| 摘要 |
<p>PURPOSE:To eliminate a need of the stage of a special wafer process before as well as after packaging and to easily and surely identify write data by applying a voltage higher than the normal operating voltage to an input signal line to detect whether the input signal line is made conductive or not. CONSTITUTION:Plural MOS transistors TRs 11 are connected in series between a MOS TR 10 for data write due to ion implantation and an input signal line 12 for the purpose of obtaining the sum of threshold voltages higher than the normal operating voltage of the MOS TR. At the time of identifying write data, the voltage higher than the normal operating voltage is applied to the input signal line 12 to detect whether the input signal line 12 is made conductive or not, thereby identifying write data of the MOS TR 10 for data write. Thus, the stage of a special wafer process is unnecessary before as well as after packaging, and write data is easily and surely identified.</p> |
