Patent ID: 7184545

Claim:
A semiconductor integrated circuit comprising: a ROM for storing plural confidential data thereon address by address which has no external direct input path and can be read only from an internal circuit inside of the integrated circuit; a tester for testing the ROM address by address; a storage device, which is included in the ROM, for storing plural redundancy check data address by address that have been obtained by performing a predetermined calculation on each of the corresponding plural confidential data, the plural redundancy check data an each of the corresponding plural confidential data being stored at mutually different addresses on the ROM; a checker for performing the same calculation as the predetermined calculation on each of the plural confidential data that has been read out from the ROM address by address; a comparator for comparing a result of the calculation performed by the checker to each of the corresponding plural redundancy check data stored in the storage device address by address; and an address decoder which enables an operation of the comparator if an address is for the redundancy check data, and disables the operation of the comparator if the address is for the confidential data.