Patents by Inventor Brady L. Keays

Brady L. Keays 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: 7774683
    Abstract: Improved memory devices, circuitry, and data methods are described that facilitate the detection and correction of data in memory systems or devices in combination with a stored record of known flaws, errors, or questionable data bits of a read memory row or block to allow for more efficient processing and correction of these errors. An embodiment of the present invention utilizes an erasure pointer that can store the location of N bad or questionable bits in the memory segment that is currently being read, where for each bit stored by the erasure pointer the embodiment also contains 2N ECC generators to allow the read data to be quickly checked with the known bad bits in each possible state. This allows the read data to then be easily corrected on the fly before it is transferred by selecting the bad bit state indicated by the ECC generator detecting an uncorrupted read.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: August 10, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Brady L. Keays, Shuba Swaminathan, William H. Radke
  • Publication number: 20090125670
    Abstract: An improved Flash memory device with a distributed erase block management (EBM) scheme is detailed that enhances operation and helps minimize write fatigue of the floating gate memory cells of the Flash memory device. The Flash memory device of the invention combines the EBM data in a user data erase block by placing it in an EBM data field of the control data section of the erase block sectors. Therefore distributing the EBM data within the Flash memory erase block structure. This allows the Flash memory to update and/or erase the user data and the EBM data in a single operation, to reduce overhead and speed operation. The Flash memory also reduces the process of EBM data structure write fatigue by allowing the EBM data fields to be load leveled by rotating them with the erase blocks they describe.
    Type: Application
    Filed: November 17, 2008
    Publication date: May 14, 2009
    Inventor: Brady L. Keays
  • Publication number: 20090019340
    Abstract: Methods are described that facilitate the detection and correction of data in memory systems or devices by encoding the data bits of a memory row or block in a non-systematic ECC code. This allows memory embodiments of the present invention to utilize reduced complexity error detection and correction hardware and/or routines to efficiently detect and correct corrupted user data in a segment of memory, such as a sector, word line row, or erase block. User data is not stored in a plaintext format in the memory array, allowing for an increased level of data security. The ECC code is distributed throughout the stored data in the memory segment, increasing the robustness of the ECC code and its resistance to damage or data corruption.
    Type: Application
    Filed: September 18, 2008
    Publication date: January 15, 2009
    Inventors: William H. Radke, Shuba Swaminathan, Brady L. Keays
  • Patent number: 7454558
    Abstract: An improved Flash memory device with a distributed erase block management (EBM) scheme is detailed that enhances operation and helps minimize write fatigue of the floating gate memory cells of the Flash memory device. The Flash memory device of the invention combines the EBM data in a user data erase block by placing it in an EBM data field of the control data section of the erase block sectors. Therefore distributing the EBM data within the Flash memory erase block structure. This allows the Flash memory to update and/or erase the user data and the EBM data in a single operation, to reduce overhead and speed operation. The Flash memory also reduces the process of EBM data structure write fatigue by allowing the EBM data fields to be load leveled by rotating them with the erase blocks they describe.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: November 18, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 7444579
    Abstract: Improved memory devices, circuitry, and data methods are described that facilitate the detection and correction of data in memory systems or devices by encoding the data bits of a memory row or block in a non-systematic ECC code. This allows memory embodiments of the present invention to utilize reduced complexity error detection and correction hardware and/or routines to efficiently detect and correct corrupted user data in a segment of memory, such as a sector, word line row, or erase block. Additionally, in embodiments of the present invention user data is not stored in a plaintext format in the memory array, allowing for an increased level of data security. Further, in embodiments of the present invention, the ECC code is distributed throughout the stored data in the memory segment, increasing the robustness of the ECC code and its resistance to damage or data corruption.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: October 28, 2008
    Assignee: Micron Technology, Inc.
    Inventors: William H. Radke, Shuba Swaminathan, Brady L. Keays
  • Patent number: 7389465
    Abstract: Data is read from a memory array. Before being stored in a data buffer, a Hamming code detection operation and a Reed-Solomon code detection operation are operated in parallel to determine if the data word has any errors. The results of the parallel detection operations are communicated to a controller circuit. If an error is present that can be corrected by the Hamming code correction operation, this is performed and the Reed-Solomon code detection operation is performed on the corrected word. If the error is uncorrectable by the Hamming code, the Reed-Solomon code correction operation is performed on the word.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: June 17, 2008
    Assignee: Micron Technology, Inc.
    Inventors: William H. Radke, Shuba Swaminathan, Brady L. Keays
  • Patent number: 7350044
    Abstract: An improved Flash memory device, control circuit, or data handling methods is described that facilitate the moving and consolidating data in split and non-split user/overhead data sector architectures, moving and storing user and overhead data from and to separate non-volatile memory devices, differing erase blocks, or differing sectors of an erase block. This enables ECC checking and masking while moving data. In addition, the use of a split data storage approach is enabled that avoids the issue of potential corruption of both the user data and overhead data due to each being held within close proximity to each other on the same physical row by allowing user/overhead data split across two erase blocks to be easily moved, consolidated, and managed.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: March 25, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 7322002
    Abstract: Improved memory devices, circuitry, and data methods are described that facilitate the detection and correction of data in memory systems or devices in combination with a stored record of known flaws, errors, or questionable data bits of a read memory row or block to allow for more efficient processing and correction of these errors. An embodiment of the present invention utilizes an erasure pointer that can store the location of N bad or questionable bits in the memory segment that is currently being read, where for each bit stored by the erasure pointer the embodiment also contains 2N ECC generators to allow the read data to be quickly checked with the know bad bits in each possible state. This allows the read data to then be easily corrected on the fly before it is transferred by selecting the bad bit state indicated by the ECC generator detecting an uncorrupted read.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: January 22, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Brady L. Keays, Shuba Swaminathan, William H. Radke
  • Patent number: 6948026
    Abstract: An improved Flash memory device with a distributed erase block management (EBM) scheme is detailed that enhances operation and helps minimize write fatigue of the floating gate memory cells of the Flash memory device. In the prior art, erase block management of a Flash memory device, which provides logical sector to physical sector mapping and provides a virtual rewriteable interface for the host, requires that erase block management data be kept in specialized EBM data tables to keep the state of the Flash memory device in case of loss of power. This placement of EBM data in a separate erase block location from the user data slows the Flash memory operation by requiring up to two writes and/or block erasures for every update of the user data.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: September 20, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6654292
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: November 25, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6650571
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: November 18, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6646926
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: November 11, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6646927
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: November 11, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6618294
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: September 9, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6618293
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: September 9, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6614695
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: September 2, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Patent number: 6603682
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: August 5, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Publication number: 20030072182
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Application
    Filed: November 18, 2002
    Publication date: April 17, 2003
    Applicant: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Publication number: 20030072181
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Application
    Filed: November 18, 2002
    Publication date: April 17, 2003
    Applicant: Micron Technology, Inc.
    Inventor: Brady L. Keays
  • Publication number: 20030072178
    Abstract: A method and apparatus for erase operations of a flash memory block. In one embodiment, a method comprises erasing a predetermined percent of rows in a memory block, analyzing a number of erase pulses used to erase the predetermined percent and calculating an acceptable number of additional erase pulses which could be applied to the memory block to erase the remaining rows. In another embodiment, a flash memory device comprises a memory array, a controller and a register. The memory array has a plurality of blocks of flash memory cells. The memory cells in each block are arranged in rows. The controller is used to control memory operations to the memory array and the register is coupled to the controller to track the erase status of each row of memory cells.
    Type: Application
    Filed: November 18, 2002
    Publication date: April 17, 2003
    Applicant: Micron Technology, Inc.
    Inventor: Brady L. Keays