| 摘要 |
<p>PURPOSE:To improve the reliability of a computer by effectively executing the write permission control to a backup type read/write memory at the time of the occurrence of a momentary break or the like of battery power. CONSTITUTION:A stabilized power supply circuit A is provided, and a microcomputer B (incorporating the read/write memory) is driven by the output from this circuit A. A voltage detecting means C is set which detects that the supply voltage obtained from the stabilized power supply circuit A is reduced to a value lower than a set voltage, and the memory write operation of the microcomputer B is stopped and controlled at the time of detecting the reduction of the supply voltage by the detecting means C. When the supply voltage is restored beyond the set value, a restoration detecting means D of the supply voltage gives a command to a switching means E (specific time width delay) to give a memory write restoration command to the microcomputer B after the delay of a specific time width. Thus, an abnormal value is surely prevented from being written in the memory to secure the normal operation of the microcomputer B.</p> |
