Re: Full adder

Posted by cadet1620 on Feb 05, 2013; 11:53pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Full-adder-tp4026235p4026236.html

joobcode wrote

Why does this simplification not work?

Carry:
A'BC+AB'C + ABC'+ABC good
C(A'B+AB') + A(BC'+BC) good
C               + AB           bad

What am I missing?

Bad algebra in the last step. The teacher in me says, "Show your work." How'd you get from step 2 to 3? What you're aiming for is:
    Cout = AB + AC + BC

--Mark