Apparatus with multi-bit cell read mechanism and methods for operating the same
AssigneeMicron Technology, Inc.
InventorsMatteo Impala', Mattia Robustelli, Innocenzo Tortorelli
Life of this patent
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Abstract
Methods, apparatuses and systems related to reading data from memory cells configured to store more than one bit are described. The apparatus may be configured to determine a polarity data associated with reading data stored at a target location. In reading the data stored at the target location, the apparatus may apply one or more voltage levels across different polarities according to the determined polarity data.
Claims20
A memory device, comprising:
- rewritable memory cells including multi-level cells (MLCs) that are each configured to store two bits using a set of storage states that correspond to a minimum threshold voltage (Vt), a maximum Vt, a ternary (T) state, and at least one intermediate (I) state for positive and negative polarities;
- and
- a logic circuit operably coupled to the memory cells and configured to:
- determine a polarity data associated with reading a target location amongst the MLCs;
- detect a storage state at the target location based on applying a sequence of voltage levels for a first polarity and then a second polarity, wherein the sequence of the first and second polarity is selected according to the polarity data and is configured to write over an intermediate Vt in distinguishing between the T state and the at least one I state;
- and
- control application of a reprogramming voltage along the second polarity for reestablishing the storage state, wherein the reestablished storage state corresponds to the intermediate Vt.
An apparatus, comprising:
- rewritable memory cells including a subset of cells that are each configured to store more than one bit using a set of storage states that correspond to a minimum threshold voltage (Vt), a maximum Vt, a ternary (T) state, and at least one intermediate (I) state;
- and
- a logic circuit operably coupled to the memory cells and configured to:
- determine a polarity data associated with reading a target location amongst the subset of cells;
- detect a storage state at the target location based on applying a sequence of voltage levels for a first polarity and then a second polarity,
- wherein the sequence of the first and second polarity is selected according to the polarity data and
- wherein applying the sequence of voltage levels results in removing a previously established I state in distinguishing between the T state and the at least one I state;
- control application of a reprogramming voltage along the second polarity for reestablishing the storage state;
- and
- separate from or simultaneously with application of the reprogramming voltage, update the polarity data after detecting the storage state, wherein the polarity data is updated to a value different than before the detection of the storage state.
A method of operating a memory device that includes rewritable memory cells that are each configured to store more than one bit using to a minimum threshold voltage (Vt), a maximum Vt, a ternary (T) state, and at least one intermediate (I) state, the method comprising:
- determining a polarity data associated with reading a target location amongst the subset of cells;
- detecting a storage state at the target location based on applying a sequence of voltage levels for a first polarity and then a second polarity,
- wherein the sequence of the first and second polarity is selected according to the polarity data, and
- wherein applying the sequence of voltage levels results in removing a previously established I state in distinguishing between the T state and the at least one I state;
- controlling application of a reprogramming voltage along the second polarity for reestablishing the storage state;
- and
- separate from or simultaneously with application of the reprogramming voltage, updating the polarity data after detecting the storage state, wherein the polarity data is updated to a value different than before the detection of the storage state.
Dependencies are inferred from the claim text.