Re: ALU Implementation - the road traveled thus far

Posted by WBahn on Jun 07, 2019; 5:01pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/ALU-Implementation-the-road-traveled-thus-far-tp4033278p4033291.html

You can't do a subbus of an internal node. That is admittedly annoying. But there is a way around it that is explained in the Survival Guide. The key is that you can have multiple instances of a given input/output port on a part and you CAN subbus them.

So say that Fred has a port named bus and you need to feed the whole thing to another part for one purpose and just the #1 bit to a different part for a different purpose. You can do

Fred(bus = theWholeThing, bus[1] = aSingleBit);