An embedded system could be thought of as a computer system, which has a dedicated function within a mechanical or electrical system, these come often with a real time computing system. These are systems that are embedded as a part of the entire system and more often include hardware or mechanical parts. This by contrast a general purpose computer such as general purpose computers, for example a personal computer. These are designed such that they are flexible to meet the wide range of the end user products. These embedded systems control many devices in daily use now a days.
Characteristics and design of an embedded system:
Embedded systems are designed to do some specific tasks. They are unlike general purpose computers made for performing multiple tasks. Now, according to the definitions some of them have real time performance constraints to be met. These are mainly because of reasons such as safety and the usability. Also, there are some systems that do not have such demands to be met, thus these are normally of lower cost than the others.
Embedded systems are not always standalone devices. Many of them also contain some computerized parts that installed in a bigger machine serve a more general purpose. We can look at the Gibson Robot Guitar which features embedded systems whose main motto is to turn the strings of the robot.
The programs written for burning into an embedded system is known as firmware. These are stored only in read only memory and flash memory chips. One of the characteristics in that they run on very limited computer resources.
User interface used in embedded systems:
The Embedded systems may range from no user interface at all to only one user to multiple and complex graphical user interface depending upon the model and its function. The simple embedded systems use LEDs or buttons or graphical LCDs. Now, some of them use the user interface remotely with the help of a serial or network.
This approach has got many benefits:
- It extends the capability of the embedded system
- It avoids the cost created by installing an extra display
- It also simplifies the BSP
- Finally it allows a programmer to build a rich user interface on the PC.
Processors used in embedded systems:
These processors can be broken into two broad categories:
- Ordinary Microprocessors: These use separate circuits for memory and peripherals.
- Microcontrollers: These have on-chip peripherals, thus in turn reducing the power consumption, then also the size and cost.
Microcontrollers of many kinds and types have been developed for the embedded systems. Now, simple or general purpose microprocessors are also used in them. But these usually need a lot more circuitry than the microcontrollers. Thus microcontrollers are more favorable.
To know more about Embedded systems and their design characteristics Download pdf: All about Embedded systems