Patents by Inventor Sreejit Chakravarty

Sreejit Chakravarty 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).

  • Publication number: 20240027516
    Abstract: Embodiments herein relate to a test, repair, and diagnostic solution for chip-to-chip interconnects. In one aspect, on a first chip, a first finite state machine (FSM) is coupled to a set of transmit lanes. To test each transmit lane, one at a time, the first FSM is to apply a first periodic signal to a transmit lane under test and concurrently apply a second periodic signal to other transmit lanes of the set of transmit lanes, where a phase of the first periodic signal is opposite to a phase of the second periodic signal. A comparator compares a detected signal on the lane under test to an expected response. The comparator can be on the first chip, when the first chip is tested alone, or on a second chip, where the two chips are tested together.
    Type: Application
    Filed: July 22, 2022
    Publication date: January 25, 2024
    Inventors: Sreejit Chakravarty, Adithya Kashyap, Vijaya Chelli, Micha Shahar, Rakesh Kandula, Dovev Amosi
  • Publication number: 20230084463
    Abstract: Runtime memory BIST techniques are described herein. In one example, a system such as an SoC includes logic to schedule runtime testing of the memory that is non-destructive in multiple phases. Running testing of memory in multiple phases includes triggering a memory built-in self-test (BIST) testing of a subset of memory locations in a phase, where the processing logic is to pause access to the memory during the phase. The processing logic can resume access to the memory between testing phases. The next region of the memory can be tested in the phase that follows. This process can continue until the entire memory is tested, without requiring the system to be powered down.
    Type: Application
    Filed: November 18, 2022
    Publication date: March 16, 2023
    Inventors: Sreejit CHAKRAVARTY, Rakesh KANDULA, Deep BAROT, Vishal VENDE
  • Patent number: 11335428
    Abstract: The disclosed embodiments relate to method, apparatus and system for testing memory circuitry and diagnostic components designed to test the memory circuitry. The memory may be tested regularly using Memory Built-In Self-Test (MBIST) to detect memory failure. Error Correction Code (ECC)/Parity is implemented for SRAM/Register Files/ROM memory structures to protect against transient and permanent faults during runtime. ECC/Parity encoder and decoder logic detect failure on both data and address buses and are intended to catch soft error or structural fault in address decoding logic in SRAM Controller, where data may be read/written from/to different locations due to faults. ECC/parity logic on the memory structures are subject to failures. In certain exemplary embodiments, an array test controller is used to generate and transmit error vectors to thereby determine faulty diagnostic components. The test vectors may be generated randomly to test the diagnostic components during run-time for in-field testing.
    Type: Grant
    Filed: October 9, 2018
    Date of Patent: May 17, 2022
    Assignee: INTEL CORPORATION
    Inventors: Asad Azam, R Selvakumar Raja Gopal, Sreejit Chakravarty, Kaitlyn Chen
  • Patent number: 11257560
    Abstract: A die-to-die repeater circuit includes a transmit circuit coupled to a die-to-die interconnect, the transmit circuit including at least one flip flop to function as a part of a linear feedback shift register (LFSR) to transmit a value across the die-to-die interconnect for design for test (DFT) to check proper operation of the die-to-die interconnect, and a receive circuit coupled to the die-to-die interconnect, the receive circuit including at least one flip flop to function as part of a multiple input shift register (MISR).
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: February 22, 2022
    Assignee: INTEL CORPORATION
    Inventors: Sreejit Chakravarty, Fei Su, Puneet Gupta, Wei Ming Lim, Terrence Huat Hin Tan, Amit Sanghani, Anubhav Sinha, Sudheer V Badana, Rakesh Kandula, Adithya B. S.
  • Patent number: 10859627
    Abstract: A processor, including: a core; system test circuitry, the system test circuitry to be locked during operational processor operation; reset circuitry including a kick-off test (KOT) input, the reset circuitry to detect a reset with the KOT input asserted, and to initiate an in-field system test (IFST) mode; a test interface controller to receive in IFST mode an encrypted test packet having a signature, verify the signature of the test packet, and decrypt the test packet; and IFST control circuitry to cause the system test circuitry to perform an IFST test according to the decrypted test packet and to log or report results.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: December 8, 2020
    Assignee: Intel Corporation
    Inventors: Sreejit Chakravarty, Oscar Mendoza, Ramasubramanian Rajamani, Bryan J. Gran, Sorin Iacobovici, Neel Shah, Michael Neve de Mevergnies, John Cruz Mejia, Amy L. Santoni
  • Patent number: 10491381
    Abstract: A processor, including: a core; system test circuitry, the system test circuitry configured to be locked except during an in-field system test (IFST) mode; IFST control circuitry; and a test interface controller, including: a data interface to receive a test packet; a parser to parse the test packet into a key, a signature, and a stored hash-of-hashes; a decryption circuit to decrypt the signature according to the key and to generate a computed hash-of-hashes; a hash circuit to verify the stored hash-of-hashes against the computed hash-of-hashes; and an IFST interface, wherein the test interface controller is to signal the IFST control circuitry to place the system test circuitry in IFST mode.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: November 26, 2019
    Assignee: Intel Corporation
    Inventors: Neel Shah, Kirk S. Yap, Amy L. Santoni, Michael Neve de Mevergnies, Oscar Mendoza, Sreejit Chakravarty, Ramasubramanian Rajamani, Bryan J. Gran, Sorin Iacobovici
  • Publication number: 20190096503
    Abstract: A die-to-die repeater circuit includes a transmit circuit coupled to a die-to-die interconnect, the transmit circuit including at least one flip flop to function as a part of a linear feedback shift register (LFSR) to transmit a value across the die-to-die interconnect for design for test (DFT) to check proper operation of the die-to-die interconnect, and a receive circuit coupled to the die-to-die interconnect, the receive circuit including at least one flip flop to function as part of a multiple input shift register (MISR).
    Type: Application
    Filed: September 27, 2017
    Publication date: March 28, 2019
    Inventors: Sreejit CHAKRAVARTY, Fei SU, Puneet GUPTA, Wei Ming LIM, Terrence Huat Hin TAN, Amit SANGHANI, Anubhav SINHA, Sudheer V BADANA, Rakesh KANDULA, Adithya B. S.
  • Publication number: 20190051370
    Abstract: The disclosed embodiments relate to method, apparatus and system for testing memory circuitry and diagnostic components designed to test the memory circuitry. The memory may be tested regularly using Memory Built-In Self-Test (MBIST) to detect memory failure. Error Correction Code (ECC)/Parity is implemented for SRAM/Register Files/ROM memory structures to protect against transient and permanent faults during runtime. ECC/Parity encoder and decoder logic detect failure on both data and address buses and are intended to catch soft error or structural fault in address decoding logic in SRAM Controller, where data may be read/written from/to different locations due to faults. ECC/parity logic on the memory structures are subject to failures. In certain exemplary embodiments, an array test controller is used to generate and transmit error vectors to thereby determine faulty diagnostic components. The test vectors may be generated randomly to test the diagnostic components during run-time for in-field testing.
    Type: Application
    Filed: October 9, 2018
    Publication date: February 14, 2019
    Applicant: Intel Corporation
    Inventors: Asad Azam, R Selvakumar Raja Gopal, Sreejit Chakravarty, Kaitlyn Chen
  • Publication number: 20190007200
    Abstract: A processor, including: a core; system test circuitry, the system test circuitry configured to be locked except during an in-field system test (IFST) mode; IFST control circuitry; and a test interface controller, including: a data interface to receive a test packet; a parser to parse the test packet into a key, a signature, and a stored hash-of-hashes; a decryption circuit to decrypt the signature according to the key and to generate a computed hash-of-hashes; a hash circuit to verify the stored hash-of-hashes against the computed hash-of-hashes; and an IFST interface, wherein the test interface controller is to signal the IFST control circuitry to place the system test circuitry in IFST mode.
    Type: Application
    Filed: June 29, 2017
    Publication date: January 3, 2019
    Inventors: Neel Shah, Kirk S. Yap, Amy L. Santoni, Michael Neve de Mevergnies, Oscar Mendoza, Sreejit Chakravarty, Ramasubramanian Rajamani, Bryan J. Gran, Sorin Iacobovici
  • Publication number: 20190004112
    Abstract: A processor, including: a core; system test circuitry, the system test circuitry to be locked during operational processor operation; reset circuitry including a kick-off test (KOT) input, the reset circuitry to detect a reset with the KOT input asserted, and to initiate an in-field system test (IFST) mode; a test interface controller to receive in IFST mode an encrypted test packet having a signature, verify the signature of the test packet, and decrypt the test packet; and IFST control circuitry to cause the system test circuitry to perform an IFST test according to the decrypted test packet and to log or report results.
    Type: Application
    Filed: June 29, 2017
    Publication date: January 3, 2019
    Inventors: Sreejit Chakravarty, Oscar Mendoza, Ramasubramanian Rajamani, Bryan J. Gran, Sorin Iacobovici, Neel Shah, Michael Neve de Mevergnies, John Cruz Mejia, Amy L. Santoni
  • Patent number: 9256505
    Abstract: Methods and systems for generating data transformations to improve ROM yield and programming time. A bit flip register can be configured in association with the ROM and a binary string can be read into the bit flip register on reset. Subsequently, data output from the ROM can be selectively complemented utilizing a content of the bit flip register and the content of the bit flip register can be programmed into the ROM in order to reduce programming time for each ROM. A defective cell can be tolerated by selectively flipping a column with respect to the defective cell to improve yield. A built-in self-test (BIST) engine that generates addresses up to and including content of an address limiting register can be employed to limit the ROM access to a programmed part during testing in order to tolerate defects in any unused location.
    Type: Grant
    Filed: March 17, 2014
    Date of Patent: February 9, 2016
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventor: Sreejit Chakravarty
  • Publication number: 20150261636
    Abstract: Methods and systems for generating data transformations to improve ROM yield and programming time. A bit flip register can be configured in association with the ROM and a binary string can be read into the bit flip register on reset. Subsequently, data output from the ROM can be selectively complemented utilizing a content of the bit flip register and the content of the bit flip register can be programmed into the ROM in order to reduce programming time for each ROM. A defective cell can be tolerated by selectively flipping a column with respect to the defective cell to improve yield. A built-in self-test (BIST) engine that generates addresses up to and including content of an address limiting register can be employed to limit the ROM access to a programmed part during testing in order to tolerate defects in any unused location.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 17, 2015
    Applicant: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Publication number: 20150262710
    Abstract: Methods and systems for reducing memory test time utilizing a serial per march element communicating architecture. A small number of slow speed signals can be configured between a BIST wrapper and a BIST controller to transfer information in accordance with a BIST sequence that includes a number of march elements. An information transfer protocol can be implemented between the BIST wrapper and the BIST controller to transfer Information with respect to each march element that includes a number of BIST operations, address sequencing information, and data pattern. A command register can be loaded utilizing the slow speed signals and slow speed clock and content of the command register can be decoded. An encoded BIST operation can then be executed once for each BIST operation per march element. The serial per march element communicating architecture reduces test time as a communication overhead and a requirement for high speed wires are eliminated.
    Type: Application
    Filed: March 14, 2014
    Publication date: September 17, 2015
    Applicant: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Patent number: 8793549
    Abstract: A self-test module for use in an electronic device includes a test controller and a memory. The memory is configured to receive test vectors from the test controller. A comparator is configured to receive the test data from the memory via an output data path. A strobing buffer is located in the output data path between an output from the memory and an input to the comparator. The strobing buffer is configured to selectively enable the test vectors to propagate from the memory output to the comparator input.
    Type: Grant
    Filed: August 11, 2010
    Date of Patent: July 29, 2014
    Assignee: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Patent number: 8711645
    Abstract: A multiport latch-based memory device includes a latch array, a plurality of first multiplexers, and a second multiplexer. The latch array is responsive to output data from an input data register in a functional mode associated with the latch-based memory device. The plurality of first multiplexers is responsive to output data from the latch array in the functional mode. The plurality of first multiplexers is responsive to output data from the input data register in a test mode associated with the latch-based memory device. The second multiplexer selectively provides output data from the plurality of first multiplexers to the input data register in the test mode, thereby providing a data path bypassing the latch array in the test mode. Embodiments of a corresponding method and computer-readable medium are also provided.
    Type: Grant
    Filed: March 27, 2012
    Date of Patent: April 29, 2014
    Assignee: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Patent number: 8656233
    Abstract: A scan cell is configured to receive first, second and third data bits at respective first, second and third data inputs. A control input is configured to receive a control signal. Latching logic is configured to latch data received at the first and second latch inputs to a scan cell output. The first latch input is configured to receive the first data bit. Selection logic is configured to select between the second and third data bits depending on a state of the control signal, and to provide the selected bit to the second latch input.
    Type: Grant
    Filed: December 30, 2010
    Date of Patent: February 18, 2014
    Assignee: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Patent number: 8583973
    Abstract: An integrated circuit chip that supports stored-pattern (SP) logic built-in self-testing (LBIST) includes a device under test (DUT) and a test controller. System-level SP LBIST testing is performed using an external, system ATE (automated test equipment) that transmits test input data to the test controller for application to the DUT, which generates test output data that is transmitted from the test controller to the system ATE, which performs golden signature comparisons on the test output data. During system-level DUT testing, all communications between the system ATE and the chip are via a single interface, such as a conventional, serial JTAG port.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: November 12, 2013
    Assignee: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Publication number: 20130258786
    Abstract: A multiport latch-based memory device includes a latch array, a plurality of first multiplexers, and a second multiplexer. The latch array is responsive to output data from an input data register in a functional mode associated with the latch-based memory device. The plurality of first multiplexers is responsive to output data from the latch array in the functional mode. The plurality of first multiplexers is responsive to output data from the input data register in a test mode associated with the latch-based memory device. The second multiplexer selectively provides output data from the plurality of first multiplexers to the input data register in the test mode, thereby providing a data path bypassing the latch array in the test mode. Embodiments of a corresponding method and computer-readable medium are also provided.
    Type: Application
    Filed: March 27, 2012
    Publication date: October 3, 2013
    Applicant: LSI CORPORATION
    Inventor: Sreejit Chakravarty
  • Patent number: 8499230
    Abstract: A path monitor, a method of monitoring a path, an integrated circuit and a library of standard logic elements. In one embodiment, the path monitor includes: (1) a delay element having an input couplable to an input of a clocked flip-flop associated with a path to be monitored and configured to provide a predetermined delay and (2) a clocked exclusive OR gate having a clock input, a first input coupled to an output of the delay element, a second input couplable to the output of the clocked flip-flop and an output at which the clocked exclusive OR gate is configured to respond to a clock signal to provide an error signal only when logic levels of the first input and the second input differ.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: July 30, 2013
    Assignee: LSI Corporation
    Inventor: Sreejit Chakravarty
  • Patent number: 8473890
    Abstract: A timing error sampling generator, a method of performing timing tests and a library of cells are provided. In one embodiment, the timing error sampling generator includes: (1) a hold delay element having an input and an output and configured to provide a hold violation delayed signal at said output by providing a first predetermined delay to a clock signal received at said input, said first predetermined delay corresponding to a hold violation time for a path to be monitored and (2) a hold logic element having a first input coupled to said input of said hold delay element, a second input coupled to said output of said hold delay element and an output at which said hold logic element is configured to respond to said first and second inputs to provide a clock hold signal when logic levels at said first and second inputs are at a same level.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: June 25, 2013
    Assignee: LSI Corporation
    Inventors: Alexander Tetelbaum, Sreejit Chakravarty