摘要 |
<p>PURPOSE:To simplify diffusion processes by using a program circuit as a means which switches the controlling function of clock signals against the 1st output means which obtains inner chip selecting signals and the 2nd output means which obtains inner output terminal controlling signals. CONSTITUTION:A program circuit is constituted in such a way that, when a polysilicone resistance R is un-cut, the output of an inverter circuit A22 becomes 'H' in level and, when the resistance R is cut, the output becomes 'L' in level. Namely, clock signals I2 have a negative-logic chip selecting function and the function of clock signals I1 varies depending upon the setting condition of the output signal PGM of the program circuit. When the output signal PGM is an 'H' level, the clock signals I1 have a negative-logic output terminal controlling function and when the signal PGM is an 'L' level, a positive-logic chip selecting function. Therefore, only one kind of mask can be used throughout all diffusion processes and as a result, the diffusion processes can be simplified.</p> |