Embedded Systems Hardware Lecture PDF

Embedded Systems Hardware (ECE202) Dr. Rohit Singh 1  Introduction to the embedded system Syllabus Dr. Rohit Singh 2  Introduction to the Embedded System System: A...

Embedded Systems Hardware (ECE202) Dr. Rohit Singh 1  Introduction to the embedded system Syllabus Dr. Rohit Singh 2  Introduction to the Embedded System System: A system is an arrangement in which all its unit assemble work together according to a set of rules. In short, we can say, in a system, all its sub-components depend on each other. Ex: watch, cell phone, etc. Embedded System ✓ It can be thought off as embedding a computer in an appliance, but that computer must not be a general-purpose computer. ✓ It can be thought off as a computerSyllabus hardware system having software embedded in it. ✓ It can be independent or may be part of a large system. ✓ It is a microprocessor or microcontroller-based system which is designed to perform a specific task. Text book definition: It can be defined as a microprocessor or microcontroller based, software driven, reliable, real-time control system. Dr. Rohit Singh 3  Introduction to the Embedded System (components of embedded system) It has three components ✓ Hardware ✓ Application software ✓ It has real time operating system (RTOS) that supervises the application Syllabus software. Types of RTOS ✓ Hard real time: missing deadline causes failure. ✓ Soft real time: missing deadline results in degraded performance Dr. Rohit Singh 4  Introduction to the Embedded System (characteristics of an embedded system) ✓ Single functioned: It usually performs a specified operation and does the same repeatedly. ✓ Tightly constrained: Design metrics is a measure of an implementations features such as its cost, size, power, and performance. ✓ Reactive and real time: It must continually react to changes in the system’s environment and must compute certain results in real time without any delay. Syllabus ✓ Microprocessor or microcontroller based ✓ Memory: It must have a memory, as its software usually embeds in ROM. It does not need any secondary memories in the computer. ✓ Connected: It must have connected peripherals to connect input and output devices. ✓ HW-SW system: Software is used for more features and flexibility. Hardware is used for performance and security. Dr. Rohit Singh 5  Introduction to the Embedded System (Basic architecture of an embedded system) Processor & Sensor A-D converter ASIC D-A converter Actuator Syllabus Memory Sensor: It measures the physical quantity and converts it into an electrical signal. A sensor stores the measured quantity to the memory. Processor & ASIC: It process the data to measure the output and store it to the memory. ASIC: Application specific integrated circuit Dr. Rohit Singh 6  Introduction to the Embedded System (Detail architecture of an embedded system) ASIC Memory Software Input A to D CPU D to A Output Human Auxiliary Diagnostic tool interface System Casing Packaging Auxiliary system is providing a supplementary or additional help and support. Dr. Rohit Singh 7  Introduction to the Embedded System (Implementing embedded system) ✓ Hardware Processing element Peripherals ▪ Input and output devices ▪ Interfacing sensors and actuators ▪ Interfacing protocols Memory ✓ Software System software Application software Dr. Rohit Singh 8  Introduction to the Embedded System (Hardware evolution) (Higher degree of integration) System on chip Faster clock rate Application specific processors Digital signal processor (DSP) General purpose microprocessor & microcontrollers Dr. Rohit Singh 9  Introduction to the Embedded System (Expectation from software for embedded system) ✓ Program must be logically and temporally (delays, time out, etc.) correct. ✓ Must deal with inherent physical concurrency ▪ Reactive system ✓ Reliability and fault-tolerance are critical issues ✓ Application specific and single purpose Dr. Rohit Singh 10  Introduction to the Embedded System (Challenges in embedded system design) ✓ How much hardware do we need? ▪ What is word size of the CPU? Size of memory? ✓ How do we meet our deadlines? ▪ Faster hardware or cleverer software? ✓ How do we minimize power? ▪ Turn off unnecessary logic? Reduce memory accesses? Dr. Rohit Singh 11  Introduction to the Embedded System (Embedded system design (Global picture)) Multi-objective Multi-discipline Life-cycle Dependability Electronic hardware Requirements Affordability Software Design Safety Mechanical hardware Manufacturing Security Control algorithms Deployment Scalability Human Logistics Timeliness Retirement plan Dr. Rohit Singh 12  Introduction to the Embedded System (Design goals) ✓ Performance ▪ Overall speed, deadline ✓ Functionality and user interface ✓ Manufacturing cost ✓ Power consumption ✓ Other requirements (physical size, etc.) Dr. Rohit Singh 13  Introduction to the Embedded System (Design and development process) ✓ Requirements ✓ Specifications ✓ Architecture ✓ Component design ✓ System integration Dr. Rohit Singh 14  Introduction to the Embedded System (Functional vs. non-functional requirements) ✓ Functional requirements: ▪ Output as a function of input ✓ Non-functional requirements: ▪ Time required to compute the output ▪ Size ▪ Weight ▪ Power consumption ▪ Reliability ▪ etc. Dr. Rohit Singh 15  Introduction to the Embedded System (Top-down vs. bottom-up approach) ✓ Top-down design: ▪ Start from most abstract description ▪ Work to most detailed ✓ Bottom-up design: ▪ Work from small components to big system ✓ Real design uses both techniques Dr. Rohit Singh 16  Introduction to the Embedded System (Concluding remarks for the introduction of embedded system) ❑ Embedded systems are all around us. ❑ Embedded systems pose many design challenges like design time, deadline, power consumption, etc. Dr. Rohit Singh 17  Introduction to the Embedded System (Examples of embedded systems) Dr. Rohit Singh 18  Introduction to the Embedded System (Examples of embedded systems) Dr. Rohit Singh 19  Syllabus Dr. Rohit Singh 20