An Embedded system has its own unique characteristics, which make us identify and decide the system as the embedded system. Some of the characteristics include dedicated operation, speed, less power, compact size, low cost, etc.
In the following section, some interesting characteristics are discussed.
Performs specific Function
All embedded systems are designed to execute a specific function repeatedly. For example, if you consider a washing machine, its function is only to wash clothes. Washing is its dedicated functionality and it cannot be used for any other purposes like cooling or heating.
Similarly, an ATM machine is used to withdraw money and do transactions but it cannot be used for controlling room temperature. Similarly, pagers, microwave oven, automotive cruise control systems, modem are some of the applications which perform specific functions.
Tightly Constraint system
Whatever system is being designed, they have certain constraints. In the same way, an embedded system has several constraints like product cost, performance, size and power. In fact, these four parameters decide the success of any embedded System.
Let us consider an example of buying a mobile phone. If the mobile phone costs in lakhs, would you buy it? No, instead you look for different options like low budget phones.
If it takes half an hour for making a call and if it also hangs frequently, would you opt it? No Way, the frustration level will rise if the phone hangs continuously.
What would you do, if the phone is weighing 3 kilograms, will you prefer it? No, we prefer less weight products. The mobile phone should also be capable of retaining the charge for some reasonable amount of time. Else the battery will drain faster and we have to keep the charger handy all the time.
What it means? Cost of the product, its performance, size and the power always matters the most while designing an embedded system.
Real Time and Reactive behavior
A real-time system is a system intended to serve real-time applications which process the data as it comes in, typically without any buffering delays. If there occurs any delay in responding, then the result might be dangerous.
Let us take an example of a person travelling in a car. Unfortunately a lorry seems to be coming opposite to the car. What would the driver do?
The driver would apply the brake. Immediately after applying the brake, the car should stop without delay. This is a real-time and reactive behavior of the system. The brake may be applied at any point in time. So, when an embedded system is operating in real-time, it must be in a situation to respond to its input without any delay in execution.
An automotive cruise control system, flight landing gear control, ECG machine output are some of the examples of real-time and reactive characteristics of an embedded system.
Perform Complex function
The processor inside the embedded system should perform operations that are complex in nature. Let us consider an example of a washing machine. It is used to wash clothes at different temperatures and at different timings. It is also used to dry the clothes, drain the water in tub, clean the tub, etc.
To perform these functions, it needs a lot of complex algorithms. Many embedded systems are distributed into smaller units to perform complex functions.
Minimal user Interface
Generally, embedded systems have a simple user interface, an interesting characteristics of embedded system. In older days, mobile phones with keypads are available in the market. But look at the phone available in our hands now. Todays’ phone has become smarter with least interfaces.
So designing a system with an easier and comfortable interface is most important. At the same time, it should have options required for the operation of the device. In examples like ATM machines, washing machines, microwave ovens, etc you can look at the compact interface for its operation.
Operates in Harsh environment
The embedded system is designed to operate in different environments where humans cannot enter, either it is a cold or hot condition. Whatever may be the condition, the systems designed to work in that condition should withstand that environment.
The designers should always remember the operating environment while designing an embedded system. For example, if a system is designed to operate in a rainy condition, then there should not be any compromise for the formation of corrosion in the system.
Some environments may have vibrations, shock, power fluctuations, etc. These factors are to be considered while designing an embedded system for that condition.
Requires less power
For most embedded systems, power management is one of the critical factors in its design. The design should be in such a way that the heat dissipation should be minimized. If not, we have to install cooling equipment to reduce the heat produced. But that will lead to a bulky product.
Also, embedded systems like digital cameras, digital watches, space rover operates independently. These systems are operated with a battery mounted inside the system. Hence choosing the low-power components with power-saving modes is important while designing a system.