Question

Explain the any two types of algorithms in details. in embedded system

Answer 1

Embedded Systems Unit 1 EMBEDDED SYSTEM: AN INTRODUCTION 1.1 DEFINITION OF AN EMBEDDED SYSTEM  An embedded system is a combination of 3 things: a. Hardware b. Software c. Mechanical Components. And it is supposed to do one specific task only.  Example 1: Washing Machine A washing machine from an embedded systems point of view has: a. Hardware: Buttons, Display & buzzer, electronic circuitry. b. Software: It has a chip on the circuit that holds the software which drives controls & monitors the various operations possible. c. Mechanical Components: the internals of a washing machine which actually wash the clothes control the input and output of water, the chassis itself.  Example 2: Air Conditioner An Air Conditioner from an embedded systems point of view has: a. Hardware: Remote, Display & buzzer, Infrared Sensors, electronic circuitry. b. Software: It has a chip on the circuit that holds the software which drives controls & monitors the various operations possible. The software monitors the external temperature through the sensors and then releases the coolant or suppresses it. c. Mechanical Components: the internals of an air conditioner the motor, the chassis, the outlet, etc  An embedded system is designed to do a specific job only. Example: a washing machine can only wash clothes, an air conditioner can control the temperature in the room in which it is placed.  The hardware & mechanical components will consist all the physically visible things that are used for input, output, etc.  An embedded system will always have a chip (either microprocessor or microcontroller) that has the code or software which drives the system. 1.2 HISTORY OF EMBEDDED SYSTEM  The first recognised embedded system is the Apollo Guidance Computer(AGC) developed by MIT lab.  AGC was designed on 4K words of ROM & 256 words of RAM.  The clock frequency of first microchip used in AGC was 1.024 MHz.  The computing unit of AGC consists of 11 instructions and 16 bit word logic.2. Embedded Systems Unit 1  It used 5000 ICs.  The UI of AGC is known DSKY(display/keyboard) which resembles a calculator type keypad with array of numerals.  The first mass-produced embedded system was guidance computer for the Minuteman-I missile in 1961.  In the year 1971 Intel introduced the world’s first microprocessor chip called the 4004, was designed for use in business calculators. It was produced by the Japanese company Busicom. 1.3 EMBEDDED SYSTEM & GENERAL PURPOSE COMPUTER The Embedded System and the General purpose computer are at two extremes. The embedded system is designed to perform a specific task whereas as per definition the general purpose computer is meant for general use. It can be used for playing games, watching movies, creating software, work on documents or spreadsheets etc. Following are certain specific points of difference between embedded systems and general purpose computers: Criteria General Purpose Computer Embedded system Contents It is combination of generic hardware and a general purpose OS for executing a variety of applications. It is combination of special purpose hardware and embedded OS for executing specific set of applications Operating System It contains general purpose operating system It may or may not contain operating system. Alterations Applications are alterable by the user. Applications are non-alterable by the user. Key factor Performan ce” is key factor. Application specific requirements are key factors. Power Consumpti on More Less Response Time Not Critical Critical for some applications3. Embedded Systems Unit 1 1.4 CLASSIFICATION OF EMBEDDED SYSTEM The classification of embedded system is based on following criteria’s:  On generation  On complexity & performance  On deterministic behaviour  On triggering 1.5.1 On generation 1. First generation(1G):  Built around 8 bit microprocessor & microcontroller.  Simple in hardware circuit & firmware developed.  Examples: Digital telephone keypads. 2. Second generation(2G):  Built around 16-bit μp & 8-bit μc.  They are more complex & powerful than 1G μp & μc.  Examples: SCADA systems 3. Third generation(3G):  Built around 32-bit μp & 16-bit μc.  Concepts like Digital Signal Processors(DSPs), Application Specific Integrated Circuits(ASICs) evolved.  Examples: Robotics, Media, etc. 4.