Memory with error correction configured to prevent overcorrection

Abstract

A non-volatile memory array storing data and ECCs includes error correcting logic. A data set can be read by performing iterations including sensing data using a read bias, and producing an indication of errors in the sensed data. A first iteration uses a first read bias. In each iteration, if the indication in a current iteration is less than a threshold, then the data is output from the selected cells sensed in the present iteration. If the indication in the current iteration exceeds the threshold, then another iteration is performed using a moved read bias, unless the indication in the current iteration shows an increase in errors relative to a previous iteration, in which case then sensed data from the previous iteration is output. Double buffering logic can be used to store sensed data during a current and a previous iteration.