| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a method and a device for storing and controlling the data of an external memory by which the service life of a flash memory is prolonged without needing the waiting time for data erase and the time of calculating the number of calculation. SOLUTION: Flash memories 7a-7c for re-writing store data in the order from 7a to 7c and a CPU 2 applies garbage collection of the memory 7a to the 7d in the flash memory 7d, 7e for garbage collection when the free region of memory 7c is exhausted and at the same time, when a write access comes from a host 1, gives first precedence in the application of this to memory 7d. When the garbage collection of memory 7a finishes, the garbage collection of memory 7b is applied to memory 7e and concurrently data of memory 7a is erased. Memory 7c becomes flash memory for rewritten data by the CPU 2. When the garbage collection of memory 7b finishes, data is erased in a lump to make memory 7e flash memory for rewritten data. Next, garbage collection of memory 7c is similarly processed.</p> |
