Abstract: A data transfer apparatus includes a reception unit that receives and stores data from a first apparatus therein, and a transmission unit that stores data transferred from the reception unit and transmits the data to a second apparatus. The transmission unit includes an information holding unit that holds data information relating to the data transferred thereto for each transfer path, a common holding unit commonly used by the plurality of transfer paths, and a first controller that performs, based on an inputting situation of the data information for each transfer path, control for inputting the data information to the information holding unit after passing the common holding unit. The reception unit includes a suppression unit that suppresses new data transfer to the transmission unit in response to an information amount of the information held in the common holding unit.

Abstract: A bus connecting ports of a crossbar switch in a ring form is provided, and the configuration information of registers in ports is transferred between ports via the bus and updated, and thus a wiring length of the bus connecting the registers is reduced.

Abstract: A port A request queue is configured with a port AQ0 to a port AQn for each of request types Q0 to Qn connected with a requester resource busy flag controller Q0 to a requester resource busy flag controller Qn, respectively. A port A resource checking unit of a port X arbiter unit gives instructions to the requester resource busy flag controller of the port AQ0 to turn a busy flag on when it is determined that a data request from the port AQ0 has difficulty in being output to a port X inter-port arbiter unit due to resources being busy as a result of referring to a resource information unit of a port X resource managing unit. The port AQ0 inhibits output of a data request as long as the busy flag is on.

Abstract: A port A request queue is configured with a port AQ0 to a port AQn for each of request types Q0 to Qn connected with a requester resource busy flag controller Q0 to a requester resource busy flag controller Qn, respectively. A port A resource checking unit of a port X arbiter unit gives instructions to the requester resource busy flag controller of the port AQ0 to turn a busy flag on when it is determined that a data request from the port AQ0 has difficulty in being output to a port X inter-port arbiter unit due to resources being busy as a result of referring to a resource information unit of a port X resource managing unit. The port AQ0 inhibits output of a data request as long as the busy flag is on.