A method of determining an initial state of a reference cell in a fabricated memory array includes performing a first read operation of the reference cell by comparing current through the reference cell with the average current passing through a pair of data cells, and storing the result of the first read operation; inverting the value of one of the pair of the data cells; performing a second read operation of the reference cell, and storing the result of the second read operation; inverting the value of the other of the pair of the data cells; performing a third read operation of the reference cell, and storing the result of the third read operation. A majority compare operation of the results of the first, second and third operations is performed, wherein the result of the majority compare operation is the initial state of the reference cell.