SECURITY CIRCUIT FOR NON-VOLATILE MEMORY

摘要

PROBLEM TO BE SOLVED: To provide a security circuit of a non-volatile memory that protects data by prohibiting data decoding by the third party and enables rewrite of the data as well. SOLUTION: An output control part of a security circuit allows an output to outside of data read out from a read-out circuit 4 when information read out by a read-out circuit 18 indicates release of security. Moreover, when the information indicates a lock state of the security, the data are allowed to be outputted to outside of the data if all the data are detected to be '0' by a first detection circuit 6 at the time of program verify operation or all the data are detected to be '1' by a second detection circuit 8 at the time of deletion verify operation.