I need to know how to design 4-bit full adder using half adder. Also, the design of logic diagram is needed. Just a simple question.

 

Ok I will help you with this one since I have the schematic and derivations for a Full Adder comprosed of Half Adders (4 inverters, 6 NORs and an Or gate), but I won't just give it to you.

So have you attempted this question? If so what have you come up with?

If not, can you tell me what the truth-table is for a half and full adder?

Dave