Not not working

Posted by methermeneus on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Not-not-working-tp2744119.html

The variables have been changed to protect the people who are still working on the implementation.

I'm trying to write the HDL implementations for chapter 1, and I ran into a brick wall on Mux. For some reason, when I try to include Not as a part, it doesn't do anything. I'm pretty sure I wrote it correctly:

Not(in=x, out=notx);

and put it into the header correctly:

CHIP Mux {
   IN x, y, z;
   OUT out;

but when I test it in the hardware simulator, notx=1 regardless of what x is. It does this with both the Not implementation I wrote for the project and the built-in implementation. Furthermore, the Not part works just fine in Xor, and I double-,triple-, and quadruple-checked that I wrote both the same way, and everything else in the Mux implementation outputs what it ought to based upon its inputs.

Anyone have any ideas? I checked other online resources to see if I'd designed my multiplexor correctly, but this strikes me as possibly indicative of a bigger problem.

EDIT: The Not part also works fine in DMux. If I encounter another implementation in which it doesn't work, I'll list it here.