Embedded Systems - CPE24

Embedded system Is this possible? A Doctor is configuring a cardiac Pacemaker inside his patient’s chest while sitting 2 kms away. Another person is travelling in a driverless car that takes him from Mumbai to New Delhi using his inbuilt navigation program.  Advances in Technology have...

Embedded system Is this possible? A Doctor is configuring a cardiac Pacemaker inside his patient’s chest while sitting 2 kms away. Another person is travelling in a driverless car that takes him from Mumbai to New Delhi using his inbuilt navigation program.  Advances in Technology have taken place at such a speed that these fictitious scenario are likely to be translated into reality very soon in a couple of years. Real Time Operating System (RTOs) and Embedded system are the major technologies that will play a major role in making the above fairy tales come true. What is a System? A system is an arrangement where all its component work according to the specific defined rules. It is a method of organizing, working, or performing one or more tasks according to a fixed plan. What is an Embedded System? is a combination of computer software and hardware which is either fixed in capability or programmable. An embedded system can be either an independent system, or it can be a part of a large system. It is mostly designed for a specific function or functions within a larger system. For example, a fire alarm is a common example of an embedded system which can sense only smoke. Why Sudden interest in Embedded systems? Possible Reasons: Processors have shrunk in size with increased performance Power consumption has drastically reduced. Cost of processors have come down to affordable level. There is a greater awareness now that rather than a totally hardwired electronic system, incorporation of a programmable processor in a circuit makes the design more robust with the reduction in the design time cycle. The concept of a development environment where you can prototype the system and do a simulation/emulation also reduces the design cycle and total development time. Why Sudden interest in Embedded systems? The latest model of the Ford car has more than 21 microcontrollers performing functions such as anti-lock breaking system, fuel management, air-condition management, etc. Development of standard run time platforms like Java, which enabled their use in Myriad ways that were unimaginable in the past. Emergence of several integrated software environments which simplified the development of the applications. Coming together of Embedded systems and the Internet which make possible networking of several Embedded systems to operate as a part of large system across networks - be it a LAN, WAN or the internet. Embedded Systems are everywhere wristwatches, washing machines, microwave ovens, elevators, mobile telephones, printers, FAX machines, Telephone exchanges, automobiles, aircrafts Laser Printers are one of the examples of Embedded Systems which uses embedded systems to manage various aspect of the printing. Apart from performing the main task of printing, it has to take user inputs, manage communication with the computer system, to handle faults, and sense papers left on the tray, etc. Examples of Microcomputer applications Consumer Function Performed by Microcomputer Washing Machine Controls the water & spin cycles Accepts key touches and sends infrared (IR) pulses to base Remote controls systems Exercise equipment Measures speed, distance, calories, heart rate, logs workouts Clocks and watches Maintains the time, alarm and display Games and toys Entertains the user, joystick input, video output Audio/video Interacts with the operator & enhances performance Examples of Microcomputer applications Communication: Telephone answering machines Plays outgoing message, saves and organizes messages Telephone system Interactive switching and information retrieval Key pad and inputs, sound I/O, and communicates with Cellular phones and pagers central station ATM machines Provides both security and banking convenience Examples of Microcomputer applications Automotive Automatic braking Optimizes stopping on slippery surfaces Noise cancellation Improves sound quality by removing background noise Theft deterrent devices Keyless entry, alarm systems Electronic ignition Controls sparks and fuel injectors Power windows & seats Remembers preferred settings for each driver Collects & provides the driver with necessary Instrumentation information Examples of Microcomputer applications Military Smart weapons Recognizes friendly targets Missile guidance systems Directs ordinance at the desired target Global positioning systems Determines where you are on the planet Examples of Microcomputer applications Industrial Setback thermostats Adjusts day/night thresholds, thus saving energy Traffic control systems Senses car positions and controls traffic lights Robot systems Input from sensors, controls the motors Bar code readers and Input from readers, output to writers for inventory writers control and shipping Automatic sprinklers Used in farming to control the wetness of the soil Examples of Microcomputer applications Medical: Apnea monitors Detects breathing & alarms if the baby stops breathing Cardiac monitors Measures heart functions Renal monitors Measures kidney functions Drug delivery Administers proper doses Cancer treatments Controls doses of radiation, drugs, or heat Prosthetic devices Increases mobility for the handicapped Dialysis machines Performs functions normally done by the kidney Pacemaker Helps the heart beat regularly Controller’s function is to monitor parameters of physical process of its surrounding system to control these processes whenever needed Example: a simple thermostat controller periodically reads the temperature of the chamber displays the reading and switches on or off the cooling system, as required. What goes into an Embedded System An Embedded system is a device controlled by instructions stored on a chip. These devices are usually controlled by a microprocessor that executes the instructions stored on a Read Only Memory (ROM) chip. One of the most popular Real Time Operating Systems (RTOS) is in use today is QNX (pronounced `queue nicks’). It is used for everything from medical instrumentation and monitoring nuclear reactors, to traffic lights and industrial process control. In fact, it is so widely used that we use devices having QNX several times a day without being aware of it. What goes into an Embedded System An embedded system has a digital signal processor, a variety of I/O devices connected to sensors and actuators. Controllers and DSP are programmable parts, customizable for different application by writing software. History of Embedded system Here, are important milestones from the history of embedded system: In 1960, embedded system was first used for developing Apollo Guidance System by Charles Stark Draper at MIT. In 1965, Autonetics, developed the D-17B, the computer used in the Minuteman missile guidance system. In 1968, the first embedded system for a vehicle was released. Texas Instruments developed the first microcontroller in 1971. In 1987, the first embedded OS, VxWorks, was released by Wind River. Microsoft’s Windows embedded CE in 1996. By the late 1990s, the first embedded Linux system appeared. The embedded market reach $140 billion in 2013. Analysts are projecting an Embedded market larger than $40 billion by 2030. Characteristics of an Embedded System Characteristics of an Embedded System Requires real time performance It should have high availability and reliability. Developed around a real-time operating system Usually, have easy and a diskless operation, ROM boot Designed for one specific task It must be connected with peripherals to connect input and output devices. Offers high reliability and stability Needed minimal user interface Limited memory, low cost, fewer power consumptions It does not need any secondary memory in computer. Important terminologies used in embedded system Reliability -This measure of the survival probability of the system when the function is critical during the run time. Fault-Tolerance - Fault-Tolerance is the capability of a computer system to survive in the presence of faults. Real-Time - Embedded system must meet various timing and other constraints. They are imposed on it by the real-time natural behavior of the external world. For example, an air force department which keeps track of incoming missile attacks must precisely calculate and plan their counter-attack due to hard real-time deadline. Otherwise, it’ll get destroyed. Important terminologies used in embedded system Flexibility -It’s building systems with built-in debugging opportunities which allows remote maintenance. For example, you are building a spacecraft which will land on another planter to collect various types of data and send collected detail back to us. If this spacecraft went insane and lost the control, we should be able to make some important diagnostic. So, flexibility is vital while designing an embedded system. Portability - Portability is a measure of the ease of using the same embedded software in various environments. It requires generalized abstractions between the application program logic itself and the low- level system interfaces. Design Challenges Embedded system have different constraints then general Cost may matter more than speed Long life cycle may dominate design decisions Reliability/safety may constrain design choices Correct functioning is crucial safety-critical applications damage to life, economy can result Real-time systems not only right output but at right time imagine a delay of few minutes in pacemaker system Design Challenges They are concurrent systems System and environment run concurrently multi-functional They are Reactive Systems Once started run forever Termination is a bad behavior Compare conventional computing (transformational systems) Reactive Systems Reactive Systems are systems that have continuous interaction with their environment. Hardware and OS are typical examples. In general, all embedded systems are reactive. These systems can be contrasted with conventional software systems like data processing applications. The latter are called transformational systems. These systems take input from the environment, transform these inputs and terminate giving the outputs. Their interaction with the environment is limited: once at the time of taking inputs and once at the end when the outputs are generated. Design Challenges Stringent resource constraints compact systems Simple processors limited memory quick response good throughput low power Embedded System Design Involves HW and SW Design Software for flexibility Hardware for speed Co-design of Software and Hardware nonstandard HW -ASIC System Partitioning -difficult step Choice of programmable parts and ASICs Embedded System Design Communication between ASIC and SW Timing is crucial Common languages for HW and SW –Hardware C, SpecC, SpecCharts, Statecharts Architecture of the Embedded System Architecture of the Embedded System 1) Sensor: Sensor helps you to measures the physical quantity and converts it to an electrical signal. It also stores the measured quantity to the memory. This signal can be ready by an observer or by any electronic instrument such as A2D converter. 2) A-D Converter: A-D converter (analog-to-digital converter) allows you to convert an analog signal sent by the sensor into a digital signal. 3) Memory: Memory is used to store information. Embedded System majorly contains two memory cells 1) Volatile 2) Non volatile memory. Architecture of the Embedded System 4) Processor & ASICs: This component processes the data to measure the output and store it to the memory. 5) D-A Converter: D-A converter (A digital-to-analog converter) helps you to convert the digital data fed by the processor to analog data. 6) Actuator: An actuator allows you to compare the output given by the D-A converter to the actual output stored in it and stores the approved output in the memory. Types of Embedded System Types of Embedded System Small Scale Embedded Systems: designed with a single 8 or 16-bit microcontroller. operated with the help of a battery. Uses an editor, assembler, (IDE), and cross assembler Medium Scale Embedded Systems: designed using 16 or 32-bit microcontrollers. both hardware and software complexities. C, C++, Java, and source code engineering tool Sophisticated Embedded Systems have lots of hardware and software complexities. require IPS, ASIPS, PLAs, configuration processor, or scalable processors. need hardware and software co-design & components which needs to combine in the final system. What is Microcontroller? A microcontroller is a single-chip VLSI unit which is also called microcomputer. It contains all the memory and I/O interfaces needed, whereas a general-purpose microprocessor needs additional chips to offered by these necessary functions. Microcontrollers are widely used in embedded systems for real-time control applications. What is a Microprocessor? A microprocessor is a single chip semiconductor device. Its CPU contains a program counter, an ALU a stack pointer, working register, a clock timing circuit. It also includes ROM and RAM, memory decoder, and many serial and parallel ports.  Difference between Microprocessor and Microcontroller Microprocessor Microcontroller It uses functional blocks like register, ALU, timing, and It uses functional blocks of microprocessors like RAM, control units. timer, parallels I/O, ADC, and DAC. In Microprocessor, bit handling instruction is less, One Microcontroller offers many kinds of bit handling or two types only. instruction. Offers rapid movements of code and data between Offers rapid movements of code and data in the external memory and microprocessor. microcontroller. Helps you to design general purpose digital computers Helps you to design application-specific dedicated system. systems. It allows you to do multitasking at a time. It is a single task oriented system. In Microcontroller system, the fixed number for memory In Microprocessor system, you can decide the number or I/O makes a microcontroller ideal to complete the of memory or I/O ports needed. specific task. Offers support for external memory and I/O ports, This type of system is lightweight and cheaper compares which makes it heavier and costlier system. to the microprocessor. External devices need more space, and their power This type of system consumes less amount of space, and consumption is quite higher. power consumption is also very low. KEY DIFFERENCES Microprocessor consists of only a Central Processing Unit, whereas Micro Controller contains a CPU, Memory, I/O all integrated into one chip. Microprocessor is used in Personal Computers whereas Micro Controller is used in an embedded system. Microprocessor uses an external bus to interface to RAM, ROM, and other peripherals, on the other hand, Microcontroller uses an internal controlling bus. Microprocessors are based on Von Neumann model Micro controllers are based on Harvard architecture Microprocessor is complicated and expensive, with a large number of instructions to process but Microcontroller is inexpensive and straightforward with fewer instructions to process. Types of Microcontroller 8 bit Microcontroller 16 bit Microcontroller 32 bit Microcontroller Embedded Microcontroller External memory Microcontroller Types of Microprocessor Complex Instruction Set Microprocessors The Application Specific Integrated Circuit Reduced Instruction Set Microprocessors Digital Signal Multiprocessors (DSPs) Features of Microcontroller Processor reset Program and Variable Memory (RAM) I/O pins Device clocking central processor Instruction cycle timers Features of Microprocessor Offers built-in monitor/debugger program with interrupt capability Large amount of instructions each carrying out a different variation of the same operation Offers Parallel I/O Instruction cycle timer External memory interface Applications of Microcontroller Mobile phones Automobiles CD/DVD players Washing machines Cameras Security alarms Keyboard controllers Microwave oven Watches Mp3 players Applications of Microprocessor Calculators Accounting system Games machine Complex industrial controllers Traffic light Control data Military applications Defense systems Computation systems  Applications of Embedded Systems Robotic science Automotive Ground Vehicles Engine Control Drones Ignition System Underwater Vehicles Brake System Industrial Robots Medical Networking Dialysis Machine Router Infusion Pumps Hubs Cardiac Monitor Gateways Prosthetic Device Electronics Instruments  Applications of Embedded Systems Automobiles Industrial Control Fuel Injection Robotics Lighting System Control System Door Locks Missiles Air Bags Nuclear Reactors Windows Space Stations Parking Assistant System Shuttles Anti-stealing Alarms Whippers Motion  Applications of Embedded Systems Home Devices TVs Digital Alarm Air Conditioner DVD Video Player Cameras