| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device, wherein reading operation can be performed with a large operation margin by setting a proper reference current even when affected by a second bit effect. <P>SOLUTION: Charge is accumulated in a charge accumulation area of one reference cell between two reference cells so as to be equivalent to a memory cell characteristic with the minimum current. In addition, charge is accumulated in a charge accumulation area of the other reference cell so as to be equivalent to a memory cell characteristic with the maximum current. A current equalizing circuit 104 equalizes respective currents output from the reference cells and outputs the currents as a reference current R_REF1. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
