Nonvolatile memory, its data updating method, and card reader equipped with such nonvolatile memory

1. A nonvolatile memory comprising:

a data writing region to store necessary data; and

a data saving region to temporarily store data when rewriting data, wherein each of the data writing region and the data saving region has an end flag region to indicate a completion of data writing, and a data error detection region in a center area thereof.

2. A method for updating data in a nonvolatile memory, the method comprising the steps of:

writing in a RAM data stored in a data writing region of the nonvolatile memory;

updating the data in the RAM;

updating a data error detection region in the RAM based on the data updated;

writing in a data saving region of the nonvolatile memory the data updated in the RAM;

updating an end flag region of the data saving region;

deleting the data from the data writing region; writing in the data writing region the data in the RAM;

updating an end flag region of the data writing region; and

deleting the data from the data saving region.

3. A method for updating data in a nonvolatile memory according to claim 2 , wherein the data updated in the RAM remains in at least one of the data writing region and the data saving region in the nonvolatile memory.

4. A method for updating data in a nonvolatile memory according to claim 2 , wherein the data updated in the RAM directly written from the RAM to the data saving region of the nonvolatile memory.

5. A method for updating data in a nonvolatile memory according to claim 2 , wherein the data updated in the RAM and stored in the data saving region in the nonvolatile memory is written in the data writing region of the nonvolatile memory instead of writing in the data updated in the RAM directly from the RAM to the data saving region of the nonvolatile memory.

6. A method for updating data in a nonvolatile memory according to claim 2 , wherein old data remains in the data writing region in the nonvolatile memory until the data updated in the RAM is written in the data saving region of the nonvolatile memory.

7. A method for updating data in a nonvolatile memory according to claim 2 , wherein old data in the data writing region in the nonvolatile memory is erased after the data updated in the RAM is written in the data saving region of the nonvolatile memory.

8. A method for updating data in a nonvolatile memory according to claim 7 , wherein, after the old data in the data writing region in the nonvolatile memory is erased, at least one of the data saving region and the data writing region stores the data updated in the RAM.

9. A method for updating data in a nonvolatile memory according to claim 7 , wherein, after the old data in the data writing region in the nonvolatile memory is erased, both of the data saving region and the data writing region store the data updated in the RAM.

10. A method for updating data in a nonvolatile memory according to claim 2 , further comprising the steps of referring to the data error detection region and the end flag region in at least one of the data writing region and the data saving region upon starting an operation of the nonvolatile memory; and determining if at least one of the data stored in the data writing region and the data saving region is valid.

11. A method for updating data in a nonvolatile memory according to claim 2 , wherein, when the data in the data saving region is judged to be valid, the data is written in the data writing region.

12. A method for updating data in a nonvolatile memory according to claim 2 , wherein, when the data in the data writing region is judged to be valid, the data remains in the data writing region but the data in the data saving region is deleted.

13. A card reader device comprising a nonvolatile memory, the nonvolatile memory comprising:

a data writing region to store necessary data; and

a data saving region to temporarily store data when rewriting data, wherein each of the data writing region and the data saving region has an end flag region to indicate a completion of data writing, and a data error detection region in a center area thereof.

14. A method for updating data in a nonvolatile memory of a card reader device, the method comprising the steps of:

writing in a RAM data stored in a data writing region of the nonvolatile memory;

updating the data in the RAM;

updating a data error detection region in the RAM based on the data updated;

writing in a data saving region of the nonvolatile memory the data updated in the RAM;

updating an end flag region of the data saving region;

deleting the data from the data writing region; writing in the data writing region the data in the RAM;

updating an end flag region of the data writing region; and

deleting the data from the data saving region.

15. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein the data updated in the RAM remains in at least one of the data writing region and the data saving region in the nonvolatile memory.

16. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein the data updated in the RAM directly written from the RAM to the data saving region of the nonvolatile memory.

17. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein the data updated in the RAM and stored in the data saving region in the nonvolatile memory is written in the data writing region of the nonvolatile memory instead of writing in the data updated in the RAM directly from the RAM to the data saving region of the nonvolatile memory.

18. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein old data remains in the data writing region in the nonvolatile memory until the data updated in the RAM is written in the data saving region of the nonvolatile memory.

19. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein old data in the data writing region in the nonvolatile memory is erased after the data updated in the RAM is written in the data saving region of the nonvolatile memory.

20. A method for updating data in a nonvolatile memory of a card reader device according to claim 19 , wherein, after the old data in the data writing region in the nonvolatile memory is erased, at least one of the data saving region and the data writing region stores the data updated in the RAM.

21. A method for updating data in a nonvolatile memory of a card reader device according to claim 19 , wherein, after the old data in the data writing region in the nonvolatile memory is erased, both of the data saving region and the data writing region store the data updated in the RAM.

22. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , further comprising the steps of referring to the data error detection region and the end flag region in at least one of the data writing region and the data saving region upon starting an operation of the nonvolatile memory; and determining if at least one of the data stored in the data writing region and the data saving region is valid.

23. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein, when the data in the data saving region is judged to be valid, the data is written in the data writing region.

24. A method for updating data in a nonvolatile memory of a card reader device according to claim 14 , wherein, when the data in the data writing region is judged to be valid, the data remains in the data writing region but the data in the data saving region is deleted.