Let’s take a look at what it takes to create some fun, out-of-the-ordinary gate implementations. As an example, let’s consider the AND gate (the others are OR, NOT, NAND, NOR, XOR and XNOR).

Of course, being an old part, it won’t work at very high frequencies, but the circuit is super simple, just using the gate and ... could use other gates, including the other XOR gates in the ...

Digital gates are fundamentally analog in nature ... and clock synthesis through frequency addition and subtraction (heterodyning) using an XOR gate as a frequency mixer.