MQX™ Lite Real-Time Operating System (RTOS)

MQX Lite RTOS is a very light MQX Kernel for resource-limited MCUs. Initially developed for the Kinetis® L Series family, it allows applications to run with less than 4 KB RAM. It is a true subset of the proven and professionally developed NXP® MQX Software Solutions, allowing for easy upward code migration. It is easily configurable within Processor Expert® Software to be used with the tool chain of your choice. You can also take advantage of all the drivers supported in Processor Expert Software, making it easy to scale from one MCU to another.

MQX Lite is packaged as a component for Processor Expert®, which is no longer being actively developed. Please consider using the Kinetis Software Development Kit which includes support for the latest Kinetis devices.

Key Benefits

  • Easy to configure – Packaged as a Processor Expert component; with configurable options: set name of task function, priority, stack size (all the same parameters as an MQX task)
  • Easy to add existing application – Just drop in the MQX Lite RTOS component, and get started in minutes
  • Very lightweight – Minimal app (hello task, idle task, interrupt stack) – less than 4 KB RAM; optimized for resource-limited MCUs like Kinetis L Series family
  • I/O capability provided by Processor Expert software – Take advantage of the broad spectrum of MCU logical device drivers; with access to libraries/stacks like USB Processor Expert component
  • Real-time, priority-based preemptive task switching – Threads execute in order of priority, allowing high-priority threads to meet their deadlines consistently, no matter how many other threads are competing for CPU time
  • Programming model allows upward code migration – MQX Lite RTOS is a true subset of the full MQX RTOS: code built with MQX Lite RTOS will easily move to the full MQX RTOS


MQX Lite RTOS is available as a component within the following NXP software offerings:

MQX vs. MQX Lite Software Comparison

Delivery Mechanism Traditional installer with full source for Kernel, services and BSPs Processor Expert (PEx) Kernel and services component, configurable software generated by PEx
I/O Drivers MQX POSIX compatible drivers with option for using PEx drivers PEx drivers only
Configurability User selects needed services from full or lightweight versions Reduced services available; lightweight options only