| 摘要 |
<p>An IC card of the present invention is capable of preventing an internal battery from being rapidly consumed and internal data from being volatilized due to frequent use or erroneous starts caused by external noise. The number of starts of the card and the number of erroneous starts thereof are respectively counted by registers formed in an RAM. When one of these start numbers reaches a set value, the receiving circuit selected is switched to another receiving circuit having a higher threshold value and requiring no bias current, or the threshold value of the receiving circuit is increased by an inhibit circuit so that the internal power consumption of the card is suppressed, and the card is not affected by external noise. In addition, when the value of one of the registers reaches a set value, the external device informs the user of the fact that the value reaches a set value, using sound or a display. <IMAGE></p> |
