2 Lab

1. Design a 4-bit adder using the half adders.
2. Using a decoder add a sel and the needed components to be able to select whether your design acts as a 4-bit adder or 4-bit subtractor.
3. Simulate your circuit and verify its operation. You will need to try enough combinations to verify that the results of the addition and subtraction along with $C$ and $V$ are correct.
4. Add the BCD decoder you designed in last week's lab to output the add/subtractor so you can display the output on you 7-segment display.
5. Connect your sel and your inputs to hardware switches, and connect the output to the 7-segment display.