Patents by Inventor Sau C. Wong

Sau C. Wong 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: 7554844
    Abstract: Techniques are used to store information in a medium such as the memory cells of an integrated circuit, and also retrieval of information from the medium. The integrated circuit includes nonvolatile memory cells (416) capable of multilevel or analog voltage level storage. The integrated circuit may store or record information in analog or digital form, or both. Information is stored in and retrieved from the integrated circuit using a user-selected sampling frequency. The user's selection of the sampling frequency is stored within the integrated circuit.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: June 30, 2009
    Assignee: SanDisk Corporation
    Inventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
  • Patent number: 7397697
    Abstract: A multibit-per-cell non-volatile memory divides the suitable threshold voltages of memory cells into ranges corresponding to allowed states for storage of data and ranges corresponding to forbidden zones indicating a data error. A read process checks whether a threshold voltage is in a forbidden zone. Alternately, a refresh process includes reprogramming the threshold voltage into an allowed state. In the case of a flash memory, a refresh reads a sector of the memory and saves corrected data from the sector in a buffer or another sector. The corrected data from the buffer or other sector can be written back in the original sector, or the corrected data can be left in the other sector with addresses of the original sector being mapped to the other sector. Refresh process for the non-volatile memory can be performed in response to detecting a threshold voltage in a forbidden zone or periodically.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: July 8, 2008
    Assignee: SanDisk Corporation
    Inventors: Hock C. So, Sau C. Wong
  • Patent number: 7349255
    Abstract: A non-volatile semiconductor memory includes: multiple write pipelines, each including a memory array; a timing circuit which sequentially starts programming operations in the pipelines; and a shared charge pump and voltage regulation circuit that drives a current through the memory cells being programmed. Staggering the starts of programming operations reduces the current demand on the charge pump because spikes that occur at the starts of programming operations, for example, when using channel hot electron injection, are distributed over time rather than occurring all at once. Noise, which can reduce the accuracy of write operations, is also reduced because the total current required from the charge pump is more nearly constant. As further aspect of the invention, each write pipeline can perform a write operation as alternating programming cycles and verify cycles.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: March 25, 2008
    Assignee: SanDisk Corporation
    Inventor: Sau C. Wong
  • Patent number: 7298670
    Abstract: Techniques are used to store information in a medium such as the memory cells of an integrated circuit, and also retrieval of information from the medium. The integrated circuit includes nonvolatile memory cells (416) capable of multilevel or analog voltage level storage. The integrated circuit may store or record information in analog or digital form, or both. Information is stored in and retrieved from the integrated circuit using a user-selected sampling frequency. The user's selection of the sampling frequency is stored within the integrated circuit.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: November 20, 2007
    Assignee: SanDisk Corporation
    Inventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
  • Patent number: 7268809
    Abstract: A digital imaging system uses a high density, high speed analog/multi-level memory to temporarily store image data at high rates for extended periods of time. A portion of the stored data is transmitted for image processing and compression. When image processing and compression on the data are completed, another portion of the stored data is transmitted for processing. As a result, high speed image capture for extended periods is possible because the processing speed of the image processing and compression no longer limit the time required between high speed bursts or the length of a high speed burst.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: September 11, 2007
    Assignee: San Disk Corporation
    Inventors: Sau C. Wong, Leo Petropoulos
  • Patent number: 7170781
    Abstract: A multibit-per-cell non-volatile memory divides the suitable threshold voltages of memory cells into ranges corresponding to allowed states for storage of data and ranges corresponding to forbidden zones indicating a data error. A read process in accordance automatically checks whether a threshold voltage is in a forbidden zone. In an alternative embodiment, a refresh process includes reprogramming the threshold voltage into an allowed state. In the case of a flash memory, a refresh reads a sector of the memory and saves corrected data from the sector in a buffer or another sector. The corrected data from the buffer or other sector can be written back in the original sector, or the corrected data can be left in the other sector with addresses of the original sector being mapped to the other sector.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: January 30, 2007
    Assignee: SanDisk Corporation
    Inventors: Hock C. So, Sau C. Wong
  • Patent number: 7106632
    Abstract: Techniques are used to store information in a medium such as the memory cells of an integrated circuit, and also retrieval of information from the medium. The integrated circuit includes nonvolatile memory cells (416) capable of multilevel or analog voltage level storage. The integrated circuit may store or record information in analog or digital form, or both. Information is stored in and retrieved from the integrated circuit using a user-selected sampling frequency. The user's selection of the sampling frequency is stored within the integrated circuit.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: September 12, 2006
    Assignee: SanDisk Corporation
    Inventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
  • Patent number: 7080192
    Abstract: A non-volatile, multi-bit-per-cell, Flash memory uses a storage process and/or architecture that is not sector-based. A data block can be stored without unused storage cells remaining in the last sector that stores part of the data block. For an operation erasing one or more data blocks, data blocks to be saved are read from an array and stored temporarily in a storage device. The entire array is then erased, after which the saved data blocks are rewritten in the memory with the amount of storage originally allocated to the erased data now being available for new data. This data arrangement does not subject any memory cells to a large accumulated cell disturbance because all data is read from the array and freshly re-written back into the array every time a record operation occurs. Additionally, the separate sectors in the memory device do not have different endurance histories that must be accounted for to extend the life of the memory.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: July 18, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sau C. Wong
  • Patent number: 6944058
    Abstract: A non-volatile semiconductor memory includes: multiple write pipelines, each including a memory array; a timing circuit which sequentially starts programming operations in the pipelines; and a shared charge pump and voltage regulation circuit that drives a current through the memory cells being programmed. Staggering the starts of programming operations reduces the current demand on the charge pump because spikes that occur at the starts of programming operations, for example, when using channel hot electron injection, are distributed over time rather than occurring all at once. Noise, which can reduce the accuracy of write operations, is also reduced because the total current required from the charge pump is more nearly constant. As further aspect of the invention, each write pipeline can perform a write operation as alternating programming cycles and verify cycles.
    Type: Grant
    Filed: June 13, 2003
    Date of Patent: September 13, 2005
    Assignee: SanDisk Corporation
    Inventor: Sau C. Wong
  • Patent number: 6898117
    Abstract: A memory architecture for a non-volatile analog or multiple-bits-per-cell memory includes multiple separate memory arrays and multiple read/write pipelines. The multiple read/write pipelines share a read circuit and/or a write circuit to reduce the circuit area of each pipeline and the circuit area of the memory as a whole. In one embodiment, a shared write circuit generates a programming voltage that changes with an input signal representing values to be written to the memory. Each pipeline includes a sample-and-hold circuit that samples the programming voltage when the pipeline begins a write operation. The write circuit can additionally generate a verify voltage that a second sample-and-hold circuit in each pipeline samples when starting a write operation.
    Type: Grant
    Filed: October 18, 2001
    Date of Patent: May 24, 2005
    Assignee: SanDisk Corporation
    Inventors: Hock C. So, Sau C. Wong
  • Patent number: 6760068
    Abstract: A method and system using a sensor array includes a programmable analog/multi-level memory array for modifying individual outputs from elements in the sensor array in order to obtain a desired sensor array output. The memory array can be programmed with data corresponding to desired modifications, such as low and high offset voltage correction, low gain correction, and gamma correction. Consequently, by utilizing arithmetic circuits, the adverse effects of corrupted elements in a sensor can be corrected by re-programming the memory array with different modification data as the need arises.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: July 6, 2004
    Assignee: SanDisk Corporation
    Inventors: Leo Petropoulos, Sau C. Wong
  • Patent number: 6760262
    Abstract: An integrated circuit detects the voltage level of the supply voltage to the integrated circuit. Circuity on the integrated circuit including the charge pump circuity adjusts to operate more effectively or efficiently at the voltage level of the supply voltage.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: July 6, 2004
    Assignee: SanDisk Corporation
    Inventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
  • Patent number: 6662263
    Abstract: A non-volatile, multi-bit-per-cell, Flash memory uses a storage process and/or architecture that is not sector-based. A data block can be stored without unused storage cells remaining in the last sector that stores part of the data block. For an operation erasing one or more data blocks, data blocks to be saved are read from an array and stored temporarily in a storage device. The entire array is then erased; after which the saved data blocks are rewritten in the memory with the amount of storage originally allocated to the erased data now being available for new data. This data arrangement does not subject any memory cells to a large accumulated cell disturbance because all data is read from the array and freshly re-written back into the array every time a record operation occurs. Additionally, the separate sectors in the memory device do not have different endurance histories that must be accounted for to extend the life of the memory.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: December 9, 2003
    Assignee: Multi Level Memory Technology
    Inventor: Sau C. Wong
  • Publication number: 20030206469
    Abstract: A non-volatile semiconductor memory includes: multiple write pipelines, each including a memory array; a timing circuit which sequentially starts programming operations in the pipelines; and a shared charge pump and voltage regulation circuit that drives a current through the memory cells being programmed. Staggering the starts of programming operations reduces the current demand on the charge pump because spikes that occur at the starts of programming operations, for example, when using channel hot electron injection, are distributed over time rather than occurring all at once. Noise, which can reduce the accuracy of write operations, is also reduced because the total current required from the charge pump is more nearly constant. As further aspect of the invention, each write pipeline can perform a write operation as alternating programming cycles and verify cycles.
    Type: Application
    Filed: June 13, 2003
    Publication date: November 6, 2003
    Inventor: Sau C. Wong
  • Publication number: 20030202389
    Abstract: Techniques are used to store information in a medium such as the memory cells of an integrated circuit, and also retrieval of information from the medium. The integrated circuit includes nonvolatile memory cells (416) capable of multilevel or analog voltage level storage. The integrated circuit may store or record information in analog or digital form, or both. Information is stored in and retrieved from the integrated circuit using a user-selected sampling frequency. The user's selection of the sampling frequency is stored within the integrated circuit.
    Type: Application
    Filed: February 5, 2003
    Publication date: October 30, 2003
    Applicant: SanDisk Corporation, a Delaware Corporation
    Inventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
  • Patent number: 6624773
    Abstract: A scrambling or encryption method involves analog-to-digital, digital-to-analog, analog-to-analog or digital-to-digital conversions that are constructed from one or more analog-to-digital or digital-to-analog conversions. For example, encryption of an analog signal converts the analog signal to an intermediate digital signal that is converted back into a scrambled analog signal. Encryption of a digital signal converts the digital signal to an intermediate analog signal that is converted back into an encrypted digital signal. The conversions between analog form and digital form and back can be repeated. A codec scrambling/descrambling and encryption/decryption implements one or more different analog-to-digital conversions and one or more digital-to-analog conversions. One embodiment of the codec includes a programmable conversion array that includes an array of transistors such as floating gate transistors in memory cells.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: September 23, 2003
    Assignee: SanDisk Corporation
    Inventor: Sau C. Wong
  • Publication number: 20030161171
    Abstract: An integrated circuit detects the voltage level of the supply voltage to the integrated circuit. Circuity on the integrated circuit including the charge pump circuity adjusts to operate more effectively or efficiently at the voltage level of the supply voltage.
    Type: Application
    Filed: March 4, 2003
    Publication date: August 28, 2003
    Applicant: INVOX TECHNOLOGY, a California Corporation
    Inventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
  • Patent number: 6606267
    Abstract: A non-volatile semiconductor memory includes: multiple write pipelines, each including a memory array; a timing circuit which sequentially starts programming operations in the pipelines; and a shared charge pump and voltage regulation circuit that drives a current through the memory cells being programmed. Staggering the starts of programming operations reduces the current demand on the charge pump because spikes that occur at the starts of programming operations, for example, when using channel hot electron injection, are distributed over time rather than occurring all at once. Noise, which can reduce the accuracy of write operations, is also reduced because the total current required from the charge pump is more nearly constant. As further aspect of the invention, each write pipeline can perform a write operation as alternating programming cycles and verify cycles.
    Type: Grant
    Filed: October 18, 2001
    Date of Patent: August 12, 2003
    Assignee: SanDisk Corporation
    Inventor: Sau C. Wong
  • Patent number: 6594036
    Abstract: A digital imaging system uses an analog/multi-level memory to store image data. The stored analog/multi-level data can then be accessed directly by an analog device or the data can be accessed by an A/D converter for conversion to a digital format. The digital data is then routed to any number of desired digital devices. By using an analog/multi-level memory instead of a digital memory to store image data, problems associated with storing large amounts of digital data are minimized or eliminated, such as loss of information from image compression and high costs of large digital memories and signal processing and compression circuits.
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: July 15, 2003
    Assignee: SanDisk Corporation
    Inventors: Sau C. Wong, Leo Petropoulos, John H. Chan
  • Publication number: 20030090580
    Abstract: A method and system using a sensor array includes a programmable analog/multi-level memory array for modifying individual outputs from elements in the sensor array in order to obtain a desired sensor array output. The memory array can be programmed with data corresponding to desired modifications, such as low and high offset voltage correction, low gain correction, and gamma correction. Consequently, by utilizing arithmetic circuits, the adverse effects of corrupted elements in a sensor can be corrected by re-programming the memory array with different modification data as the need arises.
    Type: Application
    Filed: December 31, 1998
    Publication date: May 15, 2003
    Inventors: LEO PETROPOULOS, SAU C. WONG