| 摘要 |
<p>PURPOSE:To switch an option circuit by changing the position of piling an implantation for a ROM code at the time of changing a program and to eliminate the usual necessity of an aluminum mask correction. CONSTITUTION:A switch circuit is constituted of four enhancement transistors 1 to 4 and the level of an output 5 is decided in accordance with which of the enhancement transistors 2 or 4 the impra for the ROM code is piled into. Only by changing the position of piling the implantation for the ROM code, a signal level more stable than when a power source is inputted is gained from the switch circuit and the penetrated current of the switch circuit is eliminated.</p> |
