MADE BY:PRERNA SHARMA

Electronics & Telecommunication

EMBEDDED TECHNOLOGY

TOPICS TO BE DISCUSSED

• System• Embedded System• Components• Classifications• Processors• Applications

INTRODUCTION TO EMBEDDED TECHNOLOGY The embedded system is a combination of

computer hardware, software additional electrical & mechanical parts

A computer is used in such devices primarily as a means to simplify the system design and to provide flexibility.

Embedded systems employ the use of a RTOS (Real-Time Operating System).

WHAT IS AN EMBEDDED SYSTEM? Any device that includes a programmable

computer but is not itself a general purpose computer is called as embedded system . So embedded system are design to work for a specific task

In an embedded system the hardware and operating system are tightly coupled with each other so you can’t distinguish between the two.

Common examples of embedded systems include MP3 players, navigation systems on aircraft and intruder alarm systems, etc.

Embedded systems are playing important roles in our lives every day, even though they might not necessarily be visible. Some of the embedded systems we use every day control the menu system on television, the timer in a microwave oven, a cell phone, an MP3 player.

WHY STUDY EMBEDDED SYSTEMS?

TYPICAL EMBEDDED SYSTEM CONTAINS:

• Mobile• T.V.

DEVICE

• Microprocessor• Microcontroller• Digital Signal Processor

PROCESSORS

CLASSIFICATION OF EMBEDDED SYSTEM:

1.Reactive embedded systemIt changes according to environment.Ex: Night & day vision image.

Non –reactive embedded systemIt never changes according to any kind of change. Ex: Washing machine

2. Single function embedded systemIt executes same program repeatedly.Ex :ECG machine.

Non real time embedded systemIt has no time constraint

3. Real time embedded systemIt works within a timeframe Ex: rapid opening and closing of shutter.

Multi function embedded systemIt can execute multiple types of related job. Ex : Smartphone

SOME IMPORTANT POINTS WHILE DEVELOPING AN EMBEDDED SYSTEM ARE AS FOLLOWS:

Cost Size Power consumption Memory requirement Development time Reliability

Processors used in Embedded Systems

Microprocessors

Microcontrollers

Digital Signal Processors

(DSP)

MICROCONTROLLERS

All the small embedded system has Microcontrollers instead of Microprocessors. It is used where there nothing is to be processed and inspite of that it controls the execution.

WHY MICROCONTROLLERS?

A microcontroller is a single silicon chip with memory and all Input/Output peripherals on it. Hence a microcontroller is also popularly known as a single chip computer. Normally, a single microcomputer has the following features :

o Arithmetic and logic unit o Memory for storing programo EEPROM for nonvolatile data storageo RAM for storing variables and special function

registerso Input/output ports

o Timers and counterso Analog to digital convertero Circuits for reset, power up, serial

programming, debuggingo Instruction decoder and a timing and control

unito Serial communication port

MEMORY ARCHITECTURE OF MICROCONTROLLER

Used in PC’s. Data and program

are fetched together.

Used in Embedded systems.

It allows parallel path for both data and instructions.

Princeston Model Harvard Model

Processor

Memory data and program

Controller

Program memory

Data memory

REGISTERS

All the Microcontrollers has internal memory called as registers, named as R0, R1, R2, R3……..

In case of AVR, we can have 32 such general purpose registers.

But there are many other types of registers also such as i/p – o/p register etc.

Registers are fast than RAM. So, for calculations ALU always uses registers.

Registers are limited in nos., so data is stored and retrieved from memory. This is called as Load store Architecture or Reg.-Reg. Architecture.

BUSES

Buses are the communication media which sends and receive signals, and is used to connect all internal components of Microcontroller.

Buses has three types of lines, according to which buses are of three types:- Data BUS Address BUS Control BUS

STANDARD DEVELOPMENT BOARD(K-SET)

WHY AVR MICROCONTROLLERS ?

It is a microcontroller created by ATMEL company.

It gives freedom to be programmed in various languages.

ATMEL has a large range of M.C., from the 6pined tiny series to the 100pined mega series.(in various different families)

High performance Low power consumption Integrated EEPROM and SRAM. Atmel AVR 8-bit to 32-bit microcontrollers

provides great design flexibility to developers.

FEATURES OF EMBEDDED SYSTEM

Embedded systems do a very specific task, they cannot be programmed to do different things.

Embedded systems have very limited resources, particularly the memory. Generally, they do not have secondary storage devices such as the CDROM or the floppy disk.

Embedded systems have to work against some deadlines. A specific job has to be completed within a specific time. In some embedded systems, called real-time systems, the deadlines are stringent. Missing a dead line may cause a catastrophe – loss of life or damage to property.

Embedded systems are constrained for power, As many embedded systems operate through a battery, the power consumption has to be very low.

Embedded systems need to be highly reliable. Once in a while, pressing ALT-CTRL-DEL is OK on your desktop, but you cannot afford to reset your embedded system.

Some embedded systems have to operate in extreme environmental conditions such as very high temperatures and humidity.

Getting Started withEmbedded Programming

PROGRAMMING MODEL

Statements

Compile (data + machine instruction)

Stored in specified memory(FLASH MEMORY)

Execution only data is copied to RAM

Char st[ ] = “HELLO”;main( ){--------------;--------------;}

IMPORTANT POINTS

Embedded system don’t have hard disk instead of that have a memory called as Flash memory.

So, in all Embedded system program is stored in Flash memory and the data is executed in RAM.

Flash is some what like Read Only Memory(ROM) in this we can write the data once but we cannot modify it again and again so it is copied to RAM for execution.

Once a program is executed the RAM discard the copy of data.

STEPS TO CREATE A PROGRAM

Create the program in “PROGRAMMABLE NOTEPAD”.

Open the ‘CYGWIN’ shell. It is the command prompt to execute embedded system programs.

Build Burn

DESIGN OF AN EMBEDDED SYSTEM – A CASE STUDY

To understand the design of a simple embedded system let us first consider the idea of a data system. The data acquisition system is shown in the next slide.

For example let me consider a simple case of temperature measurement embedded system.

o First we must select a temperature sensor like thermistor or AD590 or LM35 or LM335 or LM75 etc.

o After this the analog data is converted into digital data and at the same time proper signal conditioning is done.

o This digital input is fed to the microcontroller through its ports.

o By developing a suitable program (Embedded C or Assembly) the data is processed and controlled.

o For this purpose keil or Ride or IAR ARM Embedded workbench C compilers can be used.

o Once the program is debugged, and found error free it can be dumped into the microcontroller flash memory using ISP (Philips - Flash magic or any ISP).

o Now, your microcontroller chip acts as an embedded chip.

ATMEGA32 ARCHITECTURE

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