| 摘要 |
A self-stop circuit has a nonvolatile storage element (20), and a write terminal (50) and an erase circuit (30) for controlling the amount of electric charges charged in or discharged from the nonvolatile storage element (20). A determination circuit (40) determines that the amount of electric charges accumulated in the nonvolatile storage element (20) falls below a threshold, so as to detect an elapsed time. Thereby, the end of the lifespan of a product is detected and the operation of the product is stopped or modified after the end of the lifespan. When the operation is desired to be restored, electric charges are injected into the nonvolatile storage element (20) again, or a cancel signal is supplied through an external terminal (53) to the determination circuit (40).
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