10-04-2017, 09:04 PM
ABSTRACT
Within the last ten years real-time systems research has been transformed from a
niche industry into a mainstream enterprise with clients in a wide variety of industries
and academic disciplines. It will continue to grow in importance and affect an increasing
number of industries as many of the reasons for the rise of its prominence will persist for
the foreseeable future.
What is RTOS?
Real Time Computing and Real Time Operating Systems( RTOS ) is an
emerging discipline in software engineering. This is an embedded technology whereby
the application software does the dual function of operating system also. In RTOS the
correctness of the system depends not only on the logical result but also on the time at
which the results are obtained.
Real-time System
? Provides deterministic response to external events
? Has the ability to process data at its rate of occurrence
? Is deterministic in its functional & timing behavior
? Whose timing is analyzed in the worst cases not in the typical, normal cases to
guarantee a limiting response in any circumstances.
The seminar will basically provide a practical understanding of the goals,
structure and operation of a real-time operating system (RTOS). The basic concepts of
real-time system like the RTOS Kernel will be given a detailed description. The structure
of the kernel is discussed, stressing the factors which affect response times and
performance. Examples of RTOS functions such as scheduling, interrupt processing and
intertask communication structures will also be discussed. Features of commercially
available RTOS products are also presented.
1.1 Definition
A real-time system is one where the timeliness of the result of a calculation is important
Examples include military weapons systems, factory control systems, and Internet video and
audio streaming. Different definitions of real-time systems exist. Here are just a few:
- Real-time computing is computing where system correctness depends not only on the
correctness of the logical result of the computation but also on the result delivery time.
- A Real-Time System is an interactive system that maintains an on-going relationship
with an asynchronous environment, i.e. an environment that progresses irrespective of the Real
Time System, in an uncooperative manner.
- Real-time (software) (IEE 610.12 - 1990): Pertaining a system or mode of operation in
which computation is performed during the actual time that an external process occurs, in order
that the computation results may be used to control, monitor, or respond in a timely manner to
the external process.
From the above definitions its understood that in Real Time Systems, the
TIME is the biggest constraint. This makes real time systems different from ordinary systems.
Thus in RTS data needs to be processed at some regular and timely rate. Also it should have fast
response to events occurring at nonregular rates.
In real world systems there is some delay between presentation of inputs and
appearance of all associated outputs called the Response time. Thus a real time system must
satisfy explicit response time constraints or risk severe consequences including failure.
Complete information in this pdf:
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