RTOS offers ‘tickless' power-saving mode on Energy Micro EFM32 Cortex-M MCUs



Energy Micro, the energy friendly microcontroller and radio company, announced the immediate availability of the Keil RTX real-time operating system (RTOS) as part of its Simplicity Studio tool suite. The Keil RTX, which has been optimised for ARM Cortex-M 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 the 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 operations. "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." 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. Energy Micro