A packet communication control device configured to transfer a first data reception request and a second data transmission request accompanied by a data packet, via a communication pathway, wherein said packet communication control device comprises: a plurality of sending units (50-1∼50-N); and a multiplex control circuit (54, 56, 58) configured to control the transfer operation from a selected sending unit, wherein said multiplexer control circuit comprises: a first arbitration circuit configured to arbitrate the first data reception request of said plurality of sending units (50-1∼50-N); a second arbitration circuit configured to arbitrate the second data transmission request of said plurality of sending units (50-1∼50-N); and an arbitration control circuit configured to select said sending unit to execute a transfer of the data packet accompanied with the second data transmission request to a data communication pathway with synchronization to the transfer of the second data transmission request to the control communication pathway according to an arbitration result of said second arbitration circuit when the data communication pathway is not occupied and to select said sending unit to execute the transfer of the first data reception request to the control communication pathway according to the arbitration result of said first arbitration circuit when the data communication pathway is occupied, and wherein the package communication control device further comprises: a multiplexer configured to transfer, from the sending unit, the first data reception request and the second data transmission request to a control communication pathway and to transfer the data packet to a data communication pathway, respectively. a plurality of sending units (50-1∼50-N); and a multiplex control circuit (54, 56, 58) configured to control the transfer operation from a selected sending unit, wherein said multiplexer control circuit comprises: a first arbitration circuit configured to arbitrate the first data reception request of said plurality of sending units (50-1∼50-N); a second arbitration circuit configured to arbitrate the second data transmission request of said plurality of sending units (50-1∼50-N); and an arbitration control circuit configured to select said sending unit to execute a transfer of the data packet accompanied with the second data transmission request to a data communication pathway with synchronization to the transfer of the second data transmission request to the control communication pathway according to an arbitration result of said second arbitration circuit when the data communication pathway is not occupied and to select said sending unit to execute the transfer of the first data reception request to the control communication pathway according to the arbitration result of said first arbitration circuit when the data communication pathway is occupied, and wherein the package communication control device further comprises: a first arbitration circuit configured to arbitrate the first data reception request of said plurality of sending units (50-1∼50-N); a second arbitration circuit configured to arbitrate the second data transmission request of said plurality of sending units (50-1∼50-N); and an arbitration control circuit configured to select said sending unit to execute a transfer of the data packet accompanied with the second data transmission request to a data communication pathway with synchronization to the transfer of the second data transmission request to the control communication pathway according to an arbitration result of said second arbitration circuit when the data communication pathway is not occupied and to select said sending unit to execute the transfer of the first data reception request to the control communication pathway according to the arbitration result of said first arbitration circuit when the data communication pathway is occupied, and wherein the package communication control device further comprises: a multiplexer configured to transfer, from the sending unit, the first data reception request and the second data transmission request to a control communication pathway and to transfer the data packet to a data communication pathway, respectively.