| 摘要 |
PURPOSE:To prevent surely a malfunction of an IC card and to increase reliability by enabling the IC card to check unerased part in an information erasing process and outputting an erasing error signal when the card has any unerased part. CONSTITUTION:A collation for sure erasing process can be executed by checking all bits in an EEPROM after execution of erasing process of information. In an erasing mode, the information of each address of the EEPROM is read out to a microcomputer in the card after erasing process S30 of information stored, and checked S31 for whether it is the initial state information of the EEPROM. If there is even one address which is not in the initial state of memory, an erasing error signal is outputted S34, and confirmed by an external device until an erasing process of information is executed completely. Accordingly, the danger of causing malfunction by using a card in which the information is not erased perfectly can be prevented surely. |
