Unformatted text preview: er Occurrence Name Pri. Pri. Run Time A 3 3 10 s Periodic, tb A = 54 s. B 3 2 4 s Twice, any time between occurrences of A. C 3 1 12 s Once, any time between occurrences of A. D 2 1 50 s Periodic, tb D = 23 ms. E 1 1 10 s One shot. Event B will not recur until after a previous occurrence of event B has been responded to. That is, there cannot be an occurrence of B after an occurrence of B and before the response for this occurrence of B . Events A and C occur the same number of times, B occurs twice as many times as A and C . Solution:
Strong Priority Level 3: Latency of A: tl A = th C = 12 s. Latency of B : tl B = th A + th C = 22 s. Event B can occur twice just before and just after A so: Latency of C : tl C = th A + 4th B = 26 s. Actual run times: ta A = th A, ta B = th B , and ta C = th C . Since there is no preemption at the highest strong priority level response times are sum of latency and actual run times: tr A = tl A + ta A = 22 s, tr B = tl B + ta B = 26 s, and tr C = tl C + ta C = 38 s.
EE 4770 Lectu...
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- Fall '99
- Trigraph, Central processing unit, Interrupt, CPU time, Priority level, Lecture Transparency