Explore how transistors combine to form logic gates, the fundamental building blocks that power every digital computation in modern computers.
Today, Computation rules the world and has never been more important or more powerful. No matter where you look, technology is everywhere. It's really quite fascinating to watch technology progress so rapidly. We truly are living in unprecedented times with incredible discoveries, innovations, and inventions being made every single day. In recent history these revolutions are happening rapidly. In a short time we've seen the advent of the computer (and all its necessary components) which fundamentally changed how the world operates, the world wide web (and everything that came with it), culminating in the start of the age of information in which AI and LLM's have come roaring like nobodies business. The amount of power and knowledge at the average persons fingertips is mind blowing. The amount of research, blood, sweat, and tears that it took to get us to this point is admirable to say the least and I would like us all to take a moment to appreciate how far we've come. How does it all work though? How did we get this far? To answer this question we'll start from the ground up.
Every single computation that is happening in your computer, smartphone, or any other digital device for that matter, ultimately boils down to thousands-billions of EXTREMELY tiny switches turning on and off called transistors. Transistors control electrical current. If the transistor is in the on state, it will allow current to flow through. On the other hand, if the transistor is in the off state it will block current from flowing through. Modern processors use binary to control the transistors, 1 is on and 0 is off.
Logic gates are perhaps the most important part of the operation. At a high level, logic gates are the "brain cell" and "workhorse" of the operation. You could think of them as a microscopic electronic decision maker. Each logic gate is made from 2-6 transistors that are connected together with microscopic metal "wires" known as traces. In modern day processors there's about 10-20 billion transistors that form something like 2-5 million logic gates. The crazy part about this is that they're all on a chip roughly the size of a thumbnail.
There are seven basic types of logic gates, the alphabet or fundamental building blocks of logic gates if you will, that can be combined into several different types of complex functional units.
This post is part of an ongoing series exploring computer architecture from the ground up. Future sections will cover:
Stay tuned for more deep dives into the fascinating world of digital computing!
Data scientist and ML engineer focused on building intelligent systems. Writing about machine learning, software architecture, and the journey from data to production.
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