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US 2018/0122464 A1Published application
Apparatuses and methods for sensing a phase-change test cell and determining changes to the test cell resistance due to thermal exposure
AssigneeMicron Technology, Inc.
InventorsJason Brand, Jason Snodgress
Life of this patent
Estimating the term…
Abstract
A phase change memory array may include at least one cell used to determine whether the array has been altered by thermal exposure over time. The cell may be the same or different from the other cells. In some embodiments, the cell is only read in response to an event. If, in response to that reading, it is determined that the cell has changed state or resistance, it may deduce whether the change is a result of thermal exposure. Corrective measures may then be taken.
Claims20
An apparatus comprising:
- a phase change memory array;
- and
- a controller coupled to the phase change memory array, the controller configured to measure a respective resistance of selected phase change memory cells of the phase change memory array, the controller further configured to determine whether the respective resistance of a phase change memory cell of the selected phase change memory cells has changed from a respective initial resistance by more than a threshold amount.
An apparatus comprising:
- a phase change memory array having a plurality of test cells;
- and
- a controller coupled to the phase change memory array, the controller configured to measure a respective characteristic of the plurality of test cells, the controller further configured to determine whether the respective characteristic of a test cell of the plurality of test cells has changed from a respective initial characteristic by more than a threshold amount.
An apparatus comprising:
- a phase change memory array comprising test cells located at each corner and a center;
- and
- a controller coupled to the phase change memory array, the controller configured to measure a respective resistance of the test cells of the phase change memory array and to initiate a refresh when the respective resistance a subset of the test cells changes from a respective initial resistance by more than a threshold amount.
Dependencies are inferred from the claim text.