Building a safe and secure embedded world

Power consumption

Smart energy-saving methods

ARM Energy Probe

Designing embedded systems for low energy consumption is a complex task. The silicon industry offers a wide variety of microcontroller devices and many integrate specific features that increase energy efficiency. Unfortunately, no standards or benchmarks exist today for comparing the energy efficiency of microcontrollers. Even the application requirements have a huge impact and therefore it is hard to select the best matching microcontroller for an energy critical application.

Also the application software itself has a major impact to energy consumption. It is important to choose the system configuration carefully for the requirements of the application and to select the best matching software design pattern. Needless to say, development tools used for creating the application should be specifically designed for embedded programming and configured towards energy efficiency.

While creating the application software the programmer should use these guidelines:

  • Run the clocks in the embedded system as slowly as practical.
  • Use the best matching power-saving modes.
  • Disable peripherals that are not required.
  • Optimize the code towards fast execution speed.
  • Power consumption, particular current, is not a digital value. Rise and fall times depends on the system. Measurement is required to validate the theory.

Software is ultimately responsible for energy efficiency

The ARM processor processor technology stands out due to the indisputable energy efficiency. Between the processor itself and the final product shipping, many things can dramatically impact on energy consumption. The software can mke all the difference concerning the power consumption In this respect.

When using DS-5 with the Streamline performance analysis, the ARM Energy probe can assist in the optimization of the software. In this combination Streamline can acquire real power data from your board and correlate it with all the other software and hardware statistics, including DVFS and cpuidle, to show you the true picture of your power management. Alternatively, Streamline can read and display these measurements directly from your Linux hwmon subsystem.

Power measurement in the hands of software developers

The Energy Probe has been specifically designed with software developers in mind. Its easy setup and low cost make it ideal to be incorporated in the workflow of all software developers. The probe does not require any additional debug or trace hardware to analyse Linux or Android™ systems. Measurement channels acquire the voltage drop across sense resistors on the target board and send to the host via USB 2.0. The synchronization of Energy Probe and target data is done on the PC using DSP algorithms that correlate CPU power consumption with load.

Watch the Energy Probe introduction video.

Search form Contact Onlineshop