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).
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Patent number: 7606079Abstract: 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: GrantFiled: April 25, 2007Date of Patent: October 20, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
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Patent number: 7554844Abstract: 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: GrantFiled: October 22, 2007Date of Patent: June 30, 2009Assignee: SanDisk CorporationInventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
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Publication number: 20080266973Abstract: 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: ApplicationFiled: April 25, 2007Publication date: October 30, 2008Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
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Publication number: 20080266975Abstract: 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: ApplicationFiled: April 25, 2007Publication date: October 30, 2008Inventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
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Patent number: 7440327Abstract: 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: GrantFiled: April 25, 2007Date of Patent: October 21, 2008Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
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Patent number: 7397697Abstract: 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: GrantFiled: January 5, 2007Date of Patent: July 8, 2008Assignee: SanDisk CorporationInventors: Hock C. So, Sau C. Wong
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Patent number: 7298670Abstract: 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: GrantFiled: July 27, 2006Date of Patent: November 20, 2007Assignee: SanDisk CorporationInventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
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Patent number: 7170781Abstract: 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: GrantFiled: April 7, 2005Date of Patent: January 30, 2007Assignee: SanDisk CorporationInventors: Hock C. So, Sau C. Wong
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Patent number: 7106632Abstract: 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: GrantFiled: February 5, 2003Date of Patent: September 12, 2006Assignee: SanDisk CorporationInventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
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Patent number: 6898117Abstract: 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: GrantFiled: October 18, 2001Date of Patent: May 24, 2005Assignee: SanDisk CorporationInventors: Hock C. So, Sau C. Wong
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Patent number: 6760262Abstract: 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: GrantFiled: March 4, 2003Date of Patent: July 6, 2004Assignee: SanDisk CorporationInventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
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Publication number: 20030202389Abstract: 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: ApplicationFiled: February 5, 2003Publication date: October 30, 2003Applicant: SanDisk Corporation, a Delaware CorporationInventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
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Publication number: 20030161171Abstract: 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: ApplicationFiled: March 4, 2003Publication date: August 28, 2003Applicant: INVOX TECHNOLOGY, a California CorporationInventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
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Patent number: 6556465Abstract: 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: GrantFiled: March 27, 2002Date of Patent: April 29, 2003Assignee: SanDisk CorporationInventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
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Patent number: 6549456Abstract: 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: GrantFiled: June 29, 1999Date of Patent: April 15, 2003Assignee: SanDisk CorporationInventors: Carl W. Werner, Andreas M. Haeberli, Leon Sea Jiunn Wong, Cheng-Yuan Michael Wang, Hock C. So, Sau C. Wong
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Publication number: 20030021149Abstract: 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: ApplicationFiled: October 18, 2001Publication date: January 30, 2003Inventors: Hock C. So, Sau C. Wong
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Publication number: 20020149987Abstract: 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: ApplicationFiled: March 27, 2002Publication date: October 17, 2002Applicant: INVOX TECHNOLOGYInventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
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Publication number: 20020136044Abstract: 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: ApplicationFiled: June 29, 1999Publication date: September 26, 2002Inventors: CARL W. WERNER, ANDREAS M. HAEBERLI, LEON SEA JIUNN WONG, CHENG-YUAN MICHAEL WANG, HOCK C. SO, SAU C. WONG
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Patent number: 6370075Abstract: 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: GrantFiled: June 29, 1999Date of Patent: April 9, 2002Assignee: SanDisk CorporationInventors: Andreas M. Haeberli, Sau C. Wong, Hock C. So, Carl W. Werner, Cheng-Yuan Michael Wang, Leon Sea Jiunn Wong
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Patent number: 6345000Abstract: 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: GrantFiled: November 25, 1998Date of Patent: February 5, 2002Assignee: SanDisk CorporationInventors: Sau C. Wong, Hock C. So, Cheng-Yuan Michael Wang, Roger Ying Kuen Lo