DATE 99

1Universität TübingenTechnische Informatik

Karlheinz WeißU T

Emulation of a Fast Reactive Embedded System Emulation of a Fast Reactive Embedded System using a Real Time Operating Systemusing a Real Time Operating System

Karlheinz WeißKarlheinz Weiß

Thorsten SteckstorThorsten Steckstor

Wolfgang RosenstielWolfgang Rosenstiel

DATE 99

2Universität TübingenTechnische Informatik

Karlheinz WeißU T

Emulation environment: SPYDER-CORE-P1Emulation environment: SPYDER-CORE-P1

DRAM1-128MB

EmbeddedPowerPCPPC403

25..80MHz

32 bitmicrocontroller

bus

I

extensionheaders

Acteladd-on

II

FPGAarchitectures

XilinxXC6000

XilinxXC4000

microcontrollercore

peripheriedevices

Internet

FLASH8MB

Ethernet10MBit

2 serialports

DPRAM2KB

driver

8 Bit I/O bus

analogmodule

CORE-P1 AT-ISA add-on board

SPYDER-CORE-P1 hardware

VxWorks real-time operating system

int_service controll C-server

http-server

ASI application sofware

TCP/IP

AT-ISAbus

microcontrollerregisterinterface

tele_receive

tele_send

ASI-UART

from

to

analogmodule

Initial ASI hardware (single channel)

Target chip: XC4005E, 166 CLBs, utilization: 85%

DATE 99

3Universität TübingenTechnische Informatik

Karlheinz WeißU T

Embedded system performance analysisEmbedded system performance analysis

s

t

0 100 200

Int.

E/A

60

semTake

ASI real-time critical constant (220s)

30

PPC403GA/33MHzint_reaction

Task-change

80 40

control task

int_service

all caches disabled

10

RTOS

time used by RTOStime used by the application50s (23%) 170s (77%)

1.0

0.5

1.5

25 33 40 80

40%

403GA 403GCX 16KB/8KB

without caches

with I & D-cache

oversizedunder-

microcontroller

minimal

2KB/1KB

real-time execution time used (s)real-time critical constant (220 s)

sized

clock frequency (MHz)

performance gain for

non-real-time critical tasks

DATE 99

4Universität TübingenTechnische Informatik

Karlheinz WeißU T

ResultsResults

The minimum microcontroller clock frequency is The minimum microcontroller clock frequency is 33 MHz33 MHz

At the minimum working pointAt the minimum working point 77% 77% of the total execution time is of the total execution time is consumed by the RTOSconsumed by the RTOS

At the minimal working point the improvement in execution At the minimal working point the improvement in execution performance with caches is performance with caches is 40%40%

This 40% enhancement can only be used for This 40% enhancement can only be used for non-real-timenon-real-time critical critical system services e.g. Internet communicationsystem services e.g. Internet communication