| 摘要 |
<p>PURPOSE: To prolong the service life of a semiconductor storage device by assigning one block of recording areas divided into plural blocks to a standby block and making the standby block succesively take the place of a common-use block whose number of rewriting has reached a prescribed number of rewriting. CONSTITUTION: Data storage area 1 is divided into plural storage areas and a prescribed number of blocks are assigned to common-use blocks and remaining blocks are assigned to standby blocks. The numbers of rewriting performed till now are stored in one parts of respective storage blocks. A block selection part 3 transforms a logical address inputted from the outside into the physical address of the common-use block referring an address transformation table via a data control part 2. A block managing part 4 inspects the number of rewriting till now of an accessed common-use block and selects one block among standby blocks every time when the number of the block reaches a prescribed number of rewriting, for example, 1024 times and then transfers data by changing the address transformation table 5 so as to make the common-use block replaced with a standby block selected from among the standby blocks and by instructing the data control part 2 to excute a common-use-standby alternation.</p> |
