摘要 |
<p>A card system in which a data transmitting side transmits a parity signal based upon the content of data together with the data over a signal line when the data is transmitted and received between an IC card (10) and a card reader/writer(20) for the reading or writing of the data, and a receiving side checks, based upon the content of received data and the parity signal, whether or not there is any error in the received data and transmits back to the transmitting side a data retransmission request signal requesting the transmitting side to retransmit the data when there is an error, and in which the IC card (10) corrects the level of the signal line in order to request the data transmitting side to transmit the next data when it is verified, based upon the content of the data and the parity signal which are received on the data receiving side, that there is no error in the reception of the data. <IMAGE></p> |