Patent ID: 7079418

Claim:
A semiconductor storage apparatus having a nonvolatile memory and a first sense amplifier comparing the level of a read-out signal read out from the nonvolatile memory with a first reference level, the semiconductor storage apparatus comprising: a detector operable to output, when detecting that a difference between the level of the read-out signal and the first reference level is smaller than a predetermined level difference, a detection signal indicative of the difference being smaller than the predetermined level difference, Wherein the detector includes: a second sense amplifier operable to compare the level of the read-out signal with a second reference level that is higher than the first reference level, the second sense amplifier outputting a logical value corresponding to the level of the read-out signal; a third sense amplifier operable to compare the level of the read-out signal with a third reference level that is lower than the first reference level, the third sense amplifier outputting a logical value corresponding to the level of the read-out signal; and a detection circuit operable to be fed with the logical values outputted from the first to the third sense amplifiers, the detection circuit outputting the detection signal when all of the logical values do not coincide with one another.