US Patent 7702934 Semiconductor device and BIOS authentication system

A semiconductor device comprises a semiconductor substrate, a basic module having a memory cell unit composed of first nonvolatile memory cells or a processor unit on a part of the substrate, an authentication module which has second nonvolatile memory cells in an area different from that of the basic module on the substrate, and stores an authentication code, and a lifetime control module which has aging devices configured by third nonvolatile memory cells in an area different from those of the basic module and the authentication module on the substrate, and which is turned on for a fixed period by storage of charges and permits reading of the authentication module only during an on-period of the aging devices.