The term ‘embedded systems’ is quite a complex one. An embedded system is a special purpose computer that is used inside of a device. It is basically a combination of hardware and software designed to perform a specific function. These smart systems can take decisions in different conditions. Built into the devices, these are invisible to our eyes but have all the processing power of computers. They form the components of a larger system. This, in turn, is preprogrammed to perform a range of functions, usually with minimal operator intervention.
High profile embedded chips is scaleable, generate small amounts of heat, and consume less power. These are generally preferred for their speed, accuracy and reliability. On larger scale, programmable devices or systems are generally used to monitor or control processes and equipment.
In embedded systems, the hardware is normally unique to a given application. Computer chips are embedded into the control electronics to manage the product functionality. Thanks to their compact size and ability to perform time critical and task specific operations, embedded devices find applications in all segments of the commercial and industrial marketplace. Home appliances, mobile phones, personal digital assistants (PDA’s), cars, tiny microchips and avionics are all using embedded technology.
For example, take the case of Internet-the most important of all applications. The Internet is itself a huge embedded system. Today, typical access to the Internet is via broadband technology, GSM/GPRS or CDMA modem, Ethernet LAN or Wi-Fi access points.
COMPONENTS OF AN EMBEDDED SYSTEM:
An embedded system comprises the following components:- Embedded hardware: The embedded hardware mainly consists of a microcontroller with various peripheral IC’s. A fixed size volatile memory such as DRAM or SRAM and non- volatile memory such as Flash or EPROM, connected to the microcontroller are an integral part of the device.
Depending on the target applications of the device, the peripherals can include communication devices such as serial controller, Ethernet controller, or a wireless communication controller and other application specific IC’s. Many handheld devices, these devices, also have keypads and graphical LCD screens as user interfaces.
Embedded RTOS: All embedded devices that perform complex functions have an embedded operating system inside. This operating system is typically real time in nature, i.e. it is capable of responding deterministically to time-critical external events.
Device drivers: The lowest level software that acts as glue between the operating systems and the peripheral devices is called the device driver. The device driver software controls every peripheral device that is connected to the microcontroller.
Communication stacks: If the embedded device is capable of communicating to the external world, it has a communication software stack running on the top of the operating system. In order to connect to the internet, the embedded devices need a TCP/IP stack.
Embedded applications: Finally, embedded application software performs the predefined function of the embedded device. This software can support such application as the Internet, e-mail and MP3 decoders. Many of the embedded applications, these days, support sophisticated graphical user interface screens.