| 摘要 |
<p>PURPOSE:To provide a mask ROM wherein customer identification for ROMs can be conducted electrically and easily. CONSTITUTION:In a mask ROM wherein ROM data is written by selective ion implantation in a channel region of a MOS transistor, identification circuits 131 and 132 into which customer information is written simultaneously with ion implantation and switching circuits 141 and 142 for outputting the outputs of the identification circuits 131 and 132 through output buffers 121 and 122 in the test mode are provided.</p> |
