Patents by Inventor Shubhodeep Roy Choudhury

Shubhodeep Roy Choudhury 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: 8099559
    Abstract: A system and method for intentionally invaliding translation entry valid bits in order to provoke storage interrupts when executing a test case is presented. Prior to executing the test case, an interrupt handler pseudo-randomly invalidates a number of translation entries included in a translation lookaside buffer (TLB) by changing particular valid bits in order to provoke initial storage interrupts, such as an instruction storage interrupt (ISI) or a data storage interrupt (DSI). Once the processor executes the test case that, in turn, triggers a storage interrupt, the interrupt handler uses an index counter to validate particular valid bits and invalidate other valid bits, thus provoking subsequent storage interrupts. In one embodiment, the interrupt handler also changes valid bits in a page table when the processor executes in a mode that accesses the page table in addition to the TLB.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: January 17, 2012
    Assignee: International Business Machines Corporation
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Patent number: 8019566
    Abstract: A system and method for using a single test case to test each sector within multiple congruence classes is presented. A test case generator builds a test case for accessing each sector within a congruence class. Since a congruence class spans multiple congruence pages, the test case generator builds the test case over multiple congruence pages in order for the test case to test the entire congruence class. During design verification and validation, a test case executor modifies a congruence class identifier (e.g., patches a base register), which forces the test case to test a specific congruence class. By incrementing the congruence class identifier after each execution of the test case, the test case executor is able to test each congruence class in the cache using a single test case.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: September 13, 2011
    Assignee: International Business Machines Corporation
    Inventors: Vinod Bussa, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Batchu Naga Venkata Satyanarayana
  • Patent number: 8006221
    Abstract: A system and method for generating a test case and a bit mask that allows a test case executor the ability to re-execute the test case multiple times using different machine state register bit sets. A test case generator creates a bit mask based upon identified invariant bits and semi-invariant bits. The test case generator includes compensation values corresponding to the semi-invariant bits into a test case, and provides the test case, along with the bit mask, to a test case executor. In turn, the test case executor dispatches the test case multiple times, each time with a different machine state register bit set, to a processor. Each of the machine state register bit sets places the processor in different modes.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: August 23, 2011
    Assignee: International Business Machines Corporation
    Inventors: Sampan Arora, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Sai Rupak Mohanan
  • Patent number: 7992059
    Abstract: A system and method for replicating a memory block throughout a main memory and modifying real addresses within an address translation buffer to reference the replicated memory blocks during test case set re-executions in order to fully test the main memory is presented. A test case generator generates a test case set (multiple test cases) along with an initial address translation buffer that includes real addresses that reference an initial memory block. A test case executor modifies the real addresses after each test case set re-execution in order for a processor to test each replicated memory block included in the main memory.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: August 2, 2011
    Assignee: International Business Machines Corporation
    Inventors: Divya Subbarao Anvekar, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor
  • Patent number: 7752499
    Abstract: A system and method for using resource pools and instruction pools for processor design verification and validation is presented. A test case generator organizes processor resources into resource pools using a resource pool mask. Next, the test case generator separates instructions into instruction pools based upon the resources that each instruction requires. The test case generator then creates a test case using one or more sub test cases by assigning a resource pool to each sub test case, identifying instruction pools that correspond the assigned test case, and building each sub test case using instructions included in the identified instruction pools.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: July 6, 2010
    Assignee: International Business Machines Corporation
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Patent number: 7747908
    Abstract: A system and method for creating different start cache and bus states using multiple test patterns for processor design verification and validation is presented. A test pattern generator/tester re-uses test patterns in different configurations that alter cache states and translation lookaside buffer (TLB) states, which produces different timing scenarios on a broadband bus. The test pattern generator/tester creates multiple test patterns for a multi-processor system and executes the test patterns repeatedly in different configurations without rebuilding the test patterns. This enables a system to dedicate more time executing the test patterns instead of building the test patterns. By repeatedly executing the same test patterns in a different configuration, the invention described herein produces different start cache states, different TLB states, along with other processor units, each time the test patterns execute that, in turn, changes the bus timing.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: June 29, 2010
    Assignee: International Business Machines Corporation
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Chakrapani Rayadurgam, Batchu Naga Venkata Satyanarayana
  • Patent number: 7739570
    Abstract: A system and method to reduce verification time by sharing memory between multiple test patterns and performing results checking after each test pattern executes one time is presented. A test pattern generator generates multiple test pattern sets, each of which including multiple test patterns. Each test pattern set is executed by a corresponding thread/processor until each test pattern included in the test pattern set has executed at least once. After all test patterns have executed at least once, a test pattern executor performs a memory error detection check to determine whether the system is functioning correctly. Since the invention described herein waits until all test patterns have executed before performing a memory error detection check, less time is spent on memory error detection checks, which allows more time to execute test patterns.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: June 15, 2010
    Assignee: International Business Machines Corporation
    Inventors: Sandip Bag, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Patent number: 7669083
    Abstract: A system and method for creating multiple test case scenarios from one test case by shuffling the test case instruction order while maintaining relative sub test case instruction order intact is presented. A test case generator generates and provides a test case that includes multiple sub test cases to a test case executor. In turn, the test case executor recursively schedules and dispatches the test case with different shuffled instruction orders to a processor in order to efficiently test the processor. In one embodiment, the test case generator provides multiple test cases to the test case executor. In another embodiment, the test case generator provides test cases to multiple test case executors that, in turn, shuffle the test cases and provide the shuffled test cases to their respective processor.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: February 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Sampan Arora, Sandip Bag, Vinod Bussa, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Batchu Naga Venkata Satyanarayana, Shiraz Mohammad Zaman
  • Patent number: 7661023
    Abstract: A system and method for verifying cache snoop logic and coherency between instruction cache and data cache using instruction stream “holes” that are created by branch instructions is presented. A test pattern generator includes instructions that load/store data into instruction stream holes. In turn, by executing the test pattern, a processor thread loads an L2 cache line into both instruction cache (icache) and data cache (dcache). The test pattern modifies the data in the dcache in response to a store instruction. In turn, the invention described herein identifies whether snoop logic detects the change and updates the icache's corresponding cache line accordingly.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: February 9, 2010
    Assignee: International Business Machines Corporation
    Inventors: Sampan Arora, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Chakrapani Rayadurgam
  • Publication number: 20090307468
    Abstract: A main generator generates a micro generator and initial test cases based upon a processor architecture specifications and user input, such as general purpose register availability, translation information, instruction sequences, base register available, target real memory pages, etc. In turn, the micro generator tests a processor using the initial test cases and subsequent test cases generated by the micro generator. The subsequent test cases may include modified test case properties such as changed machine state register bits, changed instruction sequence (shuffling), changed effective segment ID bits, and/or changed virtual segment ID bits. In addition to generating subsequent test cases, the micro generator performs functions such as test case dispatching, test case scheduling, test case execution, and interrupt handling.
    Type: Application
    Filed: June 6, 2008
    Publication date: December 10, 2009
    Applicant: International Business Machines Corporation
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Patent number: 7584394
    Abstract: A system and method for pseudo-randomly allocating page table memory for test pattern instructions to produce complex test scenarios during processor execution is presented. The invention described herein distributes page table memory across processors and across multiple test patterns, such as when a processor executes “n” test patterns. In addition, the page table memory is allocated using a “true” sharing mode or a “false” sharing mode. The false sharing mode provides flexibility of performing error detection checks on the test pattern results. In addition, since a processor comprises sub units such as a cache, a TLB (translation look aside buffer), an SLB (segment look aside buffer), an MMU (memory management unit), and data/instruction pre-fetch engines, the test patterns effectively use the page table memory to test each of the sub units.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: September 1, 2009
    Assignee: International Business Machines Corporation
    Inventors: Shubhodeep Roy Choudhury, Sandip Bag, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Bhavani Shringari Nanjundiah
  • Publication number: 20090070546
    Abstract: A system and method for intentionally invaliding translation entry valid bits in order to provoke storage interrupts when executing a test case is presented. Prior to executing the test case, an interrupt handler pseudo-randomly invalidates a number of translation entries included in a translation lookaside buffer (TLB) by changing particular valid bits in order to provoke initial storage interrupts, such as an instruction storage interrupt (ISI) or a data storage interrupt (DSI). Once the processor executes the test case that, in turn, triggers a storage interrupt, the interrupt handler uses an index counter to validate particular valid bits and invalidate other valid bits, thus provoking subsequent storage interrupts. In one embodiment, the interrupt handler also changes valid bits in a page table when the processor executes in a mode that accesses the page table in addition to the TLB.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Publication number: 20090070570
    Abstract: A system and method for including independent instructions into a test case for intentionally provoking interrupts that may be used in conjunction with an instruction shuffling process is presented. A test case generator builds a test case that includes intentional interrupt instructions, which are constructed to intentionally provoke an interrupt, such as an instruction storage interrupt (ISI), a data storage interrupt (DSI), and alignment interrupt, and/or a program interrupt (PI). When a processor executes the test case and invokes an interrupt to an interrupt handler, the interrupt handler does not resolve the interrupt, but rather increments an instruction address register or a link register and resumes test case execution at an instruction subsequent to the instruction that caused the interrupt.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Publication number: 20090070631
    Abstract: A system and method for creating multiple test case scenarios from one test case by shuffling the test case instruction order while maintaining relative sub test case instruction order intact is presented. A test case generator generates and provides a test case that includes multiple sub test cases to a test case executor. In turn, the test case executor recursively schedules and dispatches the test case with different shuffled instruction orders to a processor in order to efficiently test the processor. In one embodiment, the test case generator provides multiple test cases to the test case executor. In another embodiment, the test case generator provides test cases to multiple test case executors that, in turn, shuffle the test cases and provide the shuffled test cases to their respective processor.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Sampan Arora, Sandip Bag, Vinod Bussa, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Batchu Naga Venkata Satyanarayana, Shiraz Mohammad Zaman
  • Publication number: 20090070643
    Abstract: A system and method for replicating a memory block throughout a main memory and modifying real addresses within an address translation buffer to reference the replicated memory blocks during test case set re-executions in order to fully test the main memory is presented. A test case generator generates a test case set (multiple test cases) along with an initial address translation buffer that includes real addresses that reference an initial memory block. A test case executor modifies the real addresses after each test case set re-execution in order for a processor to test each replicated memory block included in the main memory.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Divya Subbarao Anvekar, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor
  • Publication number: 20090070532
    Abstract: A system and method for using a single test case to test each sector within multiple congruence classes is presented. A test case generator builds a test case for accessing each sector within a congruence class. Since a congruence class spans multiple congruence pages, the test case generator builds the test case over multiple congruence pages in order for the test case to test the entire congruence class. During design verification and validation, a test case executor modifies a congruence class identifier (e.g., patches a base register), which forces the test case to test a specific congruence class. By incrementing the congruence class identifier after each execution of the test case, the test case executor is able to test each congruence class in the cache using a single test case.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Vinod Bussa, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Batchu Naga Venkata Satyanarayana
  • Publication number: 20090070768
    Abstract: A system and method for using resource pools and instruction pools for processor design verification and validation is presented. A test case generator organizes processor resources into resource pools using a resource pool mask. Next, the test case generator separates instructions into instruction pools based upon the resources that each instruction requires. The test case generator then creates a test case using one or more sub test cases by assigning a resource pool to each sub test case, identifying instruction pools that correspond the assigned test case, and building each sub test case using instructions included in the identified instruction pools.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Rahul Sharad Moharil
  • Publication number: 20090070629
    Abstract: A system and method for generating a test case and a bit mask that allows a test case executor the ability to re-execute the test case multiple times using different machine state register bit sets. A test case generator creates a bit mask based upon identified invariant bits and semi-invariant bits. The test case generator includes compensation values corresponding to the semi-invariant bits into a test case, and provides the test case, along with the bit mask, to a test case executor. In turn, the test case executor dispatches the test case multiple times, each time with a different machine state register bit set, to a processor. Each of the machine state register bit sets places the processor in different modes.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Inventors: Sampan Arora, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Sai Rupak Mohanan
  • Publication number: 20090024876
    Abstract: A system and method for verifying cache snoop logic and coherency between instruction cache and data cache using instruction stream “holes” that are created by branch instructions is presented. A test pattern generator includes instructions that load/store data into instruction stream holes. In turn, by executing the test pattern, a processor thread loads an L2 cache line into both instruction cache (icache) and data cache (dcache). The test pattern modifies the data in the dcache in response to a store instruction. In turn, the invention described herein identifies whether snoop logic detects the change and updates the icache's corresponding cache line accordingly.
    Type: Application
    Filed: July 18, 2007
    Publication date: January 22, 2009
    Inventors: Sampan Arora, Shubhodeep Roy Choudhury, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Chakrapani Rayadurgam
  • Publication number: 20090024891
    Abstract: A system and method for pseudo-randomly allocating page table memory for test pattern instructions to produce complex test scenarios during processor execution is presented. The invention described herein distributes page table memory across processors and across multiple test patterns, such as when a processor executes “n” test patterns. In addition, the page table memory is allocated using a “true” sharing mode or a “false” sharing mode. The false sharing mode provides flexibility of performing error detection checks on the test pattern results. In addition, since a processor comprises sub units such as a cache, a TLB (translation look aside buffer), an SLB (segment look aside buffer), an MMU (memory management unit), and data/instruction pre-fetch engines, the test patterns effectively use the page table memory to test each of the sub units.
    Type: Application
    Filed: July 18, 2007
    Publication date: January 22, 2009
    Inventors: Shubhodeep Roy Choudhury, Sandip Bag, Manoj Dusanapudi, Sunil Suresh Hatti, Shakti Kapoor, Bhavani Shringari Nanjundiah