Managing a LBA Interface in a Direct Data File Memory System

• US 20080155227A1
• Filed: 12/26/2006
• Published: 06/26/2008
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Sinclair, Alan W., Wright, Barry
• Granted Patent: US 8,166,267 B2
• Time in Patent Office: Days
• US Class Current: 711/209
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control

Abstract

Data files are assigned addresses within one or more logical blocks of a continuous logical address space interface (LBA interface) of a usual type of flash memory system with physical memory cell blocks. This assignment may be done by the host device which typically, but not necessarily, generates the data files. The number of logical blocks containing data of any one file is controlled in a manner that reduces the amount of fragmentation of file data within the physical memory blocks, thereby to maintain good memory performance. The host may configure the logical blocks of the address space in response to learning the physical characteristics of a memory to which it is connected.

Claims

2-1. The method of claim 1, wherein selecting a block includes selecting the block from said at least one list that has the least amount of valid data addresses therein relative to the amount of valid data addresses in other blocks on the list.

5. A method of managing a continuous logical address space at an interface, comprising:

dividing the logical address space into blocks of distinct addresses,

initially designating addresses of data of individual file objects to be within certain of the blocks, and

thereafter redesignating addresses for at least some of the data of at least one of the individual file objects in at least one block different than initially designated.

6. The method of claim 5, wherein the redesignating addresses includes doing so without changing said at least some of the data of at least one of the individual file objects.