Generating read thresholds using gradient descent and without side information

摘要

A first bit position of a cell in solid state storage is read where a sorting bit is obtained using the read of the first bit position. A second bit position of the cell is read for a first time, including by setting a first read threshold associated with the second bit position to a first value and setting a second read threshold associated with the second bit position to a second value. The second bit position of the cell is read for a second time, including by setting the first read threshold to a third value and setting the second read threshold to a fourth value. A new value for the first read threshold and for the second read threshold is generated using the sorting bit, the first read, and the second read.

主权项

1. A system, comprising:
a solid state storage interface configured to:
read a first bit position of a cell in solid state storage, wherein a sorting bit is obtained using the read of the first bit position;read a second bit position of the cell for a first time, including by:
setting a first read threshold associated with the second bit position to a first read threshold value; andsetting a second read threshold associated with the second bit position to a second read threshold value; andread the second bit position of the cell for a second time, including by:
setting the first read threshold to a third read threshold value; andsetting the second read threshold to a fourth read threshold value; and a read threshold generator configured to generate a new value for the first read threshold and a new value for the second read threshold using: (1) the sorting bit, (2) the first read of the second bit position, and (3) the second read of the second bit position.