Learning FPGAs

Chapter 1. Introduction

FPGA stands for field programmable gate array. That mouthful is simply trying to tell you that you can program an FPGA over and over (field programmable) and that it is more or less just a large array of logic gates (gate array).

Unless you already know what all that means, it is still not very helpful, so let’s break it down a little more. An FPGA belongs to a family of devices known as programmable logic devices. These devices allow you to design a digital circuit, and the device will become that circuit. This works by configuring small blocks (known as slices) to perform logic functions and connecting them together to implement your larger design. A more detailed description of how this all works is covered later. You can reconfigure the FPGA as many times as you want, and each time it will become the new circuit without needing to physically change anything!

In this chapter, we will explain a little more about what FPGAs are and what they are good at. We will also walk you through all the steps to set up the necessary software on Windows or Linux. Unfortunately, Macs are not supported by Xilinx’s tools, but you can work through a virtual machine running a compatible operating system. You can do with this with VirtualBox and Ubuntu, both of which are free. With a working environment, we will work through a basic project that will turn on an LED when a button is pressed.

The Mojo

Throughout this book, we will be using the Mojo and its IO Shield. The ...