SOFTWARE TOOLS: Micrium Expands RTOS Family with C/OS-III -

SOFTWARE TOOLS: Micrium Expands RTOS Family with C/OS-III


San Jose, Ca. – At the Embedded Systems Conference here, Micrium introduces its uC/OS-III, an feature-enhanced version of its real-time operating system (RTOS) for embedded designs.

According to Jean Labrosse, president and CEO of Micrium, the new version of the RTOS incorporates such elements as preemptive multitasking, unlimited number of tasks and priorities, and round robin scheduling of tasks at equal priorities.

Micrium will be demonstrating the software at Booth 1844 at the ESC from March 30 through April 2, in San Jose.

He said uC/OS-III represents a natural progression from the original uC/OS-II and “addresses customers' requests to provide certain enhancements that address today's complex designs without sacrificing the existing quality and clean code they're used to.”

uC/OS-III is a preemptive multitasking kernel that always runs the most important task that is ready-to-run. It supports an unlimited number of tasks, and allows stack growth of the tasks to be monitored at run-time. It also supports an unlimited number of priority levels. Typically, however, 32 to 256 different priority levels are adequate for most applications.

Specifically useful for today's designs, said Labrosse, is round robin scheduling of tasks at equal priority. “It allows multiple tasks to run at the same priority level, each for a user-specified time period,” he said. “Each task can define its own time quanta, and each task can give up a time slice if its full time quanta is not required.

It also allows for an unlimited number of kernel objects such as tasks, semaphores, mutexes, event flags, message queues, timers, and memory partitions. C/OS-III is mostly run-time configurable, said Labrosse.

uC/OS-III provides near zero interrupt disable time and has a number of internal data structures and variables that it needs to access atomically. These critical regions are protected by locking the scheduler instead of disabling interrupts. Interrupts are disabled for almost zero clock cycles, ensuring the RTOS will be able to respond to some of the fastest interrupt sources.

Processor support includes: ARM7/9, Cortex-Mx, Nios-II, PowerPC, Coldfire, i.MX, Microblaze, H8, SH, M16C, M32C, Blackfin, and more. uC/OS-III is provided in ANSI-C source form to licensees. Beta tests are underway in Q2, and product will be available in Q3, 2009. It is priced at $9,995/end-product. To learn more go to

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