Whether the targets are IoT devices or other type of battery-powered application, the implications of ultra-low power (ULP) varies. The lowest active current is required when the power source is severely limited (e.g., energy harvesting). The lowest sleep current is required when the system spends most of its time in standby mode, waking up infrequently (periodically or asynchronously) to process a task. ULP can also imply great energy efficiency, whereby the most work is performed in a limited time period. Overall, the application requires tradeoffs on all of the above. To ensure ULP operation over periods of months, years, and decades, developers face numerous optimization challenges. An increasing number of microcontrollers ‘claim’ ULP capabilities, but developers cannot rely on datasheet parameters alone. The EEMBC® ULPMark™ standardizes datasheet parameters and provides a methodology to reliably and equitably measure MCU energy efficiency.
The ULP working group continues to develop new profiles for power analysis. There are currently two: Core Profile and Peripheral Profile. Both profiles are included in the license purchase.
The Core Profile focuses on the MCU’s core. This benchmark utilizes a common set of workloads that are portable across 8-, 16-, and 32-bit microcontrollers. The Core Profile runs on a one-second duty cycle combining these workloads with an extended period of inactivity to enable the use of microcontroller low-power modes. Please refer to the FAQ for more information on the active workload.
The Peripheral Profile focuses on the MCU’s commonly used peripherals including pulse-width modulation (PWM), analog-to-digital conversion (ADC), serial peripheral interface (SPI), and the real-time clock (RTC). The benchmark defines ten 1-second activity slots each with variable usage of ADC, SPI, PWM, RTC, allowing the MCU and peripherals to sleep after their activities have completed. The following table gives an overview of the activity in each slot. As soon as the device finishes the peripheral operation for that slot it can enter sleep. This means faster peripherals will most likely score higher since they can remain off longer.
ULPMark has been redesigned since it's first release in 2014. It now works with the EEMBC IoTConnect™ benchmark framework, the same one used by IoTMark and SecureMark. However, only the Energy Monitor is needed for ULPMark. Please see the FAQ for more information.
We're currently developing a method to consistently measure CoreMark energy and provide a standard metric and methodology. As always, member companies and licensees are continually uploading new scores.
Join the working group to help ensure a meaningful and fair representation for your company’s products.