PLEASE HELP ME. I TRIED A LOT BUT COULD NOT SUCCEED. Design a 4-bit serial multiplier in structural implementation style. First, design a 1-bit Full Adder (FA) and a 1-bit Half Adder (HA); and then use these components as building blocks in your multiplier design. ◊ Draw the circuit diagram of your multiplier (preferably using a drawing tool) in terms of FA, HA and necessary gates. ◊ Write the VHDL code for each of the following: 1 bit Full Adder, 1 bit Half Adder and the 4-bit serial multiplier. ◊ Design a testbench that would test the functionality of your multiplier. Remember to test for corner cases. Provide clear waveforms with annotations explaining your results.