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    Key FeaturesTechnical SpecificationsSupported DevicesVideoTechnical Documents


    Freescale MQX RTOS.PNG







    Freescale streamlines embedded design with MQX, a complimentary real-time operating system (RTOS) complete with USB, Ethernet, and file system stacks. The entire source code for both the kernel and stacks is available, making it highly configurable for your specific application. It has been available on Freescale processors for over 15 years, and can be found in millions of embedded devices due to its flexible nature and advanced features.


    With its many examples, extensive out-of-box applications, tutorials, and documentation, first-time RTOS users can start developing their applications from day one. For experienced RTOS developers, it’s easy to migrate legacy application code to a Freescale MQX-based platform via its easy-to-use API and POSIX compatible drivers.


    MQX is tightly integrated with the latest Kinetis processors from Freescale and provides dozens of device drivers as part of its extensive BSP support. Powerful design and development tools are also integrated with many commonly used IDEs to provide additional profiling and debugging capabilities. The Freescale MQX RTOS was designed to have a modern, component-based microkernel architecture allowing for customization by feature, size, and speed by selecting the components engineers wish to include while meeting the tight memory constraints of embedded systems.


    The Freescale MQX RTOS includes a multitasking kernel with pre-emptive scheduling and fast interrupt response, which enables fast, highly predictable response times. It also has extensive inter-process communication and synchronization facilities. Its small, configurable size conserves memory space for embedded applications and can be configured as little as 6 KB of ROM, including kernel, interrupts, semaphores, queues and memory manager. MQX RTOS also includes a TCP/IP stack (RTCS), embedded MS-DOS file system (MFS), USB host/device stack with personal health care device class (PHDC), as well as task-aware debugging. There is also an IPv6 Ethernet stack (RTCS) available. Complete source code and documentation is provided for the kernel and stacks, and there are support options available for those who desire professional software services.


    MQX is available on a number of platforms, including Kinetis (ARM® Cortex™-M4 and Cortex™-M0+), ColdFire and Power Architecture®. All the code and examples can be downloaded from


    There is also a light-weight version of MQX called MQX-Lite. 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 MQX, allowing for easy upward code migration. It is packaged as a Processor Expert component, allowing for easy configuration and implementation.



    Certifiable to Medical and Aerospace Standards
    Even if your application does not require formal certification, the robustness of the MQX™ RTOS helps provide a rock-solid platform proven in thousands of time-critical, sophisticated applications. For those who must follow a formal certification process, the MQX RTOS platform has a record of past certifications in medical specifications (CFR 820.30 Part 21, IEC 60601-1) and the aerospace requirements listed under DO-178b. Safety critical applications based on MQX RTOS include eye surgery equipment, drug injection equipment, radiation dose monitoring equipment, aircraft braking systems and aircraft navigation equipment.


    More Resources
    orangearrw.gifFreescale: CodeWarrior IDE Development Suiteorangearrw.gifFreecale Development Kits
    orangearrw.gifOperating Systems and Stacksorangearrw.gifelement14 Knode


    Key Features

    • Production quality code delivered in source
    • Business-friendly licensing model
    • A straight forward application programming interface (API) with a modular, component-based architecture
    • Designed to be customized by features, size and speed with only 8 required core components and additional optional components that can be leveraged as needed.
    • Full and lightweight components available
    • Supports inter-processor communication
    • Freescale MQX Design and Development Tools. Ready-to-run project files and task aware debugging tools are available to enabling quick development.
    • Get started in minutes. Leverage Board Support Package (BSP), demos and labs tutorials right out of the box.
    • Your own team of MQX experts. Have questions or need hands-on technical support? Numerous resources are available for help and support including the Freescale MQX RTOS Community and MQX Level 2 Support packages.
    • Full-feature middleware: USB host/device stack with personal health care device class (PHDC), RTCS communication suite and file system.

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    Technical Specifications

    • Small code density – The Freescale MQX RTOS can be configured to take as little as 8 KB of ROM and 2.5K RAM on ARM Cortex M4, including kernel, 2 task applications,1 LW Semaphore, interrupt stack, queues, and memory manager.
    • Component-based architecture – Provides a fully-functional RTOS core with additional, optional services. Components are linked in only if needed, preventing unused functions from bloating the memory footprint.
    • Full and lightweight components – Key components are included in both full and lightweight versions for further control of size, RAM/ROM utilization and performance options.
    • Real-time, Priority-based preemptive, multithreading – Priority-based preemptive scheduling allows high-priority threads to meet their deadlines consistently, no matter how many other threads are competing for CPU time.
    • Optimized for Freescale architecture – Optimized assembly code to accelerates key real-time portions of the RTOS such as context switching.
    • Scheduling – Freescale MQX RTOS provides the developer faster development time by relieving engineers from create or maintain an efficient scheduling system and interrupt handling. It is also significantly useful if one requires the use of multiple communication protocols like USB or TCP/IP.
    • Code Reuse – Freescale MQX RTOS provides a framework with a simple API to build and organize the features across Freescales broad portfolio of embedded processors.
    • Intuitive API – Writing code for Freescale MQX RTOS is straight forward with a complete API and available reference documentation.
    • Fast boot sequence – A fast boot sequence ensures the application is running quickly after the hardware has been reset
    • Simple Message Passing – Messages can be easily passed between tasks running on the same CPU or even a different CPU in the system.

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    Supported Devices

    A full list of supported devices sorted by MQX version can be found in the MQX Fact Sheet.


    Product NameProduct ID
    Flexis™ 32-bit ColdFire® V1 MicrocontrollersMCF51AC
    32-bit ColdFire® V1 MicrocontrollersMCF51CN128
    MCF51EM256MCF51EM256 32-bit MCU for Smart Meter ApplicationsMCF51EM
    Flexis 32-bit V1 ColdFire® USB MicrocontrollerMCF51JM
    One-Stop-Shop Connectivity 32-bit MicrocontrollersMCF5225X
    Integrated ColdFire V2 Ethernet MicrocontrollersMCF5223X
    32-bits Microcontrollers with USBMCF5222X
    V2 Microcontroller with Touchscreen, LCD Controller and USBMCF5227X
    32-bit Microprocessor with USB On-The-Go, Ethernet, PCI, DDR2/DDR controller and EncryptionMCF5445X
    32-bit microprocessorMPC5125
    Flexis™ 32-bit ColdFire® V1 MicrocontrollersMCF51MM
    Integrated ColdFire V2 External Memory and Ethernet MicroprocessorsMCF520X
    Power Architecture MCU, 64 MHz, Integrated DisplayPXD10
    Power Architecture MCU, 116 MHz, Dual-Core, NetworkingPXN20
    Power Architecture MCU, 264 MHz, 4 MB On-Chip Flash, Quad ADCsPXR40
    Functional Safety MCU modulePXS20
    ColdFire+ Qx FamilyMCF51Qx
    ColdFire+ Jx familyMCF51Jx
    Power Architecture Safety MCU, 180 MHz, Dual-Locking Core, 2MB On-Chip FlashPXS30
    Kinetis K10 Baseline 50 MHz MCUsK10_50
    Kinetis K10 Baseline 100 MHz MCUsK10_100
    Kinetis K10 Baseline 120 MHz MCUsK10_120
    Kinetis K20 USB 50 MHz MCUsK20_50
    Kinetis K20 USB 100 MHz MCUsK20_100
    Kinetis K20 USB 120 MHz MCUsK20_120
    Kinetis K30 Segment LCD 100 MHz MCUsK30_100
    Kinetis K40 USB and Segment LCD 100 MHz MCUsK40_100
    Kinetis K60 Ethernet Crypto 100 MHz MCUsK60_100
    Kinetis K60 Ethernet Crypto 120/150 MHz MCUsK60_120
    Vybrid VF3xx Single-chip Solution with Dual XiP Quad SPI, Dual Ethernet and L2 SwitchVF3xx
    Vybrid VF5xx Single-core Solution with Dual Ethernet and L2 SwitchVF5xx
    Vybrid VF6xx Dual Heterogeneous Core Solution with XGA Display, Dual USB, Dual Ethernet and L2 SwitchVF6xx
    Advanced Industrial Display MCUPXD20

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    Technical Documents

    Learning Center
    User GuideFreescale: User Guide for Freescale MQX RTOS
    User GuideFreescale: User Guide for Freescale MQX™ USB Host
    User GuideFreescale: User Guide for Freescale MQX™ MFS
    User GuideFreescale: User Guide for Freescale MQX™ I/O Drivers
    Quick Start GuideFreescale: Getting Started with the Freescale MQX™ RTOS
    Support User GuideFreescale: Support User Guide For Freescale MQX™ RTOS
    Fact SheetFreescale: Fact Sheet for Freescale MQX™ Software Solutions
    Application NoteFreescale: Application Note on Using Freescale MQX Libraries


    Design Elements
    Application LibraryFreescale: AN4346 - Designing a Working Prototype using MQX™ RTOS and Tower System for Kinetis Microcontrollers
    Application LibraryFreescale: AN4022 - IP Camera and USB Snapshot with Freescale MQX RTOS
    Application LibraryFreescale: AN4417 - MCU control and monitor with Twitter


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