Abstract: In the present invention, a first communication device, on the basis of a portion of a first command inputted from an external device, predicts an address and instruction contents for the first command, and outputs the same as a second command. The first communication device outputs first flag information indicating whether a second communication device needs to wait to send the second command, and sends the second command and the first flag information to the second communication device. The second communication device receives the second command and the first flag information, and, if the first flag information indicates that the second communication device does not need to wait to send the second command, sends the second command to a second external device.

Abstract: A data transfer method for a network system wherein a plurality of computers are connected to each other through a switched network is improved in terms of the TLB hit ratio. Each of the computers includes a main storage device, a processor for issuing a communication process command and a communication device for processing the communication command from the processor and communicating with another one of the computers through a switched network. The communication device includes a transmission section and a reception section each of which includes a TLB for retaining a plurality of TLB entries. When a communication command including information of that one of the computers which is a sending source is issued from the processor, the reception section determines that one of the TLB entries which is to be used in accordance with the computer of the sending source.

Abstract: When a first computer instructs transfer of data from the first computer to a second computer, a transmitting device in the first computer instructs the second computer to perform pre-read of a translation look-aside buffer, which contains a transfer-destination virtual address, in concurrence with read-out of initial data or of initial data for which the transfer-destination address has exceeded a page boundary, thereby causing virtual-address translation information to be pre-registered in a translation look-aside buffer from an address translation table of the second computer.

Abstract: A data transfer method for a network system wherein a plurality of computers are connected to each other through a switched network is improved in terms of the TLB hit ratio. Each of the computers includes a main storage device, a processor for issuing a communication process command and a communication device for processing the communication command from the processor and communicating with another one of the computers through a switched network. The communication device includes a transmission section and a reception section each of which includes a TLB for retaining a plurality of TLB entries. When a communication command including information of that one of the computers which is a sending source is issued from the processor, the reception section determines that one of the TLB entries which is to be used in accordance with the computer of the sending source.

Abstract: When a first computer instructs transfer of data from the first computer to a second computer, a transmitting device in the first computer instructs the second computer to perform pre-read of a translation look-aside buffer, which contains a transfer-destination virtual address, in concurrence with read-out of initial data or of initial data for which the transfer-destination address has exceeded a page boundary, thereby causing virtual-address translation information to be pre-registered in a translation look-aside buffer from an address translation table of the second computer.

Abstract: In a computer system, a device is inserted to and disconnected from a synchronous bus without stopping the entire system. A timing generator generates timing to issue a bus termination/start command. A bus control table manage correspondence between the requests and the replies. For logical termination, the timing generator waits until the bus control table becomes empty. A bus arbitor has an arbitration pointer which stores the highest priority. A bus operation controller clears the arbitration pointer when the insertion or disconnection occurs.