A bus control circuit configured to control connection of a bus between a plurality of bus masters and a slave module , comprising: a plurality of bus switches , an arbitration circuit configured to receive a bus-transfer request signal from each of the plurality of bus masters and output one arbitration result signal to all of the plurality of bus switches, representing that a bus-use right is to be given, in accordance with a priority order set in advance, to one of the bus masters that have issued the bus-transfer request signals; and wherein each of the plurality of bus switches comprises: a selection circuit including a plurality of input terminals configured to receive a plurality of bus transfer signals , and an output terminal configured to transmit one bus transfer signal of the plurality of input terminals to a downstream side; and a control circuit configured to receive the arbitration result signal output from the arbitration circuit and control the selection circuit based on the arbitration result signal to select one of the plurality of input terminals, and wherein a bus switch at the most downstream position of the plurality of bus switches notifies the arbitration circuit of a signal, and the slave module is connected to the output terminal of the selection circuit included in the bus switch located at a most downstream position. a plurality of bus switches , an arbitration circuit configured to receive a bus-transfer request signal from each of the plurality of bus masters and output one arbitration result signal to all of the plurality of bus switches, representing that a bus-use right is to be given, in accordance with a priority order set in advance, to one of the bus masters that have issued the bus-transfer request signals; and wherein each of the plurality of bus switches comprises: a selection circuit including a plurality of input terminals configured to receive a plurality of bus transfer signals , and an output terminal configured to transmit one bus transfer signal of the plurality of input terminals to a downstream side; and a control circuit configured to receive the arbitration result signal output from the arbitration circuit and control the selection circuit based on the arbitration result signal to select one of the plurality of input terminals, and wherein a bus switch at the most downstream position of the plurality of bus switches notifies the arbitration circuit of a signal, and the slave module is connected to the output terminal of the selection circuit included in the bus switch located at a most downstream position. a selection circuit including a plurality of input terminals configured to receive a plurality of bus transfer signals , and an output terminal configured to transmit one bus transfer signal of the plurality of input terminals to a downstream side; and a control circuit configured to receive the arbitration result signal output from the arbitration circuit and control the selection circuit based on the arbitration result signal to select one of the plurality of input terminals, and wherein a bus switch at the most downstream position of the plurality of bus switches notifies the arbitration circuit of a signal, and the slave module is connected to the output terminal of the selection circuit included in the bus switch located at a most downstream position. <EOS>