Download Real-Time Systems Exam Questions for Computer Applications Students and more Exams Computer Science in PDF only on Docsity! Cork Institute of Technology Bachelor of Science (Honours) in Computer Applications – Award (Bachelor of Science in Computer Applications – Award) (NFQ – Level 8) Summer 2005 Real-Time Systems (Time: 3 Hours) Answer any THREE questions. Note: Question 1 = 34 marks. All other questions = 33 marks. Examiners: Dr. J. Creagh Dr. D. Chambers Mr. P. O’Connor Mr. E. A. Parslow Q1. (a) (i) List each of the phases of the ROPES lifecycle. List each of the sub-phases. Describe each sub-phase in detail, giving an example(s) to clearly illustrate your understanding of the sub-phase. (10 marks) (ii) Give a detailed diagram illustrating “A single iteration pass along with the generated artifacts”. Explain your diagram. (7 marks) (b) (i) Describe the different types of Petri-Nets giving clear examples. (4 marks) (ii) With a clear series of examples, explain what a ‘conflict’ is with Petri-Nets. Should a conflict be allowed to develop for a real-time system? Explain. (5 marks) (iii) A simple dishwasher system has the following cycle: pump water in add powder heat water spray water (for 10 minutes) empty water input water spray water (for 5 minutes) empty water Firstly, list the actuators and sensors. Then, design a simple Petri-Net solution for the dishwasher cycle. (8 marks) 2 Q2. (a) “OS-9 provides a foundation for embedded real-time products”. Referring to OS-9, the development system and the OS-9 kernel, explain in detail why this statement is true. (7 marks) (b) OS-9 process scheduling utilises many queues. (i) Describe each of the OS-9 queues and give detailed examples of use. (5 marks) (ii) Describe the advantages and disadvantages of each queue. (5 marks) (c) (i) Write a C/C++ OS-9 program to send the contents of variable “struct CommData MyData” from process 1 to process 2 via pipe “/pipe/test”. Also write the receiving process, which displays the received data. Struct CommData { int x; int y; int z; }; Choose your own sample data. Note: When using OS-9 function calls, only the key parameters should be used. (6 marks) (ii) What is the main problem with using pipes as a form of communication for real- time systems? (3 marks) (d) Describe how to structure a process in OS-9 so that it may receive/handle signals. Give an example where signal numbers 300, 320, and 420 are dealt with. (7 marks)
