MEMORY LIFE EXTENSION METHOD AND APPARATUS

• US 20120232744A1
• Filed: 03/10/2011
• Published: 09/13/2012
• Est. Priority Date: 03/10/2011
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Vilar, Zimin W., Gilman, Alan K., Sopko, Tyge
• Granted Patent: US 8,909,850 B2
• Time in Patent Office: Days
• US Class Current: 701/32.8
• CPC Class Codes: G06F 12/16 Protection against loss of memory contents contains no material, see G06F11/00
• CPC Class Codes: G06F 13/16 for access to memory bus G06F13/28 takes precedence
• CPC Class Codes: G11C 16/3495 Circuits or methods to detect or delay wearout of nonvolatile EPROM or EEPROM memory devices, e.g. by counting numbers of erase or reprogram cycles, by using multiple memory areas serially or cyclically

Abstract

A memory management method including the steps of storing a value and writing data. The storing a value step stores a value representative of a number of erase/write cycles that a subset of memory space of a first memory has undergone. The first memory having an assigned predetermined maximum number of erase/write cycles. The writing data step writes data to the subset of memory space dependent upon whether the value is below the predetermined maximum number.

Claims

1. A memory management method, comprising the steps of:

storing a value representative of a number of erase/write cycles that a subset of memory space of a first memory has undergone, said first memory having an assigned predetermined maximum number of erase/write cycles; and

writing data to said subset of memory space dependent upon whether said value is below said predetermined maximum number.

2. The method of claim 1, wherein said value is stored in a second memory that has an assigned predetermined maximum number of erase/write cycles which is larger than said predetermined maximum number of said first memory.

3. The method of claim 2, further comprising the step of storing a value representative of a memory location of said first memory at which data is currently being stored.

4. The method of claim 3, wherein said value representative of a memory location is stored in said second memory.

5. The method of claim 2, further comprising the step of storing an offset value which is used to determine a memory location of said first memory at which data can be stored.

6. The method of claim 5, wherein said offset value is stored in said second memory.

7. The method of claim 1, wherein said writing step includes writing data to a new subset of memory space if said value is one of equal to and greater than said predetermined maximum number, the method being used in an embedded control unit of a vehicle.

8. An electrical control system, comprising:

a control unit having, a microcontroller, a first memory and a second memory, said first memory and said second memory being in communication with said microcontroller, said control unit using a memory management method that includes the steps of;

storing a value representative of a number of erase/write cycles that a subset of memory space of said first memory has undergone, said first memory having an assigned predetermined maximum number of erase/write cycles; and

writing data to said subset of memory space dependent upon whether said value is below said predetermined maximum number.

9. The electrical control system of claim 8, wherein said value is stored in said second memory that has an assigned predetermined maximum number of erase/write cycles which is larger than said predetermined maximum number of said first memory.

10. The electrical control system of claim 9, wherein the method further comprises the step of storing a value representative of a memory location of said first memory at which data is currently being stored.

11. The electrical control system of claim 10, wherein said value representative of a memory location is stored in said second memory.

12. The electrical control system of claim 9, wherein the method further comprises the step of storing an offset value which is used to determine a memory location of said first memory at which data can be stored, said offset value being stored in said second memory

13. The electrical control system of claim 12, wherein the electrical control system is embedded in a vehicle.

14. The electrical control system of claim 8, wherein said writing step includes writing data to a new subset of memory space if said value is one of equal to and greater than said predetermined maximum number.

15. An energy consuming device, comprising:

at least one performance measuring device that produces at least one measured value;

a first memory device;

a second memory device; and

a controller communicatively coupled to the energy consuming device, said controller being in communication with said first memory device and said second memory device, said at least one measured value being stored in a selected location in said first memory device, said first memory device having an assigned predetermined maximum number of erase/write cycles, said selected location being changed to a new selected location once said selected location has undergone a count of said erase/write cycles that is equal to said predetermined maximum number of erase/write cycles, said second memory device containing said count.

16. The energy consuming device of claim 15, wherein said second memory device has an assigned predetermined maximum number of erase/write cycles that exceeds said predetermined maximum number of erase/write cycles of said first memory device.

17. The energy consuming device of claim 16, wherein said second memory device has an assigned predetermined maximum number of erase/write cycles that is more than ten times said predetermined maximum number of erase/write cycles of said first memory device.

18. The energy consuming device of claim 15, wherein a location value representative of said selected location is stored.

19. The energy consuming device of claim 18, wherein said location value representative of a memory location is stored in said second memory device.

20. The energy consuming device of claim 15, wherein an offset value is stored in said second memory device, the offset value is used to determine a memory location of said first memory device at which said at least one measured value is stored, the energy consuming device being configured to power a vehicle.