Intel® High Level Synthesis Compiler Pro Edition: Best Practices Guide

ID 683152
Date 10/04/2021

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3.1. FPGA Architecture Overview

A field-programmable gate array (FPGA) is a reconfigurable semiconductor integrated circuit (IC).

FPGAs occupy a unique computational niche relative to other compute devices, such as central and graphics processing units (CPUs and GPUs), and custom accelerators, such as application-specific integrated circuits (ASICs). CPUs and GPUs have a fixed hardware structure to which a program maps, while ASICs and FPGAs can build custom hardware to implement a program.

While a custom ASIC generally outperforms an FPGA on a specific task, ASICs take significant time and money to develop. FPGAs are a cheaper off-the-shelf alternative that you can reprogram for each new application.

An FPGA is made up of a grid of configurable logic, known as adaptive logic modules (ALMs), and specialized blocks, such as digital signal processing (DSP) blocks and random-access memory (RAM) blocks. These programmable blocks are combined using configurable routing interconnects to implement complete digital circuits.

The total number of ALMs, DSP blocks, and RAM blocks used by a design is often referred to as the FPGA area or area that the design uses.

The following image illustrates a high-level architectural view of an FPGA: