Energy Micro has recently announced the availability of the Keil RTX real-time operating system (RTOS) as part of its Simplicity Studio tool suite. The Keil RTX has been optimized for ARM Cortex-M processors to provide flexible scheduling and high-speed operation, and has been improved to enable an ultra-low power, deep-sleep mode between tasks.
Energy Micro has implemented a tickless mode in Keil RTX. This mode allows the EFM32 Cortex M3 MCUs to wake up only when needed, either at a scheduled time or on an interrupt event. This results in much lower power consumption in sleep mode compared to other SysTick implementations.
The video below shows the difference between SYSTICK mode where the system consumes about 2.7mA in active mode, and 830 uA in sleep mode to the new tickless mode where the MCU still consume the same amount of energy in Active mode, but only 1uA in sleep mode, or in other words, an 830x improvement in power consumption.
ARM Keil RTX RTOS is available for free (as in beer), and is also provided with full source code under a BSD license that is free of charge even for commercial usage. The Keil RTX implements the RTOS API of the ARM Cortex Microcontroller Software Interface Standard (CMSIS). Windows users can download this RTOS via Simplicity Studio software suite, however it can’t be retrieved from Simplicity Studio in Linux (or I missed it), but you can still download the source code, documentation and samples from Energy Micro in a zip file.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.