| 摘要 |
PROBLEM TO BE SOLVED: To remarkably extend the life of a nonvolatile memory by writing back only changed data through the use of information of a storing means for control in the write in the nonvolatile memory. SOLUTION: An address register to control on which address area of a nonvolatile memory (flash memory) 10 a RAM is overlapped is provided and a selection signal of the RAM is controlled. The RAM is divided into a normal RAM area 12 and an emulation RAM 13 where the memory 10 and address areas are overlapped. An emulation area register 14 controls on which address area of the memory 10 the RAM 13 is overlapped. It is possible to overlap a specific area of the memory 10 on the RAM by using an address set to the register 14 and decoding a selection signal of the RAM 13. |
