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US 11,380,411 B2Granted
Threshold voltage drift tracking systems and methods
AssigneeMicron Technology, Inc.
InventorHari Giduturi
Life of this patent
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Abstract
A system may include multiple memory cells to store logical data, age tracking circuitry to track a time since a previous access of a particular memory cell, and control circuitry to access the memory cell. Such access may include a read operation of the memory cell, a write operation to the memory cell, or both. The control circuitry may determine an electrical parameter of the memory cell based at least in part on the tracked time since the previous access of the memory cell.
Claims22
A system comprising:
- a plurality of memory cells configured to store logical data;
- age tracking circuitry configured to track a time since a previous access of a memory cell of the plurality of memory cells, wherein the age tracking circuitry comprises:
- an age register configured to store an age value representative of the tracked time since the previous access of the memory cell;
- and
- clock circuitry configured to periodically update the age value of the age register at predetermined intervals;
- and
- control circuitry configured to access the memory cell, wherein the access of the memory cell comprises a read operation of the memory cell, a write operation to the memory cell, or both, wherein the control circuitry is configured to determine an electrical parameter of the memory cell based at least in part on the tracked time since the previous access of the memory cell.
4 more elements
A memory device comprising:
- a memory array comprising a plurality of memory cells associated with a plurality of memory addresses;
- a plurality of shadow registers configured to define a plurality of memory blocks of the memory array, wherein each memory block of the plurality of memory blocks comprises a subset of memory addresses of the plurality of memory addresses;
- and
- a plurality of age registers, wherein an age register of the plurality of age registers corresponds to a shadow register of the plurality of shadow registers, wherein the shadow register is configured to define a memory block of the plurality of memory blocks, wherein the age register is configured to maintain an age value corresponding to a time since a previous access of a memory cell of the memory block.
1 more element
A method comprising:
- receiving a write request;
- in response to the write request, writing data to a plurality of memory cells of a memory device;
- assigning the plurality of memory cells to a memory block, wherein assigning the plurality of memory cells to the memory block comprises:
- storing a start address of the plurality of memory cells in a shadow register;
- storing an end address of the plurality of memory cells in the shadow register;
- or
- both;
- tracking an age value of the memory block, wherein the age value comprises an indication of time passage since the data was written to the plurality of memory cells of the memory block;
- and
- accessing a memory cell of the memory block, wherein accessing the memory block comprises:
- determining a selection voltage of the memory cell based at least in part on the age value;
- determining a read sense voltage of the memory cell based at least in part on the age value;
- determining a biasing current of the memory cell based at least in part on the age value;
- or
- a combination thereof.
12 more elements
Dependencies are inferred from the claim text.