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Module6

Embedded SystemSoftware

Version 2 EE IIT, Kharagpur 1

Lesson29

Real-Time Task

Scheduling Part 1Version 2 EE IIT, Kharagpur 2

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TaskPhase

mSecExecution Time

mSecRelative Deadline

mSecPeriod

mSec

T1 20 10 20 20

T2 40 10 50 50

T3 70 20 80 80

If the tasks are to be scheduled using a table-driven scheduler, what is the length of time

for which the schedules have to be stored in the pre-computed schedule table of the

scheduler.

6. A cyclic real-time scheduler is to be used to schedule three periodic tasks T1, T2,

and T3 with the following characteristics:

TaskPhase

mSec

Execution Time

mSec

Relative Deadline

mSec

Period

mSec

T1 0 20 100 100

T2 0 20 80 80

T3 0 30 150 150

Suggest a suitable frame size that can be used. Show all intermediate steps in your

calculations.

7. Consider the following set of three independent real-time periodic tasks.

Task

Start Time

mSec

Processing Time

mSec

Period

mSec

Deadline

mSec

T1 20 25 150 100

T2 40 10 50 30

T3 60 50 200 150

Suppose a cyclic scheduler is to be used to schedule the task set. What is the

major cycle of the task set? Suggest a suitable frame size and provide a feasible schedule

(task to frame assignment for a major cycle) for the task set.

Version 2 EE IIT, Kharagpur 21