Patents by Inventor Hock C. So

Hock C. So 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: 7606079
    Abstract: Power consumption in a non-volatile storage device is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: October 20, 2009
    Assignee: SanDisk Corporation
    Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
  • 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
  • Publication number: 20080266975
    Abstract: A non-volatile storage device in which power consumption is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line.
    Type: Application
    Filed: April 25, 2007
    Publication date: October 30, 2008
    Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
  • Publication number: 20080266973
    Abstract: Power consumption in a non-volatile storage device is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line.
    Type: Application
    Filed: April 25, 2007
    Publication date: October 30, 2008
    Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
  • Patent number: 7440327
    Abstract: A non-volatile storage device in which power consumption is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: October 21, 2008
    Assignee: SanDisk Corporation
    Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
  • 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: 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: 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: 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: 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
  • 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
  • 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: 6556465
    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 27, 2002
    Date of Patent: April 29, 2003
    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: 6549456
    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: June 29, 1999
    Date of Patent: April 15, 2003
    Assignee: SanDisk Corporation
    Inventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
  • Publication number: 20030021149
    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: Application
    Filed: October 18, 2001
    Publication date: January 30, 2003
    Inventors: Hock C. So, Sau C. Wong
  • Publication number: 20020149987
    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 27, 2002
    Publication date: October 17, 2002
    Applicant: INVOX TECHNOLOGY
    Inventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
  • Publication number: 20020136044
    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: June 29, 1999
    Publication date: September 26, 2002
    Inventors: CARL W. WERNER, ANDREAS M. HAEBERLI, LEON SEA JIUNN WONG, CHENG-YUAN MICHAEL WANG, HOCK C. SO, SAU C. WONG
  • Patent number: 6370075
    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: June 29, 1999
    Date of Patent: April 9, 2002
    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: 6345000
    Abstract: A non-volatile Flash memory simultaneously performs an erase operation and a write or read operation in the same array of memory cells. The memory has a row based sector architecture, i.e., sectors that contain one or more complete rows of memory cells. During an erase operation, an erase voltage applied to the source lines for one or more rows corresponding to a sector does not affect write or read operations being performed in other sectors, i.e., other rows. Similarly, voltages applied to row lines for access to a memory cell have no effect on the erase operation being performed in another sector. A column line voltage applied for access to a memory cell has little affect on the erase operation. The memory can implement a look-ahead erase for a continuous reading or writing operation.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: February 5, 2002
    Assignee: SanDisk Corporation
    Inventors: Sau C. Wong, Hock C. So, Cheng-Yuan Michael Wang, Roger Ying Kuen Lo