According to the embodiments, a memory system includes a nonvolatile semiconductor memory and a writing-loop-count monitoring unit that monitors a loop count of an applied voltage to the nonvolatile semiconductor memory required for data writing of the nonvolatile semiconductor memory as a writing loop count. Moreover, the memory system includes a management table for managing the writing loop count in block unit that is a unit of data erasing and a life managing unit that determines a degraded state of the nonvolatile semiconductor memory based on the management table.
1. A system comprising:
a memory system; and
a management unit to be installed in a host with a display device to be connected to the memory system, the management unit configured to determine a state of a memory of the memory system,
the memory system comprising:
a first semiconductor nonvolatile memory configured to include a memory that buffers data;
a second semiconductor nonvolatile memory configured to store management information of the first semiconductor nonvolatile memory;
a controller configured to control the first and second semiconductor nonvolatile memories;
a temperature sensor configured to detect temperature in the memory system and output temperature information; and
an LED configured to indicate the status of the memory system, wherein
the second semiconductor nonvolatile memory is configured to store a first information related to a total capacity of the memory of the memory system, and a second information related to a degraded state of the memory of the memory system, and
the management unit is configured to calculate a ratio, that indicates the state of the memory of the memory system based on the first and second information, and configured to cause the display device to display a warning based upon a value of the ratio.
2. The system according to claim 1 , wherein
the management unit is configured to cause the display device to display a first warning based upon the value of the ratio, and when degradation has progressed, configured to cause the display device to further display a second warning that indicates a life of the memory system becomes shorter based upon the value of the ratio.
3. The system according to claim 1 , wherein
the management unit is configured to determine which degraded stage the degraded state is among a plurality of degraded stages, and cause the display device to display a third warning that indicates the determined degraded stage.
4. The system according to claim 2 , wherein
the first semiconductor nonvolatile memory is a NAND flash memory.
5. The system according to claim 4 , wherein
the second information is managed in block units in the first semiconductor nonvolatile memory.
6. The system according to claim 5 , wherein
the second information includes a loop count at a time of erasing in the first semiconductor nonvolatile memory for each block unit.
7. The system according to claim 5 , wherein
the second information includes a loop count at a time of writing in the first semiconductor nonvolatile memory for each block unit.
8. The system according to claim 5 , wherein
the second semiconductor nonvolatile memory is a FeRAM.
9. The system according to claim 5 , wherein
the second semiconductor nonvolatile memory is a MRAM.
10. A managing method comprising:
determining a state of a memory of a memory system, the memory system connected to a management unit to be installed in a host with a display device;
buffering data in a first semiconductor nonvolatile memory;
storing management information of the first semiconductor nonvolatile memory in a second semiconductor nonvolatile memory;
controlling the first and second semiconductor nonvolatile memories;
detecting temperature in the memory system and outputting temperature information;
indicating the status of the memory system;
storing a first information related to a total capacity of the memory of the memory system, and a second information related to a degraded state of the memory of the memory system, in the second semiconductor nonvolatile memory;
calculating a ratio that indicates a state of the memory of the memory system based on the first and second information; and
displaying a warning based upon a value of the ratio.
11. The managing method according to claim 10 , further comprising:
displaying a first warning based upon the value of the ratio, and when degradation has progressed, further displaying a second warning that indicates a life of the memory system becomes shorter based upon the value of the ratio.
12. The managing method according to claim 10 , further comprising:
determining which degraded stage the degraded state is among a plurality of degraded stages, and
displaying a third warning that indicates the determined the degraded stage.
13. The managing method according to claim 11 , wherein
the first semiconductor nonvolatile memory is a NAND flash memory.
14. The managing method according to claim 13 , further comprising:
managing the second information in block units in the first semiconductor nonvolatile memory.
15. The managing method according to claim 14 , wherein
the second information includes a loop count at a time of erasing in the first semiconductor nonvolatile memory for each block unit.
16. The managing method according to claim 14 , wherein
the second information includes a loop count at a time of writing in the first semiconductor nonvolatile memory for each block unit.
17. The managing method according to claim 14 , wherein
the second semiconductor nonvolatile memory is a FeRAM.
18. The managing method according to claim 14 , wherein
the second semiconductor nonvolatile memory is a MRAM.