Patent ID: 11923028
Assignee: nan
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 11:
12. A method, comprising:
collecting pre-decoding state information for a set of read reference voltages by reading data stored in a non-volatile storage device using the set of read reference voltages;
collecting post-decoding state information for the set of read reference voltages after decoding the data;
obtaining a first probability of state error for a first state under each read reference voltage of the set of read reference voltages and a second probability of state error for a second state under each read reference voltage of the set of read reference voltages, wherein the first state and the second state are two adjacent states distinguished by each read reference voltage, the pre-decoding state information and the post-decoding state information include how many cells are in the first state before and after the decoding, how many cells are in the second state before and after the decoding, how many cells in the first state before the decoding are corrected to the second state after the decoding and how many cells in the second state before the decoding are corrected to the first state after the decoding, the first probability of state error is equal to a number of cells in the second state before the decoding corrected to the first state after the decoding divided by a total number of cells in the first state after the decoding, and the second probability of state error is equal to a number of cells in the first state before the decoding corrected to the second state after the decoding divided by a total number of cells in the second state after the decoding;
generating comparisons of probabilities of state error for the set of read reference voltages by comparing the first probability of state error for the first state to the second probability of state error for the second state under each read reference voltage;
obtaining a set of adjustment amounts to the set of read reference voltages based on the comparisons of probabilities of state error; and
adjusting the set of read reference voltages by applying the set of adjustment amounts to the set of read reference voltages to obtain a set of adjusted read reference voltages, p1 wherein the comparisons of probabilities of state error are wrong state ratios and obtaining the set of adjustment amounts to the set of read reference voltages is further based on the set of read reference voltages.