Optimal read bias tracking system and method thereof

Abstract

A memory system includes a memory device including a plurality of cells associated with multiple pages and a controller. The controller selects a read bias set in response to a read address and modifies the read bias set to generate modified read bias set using one of a plurality of modification arrays. The controller performs a read operation on the select page using the modified read bias set. For a select read bias of the read bias set, the controller accumulates a fail bit count corresponding to a read operation using a select modified read bias of the modified read bias set into the plurality of accumulators using subtraction or addition. When an absolute value of a certain accumulator of the fail bit count is greater than a threshold, the controller shifts the select read bias in a correction direction by a specific magnitude corresponding to the accumulator sign.