Patent ID: 8775891

Claim:
A transmission device including a transmitting circuit transmitting data to a transmission path and a receiving circuit receiving the data via the transmission path, the transmitting circuit comprising: an error detection code generation unit that generates an error detection code for error detection of data to be transmitted to the receiving circuit; a transmitting circuit side transmitting unit that transmits transmission data including the data and the error detection code to the transmission path; and a transmitting circuit side receiving unit that receives data from the receiving circuit, and the receiving circuit comprising: a receiving side termination unit that terminates the transmission path at the receiving circuit side; a receiving side adjusting unit that updates a resistance value of the receiving side termination unit to an appropriate value, the appropriate value being equal or similar to the resistance value of an external reference resistor; a receiving circuit side receiving unit that receives the transmission data transmitted from the transmitting circuit via the transmission path; an error detection unit that detects an error of data received by the receiving circuit side receiving unit; a receiving circuit side transmitting unit that transmits a data retransmit request to request for retransmission of data for which the error is detected by the error detection unit to the transmitting circuit; and a receiving circuit side control unit that allows the receiving side adjusting unit to enter a resistance value adjustment period upon detecting the received data error by the error detection unit and that updates a resistance value of the receiving side termination unit to the appropriate value within the adjustment period by controlling the receiving side adjusting unit, wherein the transmitting circuit transmits invalid data to the transmission path within the resistance value adjustment period, and the receiving circuit discards the invalid data received from the transmitting circuit via the transmission path within the resistance value adjustment period.