Name of the University : Jadavpur University
Department : Power Engineering
Degree : M.Tech
Subject Name : Real-Time Embedded Systems
Sem : II
Website : jaduniv.edu.in
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/dspace.jdvu.ac.in/5508-M.%20Power%20-%20Real%20Time%20Embedded%20System.pdf
Real-Time Embedded Systems Question Paper :
Master Of Power Engineering Examination, 2009 :
2nd Semester :
Time : Three hours
Full Marks : 100
Related / Similar Question Paper :
Jadavpur University Sensors & Transducers Question Paper
Answer any five questions. :
1. b. Enumerate the assumptions for which 1a. is valid, 4
c. Define critical instant, critical zone and tax laxity, 6
2. a. Using the data of 1a. above calculate the least upper bound of maximum processor utilization n for a schedulable task set assuming
b. Assuming RM scheduling calculate the limiting value of n for an infinite task set.5 (do not derive m) 3
3. a. Tabulate the differences between Round-Robin, Interrupt-Driven and RM scheduling in a RTOS.
b. What are the requirements of a RTos? 2
c. A realtime embedded system is developed around an intel 8088 based system with a single 8259. It comprises three tasks , T2 and , with priorities in the same sequence which are connected to IRQs .5 and 6 respectively, with a default priority assignment for the IRQs. If the tasks are associated with execution times of 20, 25 and 30 msec. respectively, and the interrupt latency is 5 microsec., what is the response time of the system, if interrupt driven scheduling is assumed?
If the period at which the triggers arrive is same and it is P, what should be the minimum value of P if no overflow occurs, assuming scheduling overhead is 10% 12
4. a. Distinguish between
i)Counting and Flag semaphores
ii) Burst mode and FIFO mode semaphores , 4
c. 3 tasks , T2 and , with priorities in the same sequence are synchronized using a flag semaphore. Initially,, and T2 are in the blocked state when T3 runs for 50 ms after having set the semaphore, when it is pre-empted by . T2 runs for 30 ms. more before it is blocked again, while trying to set the same semaphore, and T3 runs for a further period of 10 ms. when it is pre-empted by T, which runs for 20 ms. and gets blocked again when it tries to set the semaphore set by T.then runs for 15ms. and resets the semaphore. If T2 and T, take further 20 ms. each to complete the activities for the particular cycle, draw the execution profile and calculate the time spent by T. in blocked mode assuming a) a burst mode semaphore and b) a FIFO mode semaphore. Calculate n for the taskset. 16
5. a. With the help of a neat sketch explain how the interrupt type is established in a 8088 based system with a single 8259 and hence explain what is the minimum duration between two interrupts connected to the same IRQ if the clock frequency is F. 14
Assuming the even address associated with the 8259 to be 20H, write the initialization sequence to program the 8259 with the following:
i) There is a single 8259
(ii) The interrupts are Level Triggered with AEOl (iii) IRQ 5 has the highest priority 6
6. What is mark bit and stop bit for asynchronous serial communication? What is the relationship between their signs. What is the significance of the mark bit? 6
b.Assuming a base address write the instruction sequence to program a UART with the following –
i) 8 bit data, no parity, 2 stop bits
(ii) Operation at 9600 baud
(iii) and Tx interrupts enabled –
iv) and Tx clock factor of 2 – 8
c)NS16550 is a better version of 8251 in which a FIFO (max. 16 element) is implemented and the interrupt is generated once the FIFO is filled upto a threshold. Calculate if the chip can be used to sink data at 19.2kbps in an interrupt driven mode, reading the FIFO in response to an interrupt takes 500 microsec. The data may be assumed to be 8 bit, no parity with 2 stop bits. 6
7.a.A CAN uses a data speed of 1 Mbps with a n bit data identifier and a m bit data length (inclusive of the identifier).
Calculate the following:
(i) arbitration time
(ii) maximum delay in transmission of a higher priority message 10
b. What is reentrancy? What are the measures by which is ensured? How do you generate reentrant code using an integrated development environment? 10
8. Two data streams d, and d2 arising out of 2 independent sources undergo sequential with a periodicity of P. The event e is generated by a task To and the transformation Ds is interfaced with D, using a synchronized buffer. Using DARTS, 20
a. represent the system using DFD
b. identify the tasks stating the criteria
C. suggest a suitable priority assignment
d, suggest a suitable synchronization mechanism for the synchronization specified in the problem