Fundamental of Embedded Systems

Discuss the Course Content.

• A system is a way of working, organizing or doing one or many tasks according to a fixed plan, program or set of rules.

• A system is also an arrangement in which all its units assemble and work together according to the plan or program.

• SYSTEM EXAMPLES

  WATCH

  WASHING MACHINE

An Embedded System is one that has computer hardware with software embedded in it as one of its important components.

• A Processor is the heart of the Embedded System.

• An embedded processor is a microprocessor that is used in an embedded system.

• For an embedded system designer knowledge of microprocessor and microcontroller is a must.

Microprocessor and Microcontroller

CPU is stand alone, RAM,ROM, I/O & timer

are separate.

CPU, RAM,ROM, I/O & timer all are on

single chip.

Designer can decide amount of RAM,ROM,

& I/O ports.

Fixed amount of on-chip RAM,ROM, & I/O

ports.

High processing power Low processing power

High power consumption Low power consumption

Typically 32/64 bit 8/16 bit

General purpose Single purpose(control oriented)

Less reliable Highly reliable

Eg.- 8086,8085

        8051

Show Layout of Embedded System

Show Some General Example of Embedded System in Picture

Show the Embedded Systems which are use in a Modern Car.

• It has Hardware Processor, Timers, Interrupt controller, I/O Devices, Memories, Ports, etc.

• It has main Application Software Which may perform concurrently the series of tasks or multiple tasks.

• It has Real Time Operating System (RTOS) RTOS defines the way the system work. Which supervise the application software. It sets the rules during the execution of the application program.A small scale embedded system may not need an RTOS.

Show the Hardware which are use in Embedded System.

Single-functioned

 Executes a single program, repeatedly

Tightly-constrained

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

 Life threatening

 24/7/365

Reactive and real-time

 Continually reacts to changes in the system’s environment

 Must compute certain results in real-time without delay

Embedded processor account for 100% worldwide

microprocessor production

• Microprocessor production

          Embedded:Desktop=100:1

• Embedded processors in a house 40-50(approx)

• Embedded processors in a modern car 50-60

• Assembly language was the pioneer for programming embedded systems till recently.

• Nowadays there are many more languages to program these systems. Some of the languages are C, C++, Ada, Forth, and Java together with its new enhancement J2ME.

• The majority of software for embedded systems is still done in C language.

Show the types of embedded System in tree form

• Embedded systems in which some specific work has to be done in a specific time period are called real-time systems.

• Real time embedded systems are classified into two types such as soft and hard real time systems.

• Stand alone embedded systems do not require a host system

like a computer, it works by itself.

• It takes the input from the input ports either analog or digital

and processes, calculates and converts the data and gives the

resulting data through the connected device-Which either

controls, drives and displays the connected devices.

• Examples:- mp3 players, digital cameras, video game

consoles, microwave ovens and temperature measurement

systems.

• These types of embedded systems are related to a network to

access the resources.

• The connected network can be LAN,WAN or the internet.

• Example:- home security system wherein all sensors are

connected and run on the protocol TCP/IP

• Mobile embedded systems are used in portable embedded devices

like cell phones, mobiles, digital cameras, mp3 players and

personal digital assistants, etc.

• The basic limitation of these devices is the other resources and

limitation of memory.

• Single 8 bit or 16bit Microcontroller.

• Little hardware and software complexity.

• They may even be battery operated.

• Usually “C” is used for developing these system.

• The need to limit power dissipation when system is running

continuously.

• Examples:- digital watches

• Programming tools:

Editor, Assembler and Cross Assembler

• Single or few 16 or 32 bit microcontrollers or

Digital Signal Processors (DSP) or Reduced

Instructions Set Computers (RISC).

• Both hardware and software complexity.

• Examples:- Ipod’s

• Programming tools:

C, C++, java, RTOS, Source code

Engineering Tool, Simulator, Debugger and

Integrated Development Environment (IDE).

• It uses more than 32 bit microcontroller.

• Enormous hardware and software complexity

• Which may need scalable processor or configurable processor and

programming logic arrays.

• Constrained by the processing speed available in their hardware units.

• Examples:-washing machine

• Programming Tools:

For these systems may not be readily available at a reasonable

cost or may not be available at all. A compiler or retargetable compiler

might have to br developed for this.

An embedded system is software designed to keep in

view three constraints:

• Available system memory

• Available processor speed

  
  

• The need to limit the power dissipation

When running the system continuously in cycles of wait

for events, run, stop and wakeup.

Show the Application of Embedded System in Different area.