Logical address offset in response to detecting a memory formatting operation
The present disclosure includes methods, devices, and systems for a logical address offset. One method embodiment includes detecting a memory unit formatting operation. Subsequently, in response to detecting the formatting operation, the method includes inspecting format information on the memory unit, calculating a logical address offset, and applying the offset to a host logical address.
1. A method for operating a memory unit, comprising:
detecting a memory unit formatting operation that formats the memory unit with a file system;
operating the memory unit with a default logical address offset or an existing saved logical address offset prior to detecting the memory unit formatting operation; and
calculating a new logical address offset in response to detecting the formatting operation.
2. The method of claim 1 , wherein the method includes applying the new offset to a host logical address.
3. The method of claim 2 , wherein the new offset is equal to a difference in logical addresses between an end of a system data area and a beginning of a subsequent physical page of memory cells or a beginning of a subsequent physical block of memory cells.
4. The method of claim 2 , wherein the method includes:
applying the new offset to a starting logical address of the user data area; and
aligning the new offset starting logical address of the user data area with an allocation unit boundary of the file system.
5. The method of claim 4 , wherein the method includes calculating a second offset to be applied to host logical addresses that are within the system data area.
6. The method of claim 1 , wherein the method includes inspecting format information on the memory unit in response to detecting the formatting operation.
7. The method of claim 6 , wherein the method includes determining a starting logical address of a user data area of the memory unit according to the format information.
8. The method of claim 7 , wherein the method includes applying a new logical address offset to a host logical address that is equal to or greater than the starting address of the user data area.
9. The method of claim 8 , wherein applying the new offset to the host logical address includes adding the new offset to the logical address.
10. The method of claim 8 , wherein the method includes using the new offset until a subsequent memory unit formatting operation is detected.
11. The method of claim 1 , wherein the method includes applying a new logical address offset to a starting logical address of a user data area; and
wherein a starting logical address of the new offset corresponds to a beginning of a physical page of memory cells or a beginning of a physical block of memory cells.
12. The method of claim 1 , wherein the method includes operating the memory unit with the default logical address offset prior to detecting the memory unit formatting operation.
13. The method of claim 12 , wherein the default logical address offset is 0.
14. A memory controller, comprising:
control circuitry configured to:
detect a memory unit formatting operation that formats the memory unit with a file system;
operate the memory unit with a default logical address offset or an existing saved logical address offset prior to detecting the memory unit formatting operation; and
calculate a new logical address offset in response to detecting the formatting operation.
15. The memory controller of claim 14 , wherein the control circuitry is configured to:
inspect format information on the memory unit in response to detecting the formatting operation; and
determine a starting logical address of a user data area of the memory unit according to the format information.
16. The memory controller of claim 14 , wherein the control circuitry is configured to:
apply the new offset to a host logical address.
17. The memory controller of claim 16 , wherein the new offset as applied to a starting logical address of a user data area of the memory unit corresponds to a beginning of a physical page of memory cells or a beginning of a physical block of memory cells.
18. The memory controller of claim 16 , wherein the controller includes memory and the control circuitry is configured to store the new offset in the controller memory.
19. The memory controller of claim 18 , wherein the control circuitry is configured to store the new offset until the control circuitry detects a subsequent formatting operation.
20. The memory controller of claim 18 , including an adder coupled to the non-volatile memory and to a memory unit interface, wherein the adder is configured to add the new offset to the host logical address prior to the host logical address being sent across the memory unit interface.
21. The memory controller of claim 14 , including a number of logical address range comparators configured to compare a host logical address with a range of logical addresses corresponding to a user data area of the memory unit to determine whether the host logical address is within the user data area.
22. A memory system, comprising:
a memory unit; and
a memory controller coupled to the memory unit, wherein the memory controller is configured to:
detect a memory unit formatting operation that formats the memory unit with a file system;
operate the memory unit with a default logical address offset or an existing saved logical address offset prior to detecting the memory unit formatting operation; and
subsequently, in response to detecting the formatting operation, calculate a new logical address offset.
23. The memory system of claim 22 , wherein, in response to detecting the formatting operation, the controller is configured to:
inspect format information on the memory unit; and
determine a starting logical address of a user data area of the memory unit according to the format information.
24. The memory system of claim 23 , wherein the memory controller is configured to inspect the format information from a partition boot record of a system data area of the memory unit.
25. The memory system of claim 23 , wherein the starting logical address of the user data area is aligned with an allocation unit boundary of the file system.
26. The memory system of claim 25 , wherein the allocation unit boundary of the file system comprises a cluster boundary.
27. The memory system of claim 23 , wherein, in response to detecting the formatting operation, the controller is configured to apply the new logical address offset to a starting logical address of a user data area of the memory unit corresponding to a beginning of a physical page of memory cells or a beginning of a physical block of memory cells.
28. The memory system of claim 22 , wherein, in response to detecting the formatting operation, the controller is configured to:
apply the first logical address offset to a host logical address.
29. The memory system of claim 22 , wherein:
the memory unit comprises a number of flash memory arrays;
the memory system includes a host interface connector coupled to the memory controller; and
the host interface connector, the memory unit, and the memory controller are part of a discrete module.
30. The memory system of claim 22 , wherein the memory system comprises a solid state drive.
31. The memory system of claim 22 , wherein the memory controller is configured to operate the memory unit with the default logical address offset before the memory controller detects a memory unit formatting operation.