Quantitative Evaluation of Embedded Systems

1. Quantitative Evaluation of Embedded Systems Latency for a periodic source

2. Latency for a periodic source A C B 30ms 10ms 10ms

3. Software-Defined Radio (W-LAN) Scr1 Scr6 Scr7 Scr2 Scr5 Scr3 Scr4 BuildHeader ModHeader Pdemod Pdecode CodeHeader Hdemod CFEnSync FFEnCE Detect O.Moreira, F. Valente, M.Bekooij, “Scheduling multiple independent hard-real-time jobs on a heterogenous multiprocessor”, in Proceedings of the 7th ACM & IEEE International conference on Embedded Software . EMSOFT 2007, pp. 57-66, 2007 Hdecode AckMode MacCRC AckCode MacAnalyse

4. Software-Defined Radio (W-LAN) * Disclaimer: this is just an illustration. The actual deployment of a W-LAN gives a graph that is too complicated to draw.

5. Latency for a periodic source A C B 30ms 10ms 10ms

6. Latency for a periodic source Press pause to calculate the MCM and a periodic schedule for it! A C B Delaying one actor will delay them all! 30ms S 10ms 10ms

7. Latency for a periodic source t0 = 0ms A C B t0 = 10ms t0 = 10ms 30ms S 10ms MCM = 20ms 10ms

8. Latency for a periodic source t0 = 0ms A C B t0 = 10ms t0 = 10ms 30ms S Latency = 10ms MCM = 20ms 10ms

9. Latency for a periodic source t0 = 0ms A C B t0 = 10ms t0 = 10ms 30ms S Latency = 10ms MCM = 20ms 10ms

10. Latency for a periodic source t0 = 0ms A C B t0 = 0ms t0 = 0ms 30ms S Latency = 10ms μ = 30ms 10ms

11. Calculating a latency bound • Given a dataflow graph with execution times Ea • Determine the MCM and choose a period μ ≥ MCM • Determine start-times Ta of a periodic schedule • Determine the minimum number δ of tokens between input and output • Latency ≤Toutput+ Eoutput + δ·μ