CHARACTERISTICS & QUALITY ATTRIBUTES OF EMBEDDED SYSTEMS UNIT II Reference: Introduction to Embedded Systems- Shibu KV

Characteristics of an ES Application & Domain specific Reactive & Real time Operates in harsh environments Distributed Small size & weight Power concerns

Quality Attributes Operational Quality attributes Non-operational Quality attributes

Operational Attributes Response Throughput Reliability Maintainability Security Safety

Non-Operational Attributes Testability & Debug-ability Evolvability Portability Time to prototype & market Per unit & per cost

Embedded Systems-Application & Domain Specific UNIT II Reference: Introduction to Embedded Systems- Shibu KV

APPLICATION SPECIFIC :WASHING MACHINE ACTUATORS: agitator, tumble tub, water drawing pump, inlet valve etc. SENSOR PART: water temperature sensor, level sensor CONTROL UNIT: micro processor/controller based board (includes User Interface)

Working of the Washing Machine: Types: Top loading Front loading WASH PHASE In top loading the agitator of the machine twists back & forth Pulls the cloth to the bottom of the tub & upon reaching the clothes work their way up. In front loading , the clothes are tumbled and plunged into the water over and over again.

SPIN PHASE Water is pumped out of the tub and the inner tub uses centrifugal force to wring out more water from the clothes The spinning at several hundred Rotations Per Minute(RPM).

AUTOMOTIVE- DOMAIN SPECIFIC ES.

INNER WORKINGS OF AUTOMOTIVE ES Automotive ES takes control of the mechanical parts/systems It varies from mirror & wiper controls to antilock brake systems(ABS) to air bag controller system. They are built around a micro controller or DSPs or hybrid of both of them, known as ECU(electronic control unit) Their can be any number of embedded controllers in a vehicle

Types of ECU. HIGH SPEED ECU: Are deployed in critical control units that require fast response. They include fuel injection systems , ABS, engine control , steering control. LOW SPEED ECU: Response is not time critical Uses low cost micro controller or DSP. For passenger and door locks , door glass controls, lamp controls etc.

AUTOMOTIVE COMMUNICATION BUSES CONTROLLER AREA NETWORK( CAN) Event driven protocol Provides medium and high speed data transfer. Supports error handling in data transmission. Generally used in safety system like airbag control, ABS and navigation system like GPS. LOCAL INTERCONNECT NETWORK (LIN): Single master , multiple slaves communication network. Low speed ,single wire communication interface Used for sensor/actuator interfacing Eg. Mirror controls , fan controls, seat positioning controls etc

MEDIA-ORIENTED SYSTEM TRANSPORT( MOST) BUS: Is for automotive audio/video equipment interfacing Is a multimedia fibre-optic point-to-point network Its implemented in star/ring topology It  transports audio, video, voice and data signals. MOST technology is used in almost every car brand worldwide, including Audi, BMW, Hyundai, Jaguar, Land Rover, Mercedes- Benz, Porsche, Toyota, Volkswagen and Volvo. Ms.Sarita Balakrishnan Assistant Professor SIES ,Sion(West).