| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a password set by a legitimate user who knows the password, from being illegally rewritten by unauthorized third persons while facilitating rewriting. <P>SOLUTION: Respective columns are successively selected by a rewrite discrimination circuit 4 to store password data into a password storage bit string group 5 from a password data input part 3. At the initial write, data of the first password storage bit strings 5-0 are stored into an internal password data register 7 as internal password data by a password decoder circuit 6. When rewriting the password, initially set and registered password data is subjected to an operation like an EXOR operation by the password decoder circuit 6 to generate internal password data, and this internal password data is stored into the internal password data register 7. <P>COPYRIGHT: (C)2008,JPO&INPIT |
