1. INTRODUCTION TO EMBEDDED SYSTEM
UNIT-I
INTRODUCTION TO EMBEDDED SYSTEM
By: Prof R. J. Jaiswal

2. OUTLINE What is an Embedded System? Applications Areas
Categories of Embedded Systems
Overview of Embedded Systems Architecture
Specialties of Embedded Systems
Recent trends in Embedded Systems
Hardware Architecture
Communication protocols like SPI, SCI, I2C, CAN
By: Prof R. J. Jaiswal

3. Introduction to Embedded System (ES)
A System is a way of working, organizing or doing one or many tasks according to a fixed plan, program, or set of rules.
Example: Analog watch
Embedded system can be defined as a computing device that does a specific focused job.
Examples: VCD, DVD player, printer, fax, etc.
Software in ES is always fixed.
ES can be characterized by some special features;
Do very specific or dedicated job.
Have time (Rvery limited resources like memory, do not have secondary storage.
Specific job completed within specific real time System).
ES are constrained for power.
ES need to be highly reliable.
ES have to operate in extreme environmental condition such as high temp, pressure, humidity, etc.
By: Prof R. J. Jaiswal

4. Embedded System (ES) ES have been defined in several ways:
Wayne Wolf author of Computers as Components – Principles of Embedded Computing System Design: “what is an embedded computing system? Loosely defined, it is any device that includes a programmable computer but is not itself intended to be a general-purpose computer”
Todd D. Morton author of Embedded Microcontroller: “Embedded Systems are electronic systems that contain a microprocessor or microcontroller, but we do not think of them as computers-the computer hidden or embedded in the system.”
David E. Simon author of An Embedded Software Primer: “People use term embedded system to mean any computer system hidden in any of these products.”
By: Prof R. J. Jaiswal

5. Contd…
Tim Wilmshurst author of An introduction to the Design of Small Scale Embedded Systems with examples from PIC, 80C51 and 68HC05/08 microcontrollers:
(a) “An embedded system is a system whose principal function is not computational, but which is controlled by a computer embedded within it.”
(b) “An embedded system is a microcontroller-based, software-driven, reliable, real time control system, autonomous, or human- or network-interactive, operating on diverse physical variables and in diverse environment, and sold into a competitive and cost-conscious market.”
Raj Kamal author of Embedded System Architecture, Programming and Design “An Embedded system is a system that has embedded software & computer hardware, which makes it a system dedicated for an application(s) or specific part of an application or a product or a part of larger system”
By: Prof R. J. Jaiswal

6. Contd… Main Definition of ES:
An Embedded system is a system that has embedded software & computer hardware or any mechanical parts, which makes it a system dedicated for an application(s) or specific part of an application or a product or a part of larger system”
By: Prof R. J. Jaiswal

7. Applications of Embedded System
Nearly 99% of the processors manufactured end up in ES.
Consumer Electronics.
Digital Camera.
Microwave Oven.
Air Conditioner.
High tech car has about to ES for transmission control.(AC, Navigation, etc)
Wrist Watches.
Palmtops (Playing Games and Word Processing)
Office Automation.
Fax Machine.
Modem.
Printer, Scanner, etc.
Industrial Automation.
Industries use ES for process control these include-
Pharmaceutical, nuclear energy, electricity generation and transmission.
To carry out specific task such as
Monitoring the temperature, pressure, humidity, voltage, current, etc and then take appropriate action based on the monitored levels to control other devices.
By: Prof R. J. Jaiswal

8. Contd… Medical Electronics. Computer Networking. Telecommunications.
ECG.
Blood pressure measuring devices, radiation, endoscopy, etc
Development in medical electronics of ES for more accurate diagnosis of diseases.
Computer Networking.
Products such as bridges, routers, ISDN, ATM, X.25 and frame relay switches which implements Data Communication Protocol
Telecommunications.
In telecommunication, the ES can be categorized as subscriber terminals and n/w equipment.
Key telephones, ISDN phones, terminal adapters, web cameras.
Multiplexers, multiple access systems, packet Assemblers Disassemblers (PADs), satellite modems, etc
IP phone, gateway, gatekeeper are latest ES that provide low cost voice communication over the internet.
Wireless Technologies.
Mobile Communication, mobile phones.
Powerful ES that provide voice communication while we are on move.
PDAs and Palmtops use to access multimedia services over the internet.
Base station controllers, module switching centers are also powerful embedded systems.
By: Prof R. J. Jaiswal

9. Contd… Instrumentation. Security. Finance.
Testing and measuring are fundamental requirements in all scientific and engineering activities.
We use in laboratories to measure parameters such as weight, temperature, pressure, humidity, voltage, current, etc.
Test equipment such as oscilloscope, spectrum analyzer, logic analyzer, radio communication test set, etc
Security.
Security of persons and info. has always been major issues.
Protect homes, office, airports and also info. we transmit & store.
Biometric system using fingerprint and face recognition are extensively used for authentication as well as for access control in high security buildings.
Finance.
Financial dealing through cash and cheques are now slowly paying way for transactions using Smart Card and ATM.
Smart card of the size of credit card has a small microcontroller and memory and it interact with smart card reader/ATM machine.
By: Prof R. J. Jaiswal

10. Categories of Embedded System
Standalone Embedded System
Digital Camera, Microwave Oven, CD Player, Air Conditioner , Television, etc.
Real Time Systems
Hard Real Time Systems
Soft Real Time Systems
Network Information Appliances
Network Process Control System, Web Camera, Door-Lock System, Weather Monitoring System
Mobile Devices
Mobile Phones, PDAs, Smart Phones, etc
By: Prof R. J. Jaiswal

11. Overview of Embedded System Architecture
The software residing on memory chip is called firmware.
Integrate the application software with OS and then transfer the entire software on the memory chip.
By: Prof R. J. Jaiswal

12. Contd… CPU Memory I/P Devices O/P Devices Communication Interface
Application Specific Circuitry
By: Prof R. J. Jaiswal

13. Specialities of Embedded System
Reliability
Performance
Power Consumption
Cost
Size
Limited User Interface
Software Upgradation Capability
By: Prof R. J. Jaiswal

14. Design Challenges: Optimizing Design Metrics
Construct an implementation that fulfills desired functionality, but a difficult challenge is to construct an implementation.
An implementation consists of a software processor with an accompanying program and a connection of digital gates.
Common relevant metrics include:
Unit cost
NRE cost
Size
Performance
Power
Flexibility
Time-to-market
Time-to-prototype
Correctness
Safety
By: Prof R. J. Jaiswal

15. Contd…
Unit cost: the monetary cost of manufacturing each copy of the system, excluding NRE cost.
NRE cost (Non-Recurring Engineering cost): The monetary cost of designing the system. Once the system is designed, any number of units can be manufactured without incurring any additional design cost (hence the term “non-recurring”).
Size: the physical space required by the system, often measured in bytes for software, and gates or transistors for hardware.
Performance: the execution time or throughput of the system.
Power: the amount of power consumed by the system, which determines the lifetime of a battery, or the cooling requirements of the IC, since more power means more heat.
Flexibility: the ability to change the functionality of the system without incurring heavy NRE cost. Software is typically considered very flexible.
By: Prof R. J. Jaiswal

16. Contd…
Time-to-market: The amount of time required to design and manufacture the system to the point the system can be sold to customers.
Time-to-prototype: The amount of time to build a working version of the system, which may be bigger or more expensive than the final system implementation, but can be used to verify the system’s usefulness and correctness and to refine the system's functionality.
Correctness: our confidence that we have implemented the system’s functionality correctly. We can check the functionality throughout the process of designing the system, and we can insert test circuitry to check that manufacturing was correct.
Safety: the probability that the system will not cause harm.
By: Prof R. J. Jaiswal

17. Time to Market Percentage Revenue Loss = Ontime – Delayed x 100 Ontime
By: Prof R. J. Jaiswal

18. Cont… Percentage Revenue Loss = Ontime – Delayed x 100 Ontime
Revenue loss = Area of on-time triangle – Area of delayed triangle
= (D (3W-D)/2 W2) X 100 %
Where D - Delayed entry time of product
W- Midpoint of Total life of product
By: Prof R. J. Jaiswal

19. Recent Trends In ES
Most of ES was written only in assembly language and hence writing, debugging and maintaining the code is difficult.
Processor Power.
The growing importance of ES can be gauged by availability of processors.
Powerful 8-bit, 16-bit, 32-bit, 64-bit microcontrollers and microprocessor are cater to different market segments.
The clock speed and the memory addressing capability of the processors are increasing.
Powerful DSP are available for real time analysis of audio and video signals.
Power of Desktop computers is available on Palmtops.
Memory.
Cost of memory chip is reducing day by day.
ES can made functionality rich, having additional feature such as networking protocol and GUI.
By: Prof R. J. Jaiswal

20. Contd… Operating System.
Advantage of embedding OS is s/w development will fast and maintaining the code is easy.
S/W can developed in high level language such as C.
If real time performance is required a real time OS can be used.
Open source s/w campaign to development of many open source OS.
Communication Interfaces and Networking Capability.
Availability of low cost chips ES can provide network capability through communication interfaces.
Advantages: it can accessed over a n/w for remote control or monitoring.
Upgrading the embedded s/w is easy
Programming Languages.
Development of embedded s/w was done on assembly languages.
Availability of cross compilers.
OO language are catching up. (Java)
By: Prof R. J. Jaiswal

21. Contd… Development Tools. Programmable Hardware.
Availability of no. of tools for development, debugging and testing as well as for modeling the ES is now giving way for fast development of robust and reliable system.
MATLAB and Simulink.
Java 2 Micro Edition (J2ME) and WAP .
Programmable Hardware.
Programmable Logic Devices(PLDs) and Field Programmable Gate Arrays (FPGAs) giving the way reducing component of an ES.
After developing the prototype mass production of FPGA can be developed which will have all the functionalities of the processor, peripherals as well as application specific circuitry.
By: Prof R. J. Jaiswal

22. Hardware Architecture
By: Prof R. J. Jaiswal

23. Central Processing Unit
Register contain the current data and operands that are being manipulated by processor.
In the external memory, processor implements a stack.
By: Prof R. J. Jaiswal

24. Contd… Processor Architecture
To do function the processor communicates with other devices using three buses, a bus being a group of signals.
Data Bus
Address Bus
Control and Status Bus
By: Prof R. J. Jaiswal

25. Contd… Fig: Von Neuman Architecture Fig: Harvard Architecture
By: Prof R. J. Jaiswal

26. Fig: Super-Harvard Architecture
Contd…
Fig: Super-Harvard Architecture
Interrupts
CISC and RISC
By: Prof R. J. Jaiswal

27. Memory Two Categories: Memory Chips: Program Memory Data Memory
RAM – Random Access Memory
ROM – Read Only Memory
PROM
EPROM
Hybrid Memory
EEPROM
Non Volatile RAM
Flash Memory
By: Prof R. J. Jaiswal

28. Contd… Clock Circuitry Watch Dog Timer/Reset Circuitry Chip Select
Input/Output Devices
Dynamic Memory Access (DMA)
Sensors and Transducers
ADC and DAC
Function Keypad
Light Emitting Diodes (LEDs)
Liquid Crystal Display (LCD)
By: Prof R. J. Jaiswal

29. Fig. Dynamic Memory Access
Contd…
By: Prof R. J. Jaiswal
Fig. Dynamic Memory Access
Debug Port
JTAG port consists of 4 signals-
TDI
TDO
TMS
TCK
Communication Interfaces

30. Communication Protocol
Serial Peripheral Interface (SPI).
Developed by Motorola.
Peripheral devices viz, memory chip, potentiometers, ADCs and DACs, rela time clock are provided with SPI interface.
By: Prof R. J. Jaiswal

31. Communication Protocol (Contd…)
Inter-Integrated Circuit (I2C)
I2C bus uses 2 wires for connecting devices.
Bidirectional & synchronous to a common clock.
Microcontroller with built in I2C are available.
100 kbps & 400 kbps are supported.
Device has unique address.
It also act as master or slave.
Multi-master bus.
By: Prof R. J. Jaiswal

32. Communication Protocol (Contd…)
Signals during transfer a bytes when using I2C bus.
CAN bus.
By: Prof R. J. Jaiswal