| 摘要 |
<p>PROBLEM TO BE SOLVED: To speedily and accurately control threshold at the time of writing and to prevent deterioration of memory cells by using a drain current detecting automatic inspection writing circuit in a non-volatile semiconductor memory such as a flash memory, and an EEPROM. SOLUTION: This memory is composed of a memory cell array 10 which arranges the memory cells that are electrically erasable and writable non-volatile semiconductor elements, a writing voltage generation circuit which supplies a predetermined writing voltage VPG to a selection memory cell 11 and a comparator 14 which compares the drain current flowing from the drain to the source of the selection memory cell 11 during the writing operation of the selection memory cell 11 with the reference currents generated in reference current generation circuits 20, 21, 22. The level of the writing voltage outputted in the writing voltage generation circuit is varied using the signals F1, F2, F3 of the output results of the comparator 14.</p> |
