Structure and Design
After going through this lesson the student will
• Learn more about the numerous day-to-day real time embedded systems
• Learn the internal hardware of a typical mobile phone
• Learn about the important components of an RTES
• Learn more about a mobile phone
• Learn about the various important design issues
• Also learn the design flow
Digital Electronics, Microprocessors
Common Examples Of Embedded Systems
Some of the common examples of Embedded Systems are given below:
Consumer electronics cell phones, pagers, digital cameras, camcorders, DVD players, portable video games, calculators, and personal digital assistants etc.
Home appliances microwave ovens, answering machines. thermostats, home security systems, washing machines. and lighting systems etc.
office automation fax machines, copiers, printers, and scanners
business equipment electronic cash registers, curbside check-in, alarm systems, card readers product scanners, and automated teller machines
automobiles Electronic Control Unit(ECU) which includes transmission control, cruise control, fuel injection, antilock brakes, and active suspension in the same or separate modules.
Let us take the same mobile phone as discussed in Lesson 1 as example for illustrating the typical architecture of RTES.
In general, a cell phone is composed of the following components:
• A Circuit board (Fig. 2.2)
• Liquid crystal display (LCD)
A typical mobile phone handset (Fig. 2.3) should include standard I/O devices (keyboard, LCD), plus a microphone, speaker and antenna for wireless communication. The Digital Signal Processor (DSP) performs the signal processing, and the micro-controller controls the user interface, battery management, call setup etc. The performance specification of the DSP is very crucial since the conversion has to take place in real time. This is why almost all cell phones contain such a special processor dedicated for making digital-to-analog (DA) and analog-todigital(AD) conversions and real time processing such as modulation and demodulation etc. The Read Only Memory (ROM) and flash memory (Electrically Erasable and Programmable Memory) chips provide storage for the phone’s operating system(RTOS) and various data such as phone numbers, calendars information, games etc.
Version 2 EE IIT, Kharagpur