Re: Chip has a circle in it's parts? Xor.hdl issues

Posted by ivant on Dec 11, 2020; 11:30am
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Chip-has-a-circle-in-it-s-parts-Xor-hdl-issues-tp4035304p4035305.html

Zhme wrote

I assumed that, noting the title of the course, we should attempt to write each basic gate from a flow built with nand gates alone.

After seeing this error message I wonder if maybe I just needed to see how the most basic of gates could be built with nand alone, and to use the gates that I've built to slowly build more advanced gates?

Yes, you should use the gates you've already build. You can build an XOR gate directly from NANDs, but later gates become too complex for our brains to handle.

Zhme wrote

I wonder if the reason for my error is that I assigned the initial inputs in more than one location? If so, how would I remedy this error and still use this convoluted approach? Thank you in advance for any support given!

You can use the inputs in multiple locations, that is not an issue.

Look at the outputs outa and outb. They are not used anywhere. Are they needed?