Memory with redundant sense amplifier

摘要

Embodiments of a memory are disclosed that may reduce the likelihood of a miss-read while reading a weak data storage cell. The memory may include a number of data storage cells, a column multiplexer, a first sense amplifier and a second sense amplifier, and an output circuit. The gain level of the first sense amplifier may be higher than the gain level of the second sense amplifier. The output circuit may include a multiplexer and the multiplexer may be operable to controllably select one of the outputs of the first and second sense amplifiers and pass the value of the selected sense amplifier. The output circuit may include a node that couples the outputs of the first and second sense amplifiers and the outputs of the first and second sense amplifiers may be able to be set to a high impedance state.

主权项

1. 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; andstore 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.