Patents by Inventor Kedarnath Balakrishnan

Kedarnath Balakrishnan 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: 10275352
    Abstract: Systems, apparatuses, and methods for identifying response data arriving out-of-order from two different memory types are disclosed. A computing system includes one or more clients for processing applications. A memory channel transfers memory traffic between a memory controller and a memory bus connected to each of a first memory and a second memory different from the first memory. The memory controller determines a given point in time when read data is to be scheduled to arrive on the memory bus from memory. The memory controller associates a unique identifier with the given point in time. The memory controller identifies a given command associated with the arriving read data based on the given point in time.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: April 30, 2019
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Kedarnath Balakrishnan, James Raymond Magro
  • Patent number: 10198216
    Abstract: In one form, a data processing system includes a memory channel having a plurality of ranks, and a data processor. The data processor is coupled to the memory channel and is adapted to access each of the plurality of ranks. In response to detecting a predetermined event, the data processor selects an active rank of the plurality of ranks and places other ranks besides the active rank in a low power state, wherein the other ranks include at least one rank with a pending request at a time of detection of the predetermined event. The data processor subsequently processes a memory access request to the active rank.
    Type: Grant
    Filed: May 28, 2016
    Date of Patent: February 5, 2019
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Kedarnath Balakrishnan, Kevin M. Brandl, James R. Magro
  • Patent number: 10037150
    Abstract: In one form, a memory controller has a memory channel controller including a command queue and an arbiter. The command queue stores memory access requests including a sub-channel number in a virtual controller mode. The arbiter is coupled to the command queue to select memory access commands from the command queue according to predetermined criteria. In the virtual controller mode, the arbiter selects from among the memory access requests in each sub-channel independently using the predetermined criteria, and sends selected memory access requests to a corresponding one of a plurality of sub-channels. In another form, a data processing system includes a plurality of memory channels and such a memory controller coupled to the plurality of sub-channels.
    Type: Grant
    Filed: August 31, 2016
    Date of Patent: July 31, 2018
    Assignee: Advanced Micro Devices, Inc.
    Inventors: James R. Magro, Kedarnath Balakrishnan
  • Patent number: 9899074
    Abstract: A data processing system includes a memory channel and a data processor coupled to the memory channel. The data processor is adapted to access at least one rank and has refresh logic. In response to an activation of the refresh logic, the data processor generates refresh cycles to a bank of the memory channel. The data processor selects one of a first state corresponding to a first auto-refresh command that causes the data processor to auto-refresh the bank, and a second state corresponding to a second auto-refresh command that causes the data processor to auto-refresh a selected subset of the bank. The data processor initiates a switch between the first state and the second state in response to the refresh logic detecting a first condition related to the bank, and between the second state and the first state in response to the refresh logic circuit detecting a second condition.
    Type: Grant
    Filed: January 17, 2017
    Date of Patent: February 20, 2018
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Kedarnath Balakrishnan
  • Publication number: 20180018105
    Abstract: In one form, a memory controller has a memory channel controller including a command queue and an arbiter. The command queue stores memory access requests including a sub-channel number in a virtual controller mode. The arbiter is coupled to the command queue to select memory access commands from the command queue according to predetermined criteria. In the virtual controller mode, the arbiter selects from among the memory access requests in each sub-channel independently using the predetermined criteria, and sends selected memory access requests to a corresponding one of a plurality of sub-channels. In another form, a data processing system includes a plurality of memory channels and such a memory controller coupled to the plurality of sub-channels.
    Type: Application
    Filed: August 31, 2016
    Publication date: January 18, 2018
    Applicant: Advanced Micro Devices, Inc.
    Inventors: James R. Magro, Kedarnath Balakrishnan
  • Publication number: 20180019006
    Abstract: A memory controller includes a host interface for receiving memory access requests including access addresses, a memory interface for providing memory accesses to a memory system, and an address decoder coupled to the host interface for programmably mapping the access addresses to selected ones of a plurality of regions. The address decoder is programmable to map the access addresses to a first region having a non-power-of-two size using a primary decoder and a secondary decoder each having power-of-two sizes, and providing a first region mapping signal in response. A command queue stores the memory access requests and region mapping signals. An arbiter picks the memory access requests from the command queue based on a plurality of criteria, which are evaluated based in part on the region mapping signals, and provides corresponding memory accesses to the memory interface in response.
    Type: Application
    Filed: July 15, 2016
    Publication date: January 18, 2018
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Kevin M. Brandl, Thomas Hamilton, Hideki Kanayama, Kedarnath Balakrishnan, James R. Magro, Guanhao Shen, Mark Fowler
  • Publication number: 20180018133
    Abstract: In one form, an apparatus includes a memory controller. The memory controller includes a command queue and an arbiter. The command queue receives and stores memory access requests. The arbiter picks the memory access requests from the command queue based on a plurality of criteria, and provides picked memory access requests to a memory channel. The arbiter includes a streak counter for counting a number of consecutive memory access requests of a first type that the arbiter picks from the command queue. When the streak counter reaches a threshold, the arbiter suspends picking requests of the first type and picks at least one memory access request of a second type. The arbiter provides the at least one memory access request of the second type to the memory channel.
    Type: Application
    Filed: September 22, 2016
    Publication date: January 18, 2018
    Applicant: Advanced Micro Devices, Inc.
    Inventor: Kedarnath Balakrishnan
  • Publication number: 20180018221
    Abstract: In one form, a memory controller includes a command queue, an arbiter, and a replay queue. The command queue receives and stores memory access requests. The arbiter is coupled to the command queue for providing a sequence of memory commands to a memory channel. The replay queue stores the sequence of memory commands to the memory channel, and continues to store memory access commands that have not yet received responses from the memory channel. When a response indicates a completion of a corresponding memory command without any error, the replay queue removes the corresponding memory command without taking further action. When a response indicates a completion of the corresponding memory command with an error, the replay queue replays at least the corresponding memory command. In another form, a data processing system includes the memory controller, a memory accessing agent, and a memory system to which the memory controller is coupled.
    Type: Application
    Filed: December 9, 2016
    Publication date: January 18, 2018
    Applicant: Advanced Micro Devices, Inc.
    Inventors: James R. Magro, Ruihua Peng, Anthony Asaro, Kedarnath Balakrishnan, Scott P. Murphy, YuBin Yao
  • Publication number: 20180018291
    Abstract: In one form, a memory controller includes a command queue and an arbiter. The command queue receives and stores memory access requests. The arbiter includes a plurality of sub-arbiters for providing a corresponding plurality of sub-arbitration winners from among the memory access requests during a controller cycle, and for selecting among the plurality of sub-arbitration winners to provide a plurality of memory commands in a corresponding controller cycle. In another form, a data processing system includes a memory accessing agent for providing memory accesses requests, a memory system, and the memory controller coupled to the memory accessing agent and the memory system.
    Type: Application
    Filed: July 15, 2016
    Publication date: January 18, 2018
    Applicant: Advanced Micro Devices, Inc.
    Inventors: James R. Magro, Kedarnath Balakrishnan, Jackson Peng, Hideki Kanayama
  • Publication number: 20170345482
    Abstract: A data processing system includes a memory channel and a data processor coupled to the memory channel. The data processor is adapted to access at least one rank and has refresh logic. In response to an activation of the refresh logic, the data processor generates refresh cycles to a bank of the memory channel. The data processor selects one of a first state corresponding to a first auto-refresh command that causes the data processor to auto-refresh the bank, and a second state corresponding to a second auto-refresh command that causes the data processor to auto-refresh a selected subset of the bank. The data processor initiates a switch between the first state and the second state in response to the refresh logic detecting a first condition related to the bank, and between the second state and the first state in response to the refresh logic circuit detecting a second condition.
    Type: Application
    Filed: January 17, 2017
    Publication date: November 30, 2017
    Applicant: Advanced Micro Devices, Inc.
    Inventor: Kedarnath Balakrishnan
  • Publication number: 20170344309
    Abstract: In one form, a data processing system includes a memory channel having a plurality of ranks, and a data processor. The data processor is coupled to the memory channel and is adapted to access each of the plurality of ranks. In response to detecting a predetermined event, the data processor selects an active rank of the plurality of ranks and places other ranks besides the active rank in a low power state, wherein the other ranks include at least one rank with a pending request at a time of detection of the predetermined event. The data processor subsequently processes a memory access request to the active rank.
    Type: Application
    Filed: May 28, 2016
    Publication date: November 30, 2017
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Kedarnath Balakrishnan, Kevin M. Brandl, James R. Magro
  • Patent number: 9576637
    Abstract: A data processing system includes a memory channel and a data processor coupled to the memory channel. The data processor is adapted to access at least one rank and has refresh logic. In response to an activation of the refresh logic, the data processor generates refresh cycles to a bank of the memory channel. The data processor selects one of a first state corresponding to a first auto-refresh command that causes the data processor to auto-refresh the bank, and a second state corresponding to a second auto-refresh command that causes the data processor to auto-refresh a selected subset of the bank. The data processor initiates a switch between the first state and the second state in response to the refresh logic detecting a first condition related to the bank, and between the second state and the first state in response to the refresh logic circuit detecting a second condition.
    Type: Grant
    Filed: May 25, 2016
    Date of Patent: February 21, 2017
    Assignee: ADVANCED MICRO DEVICES, INC.
    Inventor: Kedarnath Balakrishnan
  • Patent number: 7610540
    Abstract: Disclosed is a logic testing system that includes a decompressor and a tester in communication with the decompressor. The tester is configured to store a seed and locations of scan inputs and is further configured to transmit the seed and the locations of scan inputs to the decompressor. The decompressor is configured to generate a test pattern from the seed and the locations of scan inputs. The decompressor includes a first test pattern generator, a second test pattern generator, and a selector configured to select the test pattern generated by the first test pattern generator or the test pattern generated by the second test pattern generator using the locations of scan inputs.
    Type: Grant
    Filed: November 5, 2008
    Date of Patent: October 27, 2009
    Assignee: NEC Laboratories America, Inc.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar
  • Patent number: 7610539
    Abstract: Disclosed is a logic testing system that includes a decompressor and a tester in communication with the decompressor. The tester is configured to store a seed and locations of scan inputs and is further configured to transmit the seed and the locations of scan inputs to the decompressor. The decompressor is configured to generate a test pattern from the seed and the locations of scan inputs. The decompressor includes a first test pattern generator, a second test pattern generator, and a selector configured to select the test pattern generated by the first test pattern generator or the test pattern generated by the second test pattern generator using the locations of scan inputs.
    Type: Grant
    Filed: November 5, 2008
    Date of Patent: October 27, 2009
    Assignee: NEC Laboratories America, Inc.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar
  • Publication number: 20090119563
    Abstract: Disclosed is a logic testing system that includes a decompressor and a tester in communication with the decompressor. The tester is configured to store a seed and locations of scan inputs and is further configured to transmit the seed and the locations of scan inputs to the decompressor. The decompressor is configured to generate a test pattern from the seed and the locations of scan inputs. The decompressor includes a first test pattern generator, a second test pattern generator, and a selector configured to select the test pattern generated by the first test pattern generator or the test pattern generated by the second test pattern generator using the locations of scan inputs.
    Type: Application
    Filed: November 5, 2008
    Publication date: May 7, 2009
    Applicant: NEC Laboratories America, Inc.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar
  • Publication number: 20090119556
    Abstract: Disclosed is a logic testing system that includes a decompressor and a tester in communication with the decompressor. The tester is configured to store a seed and locations of scan inputs and is further configured to transmit the seed and the locations of scan inputs to the decompressor. The decompressor is configured to generate a test pattern from the seed and the locations of scan inputs. The decompressor includes a first test pattern generator, a second test pattern generator, and a selector configured to select the test pattern generated by the first test pattern generator or the test pattern generated by the second test pattern generator using the locations of scan inputs.
    Type: Application
    Filed: November 5, 2008
    Publication date: May 7, 2009
    Applicant: NEC LABORATORIES AMERICA, INC.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar
  • Patent number: 7484151
    Abstract: Disclosed is a logic testing system that includes a decompressor and a tester in communication with the decompressor. The tester is configured to store a seed and locations of scan inputs and is further configured to transmit the seed and the locations of scan inputs to the decompressor. The decompressor is configured to generate a test pattern from the seed and the locations of scan inputs. The decompressor includes a first test pattern generator, a second test pattern generator, and a selector configured to select the test pattern generated by the first test pattern generator or the test pattern generated by the second test pattern generator using the locations of scan inputs.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: January 27, 2009
    Assignee: NEC Laboratories America, Inc.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar
  • Publication number: 20080092093
    Abstract: A method includes inserting test points into a circuit for reducing the number of specified bits required for transition fault testing of the circuit by reducing the dependency of a second time-frame pattern of the circuit on a first time-frame pattern of the circuit. Preferably, inserting the test points includes controlling directly scan flip-flops of the circuit in the second time-frame requiring a number of scan flip-flops to be specified in the first time-frame for reducing the number of specified bits to detect transition faults.
    Type: Application
    Filed: September 20, 2007
    Publication date: April 17, 2008
    Applicant: NEC LABORATORIES AMERICA, INC.
    Inventors: Kedarnath Balakrishnan, Lei Fang
  • Patent number: 7302626
    Abstract: The present invention is directed to a logic testing architecture with an improved decompression engine that compresses the seeds of a linear test pattern generator in a manner that is independent of the test pattern set.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: November 27, 2007
    Assignee: NEC Laboratories America, Inc.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Srimat T. Chakradhar
  • Publication number: 20070266283
    Abstract: Disclosed is an apparatus and method for testing an IC having a plurality of scan chains. A test input is transmitted over a tester channel to at least one scan chain during a time interval. Specifically, a memory element stores a first test input transmitted during a first time interval and a combinational circuit connected to the memory element and scan chain transmits to the scan chain one of a) the first test input and b) a second test input transmitted over the tester channel during a second time interval occurring after the first time interval.
    Type: Application
    Filed: March 28, 2007
    Publication date: November 15, 2007
    Applicant: NEC LABORATORIES AMERICA, INC.
    Inventors: Kedarnath Balakrishnan, Seongmoon Wang, Wenlong Wei, Srimat T. Chakradhar