| 摘要 |
PROBLEM TO BE SOLVED: To stabilize memory backup power switching control by avoiding the effects of potential fluctuations at a rise in battery power +B and accessory power ACC, in memory backup power switching for a volatile memory part used in an on-vehicle information device. SOLUTION: A memory backup power control circuit 3 captures a control signal group 21 of an initialization sequence or cutoff sequence executed on the memory part 1 by a host CPU 2, and generates switch control signals SWA* and SWB* respectively for SW-A 17 adapted to be turned on to supply normal power "+2.5 V" and SW-B 18 adapted to be turned on to supply backup power "+2.5 VC" according to the control signal group 21 all by software. COPYRIGHT: (C)2006,JPO&NCIPI
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