Patents by Inventor Anil Pai
Anil Pai 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).
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Patent number: 11869619Abstract: Systems and methods are provided that combine a write duty cycle adjuster with write training to reduce detection and duty cycle errors in memory devices. Various embodiments herein perform write duty cycle adjuster operations to adjust a duty cycle of a clock signal that coordinates a data signal with a data operation on the memory device based on an error in the duty cycle, and performs write training operations to detect a skew between the data signal and the clock signal and adjust a sampling transition of the duty cycle of the clock signal to align with a valid data window of the data signal.Type: GrantFiled: May 31, 2022Date of Patent: January 9, 2024Assignee: SANDISK TECHNOLOGIES LLCInventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Prasad Ramachandra
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Publication number: 20230395108Abstract: Systems and methods disclosed herein provide for selectively activating or deactivating one or more memory of a memory array, such that related data path logic of deactivated memory dies neither detects nor processes control signals or data signals for data operations. Examples of the systems and methods provided herein operate to detect a first enable signal at a memory die and detect a first data signal on input/output (I/O) receivers of the memory die. Responsive to detecting at least the first enable signal, a bit value encoded in the first data signal is latched to obtain a first bit pattern. A second bit pattern is obtained, and, based on a comparison of the first bit pattern to the second bit pattern, the I/O receivers of the memory die are activated.Type: ApplicationFiled: June 3, 2022Publication date: December 7, 2023Inventors: SNEHA BHATIA, Sajal Mittal, Venkatesh Prasad Ramachandra, Anil Pai
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Publication number: 20230386600Abstract: Systems and methods are provided that combine a write duty cycle adjuster with write training to reduce detection and duty cycle errors in memory devices. Various embodiments herein perform write duty cycle adjuster operations to adjust a duty cycle of a clock signal that coordinates a data signal with a data operation on the memory device based on an error in the duty cycle, and performs write training operations to detect a skew between the data signal and the clock signal and adjust a sampling transition of the duty cycle of the clock signal to align with a valid data window of the data signal.Type: ApplicationFiled: May 31, 2022Publication date: November 30, 2023Inventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Prasad Ramachandra
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Publication number: 20230386584Abstract: Systems and methods are provided for correcting errors in unmatched memory devices. Various embodiments herein train a memory interface to determine a duty cycle timing for a clock signal in a data window formed by a data signal in a memory cell. The duty cycle timing identifies an initial trained timing in the data window at which a setup portion and a hold portion of the data window are approximately equal in length when the trigger signal is received at the initial trained timing. The embodiments herein also identify an event that shifts the duty cycle timing away from the initial trained timing, and triggers a retraining of the memory interface based on a determination that at least one of two points defined about the initial trained timing fails a two-point sampling.Type: ApplicationFiled: May 27, 2022Publication date: November 30, 2023Inventors: Venkatesh Prasad RAMACHANDRA, Jang Woo LEE, Srinivas RAJENDRA, Anil PAI
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Patent number: 11829281Abstract: Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.Type: GrantFiled: June 16, 2021Date of Patent: November 28, 2023Assignee: SanDisk Technologies LLCInventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Ramachandra
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Publication number: 20230377677Abstract: Techniques for mitigating/eliminating the impact of duty distortion caused by delays in clock paths within a built-in high-frequency test circuit for NAND flash are disclosed. By mitigating or eliminating the impact of duty distortion, accuracy of the valid data window measurement is ensured. Rising edges of a strobe clock signal and an inverted strobe clock signal are used to respectively locate even and odd data (or vice versa) within an input buffer of the NAND flash during respective sweeps of the strobe and inverted strobe clock signals. In this manner, even if the strobe clock signal's duty ratio is distorted, there is no impact on the valid data window measurement. Further, read latency is used to introduce delay to a read enable (RE) clock signal, thereby obviating the need for a replica controlled delay in the RE clock path and eliminating the duty distortion that would otherwise occur.Type: ApplicationFiled: May 20, 2022Publication date: November 23, 2023Inventors: HOON CHOI, Anil Pai, Venkatesh Prasad Ramachandra
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Publication number: 20220405190Abstract: Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.Type: ApplicationFiled: June 16, 2021Publication date: December 22, 2022Applicant: SanDisk Technologies LLCInventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Ramachandra
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Patent number: 11482262Abstract: Technology is disclosed herein for per pin internal reference voltage generation for data receivers in non-volatile memory systems. A receiving circuit may have an on-die voltage generator that has inputs to receive a separate voltage magnitude select signal for each data receiver on the receiving circuit. The on-die voltage generator provides a separate reference voltage for each data receiver. This allows the reference voltage for each data receiver to be calibrated separately. A separate reference voltage for each data receiver compensates for variations between data paths, and provides for a wider data valid window than if the same reference voltage were used for all data receivers. Generating the different reference voltages on-die can potentially require a large area, as well as consume considerable power and/or current. A voltage divider and multiplexers may provide the different reference voltages, which saves space and is power and current efficient.Type: GrantFiled: June 16, 2021Date of Patent: October 25, 2022Assignee: SanDisk Technologies LLCInventors: Jang Woo Lee, Srinivas Rajendra, Anil Pai, Venkatesh Ramachandra
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Patent number: 10528255Abstract: Apparatuses, systems, methods, and computer program products are disclosed for accessing non-volatile memory. An apparatus includes one or more memory die. A memory die includes an array of non-volatile memory cells, a set of ports, and an on-die controller. The set of ports includes a first port and a second port. The first port includes a first plurality of electrical contacts and the second port includes a second plurality of electrical contacts. The on-die controller communicates via the set of ports to receive command and address information and to transfer data for a data operation on the array of non-volatile memory cells. The on-die controller uses the first port and the second port in a first mode and uses the first port without the second port in a second mode. The second mode provides compatibility with an interface of a legacy type of memory die.Type: GrantFiled: November 30, 2016Date of Patent: January 7, 2020Assignee: SanDisk Technologies LLCInventors: Jiwang Lee, Anil Pai, Tianyu Tang, Ravindra Arjun Madpur, Amandeep Kaur, Ragul Kumar Krishnan, Venkata Kolagatla
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Publication number: 20180350412Abstract: An adaptive parallel-serial converter may receive parallel data comprising a data unit in a first data format and generate a data sequence comprising the data unit in a second format, different from the first data format. The adaptive parallel-serial converter may comprise a serialization circuit comprising a plurality of registers, which may be configured to shift data of the data unit in a circular, reversible pattern. Selection circuitry may select one of the registers to produce a sequence of data values as data is shifted in either a forward direction or a reverse direction. The output selection and shift direction may be configured to convert the format of the data unit as the data unit is serialized.Type: ApplicationFiled: June 6, 2017Publication date: December 6, 2018Inventors: Jiwang Lee, Anil Pai
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Publication number: 20180136843Abstract: Apparatuses, systems, methods, and computer program products are disclosed for accessing non-volatile memory. An apparatus includes one or more memory die. A memory die includes an array of non-volatile memory cells, a set of ports, and an on-die controller. The set of ports includes a first port and a second port. The first port includes a first plurality of electrical contacts and the second port includes a second plurality of electrical contacts. The on-die controller communicates via the set of ports to receive command and address information and to transfer data for a data operation on the array of non-volatile memory cells. The on-die controller uses the first port and the second port in a first mode and uses the first port without the second port in a second mode. The second mode provides compatibility with an interface of a legacy type of memory die.Type: ApplicationFiled: November 30, 2016Publication date: May 17, 2018Applicant: SanDisk Technologies LLCInventors: Jiwang Lee, Anil Pai, Tianyu Tang, Ravindra Arjun Madpur, Amandeep Kaur, Ragul Kumar Krishnan, Venkata Kolagatla