Patent attributes
A failure detection circuit that can detect the performance degradation of a FeRAM caused by thermal stress regardless of whether power is being supplied or not, and prevent the use of a deteriorated FeRAM. It comprises a detector FeRAM cell structured identically to a memory cell actually employed and used for detecting the performance degradation of the FeRAM, a filtering voltage generator circuit, which generates a filtering voltage used for determining the performance degradation, an expected value output circuit, which outputs an expected value equal to the data already stored in the detector FeRAM cell, a sense amplifier, which reproduces data stored in the detector FeRAM cell using the filtering voltage, and a comparator, which outputs an failure detection signal indicating the performance degradation of the FeRAM when the expected value and the data reproduced by the sense amplifier don't match.
