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Chapter 11. Real-time Operating System f... > FILL IN THE BLANKS TYPE QUESTIONS

FILL IN THE BLANKS TYPE QUESTIONS

  1. A system consists of ____________ and the system's software supervises the running of the tasks.

  2. ____________ means information of the present program counter, stack pointer and other CPU registers. When the context of one task ____________ and the context of other task ____________ then that task runs.

  3. RTOS controls a task which can be in one of the following states at any given instance ____________, ____________, ____________, ____________, waiting for a specific period, and waiting till some signal or message before some specific or undefined period.

  4. Real-time means ____________ from the system's start and different actions takes place in the system at different instances of this time.

  5. Real-time constraint means ____________ before which a task should start after an event(s). Realtime constraint also means the ____________ up to which it must respond to an event(s), and time limit within which it must finish.

  6. Real-time operating system (RTOS) is ____________ when the system requires ____________ to be done at the ____________ and in ____________ space. RTOS is in between software layer between ____________ and ____________ and, ____________ routines.

  7. ____________ controls the running of the tasks and interrupt-service routines using the hardware.

  8. The task of ____________ when ready, preempts (blocks) the low-priority task in order to function within the time constraints.

  9. Task in ____________ state of ready when it gets a signal for which it is waiting or gets a message for which it is waiting or time out when its waiting-period is over.

  10. ____________ are assigned to the tasks in preemptive scheduling.

  11. When the tasks run in cyclic schedule and when one completes then other is signalled to start, then scheduling is called ____________.

  12. The ____________ generates a timeout at regular (preset) intervals. It is called ____________ The ____________ interrupts the RTOS at ____________. System clock ticks are used for the ____________ actions.

  13. A task ____________ another task but it can call the function(s) to implement certain action(s).

  14. A task i waits for ____________ when OS_wait function executes for a period = ____________.

  15. A task i ____________ a signal at time t1. Then waiting task j takes the ____________ and takes over the resources (CPU, memory, IOs, etc.) and starts at time t2.

  16. A task i ____________ a semaphore (token) s1 at time t1. Then waiting task j takes the ____________ and takes over the resources (CPU, memory, IOs, etc.) and starts at time t2.

  17. A task i ____________ a ____________ into mailbox Ml at time t1. Then waiting task j the ____________ the message and takes over the resources (CPU, memory, IOs, etc.) and starts at time t2.

  18. A high priority task must be waiting for ____________, ____________, ____________, or ____________ so that the lower priority task can run in preemptive scheduling.

  19. RTX51 Tiny kernel requires only ____________ bytes of program memory codes space. When we don't need ____________, ____________, and ____________ functions we use it. Maximum number of defined tasks can be ____________. Maximum number of tasks which can be active are ____________ at an instant. It requires maximum DATA space of ____________. Bytes in Internal RAM. It requires STACK space of ____________ bytes per task.

  20. RTX51 Full has the functions for preemptive scheduling. RTX51 Full has the following features.

    (a) Generates the timer ticks (for cyclic interrupts) using ____________.

    (b) Provides for ____________ of a high priority task by switching from a lower priority task.

    (c) It has program codes of = ____________ Kbytes, data in internal RAM DATA = ____________ bytes, stack in internal RAM (IDATA) = ____________ bytes, and external memory XDATA = ____________ bytes (minimum).

    (d) It has the functions to enable preemptive scheduling.


  

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