Electronics and Russian Nesting Dolls

Electronics is cool. It’s neat that you can design the devices that you use. It’s neat that things that you can’t see can do so many things. It’s neat to work with analog and digital systems. But, I think one aspect of electronics that is often overlooked that is really neat is that it is very much like a Russian Nesting Doll. 

The biggest doll would be the devices that we use as a complete system – computers, phones, printers, controllers, etc. The smallest doll would be a single transistor (in addition to a few other basic components like LEDs). Then there’s the whole spectrum in between. 

Gates includes things like AND, OR, NOT, NAND, and so on. These are built directly out of transistors.

Components include things like a multiplexer, demultiplexer, arithmetic logic unit, controller, state machines, and so on. These are generally designed by Boolean algebra equations which are just a combination of gates.

Above the components level are integrated circuits (ICs) and processors. These generally have a specific goal and can use either multiple components or only one. For example, an adder could use an arithmetic logic unit (ALU) to do the adding, a register file to store the addends and result, a controller to tell the ALU when to add and what register files to find the addends in.

One of the best things about my digital logic design class was that it taught us how to design a processor in each little step. In other words, if I really wanted to (I don’t at all), I could design a processor that could perform a logic operation (addition, subtraction, or a bitwise operation) out of transistors. Each step just fits within the next as you take a bigger and bigger view of the system.