Patents by Inventor Perumal R. Subramonium

Perumal R. Subramonium has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9563567
    Abstract: A method and apparatus for selectively powering down a portion of a cache memory includes determining a power down condition dependent upon a number of accesses to the cache memory. In response to the detection of the power down condition, selecting a group of cache ways included in the cache memory dependent upon a number of cache lines in each cache way that are also included in another cache memory. The method further includes locking and flushing the selected group of cache ways, and then activating a low power mode for the selected group of cache ways.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: February 7, 2017
    Assignee: Apple Inc.
    Inventors: Mahnaz P Sadoughi-Yarandi, Perumal R. Subramonium, Brian P. Lilly, Hari S Kannan
  • Patent number: 9563575
    Abstract: A mechanism for evicting a cache line from a cache memory includes first selecting for eviction a least recently used cache line of a group of invalid cache lines. If all cache lines are valid, selecting for eviction a least recently used cache line of a group of cache lines in which no cache line of the group of cache lines is also stored within a higher level cache memory such as the L1 cache, for example. Lastly, if all cache lines are valid and there are no non-inclusive cache lines, selecting for eviction the least recently used cache line stored in the cache memory.
    Type: Grant
    Filed: November 2, 2015
    Date of Patent: February 7, 2017
    Assignee: Apple Inc.
    Inventors: Brian P. Lilly, Gerard R. Williams, III, Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Hari S. Kannan, Prashant Jain
  • Patent number: 9529730
    Abstract: A method and apparatus for evicting cache lines from a cache memory includes receiving a request from one of a plurality of processors. The cache memory is configured to store a plurality of cache lines, and a given cache line includes an identifier indicating a processor that performed a most recent access of the given cache line. The method further includes selecting a cache line for eviction from a group of least recently used cache lines, where each cache line of the group of least recently used cache lines occupy a priority position less that a predetermined value, and then evicting the selected cache line.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: December 27, 2016
    Assignee: Apple Inc.
    Inventors: Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Brian P. Lilly, Hari S. Kannan
  • Publication number: 20160055099
    Abstract: A mechanism for evicting a cache line from a cache memory includes first selecting for eviction a least recently used cache line of a group of invalid cache lines. If all cache lines are valid, selecting for eviction a least recently used cache line of a group of cache lines in which no cache line of the group of cache lines is also stored within a higher level cache memory such as the L1 cache, for example. Lastly, if all cache lines are valid and there are no non-inclusive cache lines, selecting for eviction the least recently used cache line stored in the cache memory.
    Type: Application
    Filed: November 2, 2015
    Publication date: February 25, 2016
    Inventors: Brian P. Lilly, Gerard R. Williams, III, Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Hari S. Kannan, Prashant Jain
  • Patent number: 9176879
    Abstract: A mechanism for evicting a cache line from a cache memory includes first selecting for eviction a least recently used cache line of a group of invalid cache lines. If all cache lines are valid, selecting for eviction a least recently used cache line of a group of cache lines in which no cache line of the group of cache lines is also stored within a higher level cache memory such as the L1 cache, for example. Lastly, if all cache lines are valid and there are no non-inclusive cache lines, selecting for eviction the least recently used cache line stored in the cache memory.
    Type: Grant
    Filed: July 19, 2013
    Date of Patent: November 3, 2015
    Assignee: Apple Inc.
    Inventors: Brian P. Lilly, Gerard R. Williams, III, Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Hari S. Kannan, Prashant Jain
  • Publication number: 20150309939
    Abstract: A method and apparatus for selectively powering down a portion of a cache memory includes determining a power down condition dependent upon a number of accesses to the cache memory. In response to the detection of the power down condition, selecting a group of cache ways included in the cache memory dependent upon a number of cache lines in each cache way that are also included in another cache memory. The method further includes locking and flushing the selected group of cache ways, and then activating a low power mode for the selected group of cache ways.
    Type: Application
    Filed: April 28, 2014
    Publication date: October 29, 2015
    Applicant: Apple Inc.
    Inventors: Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Brian P. Lilly, Hari S. Kannan
  • Publication number: 20150309944
    Abstract: A method and apparatus for evicting cache lines from a cache memory includes receiving a request from one of a plurality of processors. The cache memory is configured to store a plurality of cache lines, and a given cache line includes an identifier indicating a processor that performed a most recent access of the given cache line. The method further includes selecting a cache line for eviction from a group of least recently used cache lines, where each cache line of the group of least recently used cache lines occupy a priority position less that a predetermined value, and then evicting the selected cache line.
    Type: Application
    Filed: April 28, 2014
    Publication date: October 29, 2015
    Applicant: Apple Inc.
    Inventors: Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Brian P. Lilly, Hari S. Kannan
  • Publication number: 20150026404
    Abstract: A mechanism for evicting a cache line from a cache memory includes first selecting for eviction a least recently used cache line of a group of invalid cache lines. If all cache lines are valid, selecting for eviction a least recently used cache line of a group of cache lines in which no cache line of the group of cache lines is also stored within a higher level cache memory such as the L1 cache, for example. Lastly, if all cache lines are valid and there are no non-inclusive cache lines, selecting for eviction the least recently used cache line stored in the cache memory.
    Type: Application
    Filed: July 19, 2013
    Publication date: January 22, 2015
    Applicant: Apple Inc.
    Inventors: Brian P. Lilly, Gerard R. Williams, III, Mahnaz Sadoughi-Yarandi, Perumal R. Subramonium, Hari S. Kannan, Prashant Jain