Cyclone V SoC Power Optimization

ID 683713
Date 2/09/2015
Public
Document Table of Contents
Give Feedback

1.2.1.4. HPS Method 4: Lowering CPU Frequency

Lowering CPU frequency can reduce the amount of power the MPU consumes as shown in the following table:

Table 1.  Power Reduction for Different CPU Frequencies
Frequency Change Power Savings
From: To: Approximate Power Reduction:
800 MHz 400 MHz 190 mW
400 MHz 200 MHz 90 mW
200 MHz 100 MHz 50 mW

The Rocketboards Preloader Clocking Customization link indicates, changing SDRAM frequency is a separate exercise and should only be done using Qsys.

Note: Be aware that changes to the PLL VCOs can affect certain peripheral speeds. On the Preloader Clocking Customization link you can use the value generating tables to check if the desired peripheral speeds are met before making changes and recompiling the Preloader.