Rapid System Prototyping with FPGAs

Chapter 9

Design Constraints and Optimization

9.1 Overview

Constraints are used to influence the FPGA design implementation tools including the synthesizer, and place-and-route tools. They allow the design team to specify the design performance requirements and guide the tools toward meeting those requirements. The implementation tools prioritize their actions based on the optimization levels of synthesis, specified timing, assignment of pins, and grouping of logic provided to the tools by the design team. The four primary types of constraints include synthesis, I/O, timing and area/location constraints.

Synthesis constraints influence the details of how the synthesis of HDL code to RTL occurs. There are a range of synthesis constraints and ...