| 摘要 |
<p>PURPOSE: To heighten a characteristic concerning the incomplete writing and the incomplete erasing of memory data with respect to the variation of a manufacturing condition, a secular change and the fluctuation in an operating voltage in a nonvolatile semiconductor storage incorporating a writing or erasing time setting circuit. CONSTITUTION: A writing or erasing time setting circuit is provided with an oscillator 2 and a counter circuit 4 and also a power source potential deciding circuit 1 and a counter setting value changing circuit 3. In the case a power source potential is lowered to a level lower than a constant level V1, the output signal LVD of the power source potential deciding circuit 1 is changed to a low level to change the output of the counter setting value changing circuit 3 from the mth bit output Qm to the nth bit output Qn of the counter circuit 4 and then the pulse width of a writing or erasing pulse signal T is widened.</p> |
