Patent ID: 8780650

Claim:
An apparatus, comprising: a plurality of data storage cells; a decoder circuit configured to select a data storage cell from the plurality of data storage cells; a control circuit configured to store test data in the selected data storage cell; a first sense amplifier configured to amplify the stored test data in the selected data storage cell using a first gain level; wherein the control circuit is further configured to compare test data to the stored data amplified using the first gain level; and a second sense amplifier configured to amplify the stored test data in the selected data storage cell using a second gain level responsive to a determination that the stored test data amplified using the first gain level does not match the test data, wherein the second gain level is greater than the first gain level; and wherein the control circuit is further configured to: compare the test data to the stored test data amplified using the second gain level; and store information indicative of the strength of the selected data storage cell dependent upon the comparison of the test data to the stored data amplified using the second gain level.