Abstract: In a data read-and-write controlling device, without waiting for confirmation that data is written in a RAM, data is written in a WER and an ADR, and at the same time, address information of the data is written in the RAM write-information table. That is, the data read-and-write controlling device associates an address retained at a data register of a write controlling unit with the value (a write request is present=“1”) of a write request that makes a request for writing data in the RAM, the value being retained in a write request register, and then causes the result to be stored in the RAM write-information table as the address information.

Abstract: A transmission system includes a first device; and a second device that is connected to the first device through a plurality of transmission paths, wherein the first device includes a plurality of request storage units that are provided for the transmission paths and each store a request to be transmitted to the second device, a request determining unit that determines whether a request to be transmitted to the second device is of a type that causes a redundant request, a request resource determining unit that counts the number of the requests stored in each of the plurality of request storage units and determines the number of request storage units, a request storing unit that causes a plurality of requests, generated by copying the request to be transmitted, and a plurality of request transmitters that transmit the requests stored in the plurality of storage units.

Abstract: A transmission path selecting apparatus includes a receiving unit that receives a data transmission request and information that identifies the data transmission request, a holding unit that holds the information in association with a transmission path that was previously assigned to the information, a searching unit that searches the holding unit based on the information received with the data transmission request by the receiving unit, when the receiving unit receives the data transmission request, a transmission path selecting unit that selects a transmission path to be assigned to the data transmission request, from among a plurality of transmission paths other than a transmission path obtained as a result of the search by the searching unit, and an updating unit that updates a content held by the holding unit based on a result of the selection by the transmission path selecting unit.

Abstract: In a data read-and-write controlling device, without waiting for confirmation that data is written in a RAM, data is written in a WER and an ADR, and at the same time, address information of the data is written in the RAM write-information table. That is, the data read-and-write controlling device associates an address retained at a data register of a write controlling unit with the value (a write request is present=“1”) of a write request that makes a request for writing data in the RAM, the value being retained in a write request register, and then causes the result to be stored in the RAM write-information table as the address information.