Re: Truth Tables and resulting outputs...

Posted by cadet1620 on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Truth-Tables-and-resulting-outputs-tp3904544p3904586.html

Start with the small truth table that shows functionally what the multiplexor does.

	sel	|	out
	0	|	a
	1	|	b

In words, when sel is 0, out should have the same value as a, and when sel is 1, out should have the same value as b. In the three-variable truth table, highlighting the a and b values that are used for the given value of sel should make it easier to see where the out values come from.

	sel	a	b	|	out
	0 0 0 0	0 0 1 1	0 1 0 1	| | | |	0 0 1 1
	1 1 1 1	0 0 1 1	0 1 0 1	| | | |	0 1 0 1

--Mark