trend: embedded systems 3

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1 Eindhoven University of Technology 1 CompSOC: A Predictable and Composable Multicore System Kees Goossens The CompSOC team Kees Goossens <k.g.w.goossens@tue.nl> Group Electrical Engineering Faculty trend: embedded systems 3 phones, game consoles, cars, refrigerators, buildings,... interaction with physical world è real-time requirements [wikipedia.org] [sensimed.com] [mit.edu] 1

2 Eindhoven University of Technology 2 trend: multiple s on one embedded device 4 different domains infotainment (streaming à video analysis), games real-time control, (wireless) networking stacks [st.com] [carvoyant.com] observation: different s 5 have different characteristics and requirements FT, ST, NT, adaptive,... are designed by different parties use different models of computation (MOC) & verification approaches FT à worst case & formal verification NT à average case & simulation adaptive ST à actual case & simulation use different resource-management policies data / event / time, schedulers, power management 2

3 Eindhoven University of Technology 3 problem: design time 6 systems are complex time is short + it takes too long getting worse money - time start design start selling first profit end of life monolithic verification after integration, multiple s circular verification who to blame for errors? goal & approach 7 reduce SOC design & verification effort independent design, verification, and deployment per as the unit of verification two complexity-reducing techniques composability predictability applied to multi- system with distributed shared offering multiple programming models / models of computation 3

4 Eindhoven University of Technology 4 composability 8 virtual execution per defined by its space, time, energy budgets design, verify, deploy in a virtual no interference when integrating, executing, or switching use cases FT TT control ST KPN video FT dataflow radio FT TT control ST KPN video FT dataflow radio NT GUI NT GUI N! combinations & interleavings è N virtual s inter-dependent state 2 S x 2 S x 2 S x 2 S è independent states 2 S + 2 S + 2 S + 2 S composability 9 time-division-multiplex virtual execution s space, time, power & energy budgets no interference FT radio virtual ST video virtual. interc. mem.. interc. mem. interconnect interconnect inter- scheduling µkernel 4

5 Eindhoven University of Technology 5 composability & predictability 10 each can have its own programming model, scheduling, power management (CS)DF, KPN, TT, DSM for T use predictable schedulers, and associated real-time formalism FT radio virtual ST video virtual. interc. mem.. interc. mem. intra- scheduling & power management interconnect interconnect inter- scheduling CompSOC 11 CM CM DAM 5

6 Eindhoven University of Technology 6 CompSOC 12 CM CM DAM CompSOC T1 13 system app. TOS TOS TOS CM CM DAM 6

7 Eindhoven University of Technology 7 CompSOC T1 T2 T2 T1 14 FT dataflow HT control FT dataflow system app. TOS TOS TOS CM CM DAM CompSOC communication T2 FT dataflow HT control FT dataflow T1 system app. 15 TOS TOS TOS shared (TDM) CM CM DAM 7

8 Eindhoven University of Technology 8 CompSOC remote communication T2 FT dataflow HT control FT dataflow T1 system app. 16 TOS TOS TOS dual port not shared CM dual port DAM CM shared (TDM) CompSOC remote shared T2 FT dataflow HT control FT dataflow T1 system app. 17 TOS TOS TOS CM CM DAM shared (CCSP) 8

9 Eindhoven University of Technology 9 composability 19 s can use any programming model cyclo-static dataflow variable-rate dataflow KPN time-triggered barriers distributed-shared, with restrictions (see later) mixed-criticality predictability FT dataflow T2 HT control FT dataflow compositional creation of dataflow model 20 TOS TOS TOS CM CM DAM 9

10 Eindhoven University of Technology 10 predictability binding T2 FT dataflow HT control FT dataflow compositional creation of dataflow model 21 TOS TOS TOS 300 CM CM DAM predictability binding T2 FT dataflow HT control FT dataflow compositional creation of dataflow model 22 TOS TOS TOS CM CM DAM 10

11 Eindhoven University of Technology 11 predictability binding T2 FT dataflow HT control FT dataflow compositional creation of dataflow model 23 TOS TOS TOS CM CM DAM predictability binding T2 FT dataflow HT control FT dataflow compositional creation of dataflow model 24 TOS TOS TOS CM DAM CM

12 Eindhoven University of Technology 12 predictability with CSDF actor 1 actor 2 NOC actor 3 CSDF graph captures functionality & data dependencies mapping of on unshared resources (WCET) resource sharing & composability (SO, TDM,, L,...) (WCT) finite buffer sizes, flow control / backpressure compositional method CSDF graph is constructed of independent smaller subgraphs budgets within, and between s design flow 29 the CompSOC & SDF3 dataflow framework automatic generation of : s, NOC, controllers software: TOS, resource management, drivers, MOC libraries for s bundles ELFs virtual execution specification dynamically loaded on the at run time actor-resource binding, buffer sizes, TOS scheduling interval, scheduler settings (SO schedule, TDM slots, CCSP priorities, etc.) for dataflow s end-to-end throughput and latency analysis FPGA prototype 12

13 Eindhoven University of Technology 13 CompSOC & SDF 3 design flow 30 C NOC mem actor code dataflow graph physical specification WCET calculation smart tools, work of many people libs & TOS ELFs app ELFs ` VEP specification system system sw sw ELFs ELFs ukernel, ukernel, M, M, boot boot physical specification bitfiles bundle system bundle CompSOC & SDF 3 design flow 31 C NOC mem NOC mem actor / ess / job / task /... code CSDF / KPN/ TT /... graph virtual execution (VEP) specification physical specification predictability tools for your MOC smart tools, work of many people libs & TOS ELFs app ELFs ` VEP specification system system sw sw ELFs ELFs ukernel, ukernel, M, M, boot boot physical specification bitfiles bundle system bundle 13

14 Eindhoven University of Technology 14 conclusions 44 reduce SOC design effort independent design, verification, and execution per composability predictability bundles specify virtual execution and -specific MOC, scheduling, power management any mix of NT, ST, FT design flow FPGA prototype used in teaching MSc embedded systems lab for past 9 years, embedded control & vehicle networking courses more information: 45 CompSOC overview in SIGBED 13 and in Multi System-on-Chip. Huebner (ed), Springer, 2010 real-time NOC, DAC 10 eal-time DAM controller, DATE 13, ECTS 14 CompOSe TOS, MICPO 11 CoMiK microkernel, DATE 14 Composable power management, SAMOS 11 Design flow, FPGA World 13 SDF3, DAC 06 NEW Memory Controllers for Mixed-Time- Criticality Systems 14

15 Eindhoven University of Technology 15 acknowledgements Kees Goossens (team leader) Gabriela Breaban Sven Goossens Martijn Koedam einier van Kampenhout Yonghui Li Andrew Nelson asool Tavakoli Juan Valencia in close collaboration with the dataflow research (SDF3) at TU/e Sander Stuijk Marc Geilen and many others This research is partially supported by EU grants CATENE CA505 BENEFIC, CA703 OpenES, CT217 ESIST, ATEMIS EMC2 and DEWI. Parts of the were developed with support from Flexs, T-CEST, COMCAS, Cobra, Scalopes, TSA, NEST, NEVA, MESA. 46 end 47 for further information Kees Goossens Group Electrical Engineering Faculty 15