| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device (EEPROM) which can store three-values of information and which can increase the speed of write verifying operation, without causing a wrong verification. <P>SOLUTION: The EEPROM (electrically erasable and programable ROM) has a memory cell array 1, in which electrically rewritable memory cells are arranged in a matrix form and in which one memory cell has three storage states. It is provided a plurality of bit lines connected to the memory cell array; a plurality of word lines connected to the memory cell array; and a plurality of data latch circuits, with each being provided to corresponding bit line, each being composed of two or more binary data latch circuits, which store n-value write data to be written to the corresponding memory cell by the combination of two or more binary data, and which store n-value readout data, read out from the corresponding memory cell by the combination of two or more binary data. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
