| 摘要 |
<p>PURPOSE:To lengthen the lifetime of a nonvolatile memory without lowering the throughput of a system. CONSTITUTION:When a write enable signal 14 at a time when data are written is input to a nonvolatile memory 1, an output-data control section 5 conducts control so as to read data 11 from a memory cell array 2 and output data 11 to a comparator 3. The comparator 3 compares data 11 read from the memory cell array 2 and external data 12 written from the outside, and outputs a decision signal 13 to an AND circuit 4. The AND circuit 4 takes AND between the decision signal 13 of the comparator 3 and the write enable signal 14, and outputs the arithmetic result to an input-data control section 6 as the write enable signal. When the comparator 3 detects the coincidence of these data, the AND circuit 4 inhibits an output to the input-data control section 6 of the write enable signal 14, thus preventing write to the memory cell array 2 of the external data 12.</p> |
