6:22 AM
The Shanbhag
Embedded System(ES): Any device that includes a computer but is not itself a general purpose computer
-> Hardware & Software part of some larger system are expected to function without human intervention.
->Respond , monitor , control external environment using sensors and actuators .
Eg: PDA,printer,Cell phones etc
Characteristic of an ES:
1) Sophisticated features (functionality)
2)Real time Operation (Not always)
3)Low Manufacturing Cost
4)Application dependent processor (Not General purpose)
5)Restricted memory
6)Low power
Power consumption is critical in battery powered devices. Excessive power consumption increases system cost even in wall powered devices.
Manufacturing Cost:
1)Manufacturing cost has different components
->Non rec-curing engineering cost for design & development
->Cost of production and marketing each unit
2)Best technology choice will depend on number of units we plan to produce
Real time operation:
->Must finish operations by deadlines
* Hard Real time: Missing deadline cause failure
* Soft Real time : Missing deadline results in degraded performance
Many system are multi-rate: must handle operations at widely varying rates
Application dependent requirements:
1)Fault tolerance:Continue operation despite hardware or software faults
2)Safe:System to avoid physical or economic damage to person or property
3)Dedicated system:
*Predefined functionality:accordingly hardware and software designed
* Re programing rarely done during lifetime of the system
* real time,fault tolerance ,safe
Types of ES:
=>Similar to general computing
Eg: PDA,video games,set top boxes,Automatic Teller Machine(ATM)
