Realtime embedded systems
- 1. Real Time Embedded Systems A Complete Assignment This assignment is discuss the majors of embedded systems. 2018 Gentle_Xhaizi CIIT Vehari 2/21/2018
- 2. Prepared By: Gentle Xhaizi Cell: +923156321005 Mail: fs.ahmad65@gmail.com What is real time embedded system? Definition: An embedded system is computer system having various functions within a large mechanical or electrical system. These systems have many of functions which are so critical. Its include software and hardware devices which are connected to a system. Introduction: Real time embedded system are most popular computer nowadays. These devices are found everywhere like microwave ovens, car engines, robots etc. these computers are used for specific purposes. Embedded systems are primary and the operating system used for this purpose provides limited features. Usually they have no user interface. Mostly these systems are used to monitor and manage the devices like robotics, computerized weapons etc. and also they are used by armed forces. This system is to be designed within some larger system. These system are very different from normal system which we are use. Some of these use as general purpose computer and sometimes they are used to implement a special purpose activity like embedded systems providing just the functionality desired by user. Some of these hardware devices with special IC’s that perform their tasks without an operating system. Real time doesn’t mean real fast computer may be they will be slow. It means that you can calculate the performance accurately when a program will execute. These systems are used in the industry of consumer, medical, industrial, technology and military applications. These systems are most widely used in our routine life. For the developing of real time systems, it may involve many of activities like requirements, architectural design, timing analysis, testing, implementation and debugging. Actually these systems are the combination of computer software and hardware. Sometimes these systems are using mechanical components. Embedded systems are used sensor, signal and buttons to input information from these devices. There are two types of real time. 1. Hard real time Hard real time means that the systems that give response in required time. This system is providing guaranteed services. The examples of this system are Flight Controlling System, antimissile system, cardiac pacemaker etc. 2. Soft real time Soft real time means that the system that doesn’t give response in required time. But it doesn’t means that they give not output. They missed the deadline but not completely failure. The examples of this system are global positioning system, digital camera, robot soccer player, and wireless router system. History: Real time embedded systems are developed in 1961.the first embedded system was developed by Charles Stark Draper in 1961 named Apollo Guidance Computer. He developed this system in MIT instrumentation Lab. This system was considered the riskiest computer in Apollo project.
- 3. Prepared By: Gentle Xhaizi Cell: +923156321005 Mail: fs.ahmad65@gmail.com After this Apollo Guidance Computer another embedded system was developed named Autonetics D-17 guidance computer for the Minuteman Missile. After the production of minuteman II the D-17 was replaced with a new computer in which high volume integrated circuits are used. Why it’s needed? Why we need an embedded system? We use an embedded system for interaction with I/O devices. There are two approaches to interact with I/O devices such as Polling and interrupts. We needed embedded system to improve the quality of computing. These systems are providing reliability, power consumption and real time performance etc. 1. Polling 2. Interrupts 1. Polling: It is a simplest approaches used in the embedded system to handle I/O activities. In polling the continuous check is required for data arrival. 2. Interrupts: Interrupts can be categorized into three main parts such that external interrupts, software interrupts and internal interrupts. 2.1 External interrupts: These interrupts are called hardware interrupts. These interrupts are asynchronous events generated by external hardware devices to get the microprocessor’s attention. 2.12 Software interrupts: These interrupts are also called traps. These are unconditional in the sense that the execution of the special instruction will always generate a software interrupts. 2.13 Internal interrupts: These interrupts are also called exception. Internal interrupts are conditional in the sense that the execution of some valid instruction. Where we use embedded system in routine life? Mostly we used embedded to improve the routine life computing. These are often used in our daily life which includes: 1. ATMs 2. Thermostats 3. Digital calculator 4. Mobile Phones 5. Photocopiers 6. Video games 7. Handheld computers
- 4. Prepared By: Gentle Xhaizi Cell: +923156321005 Mail: fs.ahmad65@gmail.com 8. PDAs (personal digital assistants) 9. Households (like microwave ovens) Advantages and disadvantages of embedded systems: Everything has its own advantages and disadvantages. We do not make a perfect machine to solve our problems. Embedded systems have major advantages and disadvantages. The advantages and disadvantages are given below: Advantages of the embedded system: i. These systems are small. ii. These systems are faster to load. iii. Managing these systems is easy iv. Have a low cost v. Use fewer resources during calculation vi. Performance is better than other systems vii. These systems are easy for mass production viii. Very reliable systems ix. Have interconnections x. Improve the quality of the product Disadvantages of embedded systems: i. Up gradation of these systems are very difficult instead of other systems ii. If we have a problem, we have to reset all the settings iii. Limitation of the material iv. Difficult to troubleshoot v. Sharing data is difficult than other systems vi. These systems are not scalable vii. The interview is very hard viii. Take backups of files is very difficult ix. Technological improvements are not done in these systems Applications and examples of real-time systems Embedded systems are mostly used in our daily life in the form of commerce, military, government, educational, cultural infrastructure and medical. Included are i. Vehicle systems for automobiles, subways, aircraft, railways and ships ii. Traffic control for motorways, airspace, railways and shipping lanes iii. Process control for power plants, chemical plants and consumer products such as soft drinks and beer iv. Medical systems for radiotherapy, patient monitoring and defibrillation v. Military uses such as firing weapons, tracking, and command and control vi. Manufacturing systems with robots vii. Telephone, radio, and satellite communications viii. Computer games
- 5. Prepared By: Gentle Xhaizi Cell: +923156321005 Mail: fs.ahmad65@gmail.com ix. Multimedia systems that provide text, graphic, audio, and video interfaces x. Household systems for monitoring and controlling appliances xi. Building managers that control such entities as heat, lights, doors, and elevators