Targeting the Ultra-Low Power Domain
Whether the target is edge-nodes for the IoT or any other type of battery-power 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 or sleep 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 will require a combination of or tradeoffs on all of the above. To ensure ULP operation over periods of months, years, and decades, application developers face a number of optimization challenges. There are an increasing number of microcontrollers ‘claiming’ ULP capabilities, but developers cannot rely on datasheet parameters alone. The EEMBC ULPBench standardizes on datasheet parameters and provides a methodology to reliably and equitably measure MCU energy efficiency.
The Foundation of ULPBench
- Comparability: Make it easy to compare devices
- Transparency: Make all measurements and the setup process transparent
- Reproducibility: Make it easy to for anyone to reproduce the benchmark scores
ULPBench is a Two-Prong Approach
Prong 1: A ‘Battery’ of tests for comprehensively measuring microcontroller efficiency
- A common set of workloads that are portable across 8-, 16-, and 32-bit microcontrollers
- Enables the use of microcontroller low-power modes
- Focus on real-world applications utilizing integrated hardware functions
- Analyzes the effects of active and low-power conditions
- Download ULPBench
Prong 2: The EEMBC EnergyMonitor™
- An accurate tool for measuring energy
- Applicable for any application where current consumption ≤28mA @3Volts
- Integrated GUI for convenient data capture
- Purchase EnergyMonitor ($75USD + Shipping)
When submitting a score, please refer to the run rules.
Working Group Status
- Phase 1, the ULPBench-Core Profile, is completed. It has a focus on CPU core and RTC behavior.
- Phase 2 is in development. It focuses on energy efficiency of a microcontroller and a common set of peripherals (e.g. ADC, PWM, UART)
- Join the EEMBC ULPBench working group to help ensure a meaningful and fair representation for your company’s products. Email EEMBC for more information.
- Stefan Schauer, Texas Instruments
- Analog Devices, ARM, Atmel, Cypress, Freescale, Microchip, Nordic Semiconductor, Renesas, Silicon Labs, STMicro, Texas Instruments.
Beyond the Data Sheets of Ultra-Low-Power MCUs: What Does Energy Efficiency Really Mean? (Elektroniknet.de)
Representing ULPBench Results in Device Datasheets