| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory which allows data to be read with high accuracy, even when property variation in a manufacturing process or property fluctuation during use occurs. <P>SOLUTION: A first and second cells 50, 52 with the same structure as memory cells are provided as a reference cell 202. A memory cell current IREF1 of the first cell 50 is set to the minimum value of memory cell current after erasing. A memory cell current IREF2 of the second cell 52 is set to the maximum value of memory cell current after writing. A read circuit 206 compares a memory cell current Icell with a current (IREF1+IREF2)/2, and outputs a comparison result. Instead of the first and second cells 50, 52, a current source used in the case of erasure verification and write verification may be used. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
