When making some chips you may find that you need to come up with a particular 16 bit number eg '0000000000000001'.
It wasn't obvious to me how to do this until I read Appendix A (HDL).
Before reading this appendix I was going 'around the houses' using Not16s and Add16s to do it
This is certainly a tough one and I cracked it. The problem here is that we are confusing learning the tool and learning the material. Appendix A is the answer, yes, but we can do better to provide clues to the resolution.
I say this because I suspect many people may have done very well understanding material and actually KNOW what they need to do but can't quite implement it. Again knowing the tool vs. knowing what to do.