Re: ZR and NG using 16wayOR gate?

Posted by WBahn on Jul 08, 2020; 4:57pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/ZR-and-NG-using-16wayOR-gate-tp4034824p4034826.html

guynextdoor wrote

I am a bit lost on the ZR and NG part of the ALU

Why can I use 16wayOR gate to compute the ZR function? why do I need 8wayOR function?

I read the sub-bus section and it says:  you must create the narrower bus as an output from a chip-part.

Why do I need to create a narrower bus?

we can have out=out, out=zr, out=ng and work on them using single 16 way OR gate

Thanks for your help

Who says that you HAVE to use the Or8Way gate?

You CAN use an Or16Way if you want to -- but since it isn't one of the parts constructed in Chapter 1, it is up to you to construct it and test it adequately. But there is absolutely nothing stopping you from doing so.

Most people use only the parts that are constructed in the course of working through the projects, so they will need to use a narrower bus to be compatible with the parts they have available.