| 摘要 |
PURPOSE: To improve the secrecy protection of stored information on the semiconductor storage device. CONSTITUTION: A user writes arbitrary key code information in a nonvolatile storage circuit STR. When a comparator COMP detects data read out of a memory array MARY matching the key code information, the output state of a scramble circuit SCRBL is changed thereafter and the output is changed meaninglessly with the input, so that a normal data read is not read out thereafter. The user of the semiconductor storage device determines the key code information and a memory address wherein the data matching it is stored individually and the user constitutes a system so that the relative memory address is inhibited from being used. Only the user knows the key code information for holding the secrecy and the number of users who know the key code information is decreased, so that the reliability of the secrecy protection of stored information is improved. |
