Interfacing systems operating through a logical address space and on a direct data file basis

• US 20070033323A1
• Filed: 08/03/2005
• Published: 02/08/2007
• Est. Priority Date: 08/03/2005
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Corporation (Western Digital Corporation)
• Inventors: Gorobets, Sergey
• Granted Patent: US 7,480,766 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A re-programmable non-volatile semiconductor memory, such as flash memory, operates to store files with logical addresses including a unique file identifier and offsets of data within the file, termed direct data file storage. Data files generated by a host may be stored directly in such a memory through a file interface. But if a traditional host/memory interface using a continuous logical address space is being used to identify multiple files, the address space is divided into contiguous logical files, and then these files are treated in the same manner as files obtained directly from a host. Both types of interfaces may be included in the same memory system.

Claims

1. A method, comprising:

maintaining a continuous logical address space into which addresses of a first set of individual data files are mapped,

dividing the logical address space into groups of addresses without regard to how data of individual files are mapped, and

treating data within the groups of addresses as a second set of individual data files.

2. The method of claim 1, wherein at least some of the groups of addresses are equal in size.

3. A method of operating a memory system, comprising:

receiving a plurality of separate files of data identified by addresses within a continuous logical address space that does not contain an identification of the logical addresses of data within the separate files,

operating with the logical address space divided into a plurality of contiguous logical address groups,

logically addressing the data within the individual logical address groups by a unique group identification and offsets of data within the group, and

mapping data of the plurality of logical address groups into the memory system.

4. The method of claim 3, wherein individual ones of the plurality of logical address groups contain a predetermined amount of data.

5. The method of claim 4, wherein the memory system includes re-programmable non-volatile semiconductor memory cells divided into non-overlapping units, and wherein the predetermined amount of data of the individual logical address groups equals a data storage capacity of the individual memory cell units.

6. The method of claim 5, wherein the individual memory cell units contain at least one block of memory cells, wherein a block contains a minimum number of memory cells that are erasable together.

7. The method of claim 6, wherein the individual memory cell units contain two or more blocks of memory cells that are logically linked together as a metablock.

8. The method of claim 3, wherein the memory system operates its memory cells to individually store more than one bit of data.

9. The method of claim 3, additionally comprising:

receiving a second plurality of separate files of data identified by unique file identifications and offsets of data within the individual second plurality of files, and

mapping data of the second plurality of files directly into the memory system.

10. The method of claim 9, wherein the memory is partitioned into at least a first partition into which data of the plurality of logical address groups are mapped and a second partition into which data of the second plurality of received files are directly mapped.

11. The method of claim 10, wherein the memory is partitioned into a third partition into which data controlling operation of the memory system are stored.

12. The method of claim 11, wherein the memory is partitioned into a fourth partition that is usable to receive data from either of the plurality of logical address groups or the second plurality of received files.

13. The method of claim 9, wherein data from the plurality of logical address groups and the second plurality of received files are both mapped into a common partition of the memory.

14. The method of claim 13, wherein the memory is partitioned into the common partition and a second partition into which data controlling operation of the memory system are stored.

15. The method of claim 14, wherein the memory is additionally partitioned into a third partitions of erased units of memory cells that are usable to receive data from either of the plurality of logical address groups or the second plurality of received files.

16. A method of operating a re-programmable non-volatile memory system of a type having semiconductor memory cells divided into units of cells and an interface including a logical address space over which a plurality of data files received from a host through the interface are identified, comprising:

operating with the logical address space divided into a plurality of contiguous logical address groups having sizes equal to the storage capacity of the individual units of memory cells, and

maintaining a table for mapping the logical groups into specific ones of the units of memory cells as separate files that individually have a unique file identification and offsets of data within the file.

17. The method of claim 16, additionally comprising:

receiving a second plurality of separate files of data identified by unique file identifications and offsets of data within the individual second plurality of files, and

maintaining a table for mapping the second plurality of files directly into specific units of memory cells within the memory system.

18. A method of operating a non-volatile memory system of a type having memory cells divided into units of cells, comprising:

storing data in the memory system as files addressed by a unique file identification and offsets of data within the file,

in response to receiving host data files from outside of the memory that are addressed by a unique file identification and offsets of data within the file, directly storing the received data files in the memory system by such a file address, and

in response to receiving host data from outside of the memory that are addressed within a logical address space of the memory rather than as a host data file, storing the received host data as memory files of data addressed within predetermined groups of local address ranges, the memory files being stored by a unique file identification and offsets of data within the memory file.

19. The method of claim 18, wherein the units of memory cells within the memory system are partitioned into at least a first group into which host data files are directly mapped and a second group into which the memory data files are directly mapped.

20. The method of claim 19, wherein the units of memory cells within the memory system are partitioned into a third group into which data controlling operation of the memory system are stored.

21. The method of claim 20, wherein the units of memory cells within the memory system are partitioned into a fourth group of erased units of memory cells that are usable to receive either host data files or memory data files.

22. The method of claim 19, wherein the predetermined groups of local address ranges individually include an amount of data equal to the storage capacity of individual units of memory cells.

23. The method of claim 18, wherein the host data files and memory data files are both mapped into a common group of units of memory cells.

24. The method of claim 23, wherein the predetermined groups of local address ranges individually include an amount of data equal to the storage capacity of individual units of memory cells.

25. The method of claim 23, wherein the units of memory cells within the memory system are partitioned into the common group and a second group into which data controlling operation of the memory system are stored.

26. The method of claim 25, wherein the units of memory cells within the memory system are additionally partitioned into a third group of erased units of memory cells that are usable to receive either host data files or memory data files.

27. The method of claim 18, wherein the predetermined groups of local address ranges individually include an amount of data equal to the storage capacity of individual units of memory cells.

28. Electronic apparatus, comprising:

a first system having an interface that identifies a first set of data files by unique addresses within a continuous logical address space,

a second system having an interface that identifies a second set of data files by unique identifications of the files and offsets of data within the individual files, and

a file converter that divides the continuous logical address space into distinct groups of addresses and identifies data within these groups of addresses as the second set of data files.

29. Apparatus according to claim 28, wherein the file converter divides the continuous logical address space into distinct groups of addresses of the same size, whereby the data files of the second set of data files are also of the same size.

30. A data storage system, comprising:

an addressable memory,

an operational controller that causes addressed portions of the memory to be accessed for programming and reading data,

an interface including a continuous logical address space into which a plurality of host files may be mapped but which does not contain an identification of the addresses within the logical address space occupied by individual host files, and

address translation between (a) unique groups of addresses within the logical address space identified as logical files with a unique file identifier and offsets of data within the file but without regard to logical addresses of host files that occupy the logical address space and (b) addresses of physical portions of the memory.

31. The memory system of claim 30, additionally comprising:

a second interface for communication with a host system of host data logical files addressed by a unique host file identifier and offsets of data within the identified host file.

32. A re-programmable non-volatile memory system, comprising:

an array of memory cells that individually include at least one charge storage element and which is divided into units of memory cells,

a first address translator between (a) addresses of logical files that individually include a unique file identifier and offsets of data within the identified file and (b) physical addresses of at least some of the units of memory cells,

an operational controller that causes said at least some of the units of memory cells to be accessed for programming and reading data of the logical files,

an interface including a continuous logical address space into which a plurality of host files may be mapped but which does not contain an identification of the addresses within the logical address space occupied by individual host files, and

a second address translator between (a) groups of addresses within the logical address space identified as logical files with a unique file identifier and offsets of data within the file and (b) addresses of logical files of the first address translator.

33. The memory system of claim 32, additionally comprising:

a second interface for communication with a host system of host data logical files addressed by a unique host file identifier and offsets of data within the identified host file,

34. The memory system of claim 32, wherein the second address translator translates addresses between groups of addresses within the logical address space that individually contain the same amount of data as a storage capacity of individual units of memory cells.

35. The memory system of claim 34, wherein the units of memory cells of the array individually include at least one block of memory cells, wherein a block contains a minimum number of memory cells that are erasable together.

36. The memory system of claim 35, wherein the units of memory cells of the array individually include two or more blocks of memory cells that are logically linked together as a metablock.

37. The memory system of claim 32, wherein the operational controller additionally operates to store one of more than two measurable levels of charge on individual charge storage elements that represents the data being stored thereon, thereby to store more than one bit of data on the individual charge storage elements.

38. The memory system of claim 33, wherein the first address translator additionally operates to map addresses of those logical files formed from groups of addresses within the logical address space of the second interface into a different set of memory cell units than addresses of those host logical files passing through the first interface.

39. The memory system of claim 33, wherein the first address translator additionally operates to map addresses of those logical files formed from groups of addresses within the logical address space of the second interface and addresses of those host logical files passing through the first interface into a common set of memory cell units.