MEMORY CONTROL APPARATUS, MEMORY SYSTEM, INFORMATION PROCESSING SYSTEM, AND MEMORY CONTROL METHOD

• US 20140136752A1
• Filed: 09/27/2013
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Terada, Haruhiko
• Granted Patent: US 9,135,165 B2
• Time in Patent Office: Days
• US Class Current: 711/102
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7206 Reconfiguration of flash memory system
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G06F 2212/7211 Wear leveling
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 7/04 with means for avoiding disturbances due to temperature effects

Abstract

A memory control apparatus includes a temperature obtaining unit, a priority determination unit, and a write processing unit. The temperature obtaining unit is configured to obtain, in a memory having a plurality of measurement areas each including a plurality of unit areas, temperatures measured in the plurality of measurement areas. The priority determination unit is configured to determine a priority for each unit area in accordance with a degree of consumption and the temperature of the measurement area including the unit areas, the degree of consumption being a degree of consumption of the unit area which is caused by a write process performed. The write processing unit is configured to preferentially perform the write process with respect to the unit area having a higher priority as a data write destination.

Claims

1. A memory control apparatus, comprising:

a temperature obtaining unit configured to obtain, in a memory having a plurality of measurement areas each including a plurality of unit areas, temperatures measured in the plurality of measurement areas;

a priority determination unit configured to determine a priority for each unit area in accordance with a degree of consumption and the temperature of the measurement area including the unit areas, the degree of consumption being a degree of consumption of the unit area which is caused by a write process performed; and

a write processing unit configured to preferentially perform the write process with respect to the unit area having a higher priority as a data write destination.

2. The memory control apparatus according to claim 1, wherein

the priority determination unit determines a value of the priority to be lower, as the degree of consumption is increased, and to be lower, as the temperature is increased.

3. The memory control apparatus according to claim 1, wherein

the priority determination unit determines a value of the priority to be lower, as the degree of consumption is increased, and to be higher, as the temperature is increased.

4. The memory control apparatus according to claim 3, wherein

the priority determination unit determines the priority to be a predetermined value in the unit area included in the measurement area, the temperature of which exceeds a predetermined threshold value.

5. The memory control apparatus according to claim 1, wherein

the priority determination unit obtains a characteristic amount on the basis of the temperature of the measurement area and determines the priority when the characteristic amount exceeds a predetermined amount.

6. The memory control apparatus according to claim 1, wherein

the priority determination unit obtains a characteristic amount on the basis of the temperature of the measurement area when a power is turned on and determines the priority to be a predetermined value when the characteristic amount is equal to or smaller than a predetermined amount.

7. The memory control apparatus according to claim 1, further comprising

a consumption degree supply unit configured to supply, as the degree of consumption, a value obtained in accordance with the temperature of the unit area at a time when the write processing unit performs the write process to the priority determination unit.

8. The memory control apparatus according to claim 7, further comprising

a data exchange processing unit configured to perform a data exchange process of exchanging data in the unit area, the degree of consumption of which is higher, for data in the unit area, the degree of consumption of which is lower, out of the plurality of unit areas, to level the degrees of consumption in the plurality of unit areas.

9. The memory control apparatus according to claim 8, wherein

the data exchange processing unit determines whether a difference between a maximum value and a minimum value of the degrees of consumption of the plurality of unit areas exceeds a predetermined threshold value or not, each time the degree of consumption is obtained, and performs the data exchange process when the difference exceeds the predetermined threshold value.

10. The memory control apparatus according to claim 8, wherein

the data exchange processing unit performs the data exchange process in the measurement area, the temperature of which is equal to or less than a predetermined temperature.

11. The memory control apparatus according to claim 1, wherein

the priority determination unit determines the priority, each time a certain time period elapses.

12. The memory control apparatus according to claim 11, wherein

the priority determination unit determines the priority when a total write count exceeds a predetermined count, the total write count being a write count with respect to the memory from when a preceding determination of the priority is performed until when the certain time period elapses.

13. The memory control apparatus according to claim 11, wherein

the priority determination unit determines the priority when a total consumption degree exceeds a predetermined value, the total consumption degree being the degree of consumption of the memory from when a preceding determination of the priority is performed until when the certain time period elapses.

14. The memory control apparatus according to claim 1, wherein

the plurality of unit areas each have a physical address allocated thereto, and

when writing data to a logical address to which the physical address is unallocated is ordered, the write processing unit preferentially allocates the physical address of the unit area having a higher priority to the logical address and sets the physical address allocated as the data write destination.

15. A memory system, comprising:

a memory having a plurality of measurement areas each including a plurality of unit areas;

a temperature obtaining unit configured to obtain temperatures measured in the plurality of measurement areas;

a priority determination unit configured to determine a priority for each unit area in accordance with a degree of consumption and the temperature of the measurement area including the unit areas, the degree of consumption being a degree of consumption of the unit area which is caused by a write process performed; and

a write processing unit configured to preferentially perform the write process with respect to the unit area having a higher priority as a data write destination.

16. An information processing system, comprising:

a host computer configured to order to perform a data write process;

a memory having a plurality of measurement areas each including a plurality of unit areas;

a temperature obtaining unit configured to obtain temperatures measured in the plurality of measurement areas;

a priority determination unit configured to determine a priority for each unit area in accordance with a degree of consumption and the temperature of the measurement area including the unit areas, the degree of consumption being a degree of consumption of the unit area which is caused by a write process performed; and

a write processing unit configured to preferentially perform the ordered write process with respect to the unit area having a higher priority as a data write destination.

17. A memory control method, comprising:

obtaining, in a memory having a plurality of measurement areas each including a plurality of unit areas, temperatures measured in the plurality of measurement areas by a temperature obtaining unit;

determining a priority for each unit area in accordance with a degree of consumption and the temperature of the measurement area including the unit areas by a priority determination unit, the degree of consumption being a degree of consumption of the unit area which is caused by a write process performed; and

preferentially performing the write process with respect to the unit area having a higher priority as a data write destination by a write processing unit.