brad..Assignee: Lexar Media, Inc.
posted on
May 01, 2006 08:33PM
1...the method comprising allocating sets of contiguous logical sectors containing file data from a host system...into logical groups;
Taking 512byte sectors of a host system and converting it to logical groups of flash...tieing the sectors together in a contigious form within one block. Depending on the size of an erase block of the flash...lets say 4KB of space in each block.. and a total of 256 blocks on a flash...They`re taking 512B units previously managed on the host and allocating them into the blocks where the block is managed as 1 unit because of the contiguous effect...while not to over allocate the space...leaving room.
FWIW.. Sectors of the host system are identified as logical sectorsin the above statement..however,in typical HDD(hard disk) technology...which this is about...
Cluster: Single unit of data storage at the FATxx file system logic level....this being
Sector: Single unit of storage at the physical disk level
Cluster addressing..
Im not getting into HDD addressing...clusters are a series of address components of FAT.
You want any more on that..your on your own.
2...ensuring that a logical group includes fewer sectors than there are sector locations in a memory block in the non-volatile memory;
see previous
3...aligning the logical groups with the clusters into which the host system organizes sectors containing file data;
in other words translating the cluster addresses of the host FAT...to the logical groups...creating a lookup file within the flash.
4...writing sectors within a logical group to contiguous locations within the non-volatile memory;
The write sequence used in order to write contiguous data segments to a block.
5...organizing the non-volatile memory such that the corresponding sector in each logical group is written to a corresponding array within the memory;
6...the arrangement being such that the reading then writing of a sector of a cluster to relocate it to a different location in the non-volatile memory takes place within the same array, thereby allowing concurrent relocation of all sectors in a logical group.``
when any one sector 512B within a group need be changed the whole group is rewritten...as it is a contiguous allocated allotment. They have left the space by not over allocating
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I have addressed the differences of contiguous vs. noncontiguous
MOS is capable of both within the same flash...MOS is not a one trick poney as the simple contiguous item above.
MOS functions independent of the of the blocks...it can have related data in different blocks because of its noncontiguous ability...it can contiguously place data for special files.
It is nothing like the above.
doni