Patent ID: 7719052

Claim:
A semiconductor device having a plurality of nonvolatile memory elements each having a charge-storage film formed over a semiconductor substrate and a first gate electrode formed over the charge storage film, comprising: a first nonvolatile memory cell including one nonvolatile memory element from the plurality of nonvolatile memory elements: and a second nonvolatile memory cell including at least two nonvolatile memory elements from the plurality of multiple nonvolatile memory elements, wherein a rewriting frequency of the second nonvolatile memory cell is greater than a rewriting frequency of the first nonvolatile memory cell, wherein, in the first nonvolatile memory cell, one bit is formed from the one nonvolatile memory element, wherein, in the second nonvolatile memory cell, one bit is formed from the at least two nonvolatile memory elements, wherein a data writing operation of each nonvolatile memory element is performed by injecting hot electrons into the charge storage film thereof, wherein a data erasing operation of each nonvolatile memory element is performed by emitting the electrons from the charge storage film thereof.