1. The attached file (in this homework announcement) shows the data sheet for chip 74283 which is a 4-bit carry look-ahead adder.

1. Use two 74283 chips to design an 8-bit carry look-ahead adder/subtractor. Note that you can use a block (box) to represent 74283 and then add necessary circuits.
2. What are the delays (i.e., gate delays) of the last SUM bit and the last Cout bit of this 8-bit machine, respectively?
3. Based on the circuit designed in (a), can you design a circuit to detect overflow for this 8-bit machine adder/subtractor? If YES, please finish the design for overflow checking, and then go to answer (e).
4. If you answer NO in (c) above, assuming you can break the chips of 74283, please design the overflow checking circuit.
5. Will the addition of overflow checking circuit affect the circuit delay?