Tag memory disk cache architecture
AssigneeWestern Digital Technologies, Inc.
InventorsVirgil V. Wilkins, Ralph H. Castro, Tsun Y. Ng
Life of this patent
Estimating the term…
Abstract
The present invention is embodied in the disk drive having a cache control system that is configured to efficiently respond to host commands by forming variable length segments of memory clusters for caching disk data in contiguous ranges of logical block addresses without regard to the sequential order of the memory clusters. The cache control system has a tag memory usable only for defining the segments. The tag memory has a plurality of tag records pointing to cluster control blocks associated with the memory clusters for defining the segments. The tag memory may be accessed and updated by several state machines in the cache control system and by a microprocessor in the disk drive.
Claims14
A disk drive, comprising:
- a cache memory having a plurality of sequentially-ordered memory clusters for caching disk data of disk sectors identified by logical block addresses;
- and
- a cache control system having a tag memory only usable and configured to define variable length segments of the memory clusters, each segment for caching disk data of a contiguous range of the logical block addresses using the memory clusters without regard to the sequential order of the memory clusters.
A cache control system for caching disk data of disk sectors identified by logical block addresses using a cache memory having a plurality of sequentially ordered memory clusters, comprising a tag memory configured to define variable length segments of memory clusters, each segment for caching disk data of a contiguous range of logical block addresses using the memory clusters without regard to the sequential order of the memory clusters.
Dependencies are inferred from the claim text.