1 embedded systems development

7/31/2019 1 Embedded Systems Development

http://slidepdf.com/reader/full/1-embedded-systems-development 1/82

Embedded Systems

Dr. Y S Rao1



What are Embedded Systems• They are Embedded ‘in’

• They are not desktops

• Not mainframes or mini’s• -

, ,

• A heating furnace controller- Thermostat• mo e p one

• Medical device

• DSP based systems

•

2



Embedded Processors

Embedded vs. Desktop

Processors

Applications

Advantages:• Lower cost

• Cell phones / pagers / PDAs

• DAQ• Optimized Instruction Set

• Lower Power consumption

• Controls (Automotive,

Industrial)• Smaller footprint

Disadvantages:

• “Smart” Media

Desktop Processors:

• ower c oc spee s• Less Processing power

• es top computers

• Notebook computers / Laptops

3



Why Use Embedded Systems• ser unc ona y – portability

• User convenience, comfort - HVAC, Auto,

Appliances, GPS, TV remote, DVR, iPod

• Low power and safety – iron, coffee maker, LED

• Commercial/industrial applications

• Replace electro-mechanical systems

• os re uc on• Quality improvement

4



An Embedded System

Microcontroller

(uC)OutputsInputs

5



An Embedded Control System

Microcontroller

(uC)Outputs

Inputs

6



Beware of the computer!

• computers + SoCs = hardware / software mix

• com lete chan e in device interaction

• ever-growing number of critical applications 7



Embedded Systems on Chip

• Many processing units• Lar e embedded software

CPU GLU

RAM FPGAROM

H r w r r f w r ?

8



Wh Com uterizin Ob ects?1. Simplicity and uniformity of digital information

ex s, mages, soun s, mov es, money, orces,...

count, store, organize, transmit, encrypt, visualize,...

2. The fabulous information engine

Moore : computers => microprocessors => SoCsprogress n e sensor e

3. Advances in numerical methods

control & information theory

algorithmics

numer ca ana ys s

9



A lications and Constraintsflight-control, engines, brakes, fuel, power, climatesafety-critical => certification

trajectory, attitude, image, telecom- =

telephone, audio, TV, DVD, gamesbusiness critical => time-to market + quality

pacemakers, diabet control, robot surgeonslife-critical => TBD (!)

10



Microcontroller Manufacturers• ARM – Advanced RISC Machines

• Atmel

• Cypress- programmable blocks• Freescale Semiconductor- uC, DSP

-

• Microchip

• NEC• Renasas

• Sharp

• croe ec ron cs• Texas Instruments- uC, DSP

• Man others

11



Microcontrollers S ectrum• $0.15 - $0.20 Far Eastern parts

• - - .

• Musical gift card uC

• 8-bit 8K flash,1K RAM, 16-I/O

• -Bi 2 K fl h 2K RAM 4-I

• 32-Bit, 2M Flash, 64K RAM, TPU

• – GbE, USB HS

•

12



•

• e- reaten ng

• 24/7/365

• Can’t reboot!

13



•

• pt m ze ssem y anguage

• Limits, Inaccuracies of Fixed Precision

14



Design Issues

• Design Methodology• Time To Market• oc pee• Power Consumption•• Consumer Market: Minimize Manufacturing

Cost.

• No chance for future modification.

15



A Low End Microcontroller

Flash

I/O

x

Clock

RISC

Watch

Reset

RAM16 B tes

Dog

16



Microcontroller Functionalit• Core processor - Voltages

• y – as , , , ,

DDR2

• – n er ace vo age

• Timers• Interrupts

• Serial Communication- SPI, I2C, UART

• USB, CAN-BUS, IR, SD-Cards

– , , ompara or, p-amp

17



A Typical Microcontroller

RAM Flash EEPROM

I/OClock

CoreReset

18



Power-On Reset Modules• Internal reset

• x

• Programmable threshold voltage

• Programmable duration

• Pr r mm l r im • Brown-out condition - programmable

•• Watchdog timer

19



Batter Powered A lications• Sleep mode

• u w

• All kinds of modes available

• Reduced clock frequencies

• r i n• Selective peripherals sleep mode

• – c oc s, t mers, nterrupts

• Watchdog timer

20



Why Worry About Power ?

21



Process Technology and Supply

22



Why Worry About Power ? Portability

Battery industry does not have a Gordon Moore23



A Typical Microcontroller

RAM Flash EEPROM

I/OClock

CoreReset

24



A High End Microcontroller

JTAG NEXUS

2MB Flash

3 2

3 2

6 4

64KB SRAM

32-BitMPC5554

MMU

C h T P U

( 2 )

C a c

h e

D S P

C h D MA

64-ChI/O

A/D40-Ch

CAN Bus(3)

PLL

32-Bit External Bus

25



Microcontroller Selection Criterion• Speed of operation, complexity – 8/16/32 Bits

• Cost – HW/SW tradeoffs

• Power consumption - TI, Microchip, Freescale• Memory Size – Flash, RAM, EEPROM

• # of I/O

• Analog – A/D, DAC, Comparator, Op-amp• Serial Communication- SPI, I2C, USB, IR, GbE

• Product Family

• eve opmen oo s• Timers – input capture, output compare

26



Embedded S stems Develo ment• System development

• Electronics•

• Software

• Mechanical

•

• DFM – design for manufacturability

27



S stem Develo ment• Architecture

• - requ re

• Sub-systems interface - Master/slave

• Communication - Networking protocols

•• HW/SW tradeoffs

• u se ec on• S stem tests – regulatory agencies

28



Electronics Develo ment

• Design specs

• es gn or es a y

• uC and components selection

• Worst case analyses

• Schematics – CAD tools, Design rule checks• Simulations

• Proof of concept, Prototyping

• Design validation• Product qualification

29



Electronics Develo ment Tools

• Schematic capture- Orcad, PADS, Cadence, Mentor

• Analog simulation-pSpice, LTSpice

• Lo ic Simulation- Orcad Cadence Mentor

• VHDL, Verilog

• Worst case analyses- simulations

• Proof of conce t, Protot in - PALs, FPGAs

• DFMEA- UL, agencies approval

• Reliability predictions - MTBF

30



ASICs & Pro rammable Lo ic

• Application Specific ICs

• , , - uCs with PLDs

• Gate Arrays

• Standard Cells

• Custom ICs• Languages- VHDL, Verilog

• Functional simulation

• Timing simulations• Floor planning

• Back-annotation31



PCB La out

• CAD tools- Orcad, Protel, PADS, Allegro, Mentor

• # of layers•

• 3D fit

• - - -,

• Thermal considerations

• DRC

• Gerber output

• Fabrication

32



Real -TimeSoftware Development

Hold on there!

What is real time software?

33



Software Develo ment

• Specs

• SW Design• – ‘ ’, ,

• OS’

•• Tools – compilers, assemblers, programmers, emulators

• Real time as ects - ISRs

• SW/HW tradeoffs• S stem inte ration

34



Real Time Software Develo ment

• Timers

• Interrupts

• Priorities

35



Real Time Software

ExternalEvent

ExternalEvent

Timer 1 Timer n

Micro-

ControllerPrioritized

InputsI/OCore SW

Task 1

Task 2

Task n

36



Real Time Software Develo ment

• Interrupts – ISRs

• ‘C’ v/s Assembly

• Tasks and priorities• RTOS’

37



Programming Languages Used in

ew m e e es gns

70.0%

80.0%

90.0%

-

50.0%

60.0%1999-2000

20.0%

30.0%

.

0.0%

10.0%

Assembly C C++ Java Other

38



Use of Real-Time Kernels in

New Embedded Designs.

80.0%

100.0%

60.0%

20.0%

40.0%

0.0%

4-bit 8-bit 16-bit 32-bit 64-bit Special

39



•

they will respond to an external event.

• Real Time systems don’t have to be “real” “.

time”.

40



guarantee they provide, real time“

time” or “hard real time”.

41



•

guarantee, but missing an event is not. ,

decoding used during satellite TV

“frame time”. If this guarantee is missed, – .

but not catastrophic!

42



•

missing a timing deadline will lead to. ,

missile guidance system should not miss

43

S h ft l ti



So why use soft real time

systems at all?•

provide a real time guarantee. But if we,

guaranteed response time can be much

.• Soft real time systems would be used in

-very fast.

44

I l ti ft



Is real time software any

different•

careful.

scheduling is done at the operating system,

systems should be used.

45



•

form of an endless loop, which waits for

occur.

recovery if there is a “hang up” while

.

46



47



Software Develo ment - Tools

• Programmers- development, in-circuit, field

• mu a ors- JTAG

• Simulators

• Assemblers

• Compilers• Linkers

• Loaders

• CASE tools• V r i n n r l

48

Architecture componentsdimensioning

Word, Excel, Visio



dimensioning

communicationSystem C

Micro-Architectureconcurrencypipeline

resource sharin

Word, Visio

RTL design VHDL, Veriloggates, clocksregisters, RAMs

circuits cells, clock treesarea, speed

Verilog + ...

DFT (test)testabilityscan insertion

Place&Route

Chips

, ,

49



Translation of Code on Host : Compiling

C Source File (s)

C Compiler

C Header File (s)Preprocessing

Compiling

C Object File (s)

Linker C System Libraries

Embedded System

ost omputer

50

Th b ild d l d f



The build and load process fordesktop application programs.

Compiler

O ject Fi es

Executable

AssemblerL i n k

e r

L o a d e

Read-Write

Memory (RAM)

Run-Time Library:

r

Operating System Image: Boot

Process

51

The build and load process for



The build and load process for

em e e app cat on programs.Object Executable Files Image File

Image

File Compiler

Read-Write

Memory(RAM)

L

L o c a t o

r

Assembler

Program

Re-Entrant Library:

i n k e r

Read-Only

Initialization

Real-Time Kernel: ROM"Burner"

Memory(ROM)

52



What is ISP?• In-System Programmable

(ISP) means :

– The ability toreconfigure the logican unct ona ty o adevice, board orcomplete electronic

.

– This can be donebefore, during and

and shipment to theend user.

53



54

Mobile Phone User Interface



Mobile Phone User Interface

TouchScreen

Freescale

68HC05Radio

Freescale

Dragonball

LCD

DriverKeypad Graphics

LCD

Battery

68328Micro-

Phone

Speaker

55

Postal Mail Sorting Device



Postal Mail Sorting Device

PowerSu l

FreescalePostal Optical FlashOptical

68HCxxPiecesnco er

PLDso at on

RS232

PCApplication

56

eBook



eBook

Battery

PC/104

Pentium

Processor

PCMCIAGraphics

LCDVideoXilinxFPGA

TouchScreen

57



58

Product:Vendo V



Product:Vendo V-

MAX 720 vendingmachine.

Microprocessor:

8-bit Motorola68HC11.

59



Sonicare Plus toothbrush.

- .

60



Pro uct: M e edishwashers.

Microprocessor:- o oro a

68HC05.

61



Product: NASA's

Mars Sojourner

Rover.

Microprocessor:

8-bit Intel 80C85.

62

P d t C i C



Product: CoinCo

USQ-712 coin

chan er.

Microprocessor:

8-bit Motorola68HC912.

63



Product: Garmin

StreetPilot GPS

Receiver.

Microprocessor:16-bit.

64



65



Product: Palm Vx

handheld.

Microprocessor:

32-bit MotorolaDragonball EZ.

66



i1000plus iDEN Multi-

.

Microprocessor:

- .

67



MP3 Player.

Micro rocessor:32-bit RISC.

68



Product: RCARC5400P DVD

player.

Microprocessor:

32-bit RISC.

69



70



Product: Sony Aibo

Dog.

64-bit MIPS RISC.

71



72



73

Web Servers… get smaller



74



-

* ,

PIC 12c508

,RAM,

,

75



76



Classification

77



. u onomous

. ea - me

. e wor e

. o e a egor es 78



.•

standalone mode.

process control in manufacturing units

.• Ex: Air-conditioner, CD players

79

-



• ea – me em e e sys ems are

required to carry out specific tasks ina spec e amoun o me.

• These systems are extensively usedto carry out time critical tasks inprocess control

• Ex: Boiler Plant

80

3. Networked Embedded



Systems• Monitor plant parameters, such as

temperature, pressure, andhumidity, and the data over thenetwork to a centralized system foronline monitoring.

• Ex: Web camera monitoring the

plant floor transmits its video outputto a remote controlling organization.

81

4. Mobile``````



• Mobile gadgets need to store data

• These gadgets imbibe powerful

com utin and communicationcapabilities to perform real-time tasksand handle multimedia applications.

• The gadgets embed powerfulprocessor and OS, and a lot of memoryw t m n ma power consumpt on.

82

1 embedded systems development

Documents