Re: Output of Nand is always 1

Posted by cadet1620 on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Output-of-Nand-is-always-1-tp4025362p4025364.html

prabhuvd wrote

I did modification to And.hdl in projects\01\And.hdl

[correct implementation deleted]

i load the And.tst  and run the  And.hdl code  and i see the error : End of Script - Comparision failure at line 5

Then did a single step of the script i see the internal pin state  x always set to 1 . Where am i doing the mistake ?

The most likely problem is that you have not implemented Not.hdl yet.

The Hardware Simulator is using the Not.hdl skeleton as part of your And. The simulator behaves strangely when it encounters chips without implementations.

It is very important to implement the chips in the order presented in section 1.3.

[Also, please edit your original post to remove the correct HDL implementation.]

--Mark