Question: You are to design a new combinational logic block called the "zeros counter". The zero counter has seven inputs X1.X2,.....X7 and outputs a 3-bit binary integer O2O1O0 equal to the number of inputs that are 0. Using Full Inverters and Adders ONLY, show how to build a zeros counter.
Start your solution by drawing a logic symbol for a full adder and describe the relationship between the inputs and outputs.
Rationalize your answer by math, measurement or example, something convincing.