| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a memory system effectively using relaxation effect when using a flash memory to allow construction of a high-reliability system. <P>SOLUTION: The memory system has: a RAM 13 and a NAND memory 11 wherein an erasure unit and a write/read unit vary; and control circuits 12, 14, 15 controlling them. In the memory system, the NAND memory has a cache area and a main storage area wherein use of data to be stored is different. The control circuit has a function of managing: a first list 21 storing data showing a block area during use among the erasure units in the NAND memory; a second list 22 storing data showing an unused or already used block area; a third list 23 prepared for securing an erasure interval to the NAND memory, storing data showing the already used block area in response to the main storage area and the cache area; and a fourth list 24. The number of data entries of the third list 23 is smaller than the number of data entries of the fourth list 24. <P>COPYRIGHT: (C)2010,JPO&INPIT |
