| 摘要 |
A semiconductor memory device which includes multi-bit memory cells that store multi-bit data and memory cells that store data of fewer bits then that of the multi-bit data. Thus, the semiconductor memory device includes a plurality of memory cells which store n-bit (where n is a natural number that is equal to or larger than 2) data for one cell. Among the plurality of memory cells, h-bit (h≰n) data is stored in a memory MLC of a first region MLB, and i-bit (i<h) data is stored in a memory SLC of a second region SLB. If the number of rewritings in the memory cells of the second region SLB reaches a prescribed value, the i-bit data is stored in the memory of the first region MLB rather than the memory cells of the second region SLB. |
