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Previous Year Exam Questions for Real Time Systems - RTS of 2017 - bput by Verified Writer

by Verified WriterVerified Writer
Type: PYQInstitute: Biju Patnaik University of Technology BPUT Course: B.Tech Specialization: Electronics and Instrumentation EngineeringOffline Downloads: 11Views: 687Uploaded: 10 months ago

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Verified Writer
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Registration no: Total Number of Pages: 02 B.Tech. PECS5403 7th Semester Regular / Back Examination 2017-18 Real Time Systems BRANCH: AEIE, ECE, EIE, ETC, IEE Time: 3 Hours Max Marks: 70 Q.CODE: B351 Answer Question No.1 which is compulsory and any five from the rest. The figures in the right hand margin indicate marks. Q1 a) b) c) d) e) f) g) h) i) j) Q2 a) b) Q3 a) Answer the following questions : List the essential differences between a real-time database and a conventional database? What are the various methods used to achieve hardware fault tolerance? Differentiate between simple priority inversion and unbounded priority inversion? What are the two main purpose of using clocks in distributed real time system? Define byzantine clock. Explain with an example. What are the activities performed by handler routine when a clock interrupt occurs? What are the various real time priority levels associated with UNIX based RTOS? Differentiate between synchronous and asynchronous I/O? Which one is better suited for use in real‐time applications? Distinguish between execution time and response time of a task? What is chain blocking? How is unbounded priority inversion avoided in PCP? What is the difference between performance constraint and behavioral constraint? Describe the various types of timing constrains with suitable example. Explain the operation of priority ceiling protocol in sharing critical resources among real time task. Explain different types of priority invesions that a task might suffer due to lower priority task when the PCP is used to share critical resources among a set of real task. (5) The following table shows the details of tasks in a real-time system. The tasks have zero phasing and repeat with a period of 90 mSec. Determine a feasible schedule to be used by a table-driven scheduler. (5) Tasks T1 T2 T3 T4 b) (2 x 10) (5) Execution time (in mSec) Deadline (in mSec) Dependency 30 90 ― 15 40 T1, T3 20 40 T1 10 70 T2 A cyclic scheduler is used to run the following set of periodic tasks. Assume a single processor is present in the system and all timings are given in msec. Select the appropriate frame size. (e1 = 1, p1 = 4), (e2 = 2, p2 = 5), (e3 = 5, p3 = 20) (5)
Q4 a) b) Q5 a) b) Q6 a) b) Q7 a) b) Q8 a) b) c) d) What do you mean by priority inversion? Distinguish bounded from unbounded priority inversion. Demonstrate with a neat diagram. Briefly explain the highest locker protocol scheme for avoiding priority inversion. (5) How dynamic allocation of real time task can be made in a microprocessor? Explain with an example. Define Notion of clock and clock synchronization in context of real time systems. Explain non fault tolerance synchronization algorithm. (5) Why traditional UNIX kernel is not suitable to be used in a multiprocessor environment? Explain how Unix dynamically recomputes task priority values. Define real time communication. Explain virtual time carrier sensed multiple access protocol with a suitable example. (5) Evaluate the suitability of Windows-NT as a Real-time OS. Why is dynamically changing the priority levels of tasks important for traditional operating systems? How does this property affect real-time systems? (5) (5) Write short answer on any TWO: UNIX as a RTOS QoS parameters for real-time communication Fail safe state N-version Programming (5) (5) (5) (5 x 2)

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