임베디드시스템

Lecture #1 : 임베디드시스템 개요

강의 목차

1. 임베디드시스템 개요

2. 임베디드시스템 구성

3. 마이크로컨트롤러 개요

4. 마이크로컨트롤러 종류

5. ARM Cortext-M4 MCU 개요

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임베디드시스템 개요 (1)

“임베디드시스템” ?

VS.

3

임베디드시스템 개요 (1)

“임베디드시스템” ?

VS.

4

임베디드시스템 개요 (2)

“임베디드시스템”?

“a computer system designed for specific control functions withi

n a larger system, often with real-time computing constraints. It i

s embedded as part of a complete device often including hardwar

e and mechanical parts.”

“시스템을 동작시키는 소프트웨어를 하드웨어에 내장하여특수한 기능만을 수행하게 되는 컴퓨터 시스템” (by Wikipedia)

상반 개념: 범용 컴퓨터시스템(General-Purpose Computer

System)

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임베디드시스템 개요 (3)

“임베디드시스템”?

모바일 컴퓨팅, 유비쿼터스 컴퓨팅 그리고 IoT 시스템 구축을 위한 근간 기술

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임베디드시스템 개요 (4)

임베디드시스템 응용 정보 가전 – 디지털TV, 인터넷 냉장고, 세탁기, 가정용 오디

오 시스템

정보 단말기 – 휴대폰, PDA, 영산 전화기

통신 장비 – 전화 교환기, 라우터(router), 공유기, 홈 게이트웨어(home gateway)

게임 기기 – 소형 게임기, 지능형 장난감

항공 우주 – 비행기, 우주선, 미사일

물류, 금융, 사무기기 – POS 단말기, ATM, 프린터

차량, 교통 – 자동차, 지능형 교통 제어 시스템

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임베디드시스템 개요 (5)

임베디드시스템 응용

휴대폰 휴대용 게임기

디지털 TV 인터넷 냉장고 세탁기

전자사전 애완용 강아지 로봇

MP3 player

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임베디드시스템 개요 (5)

임베디드시스템 응용

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임베디드시스템 개요 (6)

임베디드시스템 분류

시스템 규모 및 OS 탑재 여부 등에 의한 분류

시스템 구성 및 개발방법론이 달라짐.

고수준임베디드시스템

지능형 임베디드 시스템

비교적 높은 성능의 CPU와 많은 용량의 메모리를 탑재

임베디드 리눅스 등의 임베디드 운영체제를 탑재하고 다양한 응용프로그램을 실행

예: 스마트폰, 스마트TV, 의료장비 등

단순임베디드시스템

저성능의 CPU와 저용량의 메모리를 탑재

별도의 운영체제가 없이 제어 프로그램이 탑재

예: mp3 player, 도어록, 가전장비 제어장치 등

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임베디드시스템 개요 (7)

단순 임베디드시스템 제약 요건

범용 컴퓨터 시스템 대비

1. Single-functioned

– Executes a single program, repeatedly

2. Tightly-constrained

– Low cost, low power, small, fast, etc.

3. Reactive and real-time processing

– Continually reacts to changes in the system’s environment

– Must compute certain results in real-time without delay

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임베디드시스템 구성 (1)

범용 컴퓨터 시스템 관점에서의 구성

기본 구성:

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임베디드시스템 구성 (2)

범용 컴퓨터 시스템 관점에서의 구성

구성 요소 중심:

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임베디드시스템 구성 (3)

범용 컴퓨터 시스템 관점에서의 구성

외형 및 크기 중심:

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임베디드시스템 구성 (4)

범용 컴퓨터 시스템 관점에서의 구성 – 문제점

크기가 크다(size)

비용이 비싸다(cost)

성능이 고성능이다(performance)

주변 장치가 다르다(external interface)

사람과의 인터페이스와 데이터 저장을 목적

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집적화(Integration)

임베디드시스템 구성 (5)

임베디드시스템 구성

마이크로컨트롤러 기반의 시스템 구성

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MicroController

(MCU)

Comm.

I/F

Sensors

Actuators

임베디드시스템 구성 (6)

임베디드시스템 구성

예: 자동 판매기

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키패드

마이크로컨트롤러동전제어

모듈

게이트

위치 센서

액정표시

장치

모바일

통신 모듈

입력 출력

게이트

작동기

Microcontroller (1)

Microprocessor

보통 CPU(Central Processing Unit)라고 부름

명령어 실행을 수행

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Microcontroller (2)

Microcontroller

마이크로프로세서 코어, 메모리, 주변장치 및 통신 인터페이스를 하나의 칩에 집적화

DSP(Digital Signal Processing) 기능을 내장하기도 함

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프로그램

메모리

데이터

메모리

마이크로 프로세서

코어

내부 데이터 /

어드레스 버스

주변장치

주변장치

디지털I/O

아날로그I/O

카운터 /

타이머

클럭

리셋

인터럽트

전원

Microcontroller 종류 (1)

8-bit Microcontrollers

Microchip Technology Atmel AVR

Freescale 68HC11 - based on the Motorola 6800 family

Microchip Technology PIC

Intel 8051

STMicroelectronics STM8

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Microcontroller 종류 (2)

16-bit Microcontrollers

Microchip Technology dsPIC33 / PIC24

Infineon XE166

STMicroelectronics ST10

Texas InstrumentsTI MSP430

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Microcontroller 종류 (3)

32-bit Microcontrollers

ARM Cortex-M

Freescale ColdFire

Microchip Technology Atmel AVR32

Microchip Technology PIC32

NXP Semiconductors LPC1000~LPC4000

STMicroelectronics STM32

Texas Instruments TI MSP432

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ARM Ltd

ARM founded in November 1990

Advanced RISC Machines

Company headquarters in Cambridge, UK

Processor design centers in Cambridge, Austin, Sophia Antipolis and Hsinchu

Sales, support, and engineering offices all over the world

Best known for its range of RISC processor cores designs

Other products – fabric IP, software tools, models, cell libraries - to help partner

s develop and ship ARM-based SoCs

ARM does not manufacture silicon

More information about ARM and our offices on our web site:

http://www.arm.com/aboutarm/

ARM Offices Worldwide

More information on the website - http://www.arm.com/community/index.html

ARM Connected Community – 1000+

ARM Classic Processor Portfolio

Classic, market-proven processor technology

Instruction set architecture

Processor designs

300+ partners

800+ licenses

30Bu+ shippedARM968E-S™

ARM946E-S™

SC100™

ARM922T™

ARM1176JZ(F)-S™

ARM1156T2(F)-S™

ARM1136J(F)-S™

x1-4

ARM11™ MPCore™

ARM926EJ-S™

ARM7EJ-S™

ARMv6

ARMv4

ARMv5

ARM920T™

ARM966E-S™

ARM7TDMI(S)™

ARM1022E™

ARM1026EJ-S™

ARM1020E™

SC200™

ARM720T™

ARM Cortex Advanced Processors

Architectural compatibility across a wide application range

ARM Cortex™-A family:

Applications processors for feature-

rich OS and 3rd party applications

ARM Cortex-R family:

Embedded processors for real-time

signal processing, control applications

ARM Cortex-M family:

Microcontroller-oriented processors

for MCU, ASSP, and SoC applications

ARM SecurCore™ - Tamper-resistant security<12k gates...

Cortex-M0+

Cortex-M4

Cortex-M3

Cortex-A7

...2.5GHz

Cortex-A8

Cortex-A9

Cortex-A57

Cortex-A15

Cortex-A53

Cortex-A12

Cortex-A17

Cortex-M7

Cortex-A5

Cortex-R5

Cortex-R7

Cortex-R4

Cortex-M1

SC000

SC300

Cortex-M0

The Cortex FamilyCortex-A

Cortex-R

Cortex-M

disk drives digital cameras

appliances motors audio

servers netbooks mobile applicationsset top boxes

mobile baseband

Human interfaces

EPOS terminals

Image processing

Audio interfaces

Power management

UPS

Lighting systems

AC/DC converters

Microcontrollers address broad markets

Automotive

ABS systems

Chassis control

Airbag systems

Industrial Applications

Appliances

Lighting

Motion control

Medical instrumentation

Blood pressure meters

Glucose meters

Defibrillators

Connectivity

Bluetooth

Zigbee

Ethernet

Smart Metering

Gas and water

Electricity

Connectivity

Motor control

Field oriented control

Stepper motors

BLDC motors etc

Audio

MP3 players

Wireless headsets

Virtual surround

Embedded market drivers/trends

Connectivity Connectivity becoming ubiquitous

Smart technology Observe/react to the environment

Energy efficiency Green technology trends

Ease of use

Keep programming simple

Healthy software

ecosystem required

Real-time signal

processing essential

More capability, but

not higher MHz or mW!

Excellent tools

required

Driving the Migration to 32-BitImproving Code Reuse

Automatic code from meta-languages

eg. Simulink, LabVIEW, UML

Ease of use improvements

Accelerating Time To Market

Biggest single cost in product development

System abstraction demands extra resources

Savings from portable code offset device cost

Device Aggregation

Increasing System Connectivity

Application Complexity

Continual feature growth in existing applications

Complex algorithms require advanced math

Increasing analysis at the “node”

Aggregation of DSP and MCU devices

Multiple 8-Bit devices replaced with single 32-Bit

Substantially reduced BOM & tool chains costs

MCUs increasingly connected

USB, CAN, ENET, ZigBee, etc

Potentially multiple comms channels per device

Increasing complexity of stacks

32-Bit ARM devices now available for $1

Extensive open source community

Evaluation kits available for under $50

Reduced Development Barriers

ARM Cortex-M Processors

ARM Cortex-A Series:Applications processors for

feature-rich OS and user applications

ARM Cortex-R Series:Embedded processors for

real-time signal processing

and control applications

ARM Cortex-M Series:Deeply embedded processors

optimized for microcontroller

and low-power applications

Cortex-M family optimised for deeply embedded Microcontroller and low-power applications

Why another Cortex-M processor?

Address new markets requiring digital signal control Digital Signal(Processor + Micro)Controller

An intelligent blend of MCU and DSP features demanded Upper limits of bandwidth challenged in general purpose MCUs

Hard to learn/program technology in many general purpose DSPs

Extend the Cortex-M portfolio to cover new markets Cortex-M0 for mixed signal devices and state machine replacements

Cortex-M3 for mainstream 32-bit microcontrollers

Opportunity - high end MCUs and DSC market

Introduce ARM strengths to digital signal control market Very high energy efficiency – more processing in less mW

Strong software ecosystem – easy to program and use

Cortex-M4 for digital signal control

Cortex-M4

MCU

Ease of use

C Programming

Interrupt handling

Ultra low power

DSP

Harvard architecture

Single cycle MAC

Floating Point

Barrel shifter

Cortex-M processors

Forget traditional 8/16/32-bit classifications

Seamless architecture across all applications

Every product optimised for ultra low power and ease of use

Cortex-M0 Cortex-M3 Cortex-M4

“8/16-bit” applications “16/32-bit” applications “32-bit/DSC” applications

Binary and tool compatible

Cortex-M processors binary compatible

Cortex-M4 - What’s unique about it?

Most energy efficient 32-bit

embedded processor for

digital signal controllers

Brings high performance signal

processing within the reach of the

typical MCU programmer

Highest in-class efficiency

0

0.2

0.4

0.6

0.8

1

IIR FFT

0

0.2

0.4

0.6

0.8

1

IIR FIR FFT

Cycle counts on DSP tasks compared, smaller is better

16-bit MCU 32-bit MCU 32-bit Cortex-M4

The Cortex-M4 is ~2X more efficient on most DSP tasks than

leading 16 and 32 bit MCU devices with DSP extensions

Cortex-M3 – MP4 playback in <10MHz

0 5 10 15 20 25 30

Specialised Audio DSPs

Cortex-M4(estimated)

Discrete DSPs

General Purpose MCUs

MHz required for MP3 decode, smaller is better

Cortex-M3-M4 – very easy to use Complex hardware needs to be easy to program

On most DSPs assembly optimization is a must

Cortex-M processor can be fully programmed in C

Quicker learning curve for faster application development

Easy to maintain, reuse and port

Reusing code extremely important for faster delivery

Cortex-M0 and Cortex-M3 code fully upwards compatible

CMSIS support for Cortex-M4 already available

Programming Cortex-M fully in C leads to high optimization

Full compiler support already available through ARM software tools

Instruction Set Architecture

Thumb

32-bit operations in 16-bit instructions

Introduced in ARM7TDMI® processor (‘T’ stands for Thumb)

Subsequently supported in every ARM processor developed since

Thumb-2

Enables a performance optimized blend of 16/32-bit instructions

All processor operations can all be handled in ‘Thumb’ state

Supported across the Cortex-M processor range

Thumb®

ARM7 ARM9 Cortex-A9Cortex-R4Cortex-M3Cortex-M0

Thumb instruction set upwards compatibility

Cortex-M4

Thumb-2 advantage

All Cortex-M processors are binary upward compatible

Cortex-M3 includes a rich set of additional Thumb-2 instructions

64-bit multiply support

Hardware division

UDIV and SDIV (Unsigned or Signed divide)

Instructions take between 2 & 12

cycles depending on dividend and

devisor

Instruction is interruptible

(abandoned/restarted)

Bit field manipulation

0

0.2

0.4

0.6

0.8

1

1.2

1.4

ARM7 (Thumb) Cortex-M0 Cortex-M3

Performance efficiency (DMIPS/MHz)

Assembler example

Time: 1 clock cycle

Code size: 2 bytes

Time: 8 clock cycles

Code size: 8 bytes

Time: 48 clock cycles*

Code size: 48 bytes

MULS r0,r1,r0 MOV R1,&MulOp1

MOV R2,&MulOp2

MOV SumLo,R3

MOV SumHi,R4

(Memory mapped mu

ltiply unit)

MOV A, XL ; 2 bytes

MOV B, YL ; 3 bytes

MUL AB; 1 byte

MOV R0, A; 1 byte

MOV R1, B; 3 bytes

MOV A, XL ; 2 bytes

MOV B, YH ; 3 bytes

MUL AB; 1 byte

ADD A, R1; 1 byte

MOV R1, A; 1 byte

MOV A, B ; 2 bytes

ADDC A, #0 ; 2 bytes

MOV R2, A; 1 byte

MOV A, XH ; 2 bytes

MOV B, YL ; 3 bytes

ARM Cortex-M16-bit example8-bit example (8051)

MUL AB; 1 byte

ADD A, R1; 1 byte

MOV R1, A; 1 byte

MOV A, B ; 2 bytes

ADDC A, R2 ; 1 bytes

MOV R2, A; 1 byte

MOV A, XH ; 2 bytes

MOV B, YH ; 3 bytes

MUL AB; 1 byte

ADD A, R2; 1 byte

MOV R2, A; 1 byte

MOV A, B ; 2 bytes

ADDC A, #0 ; 2 bytes

MOV R3, A; 1 byte

Consider a 16-bit multiply operation

Required for 10-bit ADC data filtering, encryption algorithms, audio

16-bit multiply operation is compared below

* 8051 needs at least one cycle per instruction byte fetch as they only have an 8-bit interface

Cortex-M3 Processor Feature Summary

Configurable Interrupt Controller:

1:240 Interrupts

1:255 Priority Levels

NMI & SysTick

Central Core:

1.25 DMIPS/MHz

Thumb-2 / Thumb ISA

Hardware Divide

1cycle Multiply

ETM (Optional)

MPU (Optional)

8-Region Memory Pro

tection Unit

Debug Access Port: J

TAG or Serial Wire

DWT (Optional)

4x Data Watchpoints

& Event Monitors

ITM (Optional)

Low-cost trace via sin

gle wire output

FPB (Optional)

8x Hardware Breakpo

ints w. program patch

ing

2x AHB-Lite Buses

I_CODE (Instruction Code Bus)

D_CODE (Data / Coefficients Code Bus)

1x AHB-Lite Buses

SYSTEM (SRAM & Fast Peripherals)

1x APB Bus

ARM Peripheral Bus (Internal & Slow Peripherals)

Wake-Up Interrupt Controller:

Low gate count

Configurable Number

of Interrupts

Suitable for separate

power domain

ARM Cortex-M4 processor