| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a data backup system which is used for an electronic device providing a low power consumption state, capable of more accurately grasping a remaining value of a secondary battery that backs up a memory when a power supply from a power source is suspended, for more sure backing up of a memory. <P>SOLUTION: A main CPU 20 stores the time point when power supply from a main power source 30 is stopped in an SRAM 23, and obtains the time period during which power supply was being suspended when the power supply is resumed, based on the time point of resumption and the time point of power supply stop which is stored. The main CPU 20 decreases a counter value representing a remaining value of a secondary battery 33 according to the power supply stop time, and increments the counter value according to the time period during which power supply is being made. The main CPU 20, upon occurrence of a transition request to a power saving mode, prohibits transition to the power saving mode in a case where the counter value is less than a threshold value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
