The document provides an overview of the OSEK/VDX automotive software standard, including its key characteristics, specification, architecture, and concepts. It describes OSEK/VDX's scalability, portability, and configurability. It also explains the standard's three processing levels, four conformance classes, the concepts of basic and extended tasks, interrupt processing, event mechanism, and mixed preemptive scheduling policy.

1. T S PRADEEPKUMAR SCS, VIT University OSEK/VDXAReal Time Operating System

2. Automotive Software Standards Introduction to OSEK/VDX OSEK/VDX Characteristics and Specification OSEK Architecture Conformance Classes (CC) Tasks Concepts Interrupts Processing Events Scheduling Policies Other OS Services Topics for discussion

4. Automotive Open System Architecture

5. OSEK/VDX

6. Open systems and the corresponding interfaces for automotive electronics / Vehicle Distributed eXecutive

7. MISRA C

9. Used for wide range of control units for 8bit to 32 bit controllers

10. Uses four conformance classes that specifies the main features

11. Portability of software

12. ISO/ANSI-C Standard interface between the application and the OS

13. Configurability

14. Standard configurable information is provided with the help of OIL (OSEK Implementation Language)

15. Statically allocated OS

17. Interrupt Level

18. A logical level for OS Activities

21. OSEK/VDX Architecture

23. An Interaction layer which provides communication services for the transfer of application messages.

24. A Network layer which provides services for the unacknowledged and segmented transfer of application messages

27. Each task in the system may be

28. Basic Task (BT)

29. Extended Task (ET)

31. To provide support for different features and requirements of the application in terms of number of tasks, memory consumption, etc

32. BCC1

33. Only basic tasks limited to one activation request per task and one task per priority, while all tasks have different priorities.

34. BCC2

35. Like BCC1, plus more than one activation request per task and more than one task per priority.

36. ECC1

37. Like BCC1, plus extended tasks.

38. ECC2

41. Basic tasks only release the processor, if

42. they terminate

43. the OSEK operating system switches to a higher-priority task, or interrupt occurs which cause the processor to switch to an interrupt service routine (ISR).

44. Extended Tasks

45. In contrast to basic tasks extended tasks are allowed to use the operating system call WaitEvent, which may result in a waiting state

46. The waiting state allows the processor to be released and to be reassigned to a lower-priority task without the need to terminate the running extended task

49. Running

50. Only one task can be in this state at any point in time

51. Ready

52. The scheduler decides which ready task is executed next

53. Waiting

54. A task cannot continue execution because it has to wait for at least one event

55. Suspended

57. ISR does not use an OS Service.

58. No OS calls from the handler

59. The designer is free to write his own handler

60. These are the faster highest priority Interrupt

61. ISR Category 2

62. ISR is handled by the OS

64. Each (ET) owns a set of events that can be triggered by other BT or ET or even ISR Category 2

65. The behavior of an ET is to wait for an Asynchronous Event calling the OS Service WaitEvent()

68. Since preemptiveness is a task attribute, preemptive and non-preemptive tasks can be mixed in the same application.

70. Error Management

71. Application Error

72. Fatal Error

73. Leads to System Shutdown

74. System Startup