Patent ID: 8719595

Claim:
A semiconductor device comprising: a boot ROM for storing a boot program; a mode ID storage section for storing a mode ID, the mode ID indicating as a current operation mode, a product operation mode for operating as a product device, or a development mode for developing a program; a program verification section for verifying a validity of an external program stored in an external memory; and a sequencer for controlling the boot program, wherein: a sequence of the boot program is controlled by the sequencer in accordance with the current operation mode indicated by the mode ID stored in the mode ID storage section, and when the mode ID indicates the development mode, the boot program is controlled by the sequencer such that the external program stored in the external memory is executed irrespective of whether the external program is valid or not, while when the mode ID indicates the product operation mode, the boot program is controlled by the sequencer such that the external program is not executed if the program verification section has failed verification of the validity and the external program is executed only if the validity of the external program is verified by the program verification section.