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, comprising:
detecting a memory unit formatting operation that is initiated across a host interface of a memory unit and 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, wherein the new logical address 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.
2. The method of claim 1 , wherein the method includes applying the new logical address offset to a host logical address.
3. The method of claim 1 , wherein the method includes:
applying the new logical address offset to a starting logical address of the user data area; and
aligning the new logical address offset starting logical address of the user data area with an allocation unit boundary of the file system.
4. The method of claim 1 , wherein the method includes calculating a second offset to be applied to host logical addresses that are within the system data area.
5. The method of claim 1 , wherein the method includes inspecting format information on the memory unit in response to detecting the formatting operation before calculating the new logical address offset.
6. The method of claim 5 , wherein the method includes determining a starting logical address of a user data area of the memory unit according to the format information.
7. The method of claim 1 , wherein the method includes using the new logical address offset until a subsequent memory unit formatting operation is detected.
8. The method of claim 1 , wherein the default logical address offset is 0.
9. A memory controller, comprising:
control circuitry configured to:
detect a memory unit formatting operation that is initiated across a host interface of a memory unit and 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, wherein the new logical address 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.
10. The memory controller of claim 9 , 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.
11. The memory controller of claim 9 , wherein the control circuitry is configured to apply the new logical address offset to a host logical address.
12. The memory controller of claim 9 , wherein the controller includes controller memory and the control circuitry is configured to store the new logical address offset in the controller memory.
13. The memory controller of claim 12 , wherein the control circuitry is configured to store the new logical address offset until the control circuitry detects a subsequent formatting operation.
14. The memory controller of claim 12 , including an adder coupled to the controller memory and to a memory unit interface, wherein the adder is configured to add the new logical address offset to a host logical address prior to the host logical address being sent across the memory unit interface.
15. The memory controller of claim 9 , 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.
16. 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 is initiated across a host interface of the memory unit and 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, wherein the new logical address 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.
17. The memory system of claim 16 , wherein, in response to detecting the formatting operation, the controller is configured to:
inspect format information from a partition boot record of a system data area of the memory unit; and
determine a starting logical address of a user data area of the memory unit according to the format information.
18. The memory system of claim 17 , wherein the starting logical address of the user data area is aligned with an allocation unit boundary of the file system.
19. The memory system of claim 16 , wherein the memory controller is configured to:
store the new logical address offset until the control circuitry detects a subsequent formatting operation; and
in response to detecting the subsequent formatting operation, calculate a subsequent new logical address offset.
20. The memory system of claim 19 , wherein the new logical address 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; and
wherein the memory controller is configured to replace the stored new logical address offset with the subsequent new logical address offset.