| 摘要 |
PURPOSE: A control device for resetting a memory is provided to prevent an illegal copy of a data stored in a memory equipped in a network equipment to use a public network or an exclusive line. CONSTITUTION: A control unit of memory reset(60) is supplied a power with a method differed to the other element inside a system. When the power offered from a supplying device of power(70) is fed, an internal power and a power of recharging battery(61) are fed to a control unit of power supply(62). The control unit of power supply(62) outputs only a higher voltage by comparing two kinds of voltages. When the power offered from the supplying device of power(70) and the recharging battery(61) are all fed, the internal voltage fed from the supplying circuit of power(70) is offered to battery backup SRAMs(64,65). When the power offered from the supplying device of power(70) is not fed, only the voltage offered from the recharging battery(61) is fed to battery backup SRAMs(64,65). The recharging battery(61) is recharged when the power supply is restarted from the supplying circuit of power(70). A switch for resetting(63) is installed in the middle of power line supplied to the battery backup SRAMs(64,65) and resets every information stored in the battery backup SRAMs(64,65) when the power supply is blocked.
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