Re: Full Adder Implementation

Posted by cadet1620 on Sep 28, 2013; 3:51pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Full-Adder-Implementation-tp4027337p4027346.html

Sobbity wrote

I guess my main issue here is I haven't yet fully grasped exactly what I can do with Boolean algebra and the best way to simply an expression.

Like normal algebra, Boolean algebra is most useful to prove or disprove a solution that you have already come up with by other means.  There are rules and guidelines for simplifying equations as in normal algebra, but they only get you so far.

A good tool for simplifying canonical representations into sum-of-product solutions is Karnaugh Maps. There are several posts about them on the forum.

 I had no problem reaching the two HalfAdders + one Or solution as I had been following the book linearly (Which has proved to be fantastic thus far). Then, when going for the more direct approach, I arrived to a 5 gate implementation such as you say but I would say it was purely chance and fooling around in whatever direction seemed right, with no certainty.

Intuition and experience will help. General problem solving techniques like working from both ends of the problem are useful, too.

For now though, the only thing I want to optimize is my comprehension, haha. Thanks again

That's one of my life goals too! One is never too old to learn.

--Mark