US Patent 7286410 Semiconductor integrated circuit

A semiconductor integrated circuit has a first nonvolatile memory area and a second nonvolatile memory area to store information in accordance with a variable threshold voltage. At least one condition of the following conditions of the first nonvolatile memory area is made different from that of the second nonvolatile memory area: erase verify determination memory gate voltage, erase verify determination memory current, write verify determination memory gate voltage, write verify determination memory current, erase voltage, erase voltage application time, write voltage, and write voltage application time in the first nonvolatile memory area.