| 摘要 |
<p>PURPOSE:To prevent the change in the storage state of an electrically write enable nonvoltage memory at the closing of a power source or the like by adding a priority circuit and inhibiting the other power source supply until the voltage for driving logical circuits is stabilized. CONSTITUTION:When the divided voltage from the 1st power source terminal 3 divided by resistances 14, 15 is not applied and the voltage from the 2nd power source terminal 7 is being applied, the output of an inverter 16 falls to a low level, and the outputs of NAND circuits 17-19 rise to a high level, giving no influence upon a semiconductor storage device 1. The same holds true of the case when the voltage from the terminal 3 is applied to the inverter 16 and the voltage from the terminal 7 is not applied. On the other hand, the output of this inverter 16 for determining priority inverts to a high level only when a driving device 2 for controlling the semiconductor storage device is stabilized by the voltage from the terminal 3 and the voltage from the terminal 7 is applied, thereby enabling the rewriting of the device 1 through the device 2.</p> |
