Wear leveling in non-volatile memories
Systems and methods for wear leveling in non-volatile memories (NVMs) are disclosed. One such system includes a cumulative control state determiner configured to determine a cumulative control state indicative of a state of random mappings between physical block addresses (PBAs) and logical block addresses (LBAs) of an NVM, an access network configured to translate a LBA to a PBA based on the cumulative control state, and a background swap scheduler configured to swap PBAs assigned to preselected LBAs based on a control state. One such method involves determining a cumulative control state indicative of a state of random mappings between physical block addresses (PBAs) and logical block addresses (LBAs) of an NVM, translating a LBA to a PBA based on the cumulative control state, and swapping PBAs assigned to preselected LBAs based on a control state.
1. A non-volatile memory system configured for wear leveling, the system comprising:
a cumulative control state determiner configured to determine a cumulative control state indicative of a state of random mappings between physical block addresses (PBAs) and logical block addresses (LBAs) of a non-volatile memory (NVM);
an access network configured to translate a LBA to a PBA based on the cumulative control state; and
a background swap scheduler configured to swap PBAs assigned to preselected LBAs based on a control state.
2. The system of claim 1 :
wherein the cumulative control state comprises a first cumulative control state and a second cumulative control state;
wherein the control state comprises a first control state and a second control state; and
wherein the second cumulative control state is a function of the first cumulative control state and the second control state.
3. The system of claim 2 , wherein the second cumulative control state comprises switch settings used to achieve a sort of a permutation of the first cumulative control state where the permutation is generated using the second control state.
4. The system of claim 1 , further comprising:
a mapping state generator configured to change from a first memory map to a second memory map after the background swap scheduler swaps a preselected number of PBAs;
wherein the first memory map and the second memory map each comprises a preselected number of PBAs.
5. The system of claim 1 , wherein the background swap scheduler is configured to swap PBAs after a preselected number of accesses of the non-volatile memory of the non-volatile memory system.
6. The system of claim 5 , wherein preselected number of accesses comprises 100 writes of the non-volatile memory.
7. The system of claim 1 , wherein the access network is further configured to:
generate a first PBA candidate from a LBA using a first function;
generate a second PBA candidate from the LBA using a second function; and
select either the first PBA candidate or the second PBA candidate for data access based on information related to a background swap of data stored at the first PBA candidate and a background swap of data stored at the second PBA candidate.
8. The system of claim 7 , wherein at least one of the first function or the second function comprises a function performed by at least one of a multi-stage interconnection network or a block cipher.
9. A method for wear leveling in a non-volatile memory system, the method comprising:
determining a cumulative control state indicative of a state of random mappings between physical block addresses (PBAs) and logical block addresses (LBAs) of a non-volatile memory (NVM);
translating a LBA to a PBA based on the cumulative control state; and
swapping PBAs assigned to preselected LBAs based on a control state.
10. The method of claim 9 :
wherein the cumulative control state comprises a first cumulative control state and a second cumulative control state;
wherein the control state comprises a first control state and a second control state; and
wherein the second cumulative control state is a function of the first cumulative control state and the second control state.
11. The method of claim 10 , wherein the second cumulative control state comprises switch settings used to achieve a sort of a permutation of the first cumulative control state where the permutation is generated using the second control state.
12. The method of claim 9 , further comprising:
changing from a first memory map to a second memory map after swapping a preselected number of PBAs;
wherein the first memory map and the second memory map each comprises a preselected number of PBAs.
13. The method of claim 9 , wherein the swapping PBAs assigned to preselected LBAs based on the control state comprises swapping PBAs after a preselected number of accesses of the non-volatile memory of the non-volatile memory system.
14. The method of claim 13 , wherein preselected number of accesses comprises 100 writes of the non-volatile memory.
15. The method of claim 9 , further comprising:
generating a first PBA candidate from a LBA using a first function;
generating a second PBA candidate from the LBA using a second function; and
selecting either the first PBA candidate or the second PBA candidate for data access based on information related to a background swap of data stored at the first PBA candidate and a background swap of data stored at the second PBA candidate.
16. The method of claim 15 , wherein at least one of the first function or the second function comprises a function performed by at least one of a multi-stage interconnection network or a block cipher.
17. A non-volatile memory system configured for wear leveling, the system comprising:
means for determining a cumulative control state indicative of a state of random mappings between physical block addresses (PB As) and logical block addresses (LB As) of a non-volatile memory (NVM);
means for translating a LBA to a PBA based on the cumulative control state; and
means for swapping PBAs assigned to preselected LBAs based on a control state.
18. The system of claim 17 :
wherein the cumulative control state comprises a first cumulative control state and a second cumulative control state;
wherein the control state comprises a first control state and a second control state; and
wherein the second cumulative control state is a function of the first cumulative control state and the second control state.
19. The system of claim 18 , wherein the second cumulative control state comprises switch settings used to achieve a sort of a permutation of the first cumulative control state where the permutation is generated using the second control state.
20. The system of claim 17 , further comprising:
means for changing from a first memory map to a second memory map after swapping a preselected number of PBAs;
wherein the first memory map and the second memory map each comprises a preselected number of PBAs.
21. The system of claim 17 , wherein the means for swapping PBAs assigned to preselected LBAs based on the control state comprises means for swapping PBAs after a preselected number of accesses of [ [a] ] the non-volatile memory of the non-volatile memory system.
22. The system of claim 21 , wherein preselected number of accesses comprises 100 writes of the non-volatile memory.
23. The system of claim 17 , further comprising:
means for generating a first PBA candidate from a LBA using a first function;
means for generating a second PBA candidate from the LBA using a second function; and
means for selecting either the first PBA candidate or the second PBA candidate for data access based on information related to a background swap of data stored at the first PBA candidate and a background swap of data stored at the second PBA candidate.