Cyclone V SoC Power Optimization

Download PDF
ID 683713
Date 2/09/2015
Public
Document Table of Contents
Document Table of Contents x
1. Cyclone V SoC Power Optimization
1. Cyclone V SoC Power Optimization x
1.1. Power Reduction 1.2. HPS Power Reduction Methods 1.3. FPGA Power Reduction Methods 1.4. Power Optimization Summary 1.5. Appendix: Power Measurement Techniques for Cyclone V SoC Dev Kit
1.2. HPS Power Reduction Methods x
1.2.1. MPU 1.2.2. Peripherals 1.2.3. HPS Power Reduction Summary
1.2.1. MPU x
1.2.1.1. HPS Method 1: Fit Code in Cache 1.2.1.2. HPS Method 2: Processor Standby Modes and Dynamic Clock Gating 1.2.1.3. HPS Method 3: CPU1 in WFI/WFE or Standby Loop 1.2.1.4. HPS Method 4: Lowering CPU Frequency
1.2.2. Peripherals x
1.2.2.1. HPS Method 5: Energy Efficient Ethernet 1.2.2.2. HPS Method 6: USB Power Management 1.2.2.3. HPS Method 7: Unused Peripherals in Reset
1.3. FPGA Power Reduction Methods x
1.3.1. FPGA Power Consumption 1.3.2. FPGA Portion Power Down 1.3.3. FPGA Power Off Step 1: Board Design (Power Rail) Choices 1.3.4. FPGA Power Off Step 2: Quiet FPGA 1.3.5. FPGA Power Off Step 3: Power Off the FPGA 1.3.6. FPGA Power Off Step 4: Wake up Event for Power on and FPGA Configuration 1.3.7. FPGA Power Off Step 5: Power On and FPGA Reconfiguration Time Considerations
1.5. Appendix: Power Measurement Techniques for Cyclone V SoC Dev Kit x
1.5.1. Power Monitoring and Measurement 1.5.2. Cyclone V SoC Development Kit Power Management ICs 1.5.3. Cyclone V SoC Development Kit Power Monitor Application 1.5.4. LTC LTpower Play Tool 1.5.5. Using the LTC2978A Linux Driver 1.5.6. Power Measurement Results on Cyclone V SoC Development Kit 1.5.7. Document Revision History
1.5.3. Cyclone V SoC Development Kit Power Monitor Application x
1.5.3.1. Starting the Application 1.5.3.2. Windows Instructions 1.5.3.3. Linux Instructions
1.5.4. LTC LTpower Play Tool x
1.5.4.1. Requirements 1.5.4.2. LTC Video Tutorial
1.5.5. Using the LTC2978A Linux Driver x
1.5.5.1. Compiling the Driver 1.5.5.2. Using the Driver
1. Cyclone V SoC Power Optimization

1.2.1.3. HPS Method 3: CPU1 in WFI/WFE or Standby Loop

On boot, CPU1 is held in reset. If you do not intend to make use of the CPU1, you should put it into a Standby Loop in order to benefit from around 90 mW of power savings.

  1. Place the following code for CPU1 at a known address in on-chip memory:
    while(1)
{
	__asm__("WFE");
}
    Note: The code is GCC specific. Similar syntax can be used with other compliers.
  2. Configure this address in the cpu1startaddr register in the system manager.
  3. Pull CPU1 out of reset (the default) using the cpu1 register in the reset manager.
Related Information
Level Two Title