| 摘要 |
PURPOSE:To decrease the number of component parts and to attain an inexpensive abnormality detecting system by attaining discrimination between a reset action done by a watchdog timer from that done by an energization detecting circuit. CONSTITUTION:When a central arithmetic processing unit CPU1 is reset owing to the abnormality occurring in a system working mode, the reset signal S4 is turned off when the time set to a differentiating circuit 12 is elapsed. Then the CPU1 reads out the memory contents of a specific address of a random access memory 2 and decides whether said memory contents are coincident or not with the data written to an address in a power supply application mode. When a reset signal produced from a watchdog timer 10 is decided, the abnormal state is recovered.
|
