Abstract: The present invention relates to a disk drive including a cache memory having a plurality of sequentially-ordered memory clusters for caching disk data stored in sectors (not shown) on disks of a disk assembly. The disk sectors are identified by logical block addresses (LBAs). A cache control system of the disk drive comprises a cluster control block memory, having a plurality of cluster control blocks (CCB), and a tag memory 22, having a plurality of tag records, that are embedded within the cache control system. Each CCB includes a cluster segment record with an entry for associating the CCB with a particular memory cluster and for forming variable length segments of the memory clusters without regard to the sequential order of the memory clusters. Each tag record assigns a segment to a continuous range of LBAs and defines the CCBs forming the segment. Each segment of the memory clusters is for caching data from a contiguous range of the logical block addresses.

Abstract: The present invention relates to disk drive having a cache control system that generates scan results that permit response to a host command using existing cached data having a logical block address (LBA) range that overlaps a host command LBA range. The cache control system forms variable length segments of memory clusters in a cache memory for caching disk data in contiguous LBA ranges. The cached LBA ranges are scanned for segments having LBA ranges overlapping with an LBA range of a host command. The cache control system is effective in exploiting any existing overlapping cache data.

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.

Abstract: The present invention relates to a disk drive 10 comprising a cache memory 14 and a cache control system having a tag memory having a plurality of tag records, and means for allocating a tag record for responding to a host command. The cache memory has a plurality of sequentially-ordered memory clusters 46 for caching disk data stored in sectors (not shown) on disks of a disk assembly 38. Conventionally the disk sectors are identified by logical block addresses (LBAs). The cache control system 12 along with the tag memory 22 and means for allocating tag records are embedded within the cache control system 12 and thereby configured only for use in defining variable length segments of the memory clusters 46. The segments are defined without regard to the sequential order of the memory clusters 46.

Abstract: The present invention relates to a disk drive including a cache memory having a plurality of sequentially-ordered memory clusters for caching disk data stored in sectors (not shown) on disks of a disk assembly. The disk sectors are identified by logical block addresses (LBAs). A cache control system of the disk drive comprises a cluster control block memory, having a plurality of cluster control blocks (CCB), and a tag memory 22, having a plurality of tag records, that are embedded within the cache control system. Each CCB includes a cluster segment record with an entry for associating the CCB with a particular memory cluster and for forming variable length segments of the memory clusters without regard to the sequential order of the memory clusters. Each tag record assigns a segment to a continuous range of LBAs and defines the CCBs forming the segment. Each segment of the memory clusters is for caching data from a contiguous range of the logical block addresses.

Abstract: The present invention relates to disk drive having a cache control system that generates scan results that permit response to a host command using existing cached data having a logical block address (LBA) range that overlaps a host command LBA range. The cache control system forms variable length segments of memory clusters in a cache memory for caching disk data in contiguous LBA ranges. The cached LBA ranges are scanned for segments having LBA ranges overlapping with an LBA range of a host command.

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.