Design a CPU 4 | Udemy

Welcome to Design a CPU 4

Are you ready to take the next big step in your CPU design journey?
In Design a CPU 4, we move beyond the basics and into advanced concepts that bring your custom processor closer to a fully functional computer system.

This course builds directly on everything you’ve learned so far in the Design a CPU series. If you’ve completed Design a CPU 1, 2, and 3, you’ve already mastered integer arithmetic, basic assembly, and core CPU organisation. Now, it’s time to push further and start developing real-world features that modern CPUs depend on.

By the end of this course, you’ll not only understand how CPUs handle floating-point numbers and organise code efficiently, but you’ll also have laid the foundations for your very own operating system.

What You’ll Learn in This Course

In Design a CPU 4, we focus on four key milestones that bring your CPU to life:

1. Integrate a Floating-Point Unit (FPU)

We start by enhancing your CPU with floating-point arithmetic capabilities. Many real-world applications — from scientific computing to graphics processing — rely heavily on floating-point operations, and now your CPU will too.

You’ll learn:

• How floating-point numbers are represented in binary
• How to integrate a hardware-based FPU into your existing CPU design
• How to handle floating-point add, subtract, multiply, divide, and square root operations
• How modern CPUs optimise speed and accuracy

This is a huge leap forward in making your CPU practical for real-world workloads.

2. Write Assembly Code Using New Instructions

With floating-point capabilities comes a powerful new set of assembly instructions.
We’ll show you how to:

• Write efficient assembly code that uses the new FPU instructions
• Optimise your programs for speed and clarity
• Debug and test floating-point operations using the emulator

By the end of this section, you’ll be confident writing both integer and floating-point programs directly on your custom CPU.

3. Organise Subroutines into Libraries

As your programs grow, code organisation becomes critical. In this course, you’ll learn best practices in computer organisation by creating reusable libraries:

• Package commonly used subroutines into separate libraries
• Link libraries together when compiling and assembling your code
• Build the early framework of your CPU’s own operating system

This approach mirrors how professional software development works, helping you develop scalable, maintainable codebases — even when working close to the hardware.

4. Run, Test, and Debug with the Emulator

Theory is nothing without practice, so we’ll spend time using the RTM-16 emulator to:

• Load and run your programs
• Test new FPU instructions in action
• Debug issues step by step
• See how your CPU executes instructions at the microcode level

The emulator makes the learning process interactive and intuitive, helping you visualise what’s happening inside the CPU.

Who This Course Is For

This course is perfect for anyone who:

• Has completed Design a CPU 1, 2, and 3 and wants to continue building
• Loves understanding how computers work at the deepest level
• Enjoys hands-on projects and learning by building
• Wants to develop skills in computer architecture, assembly language, and low-level programming
• Is considering a future in computer engineering, embedded systems, or CPU/FPU design

If you’ve ever wanted to truly build a computer from the ground up, this course will take you there step by step.

Why This Course is Different

Unlike other courses that just explain concepts, Design a CPU 4 is fully hands-on.

• You’re not just reading slides or watching diagrams — you’re building.
• You’re not just writing generic assembly — you’re creating programs that run on your own CPU.
• You’re not just learning floating-point theory — you’re designing an FPU and using it.

By the end, you won’t just understand how CPUs work — you’ll have designed, programmed, and tested one yourself.

Prerequisites

To get the most from this course, you should:

• Have completed Design a CPU 1, 2, and 3
• Be comfortable with basic assembly programming
• Have a basic understanding of binary, hexadecimal, and logic circuits

If you’re new to CPU design, start with the earlier courses first — they’ll give you the strong foundation you need to succeed here.

Your Next Step: Design a CPU 5

At the end of this course, we’ll take a quick look at what’s coming next in Design a CPU 5. This is where we move to an even higher level of abstraction:

• Building a compiler from scratch
• Designing your own high-level programming language
• Writing programs that automatically translate into assembly for your custom CPU

Everything you’re learning in Design a CPU 4 lays the groundwork for this exciting next stage.

What You’ll Achieve by the End

By completing this course, you’ll:

• Understand how floating-point numbers are handled in hardware
• Integrate an FPU into your CPU design
• Write assembly programs using extended instruction sets
• Create and manage libraries of reusable code
• Build the foundation of your own operating system
• Test, debug, and refine your work with the emulator

These are the skills professional computer architects, embedded engineers, and systems programmers rely on every day.

Let’s Get Started

Your CPU journey is about to take an exciting turn. You’ve built the foundation — now it’s time to expand your design, write powerful new code, and take the first steps towards creating your very own operating system.

Enrol today and start building the next stage of your CPU!