| 摘要 |
PURPOSE:To prevent a malfunction due to a leakage current at the time of the write and read of an EPROM, etc., by block dividing a memory array in the direction of a word line and supplying prescribed potential to a source line of a memory block. CONSTITUTION:The memory array MARY is divided to plural memory blocks MB0-MBp making the prescribed number of memory cells MC connected to the prescribed number of word lines W0-Wm a unit. Then, the sources of the memory cells MC constituting respective memory blocks MB0-MBp are common connected to corresponding source lines S0-Sp respectively. Further, for instance, grounded potential of a circuit is supplied to the source line S0 of the memory block MBO incorporating a selection memory cell, and a voltage with potential equal to or lower than the drain voltage of the selection memory cell is supplied to the source lines S1-Sp of other memory blocks MB1-MBp. Thus, even when an unselected memory cell is in an erasure state, and a threshold value voltage is lower, the threshold value voltage is hightened. |
