| 摘要 |
<p>PURPOSE:To allow a power source circuit to execute two types of initialization processings without making said circuit complicated by initializing a backup target device only if an effective signal is not outputted when a commercial power source developing power failure is restored. CONSTITUTION:At the time of the power failure of the commercial power source 50 (a power failure period T), a power unit 20 stops supplying a DC power source. However, a battery backup unit BBU 30 continues supplying the DC power source. When the commercial power source is restored, the power unit 20 begins to supply the power source. In correspondence to the restoration, a system controller 11 initializes each device. However, this time the effective signal (BBUE) 31 is active, and the controller 11 does not initialize a main memory device (MMU)13. When an effective trigger signal (BBUS) 32 from the system control part 11 comes to a low level 0, the effective signal (BBUE) 31 is triggered to come to a high level 1, and the backup function of the battery backup unit 30 acts normally.</p> |
