| 摘要 |
PROBLEM TO BE SOLVED: To achieve flexible admissibility against an unspecified many counts of access and high security characteristics against illegal access. SOLUTION: A memory for storing a program and data is provided with a non-rewritable memory 14 and a rewritable memory 16. In addition, a logic circuit part 20 is also separated into a protected module group 20A and an unprotected module group 20B discriminately. Then, malicious access is prevented by effectively using the security characteristics by the non-rewritable memory 14 and the module group 20A. Meanwhile, by using the functions of the rewritable memory 16 and the module group 20B, unspecified many users can use with convenience afforded to them, and even if illegal access is made to the rewritable memory 16 and the module group 20B, the access is prevented from extending to the non-rewritable memory 14 and the module group 20A side, thus maintaining the security characteristics. COPYRIGHT: (C)2005,JPO&NCIPI |
