| 摘要 |
<p>PURPOSE:To delay the drop of the power supply voltage and to secure the time needed for saving processing by cutting off the power supply of a prescribed input/output part with a mask unable interruption when the power supply of a data processor drops lower than a prescribed voltage level. CONSTITUTION:When the voltage drop is detected by a detecting part 1a, an interruption request part 2a produces the interruption requests NMI and IRQ. Thus a main control part 5 accepts the request NMI regardless of the presence or absence of an interruption mask and starts a cut-off instruction part 3a to cut off the power supply to an I/O 8a, an I/O 8b and so on. At the same time, the part 5 starts a saving part 4a. The part 4a stores the data in a prescribed area of a RAM 6. This data is required when the contents of a control register, etc., are restored to the original state when a power supply is recovered and the data processing is restarted.</p> |
