| 摘要 |
<p>PURPOSE:To always attain the accurate communication of data even to an external device containing different data communication protocols by selecting a communication protocol corresponding to the external device out of those communication protocols with designation of the external device. CONSTITUTION:A mask ROM 2 of an IC card 1 contains two types of communication protocols A and B. Then the communication of data is carried out to an external device (reader/writer), a CPU 4 outputs the initial data showing that the 1st and 2nd priorities are given to the protocols A and B respectively to the external device. Then a command waiting state is set by the protocol A. If the data received from the external device commands the selection of a communication protocol and designates the protocol B, a command waiting state is set by the protocol B.</p> |
