| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a convenient phase-change memory capable of a high-speed operation.SOLUTION: When performing writing of M-bit (8 bits=1 byte) data in a phase-change memory, an erasure operation and program operation are performed in units of n-bit (M>n) data. Further, when performing writing of the M-bit data, the program operation is performed in units of n-bit (M>n) data. And further, when performing reading of the M-bit data from a memory cell, a read operation is performed in units of n-bit (M>n) data. For example, writing to the phase-change memory is performed not by overwriting data but by performing programming after bringing a target memory cell to an erased state once. The sizes of erasure data and program data are set identical. The erasure and program operations are performed only for the requested data size.</p> |
