Intel® Quartus® Prime Standard Edition User Guide: Power Analysis and Optimization

ID 683506
Date 9/24/2018
Document Table of Contents
Give Feedback Toggle Rate

The toggle rate of a signal is the average number of times that the signal changes value per unit of time. The units for toggle rate are transitions per second, and a transition is a change from 1 to 0, or 0 to 1.
Note: Inaccurate signal toggle rate data is the largest source of power estimation error.

Dynamic power increases linearly with the toggle rate as you charge the board trace model more frequently for logic and routing. The Intel® Quartus® Prime software models full rail-to-rail switching. For high toggle rates, especially on circuit output I/O pins, the circuit can transition before fully charging the downstream capacitance. The result is a slightly conservative prediction of power by the Power Analyzer.