Synopsis🔗

About scmRTOS🔗

scmRTOS is compact Real-Time Preemptive Operating System intended for use with Single-Chip Microcontrollers.

scmRTOS is capable to run on tiny uCs with as small amount of RAM as 512 bytes. The RTOS is written on C++ and supports various platforms. See next sections and for more details. Additionally, the documentation is also available in PDF format.

Source code can be cloned or downloaded from Github. There are a number of sample projects that demonstrates RTOS usage.

Full distribution including RTOS sources, sample projects, documentation, etc available on releases page.

Features🔗

• Written entirely on C++.

  • High reliability.
  • Simplicity and ease-of-use.

• Introduce Extensions mechanism at kernel level.

  • User defined extensions.
  • Debug features.

• Minimal process switching latency¹.

  • 900 ns on Cortex-M4 @ 168 MHz.
  • 1.8 us on Blackfin @ 200 MHz.
  • 2.7 us on Cortex-M3 @ 72 MHz.
  • 700 ns on Cortex-A9 @ 400 MHz (with full FPU context save/restore).
  • 5 us on ARM7 @ 50 MHz.
  • 38-42 us on AVR @ 8 MHz.
  • 45-50 us on MSP430 @ 5 MHz.
  • 18-20 us on STM8 @ 16 MHz.

• Small footprint.

  • From 512 bytes of RAM.
  • From ~1K code.

Supported Target Platforms 🔗

The following target platforms are supported for now.

CPU/MCU	GCC	EW (IAR)	VDSP++ (ADI)	CCES (ADI)
MSP430	✔	✔	–	–
AVR	✔	✔	–	–
ARM7	✔	✘	–	–
Cortex-M	✔	✔	–	–
Cortex-A	✔	✘	–	–
Blackfin	✔	–	✔	✔
STM8	–	✔	–	–

'–' means toolchain does not support CPU/MCU