Cyclone V SoC Power Optimization

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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

1.5.5.2. Using the Driver

  1. Boot the Linux just compiled. From the prompt, add a “new device” to the “sysfs” representation of data from LTC2978A family devices.

    Command format: echo ltc2978 <i2c addr> > /sys/bus/i2c/devices/i2c-<n>/new_device

    Where “i2c addr” is the address of the device on the I2C/PMBus bus and “<n>” is the number of the bus where it resides. Standard I2C utilities can be used to probe the buses.

  2. Add the two LTC2978A devices, using the following commands:
    • HPS Power Monitor: echo ltc2978 0x5c > /sys/bus/i2c/devices/i2c-0/new_device
    • FPGA Power Monitor: echo ltc2978 0x5e > /sys/bus/i2c/devices/i2c-0/new_device
  3. Once the devices are added successfully, files are created in the “sysfs” filesystem for input and output voltages, temperatures and more. Please refer to the LTC2978A datasheet and the kernel documentation mentioned in the "HPS Method: USB Power Management" section for further information on what this driver has provided and how to make use of the data.

Alternately, you can use raw I2C commands to get at the same information, although this driver does some of the number conversions for you.

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