Patent ID: 8285902

Claim:
A data transfer apparatus performing data communication by transmitting a bus use request to an arbiter provided in a plurality of nodes coupled in a tree shape through a bus, the data transfer apparatus comprising: a request generation circuit which generates a highest priority request indicating that a priority level for using the bus is the highest; a determination circuit which, when a plurality of highest priority requests including a highest priority request issued at a node and a highest priority request issued at another node conflict, determines the priority level from among a first priority level, a second priority level and a third priority level, the first priority level indicating that the highest priority request issued at the node takes priority, the second priority level indicating that the highest priority request issued at the another node takes priority, the third priority level indicating that the issue of the highest priority request at the node is stopped; and a priority level setting circuit which determines the highest priority request which takes priority based on a result of the determination circuit.