Pipe arbitration using an arbitration circuit to select a control circuit among a plurality of control circuits and by updating state information with a data transfer of a predetermined size

摘要

Provided is an arbitration circuit included in a host controller that can be connected to a plurality of external devices via a plurality of pipe control circuits. The arbitration circuit includes an available state information storage unit that stores available state information. The available state information indicates an available state of the plurality of pipe control circuits and is updated by the pipe control circuit by a unit of data transfer of a predetermined communication size. The arbitration circuit further includes an arbitration unit that refers to the available state information storage unit, selects the arbitrary pipe control circuit from the available pipe control circuit, and allocates the selected pipe control circuit to the external device, while updating the available state information storage unit.

主权项

1. A host controller comprising:
a first port through which data communication is performed, wherein a first device is connected to the first port; a plurality of control circuits; a schedule control unit configured to output endpoint information of an external device to be connected; an arbitration circuit configured to, when an endpoint to which data is to be transmitted is included in the endpoint information, inform one of the plurality of control circuits of device information included in the endpoint information; and an informed control circuit configured to perform data communication with the first device through the first port based on the device information, wherein the informed control circuit is further configured to inform the arbitration circuit that a data transfer of a predetermined size has been finished by using a data transfer end notification in the data communication with the first device, and wherein the arbitration circuit is further configured to obtain the endpoint information again and to inform one of the plurality of control circuits of device information included in the endpoint information obtained again.