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News Media Alert

09 Apr 2013

CMSIS-RTOS RTX 'tickless' power-saving mode on Energy Micro EFM32


The ARM CMSIS-RTOS based RTX real-time operating system, optimised for ARM® Cortex®-M processor-devices, is now available in Energy Micro's Simplicity Studio tool suite with additional ultra-low power mode.

Oslo, Norway, 9 April, 2013 – Energy Micro, the energy friendly microcontroller and radio company, announces the immediate availability of the ARM Keil RTX real-time operating system (RTOS) as part of its Simplicity Studio tool suite. The ARM Keil RTX, which has been optimised for the ARM Cortex-M series of processors to provide flexible scheduling and high-speed operation, has been extended by Energy Micro to enable an ultra-low power, deep-sleep mode between tasks.

Energy Micro has implemented an extension to ARM Keil RTX that is referred to as a 'tickless' mode and which allows the EFM32 MCU to wake up only when needed, either at a scheduled time or on an interrupt event. This results in orders of magnitude better current consumption than competing solutions based on using the system timer, SysTick, which require a constantly running, high frequency clock. With RTX RTOS, EFM32 users can now enter a deep sleep mode, consuming less than 1uA, between normal active operation.

"Energy Micro can deliver more advanced functionality by offering a real-time operating system, and it is one of the first companies to combine this with a 'tickless' extension," said Reinhard Keil, director of MCU Tools, System Design Division, ARM. "ARM is focused on helping its partners achieve higher performance and lower power solutions. We are therefore pleased that by running the RTOS on its low-energy EFM32 microcontrollers, Energy Micro has demonstrated the potential of ARM Keil RTX for ultra-low power operation."

Energy Micro's VP of Simplicity, Øyvind Grotmol, added, "The ARM Keil RTX is a widely renowned RTOS, and we are pleased that our EFM32 customers now have a commercial grade RTOS available for free, including advanced power management capabilities and optimized for the ARM architecture."

ARM Keil RTX is provided with full source code under a BSD license that is free of charge for everyone, including for commercial usage. For easy portability, the Keil RTX implements the RTOS API of the ARM Cortex Microcontroller Software Interface Standard (CMSIS). It is available for all of Energy Micro's EFM32 MCU families via the Simplicity Studio software suite.

Simplicity Studio is a free and complete tools suite providing instant, "one-click" updated access to Energy Micro's latest datasheets, application notes, software tools, 3rd party IDE, code examples, demos and other EFM32 Gecko resources. Energy Micro's Gecko microcontroller portfolio consists over 240 device variants based on the ARM Cortex-M series.

About Energy Micro

Energy Micro is a global provider of energy friendly microcontrollers and RF transceivers based on the ARM Cortex-processor core. Consuming a quarter of the energy of competing products, the company's ultra low power EFM32 Gecko MCUs and EFR4 Draco radios target energy sensitive applications, including smart metering, building automation, security systems portable health and fitness equipment and smart accessories. The products are supported by Energy Micro's Simplicity Studio, the easy-to-use software console that helps to reduce embedded system development times by a half. Further information is available at

About ARM

ARM designs the technology that is at the heart of advanced digital products, from wireless, networking and consumer entertainment solutions to imaging, automotive, security and storage devices. ARM's comprehensive product offering includes RISC microprocessors, graphics processors, video engines, enabling software, cell libraries, embedded memories, high-speed connectivity products, peripherals and development tools. Combined with comprehensive design services, training, support and maintenance, and the company's broad Partner community, they provide a total system solution that offers a fast, reliable path to market for leading electronics companies.

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