Re: 1.1.1 text elaboration request

Posted by cadet1620 on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/1-1-1-text-elaboration-request-tp3829880p3832993.html

Except for AND, OR, NOT and ZERO you can implement the functions in canonical form, but it is often not the best implementation. The canonical form of TRUE would be:
    TRUE = xy + x~y + ~xy + ~x~y

Canonical form is just a tool that helps get you started. Consider that the canonical form of a 4-input function could need up to 15 4-input AND gates and a 15-input OR gate.

For most of this chapter, and the rest of the book, you will need to think about how to build more complex circuits using circuits you've already designed. HDL gives you Nand, true and false and you need to design
    Not using some combination of Nand, true and false,
    And using some combination of Not, Nand, true and false,
    Or using some combination of And, Not, Nand, true and false,
    etc.

--Mark