Hardware/Software Codesign

Jun.-Prof. Dr. Christian Plessl

SS 2012

Custom Computing University of Paderborn

Version 1.0.3 13.04.2012

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motivation and introduction goals and main questions in HW/SW codesign

course synopsis

lecture organization

Overview

HW/SW codesign

what is HW/SW codesign? integrated design of computer systems that consist of hardware and

software components supported by a systematic computer-aided design process

objectives handle increasing complexity of computer systems find better solutions than with a manual process reduce design time and validation time/cost explore design trade-offs (performance vs. energy efficiency vs. )

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Performance vs. size trade-offs for cryptography

soft- and hardware implementations of different cryptography algorithms

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Power efficiency of AES encryption

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same application / different implementations vastly different power efficiency depending on specialization/

generality

Schaumont 2010

General purpose vs. application specific

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performance energy efficiency

effort to change application development effort

RISC

DSP

ASIP

FPGA

ASIC

concerns

extremely high NRE cost high volume/fixed function only

high engineering effort high unit-cost

high production cost competition from off-the-shelf SoC

competition from RISC processors operating system support

low energy efficiency IP protection

sweet spot

Mix of technologies in most systems

no one-size fits all solution for economical and technological reasons different requirements reuse hard- and software implementations distribute development cost over a variety of products

majority of computer systems use a variety of HW and SW technologies programmable processing cores (RISC, DSP, uC, ) fixed co-processors/accelerators (e.g., cryptography, multimedia, ) reconfigurable accelerators (FPGA, coarse-grained arrays)

designing and programming such platforms is challenging HW/SW codesign addresses this challenge in a systematic way example: Texas Instruments OMAP processor (system on chip for mobile

computing systems)

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Example: SoC for mobile computer system

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TI OMAP 4430 system-on-chip

Texas Instruments

Example: SoC for mobile computer system

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TI OMAP 4430 system-on-chip

dual core ARM embedded RISC

GPU

multimedia co-processor

DSP

security co-processor

memory controllers

memory controllers

inpu

t/out

put c

ontro

llers

display controllers

inpu

t/out

put c

ontro

llers

input/output controllers

Texas Instruments

Example: SoC for mobile computer system

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TI OMAP 4430 system-on-chip

dual core ARM embedded RISC

GPU

multimedia co-processor

DSP

security co-processor

memory controllers

memory controllers

inpu

t/out

put c

ontro

llers

display controllers

inpu

t/out

put c

ontro

llers

input/output controllers

Texas Instruments

HW/SW codesign issues:

how to design such a platform?

how to partition the applications functionality to components?

how to determine if a particular mapping is good?

how to generate tools that support such a platform?

HW/SW codesign space

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Application

C C/ASM

C/HDL C/HDL

HDL

FPGA ASIP

DSP RISC

ASIC

software

hardware (platform)

platform programming

application mapping

platform selection

max flexibility min efficiency

min flexibility max efficiency

general purpose

application specific

domain specific

Schaumont 2010 (adapted)

Driving factors in HW/SW codesign

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improve performance improve energy efficiency reduce power density

manage design complexity decrease time-to-market reduce design & verification cost

implement more in hardware

implement more in software

Schaumont 2010 (adapted)

Main questions in HW/SW codesign

hardware/software partitioning what functionality should be programmable? what functionality should be implemented in fixed in hardware? how to create tools (compilers) that can exploit fixed functions?

system partitioning how to distribute functions to different components?

design space exploration what system implementation alternatives exist? what are their characteristics (performance, power, cost)

architecture synthesis how to translate software to hardware?

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General approach

abstract and model treat design of HW/SW system as optimization problem abstract and formalize problem and design options (e.g., using graph

problems, integer linear programing, dynamic programming, )

optimize or exact or heuristic methods determine optimal parameter settings and their sensitivity

explore explore design space and trade-offs computer aided design automation guided by human decisions

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Topics we will look at in this lecture

introduction target architectures introduction to compilers

high-level hardware architecture synthesis partitioning

hardware/software partitioning system partitioning

design space exploration estimation of design parameters

instruction set extension

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Relation to other lectures in CS curriculum

Bachelor level courses GRA/GTI

fundamentals of digital logic and computer architecture Embedded processors

architecture of embedded processors, micro controllers and DSPs compilers for special purpose processors

Embedded Systems modeling languages, hardware verification

Master level courses Reconfigurable Computing

FPGA technology (architecture, methods and applications) Architektur Paralleler Rechnersysteme

parallel programming models and languages, high-performance computing

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Benefits from attending this course

Learn about challenges and approaches in modern system design target architectures useful optimization methods a current and active research area

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Course Organization

Lecture Friday, 11:15-12:45, O1.267 Exercises Friday, 13:15-14:00, O1.267

mix of pencil and paper and programming exercises try to solve the problems yourself discussion of the problems in the exercises

Contact: Christian Plessl email: christian.plessl@uni-paderborn.de

office: O3.110, phone: 60-5399 Web page

http://homepages.uni-paderborn.de/plessl/lectures/2012-Codesign

Course Materials on the web lecture slides, exercise sheets, selected papers

Literature and acknowledgements

this course is based on materials from the following books Patrick R. Schaumont, A practical Introduction to Hardware/Software

Codesign. Springer 2010. doi:10.1007/978-1-4419-6000-9 (available in full text within UPB network)

Jrgen Teich and Christian Haubelt. Digitale Hardware/Software-Systeme. Synthese und Optimierung. Springer, 2007. doi:10.1007/978-3-540-46824-0 (available in full text within UPB network)

Giovanni De Micheli, Synthesis and Optimization of Digital Circuits. McGraw-Hill, 1994.

and on lecture materials from the Bachelor-level lecture HW/SW Codesign taught by Christian Plessl (2009-2010) and previously by Marco Platzner

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Changes

v1.0.3 (2012-04-14) corrected minor typos

v1.0.2 (2012-04-10) updated for SS2012

v1.0.1 (2011-04-01) added more slides illustrating the FPGA toolflow

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