Re: Building chips problem.

Posted by GustavoB on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Building-chips-problem-tp3468285p3705649.html



I've tried to make the cannonical representation with the example on page 9, then I just searched for a truth table generator and then I gave him this expression:

(¬x Λ y Λ ¬z) V (x Λ ¬y Λ ¬z) V (x Λ y Λ ¬z)

And the truth table matched exactly the truth table on figure 1.1 then I started to mentally mount the circuit for this boolean expression and I guess this circuit would be a big one. Does it's size matter? When I searched for multiplexor circuits, I've found some circuits and also some boolean expressions which are smaller.

For example, the multiplexor has this boolean expression:

[Edited]

But with cannonical representation, I have to make it like this:

(aΛ¬bΛ¬s) V (aΛbΛ¬s) V (¬aΛbΛs) V (aΛbΛs)

Is this difference of size important? And, what do I need to know to build smaller boolean expressions?