Compare two signals, find times when they are affected by the same processes

1. How do you know if two signals are correlated?
2. Which gate can be used to compare two signals?

How do you know if two signals are correlated?

In words, we compute a correlation by multiplying two signals together and then summing the product. The result is a single number that indicates the similarity between the signals x[n] and y[n]. What values can C(x, y) take on, and what does this tell us about the signals x[n] and y[n]?

Which gate can be used to compare two signals?

Ex-NOR Function Realisation using NAND gates

As the Ex-NOR gate gives an output of logic level “1” whenever its two inputs are equal it can be used to compare the magnitude of two binary digits or numbers and so Ex-NOR gates are used in Digital Comparator circuits.