12-06-2014, 12:53 PM
A SEMINAR ON REAL TIME OPERATING SYSTEM
REAL TIME.pptx (Size: 1.13 MB / Downloads: 11)
RTOS Introduction
RTOS is a operating system that guarantees a certain capability within a specified time constraint.
Real time operating system (RTOS) provides basic supports for scheduling, resourse management , synchronization , communication , precise timing and I/O.
It is an multitasking OS used for Real-Time applications such includes in Embedded System.
Why RTOS for Real-Time
A real-time system has well-defined, fixed time constraints.
Processing must be done within the defined constraints, or the system will fail.
A real-time system functions correctly only if it returns the correct result within its time constraints.
Operating System
Computer application today require single machine to perform many operation and the application may compete for the resources of machine.
This demands a high degree of coordination.
This coordination is handled by a system software called operating system.
RTOS : Features
Multitasking and Preemptibility
Task priority policy:
Inter task communication and synchronization:
-mailboxes, massage queue , monitors,…
Hardware access is done at low level:
Priority Inheritance
Predefined Short Latencies
Control of Memory Management
Interrupt and Event Handling
Interrupt is a hardware mechanism used to inform the CPU that an asynchronous event has occurred
It provides the functions
Defining interrupt handler
Creation and deletion of ISR
Referencing the state of an ISR
Enabling and disabling of an interrupt
Conclusion
All the RT system are predictability .
The task in Real Time Systems may have arbitrary deadlines.
The RTOS is combination of Multitasking , multiprogramming & time sharing system.
Task in Real Time System can have periodic and aperiodic behavior.