teaching: from chip function to implementation

Posted by ybakos on Nov 15, 2009; 10:30pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/teaching-from-chip-function-to-implementation-tp34534.html

Hi,
I've been working on a simple step by step process for students to methodically move from each chip function (as described in each chip API box) to the actual implementation.

Let me provide a little context.

Say a student jumps in, takes a brute-force approach toward implementation and gets stuck at Xor. He notices that the text provides a table of basic boolean functions, and sees the boolean function for xor. Aha, "x and not y or not x and y. I have all those gates and can do that."

Ideally, he then realizes that it's simple to use boolean functions to guide his implementation. Or that he can reduce the canonical form distilled from a truth table to help figure out the implementation.

This is a discovery I want my students to realize.

However, for some chips, for example Dmux, the student may get stuck again. For example, he sees the slightly different truth table and may not know how to proceed toward implementation. Or he sees the function definition and again isn't quite sure how to proceed from the chip function to the implementation.

I would appreciate any tips or ideas in how to set forth a methodical approach for students to follow, from the chip function definition to boolean function to implementation. Specifically, I'm having trouble distilling a simple process for moving from the chip function to a boolean function.

(or if you feel there's a better way, I am certainly listening)