Patents Assigned to Multi Level Memory Technology
  • Patent number: 6259627
    Abstract: A read operation for a multi-level or a multi-bit-per-cell non-volatile memory biases a selected row line cell at a fixed voltage that is above the maximum possible threshold voltage representing data and changes the column line load for a selected column line. The column line load that corresponds to the trip-point of a sense amplifier indicates the data stored in the memory cell coupled to the selected row and column lines. A corresponding write process uses the same fixed row line voltage for both program and verify cycles. The programming voltage can be the same as the row line voltage for the read operation or can depend on the data value being written. To better control programming, the duration of the program cycles and/or the load on the drain or source of the selected memory cell during a program cycle varies with time and depends on the value being written. One memory in accordance with the invention includes variable column line loads for use during read and write operations.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: July 10, 2001
    Assignee: Multi Level Memory Technology
    Inventor: Sau Ching Wong