REAL TIME AND EMBEDDED SYSTEMS

REAL TIME AND EMBEDDED SYSTEMS

Instructions: Answer Question One and Any Other Two Questions.

QUESTION ONE (30 Marks)

1. Describe real time OS and Briefly explain the  Components of real time operating system                                                                                                                                    (4 marks)
2. Differentiate between the following             (4marks)
   1. Hard and soft real time systems
   2. Sporadic and aperiodic
3. Outline two measures that must be provided for the effective control of a plant.                                                                                                                  (4marks)
4. Briefly explain factors that affect the dependability of a system                   ( 6marks)
5. To resolve static software in real time software N- version programming may be used. Describe N- version programming             (6marks)
6. Explain atleast two classes of exceptions in real time systems                                  (2marks)
7. Compare and contrast N-verstion programming and recovery blocks             (4 marks)

QUESTION TWO (20 Marks)

1. Fault prevention attempts to eliminate any possibility of faults creeping into a system before it goes operational.
   1. State and explain two stages of  fault  prevention                  (2 marks)
   2. Discuss ways in which a system can be built with the ability to continue operating in presence of fault.                                     (8 marks)
2. Briefly describe the characteristics of the real time systems             (10marks)

QUESTION THREE (20 Marks)

1. One common way of implementing hard real-time systems is to use a cyclic executive

1. i) Briefly describe cyclic executive (4marks)
2. ii) Outline atleast six problems associated with cyclic executive (6marks)
3. Describe the following concepts as used in realtime programming
4. i) Priority ceiling locking                         (5marks)
5. ii) Dispatching (5marks)

QUESTION FOUR (20 Marks)

1. Enumerate at least four applications of real time systems             (6 marks)
2. Describe the basic model of a real time system             (10marks)

1. Discuss four factors that guarantees high system reliability when adopted             (4marks)