Embedded System

Embedded system is a digital system that use microprocessor/micro-controller. It run only the specifics functions and usually used as a controller. Embedded system is real-time operation. Embedded systems actually is combination of many devices and sensors to perform certain functions and get result.

D/A Conversion – Digital to Analog converter

A/D conversion – Analog to digital converter

Actuators – type of motor for moving or controlling a mechanism or system

Special Purpose field Programmable (FPGA)

Application Specific Integrated Circuit (ASIC)

Example of Embedded Systems application

• Anti-lock breaks
• Auto-focus camera
• Modems
• MPEG decoders
• Network Cards
• Pagers
• Cruise Control

Common Characteristic

1. Single Functioned which mainly us executes a single program repeatedly
2. Usually is tightly-constraint which low cost,low power, small, fast, etc.
3. It was reactive and real-time application that continually reacts to changes in the system's environment . It have to compute certain result in real-time without delay.

Characteristic of Embedded System

Reliability is a very important characteristic for embedded systems. This is because many systems work in mission critical and life-threatening environment where system reliability is crucial. Embedded Systems are often embedded in machines that are expected to run continuously for year without fault, and tolerate the errors by themselves if an error occurs. 

Therefore the software is usually developed and tested more thoroughly than that for personal computers. Most embedded systems cannot be shutdown for maintenance, or it is very difficult to repair such as aerospace systems. Some system will lose large amounts of money when shutdown. Example like Telephone switches, factory controls, bridge and elevator controls, funds transfer and market making, automated sales and services.

Constraint of Embedded Systems

• Resource constraint – systems are limited with memory,size, power capacity , CPU speed, and functions.
• Time Constraint- Real-time system has response time deadline to meet.
• Environment Constraint – extreme operation like low temperature, high pressure, and etc
• Cost Constraint – Cost reduction of products has huge impacts on the market competition.
• Time to market constraint -Design and development cycle is very limit in order to beat the competent in the market.