Nios® II Software Developer Handbook

ID 683525
Date 8/28/2023
Public
Document Table of Contents

11.1. Overview of the MicroC/OS-II RTOS

MicroC/OS-II is a popular real-time kernel produced by Micrium® Inc. in 1992. MicroC/OS-II is a portable, ROMable, scalable, pre-emptive, real-time, multitasking kernel. MicroC/OS-II is used in hundreds of commercial applications. It is implemented on more than 40 different processor architectures in addition to the Nios® II processor.

MicroC/OS-II provides the following services:

  • Tasks (threads)
  • Event flags
  • Message passing
  • Memory management
  • Semaphores
  • Time management

The MicroC/OS-II kernel operates on top of the hardware abstraction layer (HAL) board support package (BSP) for the Nios® II processor. Because of this architecture, MicroC/OS-II development for the Nios® II processor has the following advantages:

  • Programs are portable to other Nios® II hardware systems.
  • Programs are resistant to changes in the underlying hardware.
  • Programs can access all HAL services, calling the UNIX-like HAL application program interface (API).
  • ISRs are easy to implement.
Note: MicroC/OS-II is not compatible with external interrupt controllers on the External Interrupt Controller (EIC) interface; and can only run on systems using the internal interrupt controller.

For more information about MicroC/OS-II features and usage, refer to MicroC/OS-II - The Real-Time Kernel by Jean J. Labrosse (CMP Books).