Design a 2-bit Ripple Carry Adder (RCA) using half adders or full adders as building blocks. You may use NOT gates, ANDgates, and OR gates only. Do not use XORor XNOR gates. There is no restriction onthe number of inputs to the AND and OR gates. You donot need to consider a Carry-In into the first stage ofthe adder circuit.
The inputs should bespecified as follows: A = a1a0, B= b1b0
(a) Draw the top-levelblock diagram of the adder circuit.
(b) Draw the circuitdiagram for the half adder following the constraints givenabove.
(c) Draw the circuit diagram for thefull adder following the constraints given above.