26-05-2012, 04:01 PM
REAL TIME OPERATING SYSTEM (RTOS) CONCEPTS
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What is Real Time?
1) Real time is a level of responsiveness that a user senses as sufficiently immediate or that enables the computer to keep up with some external process. 2) Real time describes a human rather than machine sense of time. 3) It is the class of computers systems that interacts with the external world in a time frame defined by the external world. 4) It is the system in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time at which the result is produced. 5) If the timing constraints of the system are not met system failure is said to have occurred.
What is RTOS?
A real time operating system (RTOS) is an operating system that guarantees a certain capability within a specified time constraint.
2) An OS is a system program that provides an interface between application programs and the computer system (hardware)
3) The applications where dependability that a certain task will finish before a particular deadline is just as obtaining the correct results.
4) Besides meeting deadlines RTOS must also be able to respond predictably to unpredictable events and process multiple events concurrently.
Types Of RTOS
1) Hard Real Time Systems: a) If it has a hard deadline for the completion of an action meaning that the deadline must always be met,otherwise the task has failed. b) This types of systems deployed in embedded safety-critical systems in which missed deadline can be catastrophic. c) Examples: aircraft ,train,car,missile and nuclear reactor control systems.
Soft Real Time Systems :
a) Soft real time by default as “Not Hard Real Time.”
b) Missing some deadlines by some amount under some circumstances may be acceptable rather than failure.
c) In this systems there is usually a rising cost associated with lateness.
d) Soft real time means systems which have reduced constraints on “lateness” but still must operate very quickly and repeatably.
[attachment=23201]
What is Real Time?
1) Real time is a level of responsiveness that a user senses as sufficiently immediate or that enables the computer to keep up with some external process. 2) Real time describes a human rather than machine sense of time. 3) It is the class of computers systems that interacts with the external world in a time frame defined by the external world. 4) It is the system in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time at which the result is produced. 5) If the timing constraints of the system are not met system failure is said to have occurred.
What is RTOS?
A real time operating system (RTOS) is an operating system that guarantees a certain capability within a specified time constraint.
2) An OS is a system program that provides an interface between application programs and the computer system (hardware)
3) The applications where dependability that a certain task will finish before a particular deadline is just as obtaining the correct results.
4) Besides meeting deadlines RTOS must also be able to respond predictably to unpredictable events and process multiple events concurrently.
Types Of RTOS
1) Hard Real Time Systems: a) If it has a hard deadline for the completion of an action meaning that the deadline must always be met,otherwise the task has failed. b) This types of systems deployed in embedded safety-critical systems in which missed deadline can be catastrophic. c) Examples: aircraft ,train,car,missile and nuclear reactor control systems.
Soft Real Time Systems :
a) Soft real time by default as “Not Hard Real Time.”
b) Missing some deadlines by some amount under some circumstances may be acceptable rather than failure.
c) In this systems there is usually a rising cost associated with lateness.
d) Soft real time means systems which have reduced constraints on “lateness” but still must operate very quickly and repeatably.