Nonconsecutive sensing of multilevel memory cells
View Patent ↗Apparatuses and methods for nonconsecutive sensing of multilevel memory cells include methods of sensing a unit of information from a multilevel memory cell (MLC) using a sensing signal. The unit of information can correspond to a page of information. The MLC can store a plurality of units of information corresponding to a plurality of pages of information. The sensing signal can change from a first sensing magnitude to a second sensing magnitude and from the second sensing magnitude to a third sensing magnitude. The second sensing magnitude can be nonconsecutive from the first sensing magnitude and/or the third sensing magnitude can be nonconsecutive from the second sensing magnitude with respect to a plurality of sensing magnitudes corresponding to a plurality of charge storage states of the MLC.
1. A method, comprising:
sensing more than one unit of information from a multilevel memory cell (MLC) by:
increasing or decreasing a magnitude of an output of the sensing signal generator serially through each of a first subset of a plurality of sensing magnitudes to sense first information from the MLC; and
increasing or decreasing the magnitude of the output of the sensing signal generator serially through each of a second subset of the plurality of sensing magnitudes to sense second information from the MLC,
wherein the first subset of the plurality of sensing magnitudes or the second subset of the plurality of sensing magnitudes includes nonconsecutive sensing magnitudes with respect to the plurality of sensing magnitudes,
wherein the first subset of the plurality of sensing magnitudes and the second subset of the plurality of sensing magnitudes each include more than one sensing magnitude, and
wherein each of the plurality of sensing magnitudes corresponds to a respective charge storage state for the MLC.
2. The method of claim 1 , wherein the method includes sensing up to three units of information from two MLCs.
3. The method of claim 2 , wherein each of the two MLCs store a non-integer number of units of information.
4. An apparatus, comprising:
an array of multilevel memory cells (MLCs);
a sensing signal generator; and
a controller coupled to the array and to the sensing signal generator and configured to:
increase or decrease a magnitude of an output of the sensing signal generator serially through each of a first subset of a plurality of sensing magnitudes to sense first information from a number of MLCs in the array; and
increase or decrease the magnitude of the output of the sensing signal generator serially through each of a second subset of the plurality of sensing magnitudes to sense second information from the number of MLCs in the array,
wherein the first subset of the plurality of sensing magnitudes or the second subset of the plurality of sensing magnitudes includes nonconsecutive sensing magnitudes with respect to the plurality of sensing magnitudes,
wherein the first subset of the plurality of sensing magnitudes and the second subset of the plurality of sensing magnitudes each include more than one sensing magnitude, and
wherein each of the plurality of sensing magnitudes corresponds to a respective charge storage state for the number of MLCs in the array.
5. The apparatus of claim 4 , wherein the controller is further configured to change the magnitude of the output of the sensing signal generator serially through each of a third subset of the plurality of sensing magnitudes.
6. The apparatus of claim 5 , wherein the third subset of the plurality of sensing magnitudes comprises a single sensing magnitude.
7. The apparatus of claim 4 , wherein each of the MLCs is configured to store a non-integer number of units of information.
8. The apparatus of claim 4 , wherein the first subset of the plurality of sensing magnitudes includes a particular order of sensing magnitudes that are nonconsecutive with respect to a plurality of charge storage states for the number of MLCs.
9. The apparatus of claim 4 , wherein the sensing signal generator comprises a component within the controller.
10. The apparatus of claim 4 , wherein the sensing signal generator is external to the controller.
11. The apparatus of claim 4 , wherein the sensing signal generator comprises a number of components located within the controller and a number of components located external to the controller.
12. The apparatus of claim 4 , wherein the array of MLCs are arranged in a NOR configuration, and wherein the controller is configured to store a non-integer number of units of information in each of the number of MLCs.
13. The apparatus of claim 4 , wherein the controller is configured to provide random access to the MLCs in the array.