Computer engineering

Logic gates, CPU architecture, pipelining, and Moore's law

What is computer engineering?

Computer engineering sits between electrical engineering and computer science — it's concerned with designing the actual physical hardware that computers are built from, including processors, memory, and embedded systems, and how that hardware executes the software covered in the Computer Science article.

Binary and logic gates

Computers represent all information using binary — just two values, typically called 0 and 1 — implemented physically as two distinguishable voltage levels in an electronic circuit. Logic gates are simple circuits that perform basic logical operations on these binary values: an AND gate outputs 1 only if both its inputs are 1; an OR gate outputs 1 if either input is 1; a NOT gate simply flips its single input. Combining large numbers of these simple gates together is how all of a computer's actual processing gets done.

Inside a processor

A computer's central processing unit (CPU) repeatedly performs a basic cycle: fetching an instruction from memory, decoding what operation it specifies, executing that operation, and storing the result — then moving on to fetch the next instruction. Modern processors perform billions of these cycles every second, and contain millions or billions of individual transistors implementing the logic gates needed to carry them out.

Embedded systems

Not every computer looks like a desktop or phone — embedded systems are specialized computers built into other devices (cars, appliances, medical equipment, industrial machinery) to control a specific function. These systems are typically designed with particular constraints in mind, like very low power consumption or the need to respond within a strict, guaranteed time limit.

Why computer engineering matters

Computer engineering underlies the design of every processor, memory chip, and embedded controller in use today, and its steady advances have been the primary driving force behind computers becoming faster, smaller, and more power-efficient over the past several decades.