Computing Fundamentals Tutor CPU Design 02: Opcodes

This video discusses the design of a complete set of opcodes for a simulated 4-Bit CPU

It is part of a series that walks through the design of a 4-bit CPU, with the intention of it being implemented in a digital simulator. While the series is very specific to this CPU, and should not be taken as a general discussion on wider CPU design, it serves as a good introduction to the concepts used in CPU design, especially as this particular design is particularly basic. In this video the opcodes for the CPU are discussed and decided. Some have been previously implied in the ALU design, and the rest are designed to make maximum use of the 4-bit opcode as a set of "flags" in order to minimise the decoding needed. The final set of opcodes covers arithmetic, register data transfers, conditional and unconditional jumps, and halt, and is usable for creating programs.

This series in turn is part of a larger series that charts the creation of a simulated 4-Bit CPU, with clear explanations of what is happening at every step of the way. Following this Super-Series is a great way to gain a strong understanding of the hardware that underpins computers, and is a great learning experience for anyone interested in computing as a career or hobby.

Roadmap:

Understanding the basics of digital electronics is fundamental to the understanding of computer hardware, and this software allows you to explore that without the need for hardware, soldering irons and the such like.