ST’s Dynamic Efficiency microcontrollers introduce Batch Acquisition Mode

June 27, 2014 // By Graham Prophet
STM32F411 STM32 Dynamic Efficiency MCUs extends the family with more advanced power-saving features including Batch Acquisition Mode (BAM): in smartphone sensor-hub applications, BAM enhances the energy savings made possible by Android KitKat operating system, and BAM extends power savings beyond smartphones into consumer, industrial and medical devices

STM32 Dynamic Efficiency MCUs improve the power-saving performance of data batching – the technique also used in Google's latest Android 4.4 (KitKat) operating system to maximise battery life - and extend the advantages to many more applications besides smartphones and tablets.

Android 4.4 uses a low-power sensor hub to manage “always-on” sensors such as accelerometers or pressure sensors, allowing the main system processor to consume less battery energy. ST’s STM32F411Dynamic Efficiency MCUs, which are engineered to deliver more performance with lower dynamic power and higher integration, are a perfect fit for sensor-hub applications. The new STM32F411’s Batch Acquisition Mode (BAM) saves up to 50% extra power by storing sensor data directly into SRAM while its own CPU core sleeps. The core wakes briefly to process this stored data before returning to power-saving mode.

As a versatile device used in a wide variety of industrial and consumer applications, the STM32F411 brings the advantages of BAM and other power-saving innovations including its new Flash-STOP mode to applications such as industrial controls, medical monitors, building automation, and wearable technology. A choice of compact packages down to 3.034 x 3.22 mm allows use where space is tight.

The STM32F411 features the ARM Cortex-M4 processor core with DSP and Floating-Point Unit (FPU), and has up to 512 kByte of Flash with high SRAM capacity of up to 128 kByte. Also hosting ST’s ART Accelerator branch cache, built in a 90nm process, and with voltage-scaling capability to minimise dynamic power and boost processing performance, the STM32 Dynamic Efficiency line is the industry’s first M4-class device to achieve RUN mode current of 100 µA/MHz executing EEMBC CoreMark code from Flash with peripherals off while also being able to run up to 100 MHz to deliver 125 DMIPS. Current in STOP mode is also very low at just 10 µA typical with all SRAM content and context saved. ART is the Adaptive Real-Time (ART) Accelerator allowing zero-wait state