Embedded Systems & Parallel Programming. - 2 - P. Marwedel, Univ. Dortmund/Informatik 12 + ICD/ES, 2007 Universität Dortmund A view on embedded systems

Embedded Systems &Parallel Programming

Peter MarwedelUniversity of Dortmund, Germany

[email protected]//ls12-www.cs.uni-dortmund.de/~marwedel

//www.icd.de/es

- 2 - P. Marwedel, Univ. Dortmund/Informatik 12 + ICD/ES, 2007

Universität Dortmund

A view on embedded systems (1)



A view on embedded systems (2)

Main reason for buying is not information processing

Embedded systems (ES) = information processing systems embedded into a larger product

Areas:1. High performance signal processing2. Control intensive applications3. High-safety application

Tight power constraints, especially for mobile applications



Inherent Power Efficiency© H

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Examples of Embedded Processors

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½ of IPE; obviously heterogeneous processors



• FAUST chip architecture 4G mobile

application 20 nodes with 23 IPs

are connected by a network

8MG / 0.13μ CMOS technology (STMicroelectronics)

NoC Example

t (mem. access) « t (communic.) try to avoid buffering of messages!



Programming modelsfor parallel embedded systems (1)



Problems with classical CS abstractions

Even the core 20th-century notion of computable is at odds with the requirements of embedded software. In this notion, useful computation terminates, but termination is undecidable. In embedded software, termination is failure-yet to get predictable timing, subcomputations must decidably terminate.

Ed Lee: Absolutely positively on time: What would it take? IEEE Computer, July, 2005

Finally an end to von-Neumann specifications?



Toward different models of computation



Other models of computation & approaches

• Various types of tasks graphs

• Kahn process networks

• Synchronous dataflow

• Partial differential equations

• Event queues

• Generated software

• ….

How much of this is used in practice already?



Generated software examples

After the successful use of SCADE on the A340, AIRBUS adopted it for several A380 projectshttp://www.esterel-technologies.com/ technology/success-stories/airbus.html

Production code generation directly from MATLAB®/Simulink®/Stateflow®

ANSI C code with the efficiency of handwritten code

Optimizations for individual processors Built-in simulation and testing

SCADE

DSPACE Targetlink

http://www.dspace.ltd.uk/ww/en/ltd/home/products/sw/pcgs/targetli.cfm



Task to Processor Mapping (1)

© L. Thiele et al.















2nd example



Demonstrated parallelism: SymTA/S Screenshot



Parallel Accelerator: Triscend A7 CSoC

• ARM7TDMI + FPGA

Source: ©Triscend



Parallel Accelerator: Chameleon

• C/Verilog –based reconfigurable platform

Application of HPC techniques?



Conclusion

Parallel embedded systems are a reality Architectures include heterogeneous MPSoCs (also

NoCs), parallel accelerators. Multiple threads a potential problem Introduction of new models of computation realistic Higher level programming acceptable Parallel execution existing standard

• for ECUs

• for MPSoCs, NoCs

• for accelerators Situation different from HPC

Documents

Embedded Systems & Parallel Programming. - 2 - P. Marwedel, Univ. Dortmund/Informatik 12 + ICD/ES, 2007 Universität Dortmund A view on embedded systems