Patents by Inventor Pi-Feng Chiu

Pi-Feng Chiu 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: 11741188
    Abstract: An innovative low-bit-width device may include a first digital-to-analog converter (DAC), a second DAC, a plurality of non-volatile memory (NVM) weight arrays, one or more analog-to-digital converters (ADCs), and a neural circuit. The first DAC is configured to convert a digital input signal into an analog input signal. The second DAC is configured to convert a digital previous hidden state (PHS) signal into an analog PHS signal. NVM weight arrays are configured to compute vector matrix multiplication (VMM) arrays based on the analog input signal and the analog PHS signal. The NVM weight arrays are coupled to the first DAC and the second DAC. The one or more ADCs are coupled to the plurality of NVM weight arrays and are configured to convert the VMM arrays into digital VMM values. The neural circuit is configured to process the digital VMM values into a new hidden state.
    Type: Grant
    Filed: July 8, 2021
    Date of Patent: August 29, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Wen Ma, Pi-Feng Chiu, Minghai Qin, Won Ho Choi, Martin Lueker-Boden
  • Patent number: 11714716
    Abstract: An apparatus is disclosed having a parity buffer having a plurality of parity pages and one or more dies, each die having a plurality of layers in which data may be written. The apparatus also includes a storage controller configured to write a stripe of data across two or more layers of the one or more dies, the stripe having one or more data values and a parity value. When a first data value of the stripe is written, it is stored as a current value in a parity page of the parity buffer, the parity page corresponding to the stripe. For each subsequent data value that is written, an XOR operation is performed with the subsequent data value and the current value of the corresponding parity page and the result of the XOR operation is stored as the current value of the corresponding parity page.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: August 1, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chao Sun, Pi-Feng Chiu, Dejan Vucinic
  • Patent number: 11556311
    Abstract: Technology for reconfigurable input precision in-memory computing is disclosed herein. Reconfigurable input precision allows the bit resolution of input data to be changed to meet the requirements of in-memory computing operations. Voltage sources (that may include DACs) provide voltages that represent input data to memory cell nodes. The resolution of the voltage sources may be reconfigured to change the precision of the input data. In one parallel mode, the number of DACs in a DAC node is used to configure the resolution. In one serial mode, the number of cycles over which a DAC provides voltages is used to configure the resolution. The memory system may include relatively low resolution voltage sources, which avoids the need to have complex high resolution voltage sources (e.g., high resolution DACs). Lower resolution voltage sources can take up less area and/or use less power than higher resolution voltage sources.
    Type: Grant
    Filed: April 16, 2020
    Date of Patent: January 17, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Wen Ma, Pi-Feng Chiu, Won Ho Choi, Martin Lueker-Boden
  • Patent number: 11556616
    Abstract: Systems and methods for reducing the impact of defects within a crossbar memory array when performing multiplication operations in which multiple control lines are concurrently selected are described. A group of memory cells within the crossbar memory array may be controlled by a local word line that is controlled by a local word line gating unit that may be configured to prevent the local word line from being biased to a selected word line voltage during an operation; the local word line may instead be set to a disabling voltage during the operation such that the memory cell currents through the group of memory cells are eliminated. If a defect has caused a short within one of the memory cells of the group of memory cells, then the local word line gating unit may be programmed to hold the local word line at the disabling voltage during multiplication operations.
    Type: Grant
    Filed: October 17, 2019
    Date of Patent: January 17, 2023
    Assignee: SanDisk Technologies LLC
    Inventors: Minghai Qin, Pi-Feng Chiu, Wen Ma, Won Ho Choi
  • Patent number: 11521658
    Abstract: An illustrative embodiment disclosed herein is an apparatus including a non-volatile memory cell and multi-bit input circuitry that simultaneously receives a plurality of bits, receives a supply voltage, converts the plurality of bits and the supply voltage into a multiply voltage, and applies the multiply voltage to the non-volatile memory cell. The non-volatile memory cell may pass a memory cell current in response to the multiply voltage. A magnitude of the multiply voltage may represent a multiplier. The memory cell current may represent a product of the multiplier and a multiplicand stored in the non-volatile memory cell.
    Type: Grant
    Filed: July 2, 2019
    Date of Patent: December 6, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
  • Patent number: 11501141
    Abstract: Enhanced techniques and circuitry are presented herein for artificial neural networks. These artificial neural networks are formed from artificial synapses, which in the implementations herein comprise a memory arrays having non-volatile memory elements. In one implementation, an apparatus comprises a plurality of non-volatile memory arrays configured to store weight values for an artificial neural network. Each of the plurality of non-volatile memory arrays can be configured to receive data from a unified buffer shared among the plurality of non-volatile memory arrays, operate on the data, and shift at least portions of the data to another of the plurality of non-volatile memory arrays.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: November 15, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Pi-Feng Chiu, Won Ho Choi, Wen Ma, Martin Lueker-Boden
  • Publication number: 20220171992
    Abstract: Exemplary methods and apparatus are disclosed that implement super-sparse image/video compression by storing image dictionary elements within a cross-bar resistive random access memory (ReRAM) array (or other suitable cross-bar NVM array). In illustrative examples, each column of the cross-bar ReRAM array stores the values for one dictionary element (such as one 4×4 dictionary element). Methods and apparatus are described for training (configuring) the cross-bar ReRAM array to generate and store the dictionary elements by sequentially applying patches from training images to the array using an unstructured Hebbian training procedure. Additionally, methods and apparatus are described for compressing an input image by applying patches from the input image to the ReRAM array to read out cross-bar column indices identifying the columns storing the various dictionary elements that best fit the image. This may be done in parallel using a set of ReRAM arrays.
    Type: Application
    Filed: February 9, 2022
    Publication date: June 2, 2022
    Inventors: Wen Ma, Minghai Qin, Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
  • Patent number: 11328204
    Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: May 10, 2022
    Assignee: SanDisk Technologies LLC
    Inventors: Won Ho Choi, Pi-Feng Chiu, Wen Ma, Minghai Qin, Gerrit Jan Hemink, Martin Lueker-Boden
  • Patent number: 11275968
    Abstract: Exemplary methods and apparatus are disclosed that implement super-sparse image/video compression by storing image dictionary elements within a cross-bar resistive random access memory (ReRAM) array (or other suitable cross-bar NVM array). In illustrative examples, each column of the cross-bar ReRAM array stores the values for one dictionary element (such as one 4×4 dictionary element). Methods and apparatus are described for training (configuring) the cross-bar ReRAM array to generate and store the dictionary elements by sequentially applying patches from training images to the array using an unstructured Hebbian training procedure. Additionally, methods and apparatus are described for compressing an input image by applying patches from the input image to the ReRAM array to read out cross-bar column indices identifying the columns storing the various dictionary elements that best fit the image. This may be done in parallel using a set of ReRAM arrays.
    Type: Grant
    Filed: February 13, 2019
    Date of Patent: March 15, 2022
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Wen Ma, Minghai Qin, Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
  • Publication number: 20210406124
    Abstract: An apparatus is disclosed having a parity buffer having a plurality of parity pages and one or more dies, each die having a plurality of layers in which data may be written. The apparatus also includes a storage controller configured to write a stripe of data across two or more layers of the one or more dies, the stripe having one or more data values and a parity value. When a first data value of the stripe is written, it is stored as a current value in a parity page of the parity buffer, the parity page corresponding to the stripe. For each subsequent data value that is written, an XOR operation is performed with the subsequent data value and the current value of the corresponding parity page and the result of the XOR operation is stored as the current value of the corresponding parity page.
    Type: Application
    Filed: August 30, 2021
    Publication date: December 30, 2021
    Inventors: Chao Sun, Pi-Feng Chiu, Dejan Vucinic
  • Patent number: 11204705
    Abstract: A memory array controller includes memory media scanning logic to sample a bit error rate of memory blocks of a first memory device. A data management logic may then move data from the first memory device to a second memory device if the bit error rate matches a threshold level. The threshold level is derived from a configurable data retention time parameter for the first memory device. The configurable data retention time parameter may be received from a user or determined utilizing various known machine learning techniques.
    Type: Grant
    Filed: March 5, 2019
    Date of Patent: December 21, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chao Sun, Pi-Feng Chiu, Dejan Vucinic
  • Publication number: 20210334338
    Abstract: An innovative low-bit-width device may include a first digital-to-analog converter (DAC), a second DAC, a plurality of non-volatile memory (NVM) weight arrays, one or more analog-to-digital converters (ADCs), and a neural circuit. The first DAC is configured to convert a digital input signal into an analog input signal. The second DAC is configured to convert a digital previous hidden state (PHS) signal into an analog PHS signal. NVM weight arrays are configured to compute vector matrix multiplication (VMM) arrays based on the analog input signal and the analog PHS signal. The NVM weight arrays are coupled to the first DAC and the second DAC. The one or more ADCs are coupled to the plurality of NVM weight arrays and are configured to convert the VMM arrays into digital VMM values. The neural circuit is configured to process the digital VMM values into a new hidden state.
    Type: Application
    Filed: July 8, 2021
    Publication date: October 28, 2021
    Inventors: Wen Ma, Pi-Feng Chiu, Minghai Qin, Won Ho Choi, Martin Lueker-Boden
  • Publication number: 20210326110
    Abstract: Technology for reconfigurable input precision in-memory computing is disclosed herein. Reconfigurable input precision allows the bit resolution of input data to be changed to meet the requirements of in-memory computing operations. Voltage sources (that may include DACs) provide voltages that represent input data to memory cell nodes. The resolution of the voltage sources may be reconfigured to change the precision of the input data. In one parallel mode, the number of DACs in a DAC node is used to configure the resolution. In one serial mode, the number of cycles over which a DAC provides voltages is used to configure the resolution. The memory system may include relatively low resolution voltage sources, which avoids the need to have complex high resolution voltage sources (e.g., high resolution DACs). Lower resolution voltage sources can take up less area and/or use less power than higher resolution voltage sources.
    Type: Application
    Filed: April 16, 2020
    Publication date: October 21, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Wen Ma, Pi-Feng Chiu, Won Ho Choi, Martin Lueker-Boden
  • Patent number: 11106534
    Abstract: An apparatus is disclosed having a parity buffer having a plurality of parity pages and one or more dies, each die having a plurality of layers in which data may be written. The apparatus also includes a storage controller configured to write a stripe of data across two or more layers of the one or more dies, the stripe having one or more data values and a parity value. When a first data value of the stripe is written, it is stored as a currant value in a parity page of the parity buffer, the parity page corresponding to the stripe. For each subsequent data value that is written, an XOR operation is performed with the subsequent data value and the current value of the corresponding parity page and the result of the XOR operation is stored as the current value of the corresponding parity page.
    Type: Grant
    Filed: February 27, 2019
    Date of Patent: August 31, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chao Sun, Pi-Feng Chiu, Dejan Vucinic
  • Patent number: 11081148
    Abstract: An illustrative embodiment disclosed herein is an apparatus including a non-volatile memory cell and multi-bit input circuitry that simultaneously receives a plurality of bits, receives a supply voltage, converts the plurality of bits and the supply voltage into a multiply voltage, and applies the multiply voltage to the non-volatile memory cell. The non-volatile memory cell may pass a memory cell current in response to the multiply voltage. A magnitude of the multiply voltage may represent a multiplier. The memory cell current may represent a product of the multiplier and a multiplicand stored in the non-volatile memory cell.
    Type: Grant
    Filed: June 12, 2020
    Date of Patent: August 3, 2021
    Assignee: SanDisk Technologies LLC
    Inventors: Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
  • Patent number: 11074318
    Abstract: An innovative low-bit-width device may include a first digital-to-analog converter (DAC), a second DAC, a plurality of non-volatile memory (NVM) weight arrays, one or more analog-to-digital converters (ADCs), and a neural circuit. The first DAC is configured to convert a digital input signal into an analog input signal. The second DAC is configured to convert a digital previous hidden state (PHS) signal into an analog PHS signal. NVM weight arrays are configured to compute vector matrix multiplication (VMM) arrays based on the analog input signal and the analog PHS signal. The NVM weight arrays are coupled to the first DAC and the second DAC. The one or more ADCs are coupled to the plurality of NVM weight arrays and are configured to convert the VMM arrays into digital VMM values. The neural circuit is configured to process the digital VMM values into a new hidden state.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: July 27, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Wen Ma, Pi-Feng Chiu, Minghai Qin, Won Ho Choi, Martin Lueker-Boden
  • Publication number: 20210117499
    Abstract: Systems and methods for reducing the impact of defects within a crossbar memory array when performing multiplication operations in which multiple control lines are concurrently selected are described. A group of memory cells within the crossbar memory array may be controlled by a local word line that is controlled by a local word line gating unit that may be configured to prevent the local word line from being biased to a selected word line voltage during an operation; the local word line may instead be set to a disabling voltage during the operation such that the memory cell currents through the group of memory cells are eliminated. If a defect has caused a short within one of the memory cells of the group of memory cells, then the local word line gating unit may be programmed to hold the local word line at the disabling voltage during multiplication operations.
    Type: Application
    Filed: October 17, 2019
    Publication date: April 22, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Minghai Qin, Pi-Feng Chiu, Wen Ma, Won Ho Choi
  • Publication number: 20210117500
    Abstract: Systems and methods for reducing the impact of defects within a crossbar memory array when performing multiplication operations in which multiple control lines are concurrently selected are described. A group of memory cells within the crossbar memory array may be controlled by a local word line that is controlled by a local word line gating unit that may be configured to prevent the local word line from being biased to a selected word line voltage during an operation; the local word line may instead be set to a disabling voltage during the operation such that the memory cell currents through the group of memory cells are eliminated. If a defect has caused a short within one of the memory cells of the group of memory cells, then the local word line gating unit may be programmed to hold the local word line at the disabling voltage during multiplication operations.
    Type: Application
    Filed: June 26, 2020
    Publication date: April 22, 2021
    Applicant: SanDisk Technologies LLC
    Inventors: Minghai Qin, Pi-Feng Chiu, Wen Ma, Won Ho Choi
  • Publication number: 20200411065
    Abstract: An illustrative embodiment disclosed herein is an apparatus including a non-volatile memory cell and multi-bit input circuitry that simultaneously receives a plurality of bits, receives a supply voltage, converts the plurality of bits and the supply voltage into a multiply voltage, and applies the multiply voltage to the non-volatile memory cell. The non-volatile memory cell may pass a memory cell current in response to the multiply voltage. A magnitude of the multiply voltage may represent a multiplier. The memory cell current may represent a product of the multiplier and a multiplicand stored in the non-volatile memory cell.
    Type: Application
    Filed: July 2, 2019
    Publication date: December 31, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
  • Publication number: 20200411066
    Abstract: An illustrative embodiment disclosed herein is an apparatus including a non-volatile memory cell and multi-bit input circuitry that simultaneously receives a plurality of bits, receives a supply voltage, converts the plurality of bits and the supply voltage into a multiply voltage, and applies the multiply voltage to the non-volatile memory cell. The non-volatile memory cell may pass a memory cell current in response to the multiply voltage. A magnitude of the multiply voltage may represent a multiplier. The memory cell current may represent a product of the multiplier and a multiplicand stored in the non-volatile memory cell.
    Type: Application
    Filed: June 12, 2020
    Publication date: December 31, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden