Non-volatile memory with dynamic wear leveling group configuration

A method, comprising:

• performing wear leveling operations on a first wear leveling group according to a first wear leveling scheme over a period of operation including performing an XOR operation on a logical address and a first bit string to obtain a physical address and changing the first bit string to swap logical addresses between pairs of physical addresses of the first wear leveling group;
• performing wear leveling operations on a second wear leveling group according to a second wear leveling scheme over the period of operation including performing an XOR operation on a logical address and a second bit string to obtain a physical address and changing the second bit string to swap logical addresses between pairs of physical addresses of the second wear leveling group;
• detecting a high level of wear of the first wear leveling group;
• in response to detecting the high level of wear of the first wear leveling group, merging at least the first wear leveling group and the second wear leveling group to form a merged wear leveling group, the second wear leveling group selected for the merging based on a low level of wear of the second wear leveling group;
• and
• performing wear leveling operations on the merged wear leveling group according to a third wear leveling scheme over a subsequent period of operation including performing an XOR operation on a logical address and a third bit string to obtain a physical address and changing the third bit string to swap logical addresses between pairs of physical addresses of the merged wear leveling group.

A system comprising:

• means for detecting a pattern of access to a plurality of physical units in a set of non-volatile memory cells in a first period of operation, each physical unit having a physical address, the plurality of physical units forming a first wear leveling group for application of a first wear leveling scheme and a second wear leveling group for application of a second wear leveling scheme, the first and second wear leveling schemes configured to change logical to physical translation a plurality of times in the first period of operation, the first wear leveling scheme applying an XOR operation on a logical address and a first bit string to obtain a physical address, the second wear leveling scheme applying an XOR operation on a logical address and a second bit string to obtain a physical address, the first and second wear leveling groups each containing a first number of physical units;
• means for dynamically selecting physical units of the plurality of physical units to form one or more merged wear leveling groups in a second period of operation based on the detected pattern of access to the plurality of physical units in the first period of operation, including selecting a second number of physical units to form a merged wear leveling group that includes all physical units of the first and second wear leveling groups in response to detecting a high level of wear of the first wear leveling group, the second wear leveling group selected based on a low level of wear of the second wear leveling group;
• and
• means for applying a third wear leveling scheme to only the merged wear leveling group including applying an XOR operation on a logical address and a third bit string to obtain a physical address and changing the third bit string to swap logical addresses between pairs of physical addresses of the merged wear leveling group.