    Assignees: Hitachi, Ltd., Hitachi Computer Eng. Co.
    Inventors: Seiji Nagai, Takaaki Nishiyama, Hiromichi Kainoh, Fujio Wakui
  • Patent number: 4780811
    Abstract: A vector processing apparatus includes a scalar processor for executing scalar instructions and a vector processor for executing vector instructions. The vector processing apparatus has status code registers (SCR) which can be referred to by both processors through a wait managing circuit. The scalar instructions each have an order assurance instruction to assure an order of execution, and the order assurance instruction and the vector instruction each have a field to designate an SCR. The wait managing circuit renders the execution of the instruction in the scalar processor or the vector processor to wait or enable in accordance with a set status or a reset status of the SCR designated by the instruction field, and sets or resets the SCR designated by the instruction field in response to the completion of execution of the instruction to control synchronization of the execution of instructions in both processors.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: October 25, 1988
    Assignees: Hitachi, Ltd., Hitachi Computer Eng. Co.
    Inventors: Tomoo Aoyama, Hiroshi Murayama