Patent ID: 8719476

Claim:
A communication system comprising: slave devices each including a request signal generation part configured to, when data to transmit is generated, generate a request signal indicating a transmission request to a master device; and a transmission part configured to transmit the request signal to the master device; and the master device including a request signal reception part configured to receive a plurality of request signals from the slave devices; a selection part configured to select one of the slave devices according to the plurality of request signals received by the reception part and at least one request signal from a CPU in the master device; a transmission part configured to transmit a signal indicating to allow data transmission or a signal for transmitting data to the slave device selected by the selection part; and a data reception part configured to receive data from the selected slave device, wherein when the selection part of the master device receives the plurality of request signals and the at least one request signal from the CPU, the selection part selects the one of the slave devices, based on priority assigned to each of the slave devices and the at least one request signal from the CPU.