主权项 |
1. A data transfer circuit being connected to transmitting circuits and receiving circuits and carrying out data transfer between the transmitting circuits and the receiving circuits, the data transfer circuit comprising:
a first arbitration unit that receives a plurality of data requests input from a port connected to one of the transmitting circuits, and selects a single data request by arbitration from the plurality of data requests; a second arbitration unit that receives the single data request selected by the first arbitration unit and other data request input from other port, and selects a data request for the data transfer by arbitration from the single data request and the other data request; a receive resource usage monitoring unit that monitors usage of receive resources of a receiving circuit receiving data corresponding to the data request for the data transfer selected by the second arbitration unit; a controller that outputs the single data request selected by the first arbitration unit to the second arbitration unit, when the usage of the receive resources monitored by the receive usage monitoring unit is not in a busy state; a data transfer unit that carries out the data transfer according to the data request selected by the second arbitration unit; a busy state resolution waiting information storage unit that stores therein busy state resolution waiting information of usage of the receive resources for each of the transmitting circuits and for each type of the data requests, and a busy state resolution waiting controller that, when the busy state resolution waiting information for any of the transmitting circuits is stored in the busy state resolution waiting information storage unit, sets usage of the receive resources in a busy state for a data request of a same type as appropriate data requests of all of the transmitting circuits, wherein the controller cancels output of the single data request selected by the first arbitration unit to the second arbitration unit and inhibits input of a data request corresponding to the single data request to the first arbitration unit, when the usage of the receive resources monitored by the receive resource usage monitoring unit is in the busy state. |