CSE4352

μC/OS-II (read as MicroC/OS-II) is the second generation of μC/OS which is a priority-based, preemptive and real-time multitasking operating system written mainly in the C programming language. It is originally published in a book by Jean J. Labrosse, μC/OS The Real-Time Kernel, which purpose was to describe the internals of a portable operating system with a small footprint. It is now a product which is maintained by Micrium Inc. and licenses are issued per product or royalty free for non-commercial educational uses. Even though the source code of μC/OS is available, it is not by any means considered free or open source software.

μC/OS-II is an extremely detailed and highly readable design study which is particularly useful to the embedded systems student. While documenting the design and implementation of the kernel, the book also walks through the many related development issues such as how to adapt the kernel for a new microprocessor, how to install the kernel, and how to structure the applications that run on the kernel.

Important features of μC/OS-II are ¹⁾:

• Highly portable, scalable and preemptive real-time multitasking kernel that you only build what you need.
• It can manage a predefined maximum number of tasks.
• It can be expanded and connected to addons such as μC/GUI and μC/FS which are GUI and File Systems for μC/OS-II
• It supports all type of processors from 8-bit to 64-bit

μC/OS-II like most modern operating systems has the following components:

• Task Management (i.e. Create, Delete, Change Priority and Suspend/Resume tasks)
• Time and Timer Management
• Fixed Sized Memory Block management.
• Inter-Task Communication (i.e. Message Mailboxes and Message Queues)
• Semaphores, Mutual Exclusion Semaphores
• Many external modules are available as the real-time addons to the core (μC/GUI, μC/FS, μC/CAN, μC/USB, μC/TCP-IP and many more).

μC/OS-II allows one to create new tasks and check the existing status of the tasks stack. Tasks can be deleted or their priority can be changed. Also μC/OS-II provides general information about a specific task and allows one to suspend or resume operation as well on a task.