| 摘要 |
PURPOSE:To input an optional signal of 1 or 0 without using a pad which impedes high integration, by selecting a light beam irradiation position and generating the 0 or 1 signal. CONSTITUTION:An MOS type FF circuit consists of inverters 11 and 12. When the P-N junction between the drain of one MOS transistor TR16 for a driver and substrate of this FF circuit is irradiated with a laser beam, the node 18 between MOSFETs 15 and 16 is held at 0 level because of a junction current between the drain and the substrate. Consequently, the other driver MOSTR14 turns off and the nose 19 between MOSTRs 13 and 14 has a level 1. Therefore, the 1 signal appears at an output terminal 17. When the P-N junction between the drain of the TR14 and the substrate is irradiated with the laser beam, the node 19 has the 0 level. Then, the 0 signal appears at the terminal 17. Thus, the 1 or 0 signal is outputted optionally. |
