Learning FPGAs

Preface

Designing digital circuits used to be something that only big companies could afford to do. It used to require creating application-specific integrated circuits (ASICs)—taking weeks or months to produce an actual chip, and requiring piles of cash or wiring together tons of individual chips to perform various logic functions. Then the field-programmable gate array (FPGA) was introduced. FPGAs are programmable logic devices. Unlike an ASIC, the function an FPGA performs is determined at runtime, so an FPGA can be configured to act like just about any digital circuit. However, it wasn’t until recently that the cost of FPGAs has dropped to a point where they are now affordable for even hobbyists.

An FPGA allows you to design digital circuits. Digital circuits are basically just a bunch of logic gates (and, or, nor, etc.) connected together to perform a specific task. The designs that you create can range from something as simple as a counter that blinks an LED to something as complex as a multicore processor.

This book starts at the very beginning, with setting up your environment and getting an LED to turn on. As you develop your skills, you will learn how to perform more-complicated tasks and eventually design your own basic processor.

The board used in this book is the Mojo (along with the IO Shield). I created the Mojo in 2013 as a simple no-shenanigans FPGA development board for the hobbyist. I ran a Kickstarter to gauge interest and fund the initial round of boards. ...