| 摘要 |
PURPOSE:To prevent the destruction of storage data by prohibiting an off-line function at the time of detecting successively the start of an abnormal routine. CONSTITUTION:An IC card delivers and receives data to a terminal equipment in an on-line mode used by connecting to the terminal equipment and executes an off-line function such as an electronic portable calculator, a clock display at the time of using individually. The switching of the one-line or the off-line is executed by deciding whether a power from the terminal equipment side is supplied or not. When the power is chattered due to a noise or a mischief, the switching is frequently generated to erroneously operate a program and destroy the storage data. In order to prevent this, when the off of the power is detected immediately after the on of the power is detected, an error count is executed, when the error count exceeds three, an off-line operation prohibit flag is erected to prohibit the off-line function. |
