| 摘要 |
<P>PROBLEM TO BE SOLVED: To prolong the service life of a battery by avoiding a backup malfunction caused by a single failure of a power failure detection circuit. <P>SOLUTION: For example, a memory backup circuit of a disk array device is provided with a direct current power source circuit for inputting external power and outputting a direct current voltage necessary to the circuit; a first power failure detection circuit for monitoring an input state of the external power; a second power failure detection circuit for monitoring an output voltage of the direct current power source circuit; a backup power source for supplying power to a nonvolatile memory when the external power is lost; a memory control means for executing backup control of the nonvolatile memory in the case of receiving a power failure detection signal from the first or second power failure detecting means; and a switching means for supplying the power of the backup power source to the memory control means for a prescribed time when only the second power failure detecting means detects voltage reduction. <P>COPYRIGHT: (C)2007,JPO&INPIT |
