1. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 1 Software engineering for real-time systems Section 1 Introduction to real-time systems

2. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 2 Objectives To: Outline the differences between general-purpose computer applications and real-time systems. Give an overview of practical real-time system structures. Describe some key environmental and performance requirements of embedded real-time computers. Describe the structures of modern microprocessors and microcomputers. Introduction

3. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 3 A modern batch system

4. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 4 Typical interactive on-line computer system

5. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 5 A real-time computer system

6. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 6 Two major categorization factors: criticality and speed. Criticality: Hard systems - deadlines (responsiveness) is critical. Failure to meet these have severe consequences (e.g. injury, damage or death). Soft systems - deadlines are less critical; in many cases significant tolerance can be permitted. Speed: –Fast systems - responses in the microseconds to hundreds of milliseconds. –Slow systems - responses in the range seconds to days. –Arbitrary boundary: 1 second (chosen because the problems shift from individual computing issues to overall system behaviour and interaction at around this point). Categorizing real-time systems

7. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 7 Major attributes of real-time systems. For hard systems emphasis is placed on the need to meet deadlines. Hard-fast systems tend to have low software complexity. For soft-fast systems emphasis is put on computation performance. In general soft systems tend to be the more complex ones (from a software perspective). Attributes of real-time systems

8. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 8 Telemetry control system

9. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 9 Sea Skua missile system

10. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 10 Submarine control console

11. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 11 Typical avionic platforms

12. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 12 Microprocessor-based vending machine units

13. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 13 Consumer communications

14. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 14 Embedded systems platforms

15. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 15 Embedded systems characteristics

16. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 16 Typical temperature specifications for real-time systems

17. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 17 Computer loading - single synchronous (periodic) task

18. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 18 Computer loading - single asynchronous (aperiodic) task

19. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 19 Computer loading - multiple asynchronous (aperiodic) tasks (I) (E 1 ) 2 ) 1 ) 1 ) 1 ) 2 ) (I) S 1 S 1 S 1 S 1 S 2 (W) S 2 ( W) = waiting time for task to complete (I) Time (E1) = Event task 1 execution (E2) = Event task 2 execution (S1) = Event signal, task1 (S2) = Event signal, task 2 (I) = Idle (spare) time

20. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 20 The computing elements of real-time systems

21. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 21 Elements of a microcomputer system

22. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 22 Timing in hardware Real-time clockProgrammable timer Address bus Chip select line Control bus To interrupt

23. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 23 The watchdog timer

24. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 24 DMA operation

25. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 25 Intelligent I/O processing Main processor I/O processorDisk store Local memory Primary bus Secondary bus

26. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 26 I/O interface peripheral

27. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 27 Highly integrated processor -Motorola MPC8240

28. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 28 Single chip microcomputer - Philips Semiconductor 8052

29. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 29 Single chip microcontroller - Fujitsu MB91F361

30. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 30 Digital signal processor structure

31. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 31 Mixed signal processor structure - Texas MSP430

32. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 32 Example system-on-a-chip (SOC) design

33. SOFTWARE ENGINEERING for REAL-TIME SYSTEMS (© J.E.Cooling 2003) Introduction to real-time systems - slide 33 Review of ‘Introduction to real-time systems’