Fujitsu Corporation

Pfu Limited

Toshiba Storage Device Corporation

Hirohide Sugahara

Akira Kabemoto

Takeshi Horie

Takashi Miyoshi

Jeffrey D Larson

Takatsugu Sasaki

Hajime Takahashi

Katsuhiko Takeuchi

Toshiyuki Muta

Jun Funaki

Yozo Nakayama

Takayuki Shimamura

Jun Sakurai

Sumie Matsubayashi

Junji Nishioka

Shinichi Utsunomiya

Naohiro Shibata

Satoshi Shinohara

Nobuyuki Myouga

Koji Suzuki

Ikuo Maeda

Toshiyuki Shimizu

Hiroaki Ishihata

Kazumi Hayasaka

Ryuji Fujita

Kazunari Matsumoto

Shin-ichi Utsunomiya

Nobuyuki Myoga

Shini-chi Utsunomiya

Hideki Nakagawa

A device interface circuit unit transfers a command and data in packet format between the unit and the host. A transport layer is provided with a receive FIFO, a command detection circuit and a send FIFO, and an application layer is provided with a receive task file register and a send task control file register. An available time is generated for each break point of a packet during data transfer in order to receive another command packet from the host. When the command packet is received from the host in the available time during data transfer, the data transfer is suspended and the received command is decoded to execute a process for continuing or canceling the data transfer, after which the data transfer is resumed.

Interface apparatus and packet transfer method

Information about an attribute of packets that are receivable corresponding to a command is registered. When a packet is received, information about an attribute of the packet received is acquired. Upon occurrence of a reception error that there is no information in the attribute registering unit corresponding to the information acquired by the attribute acquiring unit, a predetermined reception error handling routine is executed according to a type of the reception error.

Storage control apparatus, storage apparatus, storage control method, and computer-readable recording medium for executing a command based on data in received packet

A power saving of a serial interface circuit decreases the unnecessary power consumption of a serial interface circuit, while decreasing the return time and expanding the power saving range. Gates are disposed for stopping the clock supply to a digital portion of the interface circuit while maintaining operation of clock sources in the digital portions. Therefore a quick shift to and return from the power save mode by stopping and restarting clocks is implemented, which further decreases power consumption.

Serial type interface circuit, power saving method thereof, and device having serial interface

There is provided a data synchronization circuit for synchronizing a (n+1) (n: natural number) bit bus data synchronous with a first clock with a second clock, comprising: a first circuit for holding the bus data which is synchronous with the first clock and is input at each predetermined timing; a second circuit for generating a first timing signal which is synchronous with the first clock and is corresponding to the predetermined timing; a third circuit for generating a second timing signal which is synchronous with the second clock, from the first timing signal; and a fourth circuit for receiving the bus data output from the first circuit based on the second timing signal, to output the bus data in synchronism with the second clock.

Data synchronization circuit and communication interface circuit

One embodiment of the present invention provides a method for communicating transaction request information from a PCI environment over a network. Another embodiment of the present invention provides a method for communicating request packet information from a network to a PCI environment. Another embodiment of the present invention provides a system for communicating transaction request information from a PCI environment over a network. Another embodiment of the present invention provides a system for communicating request packet information from a network to a PCI environment.

PCI bridge over network

A system and method are provided for efficiently writing data from one bus device to another bus device across a network. Data packets to be transmitted are ordered and assigned sequence numbers and expected sequence numbers. The expected sequence number of a data packet corresponds to the sequence number of the data packet immediately prior to the current data packet. When a data packet arrives at the receiving bus, its expected sequence number is compared against the sequence numbers of the previous data packets received. If the previously-received data packet bears the sequence number corresponding to the expected sequence number of the newly arrived data packet, the newly arrived data is stored, and an acknowledgement is sent. If a match cannot be found then a retry request message is sent.

Simplified pipeline writes over a network

A method and system provide access assurance regarding an RDMA transaction. The system comprises an initiating device and a target device placed across a network. The initiating device and the target device are coupled to a first and a second buses, respectively. The first and the second buses are coupled to the network router through a first and a second network adaptors. An RDMA space and an associated access assurance space are assigned to the target device in the memory space of the first bus. The initiating device may RDMA the target device by directly reading from or writing into the RDMA space assigned to the target device. To obtain access assurance information regarding the RDMA transaction, the initiator performs a read from the assurance space associated with the RDMA space of the target device in the memory space of the first bus.

Access assurance for remote memory access over network

A method and apparatus for avoiding starvation at an initiator node in a computer network to which are connected at least one target node which provides service and a plurality of initiator nodes which request service from the target node. The method includes: when a request is received from the initiator node during a period that the target node is unable to provide service, returning a reject reply by attaching thereto reject time information that matches the period; when the target node is in a state capable of providing service, preferentially accepting a retry request carrying older reject time information; and when the target node is in the state capable of providing service, returning a reject reply by attaching thereto new reject time information in response to any first request received before retry requests arising from previously rejected requests are all accepted.

Method and apparatus for avoiding starvation in computer network

One embodiment of the present invention provides a method for processing a remote interrupt signal or a remote event. Another embodiment of the present invention provides a system for issuing a raw packet over a network in response to a remote interrupt or a remote event. Another embodiment of the present invention provides a network interface system configured to issue interrupt requests over a network.

Launch raw packet on remote interrupt

A computer network system and a method for fast delivery of an interrupt message over a computer network enables a first processor coupled to the computer network to very quickly send an interrupt message to a second processor coupled to the computer network, by directly writing the interrupt message to a doorbell address range associated with the second processor in the PCI memory space of a first PCI bus to which the first processor is coupled. The doorbell address range is mapped to a doorbell space in the PCI memory space of a second PCI bus to which the second processor is coupled. The first PCI bus is coupled to the computer network through a first PCI network adaptor, which processes the write transaction and send it to the network. The second PCI bus is coupled to the computer network through a second PCI network adaptor, which receives the write transaction from the network and transforms the write transaction into an interrupt message to the second processor.

Fast delivery of interrupt message over network

A PCI (peripheral component interconnect) network adaptor manages read/write requests through the establishment of dynamic queues. The PCI network adaptor establishes a unique queue for each destination node that enables the requests for each node to be processed separately. The PCI network adaptor determines whether a remote read/write request should be added to the linked list for the destination node of the request or whether the request should be rejected. If the number of pending requests for the destination node is below a predetermined threshold and the entire buffer is not full, then the request is added to the linked list for the destination node. Otherwise, the request is rejected. For write requests, if the request is added to the linked list for the destination node, then any pending read requests for that node are aborted.

Dynamic queuing for read/write requests

A multiprocessor in which a plurality of processors are connected via a system bus. The multiprocessor includes processor groups each having at least one processor, a main storage memory, a cache memory, a cache control unit, a directory memory, and a directory control unit. The directory control unit includes an invalidation command issuing unit that issues a cache line invalidation command to all reference designations stored in the directory memory in cache lines. Thus the device process time can be shortened by reducing the frequency that cache invalidation commands are issued from the cache memory.

Multiprocessor, memory accessing method for multiprocessor, transmitter

A plurality of processors, each with caches provided for a plurality of processor modules and a local storage in which a main storage is distributed and arranged are mutually connected through an internal snoop bus. The processor modules are mutually connected through a second system bus. By using two separate buses, cache coherence operations within a processor group is kept separate from cache coherence operations outside the processor group.

Coherence apparatus for cache of multiprocessor

An asynchronous access system for a computer system includes processing modules performing processes, at least one shared system memory module, and a system bus connecting the processing modules and the shared system memory module. Each of the processing modules includes a processor, a plurality of buffers coupled to the processor and to the system bus, and a controlling unit for writing data from the plurality of processors into the shared system memory module. Data is written into the shared system memory module by a processor generating write instructions to write data via the plurality of buffers and the system bus. The controlling unit controls the writing such that one writing instruction writes data into a plurality of buffers, then transfers the data to the shared system memory module via the system bus, with another writing instruction writing additional data into another plurality of buffers and transferring the additional data to the shared system memory module.

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Kawasaki, Japan

Hirohide Sugahara