A method and device for preventing a defect in a CDR circuit from hindering synchronization between connection nodes and for preventing connection failures. The CDR circuit generates a synchronization clock from received data. A connection failure processor performs a connection failure process if synchronization based on the synchronization clock between connection nodes is not established when a first predetermined time from when the reception of the received data is started elapses. A correction processor corrects operation of the CDR circuit if synchronization based on the synchronization clock between connection nodes is not established when a second predetermined time, which is shorter than the first predetermined time, from when the reception of the received data is started elapses.