A host device according to an embodiment of the present invention sends to a plurality of device units a specific token packet including address information of a first device unit and a general token transmission time derived from an execution time of a plurality of consecutive transactions upon execution of the plurality of consecutive transactions with a first device unit out of the plurality of device units. The first device unit receives the specific token packet to execute the plurality of transactions. The plurality of device units other than the first device unit receive the specific token packet to shift to and stay in a suspend state until the general token transmission time elapses, and then shift to a waiting state after the general token transmission time.