Design Recipes for FPGAs, 2nd Edition

Chapter 21

ALU Functions

Abstract

A central part of microprocessors is the ALU (Arithmetic Logic Unit). This block in a processor takes a number of inputs from registers and, as its name suggests, carries out either logic functions (such as NOT, AND, OR, and XOR) on the inputs, or arithmetic functions (addition or subtraction as a minimum), although it must be noted that these will be integer (or fixed point potentially) only and not floating point. This chapter of the book will describe how these types of low level logic and arithmetic functions can be implemented in VHDL and Verilog.

Keywords

Arithmetic and logic unit

Arithmetic functions

21.1 Introduction

A central part of microprocessors is the ALU (Arithmetic Logic Unit). This block ...