Peak ultra-low-power MCU benchmark scores for ST’s ARM-base STM32

February 20, 2015 // By Graham Prophet
STMicroelectronics says it “shatters performance limitations” for ultra low-power applications with its STM32L4 microcontrollers; this series of the family, based around an ARM Cortex-M4 core and using ultra-low-power technologies, claims to have the industry’s highest EEMBC ULPBench efficiency score

STM32L4 is aimed at next-generation energy-conscious consumer, industrial, medical, and metering applications. The first two microcontrollers in the series, the STM32L476 and STM32L486, use the 80 MHz ARM Cortex-M4 core with DSP and floating-point unit (FPU). With the added advantage of the ST ART Accelerator, which allows zero-wait execution from Flash, the devices achieve up to 100 DMIPS at 100 µA/MHz active power consumption. Up to 1 MB of dual-bank Flash supports sophisticated applications and read-while-write capability in addition to 128 kB of SRAM.

STM32L4 microcontrollers use ST’s low-power technologies, including dynamic voltage scaling to balance power consumption with processing demand, smart architecture with FlexPowerControl, and seven power-management modes with sub-mode options. These include Stop, Standby, and Shutdown with current as low as 30 nA. ST’s Batch Acquisition Mode (BAM) allows efficient data exchange with communication peripherals while in low-power mode.

The new devices have scored 123 in the standardised EEMBC ULPBench tests that compare the efficiency of ultra-low-power microcontrollers, which ST says shows that you can get higher performance and larger memory without trading power consumption. The company adds that overall low power consumption, high performance and DSP capability of the Cortex-M4 core, smart analogue features, and extensive digital connectivity of the new STM32L4 series make these devices suitable for smart connected and Internet-of-Things (IoT) applications, as well as a wide variety of industrial, medical, and consumer products.

STM32L4 will be priced from $3.40 in the LQFP64 package (10,000).


next; further architecture details...