DETERMINING REFERENCE VOLTAGE OFFSETS FOR READ OPERATIONS IN A MEMORY SYSTEM

1 . (canceled)

2 . A system, comprising:

one or more memory devices; and

one or more controllers coupled with the one or more memory devices and configured to cause the system to:

read a set of memory cells using a first reference voltage and using a second reference voltage;

determine, in response to reading the set of memory cells using the first reference voltage, a first quantity of memory cells with threshold voltages above the first reference voltage;

determine, in response to reading the set of memory cells using the second reference voltage, a second quantity of memory cells with threshold voltages above the second reference voltage; and

select, in accordance with the first quantity being greater than a target quantity and the second quantity being less than the target quantity, an offset value for a set of pages that is based at least in part on the first reference voltage and the second reference voltage.

3 . The system of claim 2 , wherein the first reference voltage is based at least in part on a first offset value, wherein the second reference voltage is based at least in part on a second offset value, and wherein the offset value is between the first offset value and the second offset value.

4 . The system of claim 3 , wherein the one or more controllers are further configured to cause the system to:

select the second offset value for the second reference voltage to be less than the first offset value based at least in part on the first quantity being greater than the target quantity.

5 . The system of claim 3 , wherein the one or more controllers are further configured to cause the system to:

select the first offset value for reading the set of memory cells based at least in part on the first offset value being between two intermediate values in a predetermined set of offset values.

6 . The system of claim 3 , wherein the one or more controllers are further configured to cause the system to:

read, before reading the set of memory cells using the second reference voltage, the set of memory cells using a third reference voltage that is based at least in part on a third offset value; and

determine, based at least in part on reading the set of memory cells using the third reference voltage, that a third quantity of memory cells with threshold voltages above the third reference voltage is greater than the target quantity, wherein the set of memory cells is read using the second reference voltage based at least in part on the third quantity being greater than the target quantity.

7 . The system of claim 6 , wherein the one or more controllers are further configured to cause the system to:

select the second offset value for the third reference voltage to be greater than the third offset value based at least in part on the third quantity being greater than the target quantity.

8 . The system of claim 2 , wherein the first reference voltage and the second reference voltage are each associated with an upper threshold voltage distribution of multiple threshold voltage distributions supported by the set of memory cells.

9 . The system of claim 2 , wherein the set of memory cells is in a first plane and the set of pages includes a second set of memory cells in a second plane, and wherein the one or more controllers are further configured to cause the system to:

read, concurrently with reading the set of memory cells using the first reference voltage, the second set of memory cells in the second plane using the first reference voltage, wherein the offset value is selected for the set of pages based at least in part on reading the second set of memory cells using the first reference voltage.

10 . The system of claim 9 , wherein the one or more controllers are further configured to cause the system to:

read, concurrently with reading the set of memory cells using the second reference voltage, the second set of memory cells in the second plane using the second reference voltage, wherein the offset value is selected for the set of pages based at least in part on reading the second set of memory cells using the second reference voltage.

11 . The system of claim 2 , wherein the one or more controllers are further configured to cause the system to:

read, before reading the set of memory cells using the first reference voltage, the set of memory cells using a third reference voltage that is based at least in part on a third offset value; and

determine, based at least in part on reading the set of memory cells using the third reference voltage, that a third quantity of memory cells with threshold voltages above the third reference voltage is greater than the target quantity, wherein the set of memory cells is read using the first reference voltage based at least in part on the third quantity being greater than the target quantity.

12 . The system of claim 2 , wherein reading the set of memory cells using the first reference voltage and the second reference voltage is part of a threshold voltage drift detection procedure for a memory system, and wherein the one or more controllers are further configured to cause the system to:

perform the threshold voltage drift detection procedure during an initialization stage of the memory system.

13 . The system of claim 2 , wherein:

reading the set of memory cells using the first reference voltage comprises comparing threshold voltages of memory cells of the set of memory cells with the first reference voltage, and wherein:

reading the set of memory cells using the second reference voltage comprises comparing threshold voltages of the memory cells with the second reference voltage.

14 . A system, comprising:

one or more memory devices; and

one or more controllers coupled with the one or more memory devices and configured to cause the system to:

read a set of memory cells using a reference voltage;

determine, in response to reading the set of memory cells using the reference voltage, a quantity of memory cells of the set of memory cells with threshold voltages above the reference voltage; and

select, in accordance with the quantity being within a threshold range of a target quantity, an offset value for a set of pages that that is based at least in part on the reference voltage.

15 . The system of claim 14 , wherein the one or more controllers is further configured to cause the system to:

read, before reading the set of memory cells using the reference voltage, the set of memory cells using a second reference voltage; and

determine, in response to reading the set of memory cells using the second reference voltage, a second quantity of memory cells of the set of memory cells with threshold voltages above the reference voltage, wherein the set of memory cells is read using the reference voltage based at least in part on the second quantity being outside the threshold range of the target quantity.

16 . The system of claim 15 , wherein the second quantity of memory cells is greater than a threshold quantity, and wherein the one or more controllers is further configured to cause the system to:

select the reference voltage to be greater than the second reference voltage based at least in part on the second quantity being greater than the threshold quantity.

17 . The system of claim 15 , wherein the second quantity of memory cells is less than a threshold quantity, and wherein the one or more controllers is further configured to cause the system to:

select the reference voltage to be less than the second reference voltage based at least in part on the second quantity being less than the threshold quantity.

18 . The system of claim 15 , wherein the one or more controllers is further configured to cause the system to:

read, before reading the set of memory cells using the second reference voltage, the set of memory cells using a third reference voltage; and

determine, in response to reading the set of memory cells using the third reference voltage, a third quantity of memory cells of the set of memory cells with threshold voltages above the reference voltage, wherein the set of memory cells is read using the second reference voltage based at least in part on the third quantity being outside the threshold range of the target quantity.

19 . The system of claim 18 , wherein the one or more controllers is further configured to cause the system to:

select the reference voltage to be between the third reference voltage and the second reference voltage based at least in part on the third quantity being greater than a first threshold and based at least in part on the second quantity being less than a second threshold.

20 . The system of claim 18 , wherein the one or more controllers is further configured to cause the system to:

select the reference voltage to be greater than the third reference voltage and greater than the second reference voltage based at least in part on the third quantity and the second quantity both being greater than a threshold.

21 . A method at a memory system, comprising:

reading a set of memory cells using a first reference voltage and using a second reference voltage;

determining, in response to reading the set of memory cells using the first reference voltage, a first quantity of memory cells with threshold voltages above the first reference voltage;

determining, in response to reading the set of memory cells using the second reference voltage, a second quantity of memory cells with threshold voltages above the second reference voltage; and

selecting, in accordance with the first quantity being greater than a target quantity and the second quantity being less than the target quantity, an offset value for a set of pages that is based at least in part on the first reference voltage and the second reference voltage.