EMBEDDED SYSTEM & its Case study for theSmart Card
INTRODUCTION • An "embedded system" is any computer system or computing device that performs a dedicated function or is designed for use with a specific embedded software application. • Embedded systems may use a ROM-based operating system or they may use a disk-based system, like a PC. But an embedded system is not usable as a commercially viable substitute for general purpose computers or devices.
Classification of an embedded system • Small scale embedded systems • Medium scale embedded systems • Sophisticated embedded systems
SMALL SCALE EMBEDDED SYSTEM • Designed with a single 8- or 16-bit microcontroller • Little hardware and software complexities and involve board-level design. • Tools for development of embedded software • Editor, assembler and cross assembler • integrated development environment (ISE) • specific to the microcontroller or processor used
MediUMScale Embedded Systems • Designed with a single or few 16- or 32- bit microcontrollers or DSPs or Reduced Instruction Set Computers (RISCs). • Employs the readily available single purpose processors. • Employ the readily available IPs for the various functions—for example, for the bus interfacing, • Both hardware and software complexities
Sophisticated Embedded Systems • Enormous hardware and software complexities and may need scalable processors or configurable processors and programmable logic arrays. • Used for cutting edge applications that need hardware and software co-design and components integration in the final system
EMBEDDED SYSTEM FOR SMART CARD A Smart Card is like an "electronic wallet". It is a standard credit card-sized plastic intelligent token within which a microchip has been embedded within its body and which makes it 'smart'. It provides not only memory capacity, but computational capability as well and thus the chip is capable of processing data.
Smart Cards can store several hundred times more data than a conventional card with a magnetic stripe and can be programmed to reveal only the relevant information • For example, it could tell a device in a store that there is sufficient balance in an account to pay for a transaction without revealing the balance amount. • Therefore, unlike the read-only plastic card, the processing power of Smart Cards gives them the versatility needed to make payments, to configure your cell phones, TVs and video players and to connect to your computers via telephone, satellite or the Internet anytime, anywhere in the world.
Design Requirements Input Devices Interfacing/Driver Circuits System Application Specific Circuits Processor Power supply, Reset & Oscillatory ckt Program Memory & Data Memory Timers Interrupt Controller Output Interfacing / Driver Circuits Parallel Ports Output Interfacing / Driver Circuits
Embedded system has three main components: • It has hardware ,the design shows the units in hardware of an embedded system. • It has main application software. The application software may perform the series of tasks or multiple tasks. • It has real time operating system that supervises the application software and provides a mechanism to let the processor run the process as per scheduling. RTOS defines the way the system works. It sets the rules during the execution of application of software. A small scale embedded system may not need an RTOS.
An embedded system has software designed to keep in view three constraints: • Available system-memory • Available processor speed • The need to limit power dissipation when running the system continuously in cycles of wait for events, run, stop and wake up.
Design challenges • Small size, low weight Many embedded computers are physically located within some larger artifact. Non- rectangular , non- planar geometries. Packaging and integration of digital, analog, and power circuits to reduce size. • Safety and reliability: In critical systems like aircraft control, even a rare failure can not be tolerated. In such systems, safety and reliability are prime requirements. • Harsh environment: Many embedded systems can not be provided controlled environment. They have to work in environments like excessive heat, vibration, shock, lightning, power supply fluctuations etc.
Difference between coding for computers and embedded systems: Languages used in embedded systems programming: Programming languages used are Assembly, C, C++, and Java
Real Time Operating Systems • A real-time system is one that not only produces logically correct results, but also produces them within the right time-interval. This means that real-time systems have safety critical characteristics and that it there will be serious performance degradation if the real-time constraints are not met. The results can range from the benign (e.g. lower audio quality) to the catastrophic (e.g. crashing airplane).
Roles to be performed by a Real Time Operating System: • Data Acquisition • Scheduling: • System-level functions: • Resource protection: • Memory allocation: • Handling different conditions such as overloading, time out:
Case study of embedded system for Smart Card • Smart cards currently are used in telephone, transportation, banking, and healthcare transactions, and soon -- thanks to developers like you -- we'll begin to see them used in Internet applications. Smart cards are already being used extensively in Japan and Europe and are gaining popularity in the U.S. In fact, three significant events have occurred recently in the smart card industry in this country: • ISO uses the term, Integrated Circuit Card (ICC) to include all those devices where an integrated circuit is contained within an ISO ID1 identification card piece of plastic
What are the advantages of using a smart card? • It Is more reliable than a magnetic stripe card. • Currently can store a hundred times more information than a magnetic stripe card. • Is more difficult to tamper with than magnetic stripes. • Can be disposable or reusable. • Can perform multiple functions in a wide range of industries. • Is compatible with portable electronic devices such as phones, personal digital assistants (PDAs), and PCs. • Is constantly evolving (after all, it incorporates a computer chip).
Types of smart cards: In all, there are five types of smart cards: • memory cards • processor cards • electronic purse cards • security cards • Java Card Integrated Circuit Cards come in two forms 1.Contact smart cards 2.Contactless smart cards
Contact smart cards: The connection is made when the reader contacts a small gold chip on the front of the card. In general however the operating power is supplied to the contactless card electronics by an inductive loop using low frequency electronic magnetic radiation. The communications signal may be transmitted in a similar way or can use capacitive coupling or even an optical connection.
Contact less smart card: • These can communicate via an antenna, eliminating the need to insert and remove the card by hand. With a contactless card, all you have to do is get close to a receiver, and the card will begin communicating with it. Contactless cards can be used in applications in which card insertion/removal may be impractical or in which speed is important.
Manufacturing & Design of smart cards • The manufacture of a Smart Card involves a large number of processes of which the embedding of the chip into the plastic card is key in achieving an overall quality product • The key parameters for the chip specification are as follows: • Microcontroller type (e.g. 6805,8051) • Mask ROM size • RAM size • Non volatile memory type (e.g. EPROM, EEPROM) • Non volatile memory size • Clock speed (external, and optionally internal) • Electrical parameters (voltage and current) • Communications parameters (asynchronous, synchronous, byte, block) • Reset mechanism • Sleep mode (low current standby operation) • Co-processor
IC Card electrical characteristics: Six contacts of IC are defined as follows: • VCC Power supply • GND Ground or reference voltage • CLK Clock • VPP Programming voltage • RST Reset signal • I/O Serial Input/output
Power supply (VCC) The power supply to the IC is defined to be between 4.75 volts and 5.25 volts with a maximum current consumption of 200mA. Clock signal The ISO standard aligns with the use of two widely used external clock frequencies, 3.579545 MHz and 4.9152 MHz Programming voltage VPP This signal is designed to provide the high voltage required to enable writing to the non volatile memory. The reset signal The reset signal is asserted by the interface device and is used to start up the program contained in the IC ROM.
The Future of Smart cards • The important thing about Smart Cards is that they are everyday objects that people can carry in their pockets, yet they have the capacity to retain and protect critical information stored in electronic form. The “smartness” of Smart Cards comes from the integrated circuit embedded in the plastic card. Embedding similar circuits in other everyday objects, such as key rings, watches, glasses, rings or earrings, could perform the same electronic function. • Also, Smart Card readers will be appearing on the PC and will enable the user to pay for goods purchased over the Internet. If you have products that have relatively low value - for example a few pages of information about your product that customer may pay 50c for - they may well pay you in the future using a Smart Card also they are a relatively new technology that already affects the everyday lives of millions of people.This is just the beginning; soon it will influence the way we shop, see the doctor, use the telephone and even enjoy leisure!!!
Conclusions Embedded system is a constantly growing field. As more and more powerful microprocessors are becoming available in low cost, more and more complex embedded systems are being developed. Requirements for embedded systems include small size, low cost, real time operation, safety and reliability. However, to be successful future tools may well need to increase scope even further to include life-cycle issues and business issues.
PRESENTED BY D.VESLY ATHIPAN ROSE & M.SEVANTHI RAJAN ECE DEPARTMENT TRP ENGINEERING COLLEGE TRICHY-1