Testing for threshold voltage and bit cell current of non-volatile memory arrays

Abstract

A method of testing non-volatile memory arrays. A first test stage including at least a first stage read uses a first step size for setting current for BCC testing and/or voltage for Vtesting for reading at least some memory cells. A second test stage including at least one second stage read uses an adjusted step size less in magnitude than the first step size for reading at least some memory cells. Provided no bit pattern match by the second test stage and/or the adjusted step size does not meet a predetermined minimum resolution (PMR), one or more additional test stages including additional array searching are added using a fixed step size less in magnitude than the adjusted step size including at least one read until a final read determines the predetermined repeating bit pattern is matched and a fixed step size for the final read meets the PMR.