Reading memory cells

A memory device comprising:

• one or more processors;
• and
• one or more computer-readable storage media storing instructions that, when executed by the one or more processors, are configured to cause the one or more processors to perform operations comprising:
• performing a first read of data from a memory array using a first voltage level;
• determining an instant bit count corresponding to a number of bits of the data obtained by the first read;
• accessing a recorded bit count corresponding to a number of bits in the data, the recorded bit count determined at a time of writing the data to the memory array;
• computing a difference between the instant bit count and the recorded bit count;
• conditioned on determining that the difference is less than or equal to a first threshold value, outputting the data read from the memory array using the first read;
• conditioned on determining that the difference is greater than the first threshold value, obtaining a number of read operations that have been performed to read the data from the memory array;
• and
• upon determining that the number of read operations is less than a threshold number of read operations, performing a second read of the data from the memory array using a second voltage level.

A method comprising:

• performing a first read of data from a memory array using a first voltage level;
• determining an instant bit count corresponding to a number of bits of the data obtained by the first read;
• accessing a recorded bit count corresponding to a number of bits in the data, the recorded bit count determined at a time of writing the data to the memory array;
• computing a difference between the instant bit count and the recorded bit count;
• conditioned on determining that the difference is less than or equal to a first threshold value, outputting the data read from the memory array using the first read;
• conditioned on determining that the difference is greater than the first threshold value, performing a second read of the data from the memory array using a second voltage level that is distinct from the first voltage level, wherein performing the second read comprises:
• conditioned on determining that the instant bit count is less than the recorded bit count by a margin greater than the first threshold value, selecting, as the second voltage level, a voltage level that is less than the first voltage level;
• and
• conditioned on determining that the instant bit count is greater than the recorded bit count by a margin greater than the first threshold value, selecting, as the second voltage level, a voltage level that is greater than the first voltage level.

A memory device comprising:

• one or more processors;
• one or more computer-readable storage media storing instructions that, when executed by the one or more processors, are configured to cause the one or more processors to perform operations comprising:
• performing a first read of data from a memory array using a first voltage level;
• determining an instant bit count corresponding to a number of bits of the data obtained by the first read;
• accessing a recorded bit count corresponding to a number of bits in the data, the recorded bit count determined at a time of writing the data to the memory array;
• computing a difference between the instant bit count and the recorded bit count;
• conditioned on determining that the difference is less than or equal to a first threshold value, outputting the data read from the memory array using the first read;
• conditioned on determining that the difference is greater than the first threshold value, performing a second read of the data from the memory array using a second voltage level that is distinct from the first voltage level, wherein performing the second read comprises:
• conditioned on determining that the instant bit count is less than the recorded bit count by a margin greater than the first threshold value, selecting, as the second voltage level, a voltage level that is less than the first voltage level;
• and
• conditioned on determining that the instant bit count is greater than the recorded bit count by a margin greater than the first threshold value, selecting, as the second voltage level, a voltage level that is greater than the first voltage level.