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US 8,077,520 B1Granted
Determining threshold voltage distribution in flash memory
AssigneeMarvell International Ltd.
InventorsXueshi Yang, Zining Wu, Gregory Burd
Life of this patent
Estimating the term…
Abstract
Methods, apparatuses, and systems for comparing threshold voltages of a plurality of flash memory cells to a plurality of reference voltages. A number of flash memory cells having threshold voltages that fall within each bin of a plurality of bins is determined. The plurality of bins each represent a plurality of threshold voltage ranges. A threshold voltage distribution of the plurality of flash memory cells is calculated based at least in part on the number of flash memory cells that fall into each of the bins.
Claims16
A method, comprising:
- comparing threshold voltages of a plurality of flash memory cells to a plurality of reference voltages to produce a plurality of comparison results;
- based at least on the comparison results, determining, for each bin of a plurality of bins, a number of flash memory cells having threshold voltages that fall within the bin, wherein the plurality of bins represent a plurality of threshold voltage ranges;
- and
- calculating a threshold voltage distribution of the plurality of flash memory cells based at least in part on the number of flash memory cells that fall into each of the bins.
1 more element
An apparatus, comprising:
- a memory bank comprising a plurality of flash memory cells;
- and
- control circuitry coupled to a reference voltage generator and to the memory bank, and configured to:
- command the memory bank to compare threshold voltages of the plurality of flash memory cells to a plurality of reference voltages produced by the reference voltage generator to in turn produce a plurality of comparison results;
- determine, based at least on the comparison results and for each bin of a plurality of bins, a number of the plurality of flash memory cells having threshold voltages that fall within the bin, wherein the plurality of bins represent a plurality of threshold voltage ranges;
- and
- calculate a threshold voltage distribution function of the plurality of flash memory cells based at least in part on the numbers of flash memory cells that fall into each of the bins.
4 more elements
A memory controller, comprising:
- an input/output interface configured to interface with a memory device;
- and
- a microcircuit, configured to:
- receive a plurality of comparison results from the memory device, wherein the comparison results represent comparisons between threshold voltages of a plurality of flash memory cells and a plurality of reference voltages;
- determine based at least on the received comparison results, for each bin of a plurality of bins, a number of flash memory cells having threshold voltages that fall within the bin, wherein the plurality of bins represent a plurality of threshold voltage ranges;
- and
- calculate a threshold voltage distribution function of the plurality of flash memory cells based at least in part on the number of flash memory cells that fall into each of the bins.
4 more elements
Dependencies are inferred from the claim text.