Segger - embOS Real Time Operating System

Real Time Operating System
embOS is a real-time operating system for embedded applications designed to offer the benefits of a fully fledged multitasking system at minimum cost. The kernel is fully interruptible and so efficient that it can be used in very time critical situations. The memory footprint in both RAM and ROM is so small that it can be used in single-chip applications, leaving maximum room for the user-program.

Despite its size and efficiency, embOS features the entire palette of communication mechanisms such as mailboxes, events and different kinds of semaphores. All tasks and communication instances can be dynamically created, deleted and configured.

embOS is fully priority controlled : out of the tasks in READY-state, the one with the highest priority is active. Tasks that have identical priorities are executed "quasi-simultaneously" in round robin. If no task is ready, embOS automatically puts the CPU in to a power-saving mode in the idle-task.

• affordable
• no royalties
• fast & efficient
• small footprint
• kernel is fully interruptible
• easy to use
• versatile
• fully preemptive
• task switches even in interrupt handlers
• support directly by developers

Developing applications with embOS

embOS comes with libraries for different memory models, initialization of the controller in "C"-source, usable sample modules and a frame application in source code form. This frame program creates 2 tasks with little functionality. By modifying this frame application, the first steps are very easy (Experienced programmers have the first multitask-program running in typically less than 1 hour). All parts that might have to be adopted to the application are provided in source code form.

Typical applications for embOS

Everything from battery-powered, single chip products to systems demanding ultra-fast response, flexibility and multiple processes:

• Battery powered measurement instruments
• programmable machine controls
• printers
• telecommunication equipment ...

Technical info

• kernel size (ROM) 1100 - 1600 byte*
• kernel RAM usage 18 - 25 byte *
• kernel CPU usage at 1 ms Interrupts with 10MHz M16C : less than .3%
• RAM usage mailbox 9 - 15 byte *
• RAM usage binary and counting semaphore 3 byte
• RAM usage resource semaphore 4 - 5 byte *
• RAM usage timer 9 - 11 byte *
• RAM usage event 0
• Basic time unit (One Tick) Default 1 ms, can be configured, Min. 100 µs (M16C@10MHz) *
• task activation time independent of no. of tasks(e.g. typ. 12 us M16C@10MHz)
• interrupt latency time Very short, since kernel is fully interruptible
• No. of tasks : Unlimited (by available RAM only)
• No. of mailboxes : Unlimited (by available RAM only)
• No. of semaphores : Unlimited (by available RAM only)
• No. of s/w timers : Unlimited (by available RAM only)
• Max. no. of priorities : 255
• Max. no. of tasks with identical priorities (Round robin scheduling) Unlimited
  
  * Depends on CPU, compiler and library model used

CPU load

The following diagram illustrates the typical CPU load imposed by embOS for the supported Mitsubishi CPUs M7700 (low end 16 bit), M16C/60 (medium 16 bit), M16C/80 (high end 16 bit) The data is based on typical clock frequencies for these CPUs and a system time tick of one ms (1000 System timer interrupts per second)

Profiling and API function call trace using new embOSView V3.06

On most CPUs a profiling build of the libraries is available. In a profiling build, embOS collects precise timing information for every task (Resolution 1 µs, Accuracy better than 2 us).

The new version 3.06 of embOS also comes with trace build libraries. All API- and user function calls can be traced and displayed using the new embOSView version 3.06. embOSView communicates with the kernel via UART and displays all available information on the tasks, incl. the CPU load. In non-profiling builds, embOSView is still able to display the information about the system, incl. all tasks. This feature does not require an add. debug task; all communication is done from within the Communication Interrupt routines. This means that it is none intrusive if embOSView is not connected and minimum intrusive while embOSView is connected.

The current version 3.06c also includes a Terminal window. The Terminal shares the serial interface with embOSView and can be used for serial input and output from within the user application.

EmbOS is an affordable , royalty-free solution to your kernel requirements.

Supported Processors
To view embOS supported processors click here...

embOS Frame Program
To see an example of embOS frame program with embOS click here...

You can download a trial version of embOS here.