Flash controller cache architecture
AssigneeSanDisck Corporation LLP
InventorsKevin M. Conley, Reuven Elhamias
Life of this patent
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Abstract
A buffer cache interposed between a non-volatile memory and a host may be partitioned into segments that may operate with different policies. Cache policies include write-through, write back and read-look-ahead. Write-through and write back policies may improve speed. Read-look-ahead cache allows more efficient use of the bus between the buffer cache and non-volatile memory. A session command allows data to be maintained in volatile memory by guaranteeing against power loss.
Claims11
A method of handling data streams between a host interface and a flash memory array within a removable memory card using a buffer cache in communication with both the host interface and the flash memory array, comprising:
- partitioning the buffer cache into at least a first segment and a second segment;
- determining a first caching policy for the first segment;
- and
- determining a second caching policy for the second segment.
A method of transferring data from a non-volatile, non-rotating memory array to a host interface in a memory card using a buffer cache disposed between the non-volatile memory array and the host interface, the host interface connecting the memory card to a host, comprising:
- receiving a first address range from the host that identifies a first portion of data to be transferred from the non-volatile memory array;
- copying the first portion of data from the non-volatile memory array to the buffer cache;
- copying a second portion of data from the non-volatile memory array to the buffer cache, the second portion of data not being identified by the host for transfer from the non-volatile memory array;
- and
- sending the first portion of data from the buffer cache to the host while keeping the second portion of data in the buffer cache.
Dependencies are inferred from the claim text.