Patents Represented by Attorney William Pennie & Edmonds LLP Galliani
  • Patent number: 5920889
    Abstract: An apparatus for processing a write miss signal from a copy-back data cache includes a load-store unit with an allocating load buffer, a non-allocating store buffer, and a priority control circuit to generate write-after-read hazards and read-after-write hazards to preserve the processing priority of entries within the allocating load buffer and the non-allocating store buffer. A prefetch circuit enqueues a prefetch command in the allocating load buffer and a store command in the non-allocating store buffer upon a write miss to the copy-back data cache. Thus, the priority control circuit forces a write-after-read hazard on the store command in the non-allocating store buffer. As a result, the prefetch command in the allocating load buffer secures an allocated line in the copy-back data cache, allowing the store command of the non-allocating store buffer to write data to the allocated line.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: July 6, 1999
    Assignee: Sun Microsystems, Inc.
    Inventors: Bruce Petrick, Dale Greenley