EMBEDDED SYSTEM SOFTWARE AND HARDWARE
An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. Embedded systems control many devices in common use today.Ninety-eight percent of all microprocessors are manufactured as components of embedded systems.
Examples of properties of typically embedded computers when compared with general-purpose counterparts are low power consumption, small size, rugged operating ranges, and low per-unit cost. This comes at the price of limited processing resources, which make them significantly more difficult to program and to interact with. However, by building intelligence mechanisms on top of the hardware, taking advantage of possible existing sensors and the existence of a network of embedded units, one can both optimally manage available resources at the unit and network levels as well as provide augmented functions, well beyond those available. For example, intelligent techniques can be designed to manage power consumption of embedded systems.
An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. Embedded systems control many devices in common use today.Ninety-eight percent of all microprocessors are manufactured as components of embedded systems.
Examples of properties of typically embedded computers when compared with general-purpose counterparts are low power consumption, small size, rugged operating ranges, and low per-unit cost. This comes at the price of limited processing resources, which make them significantly more difficult to program and to interact with. However, by building intelligence mechanisms on top of the hardware, taking advantage of possible existing sensors and the existence of a network of embedded units, one can both optimally manage available resources at the unit and network levels as well as provide augmented functions, well beyond those available. For example, intelligent techniques can be designed to manage power consumption of embedded systems.
What are they?
An embedded system is a combination of hardware
and software that is designed to carry out a certain task or tasks,
meaning it has a specific function. They are ‘embedded’ within a larger
electrical system. General purpose computers such as personal computers
(PC’s) on the other hand, are designed to satisfy a wide range of needs.
Embedded systems can be found in a variety of common electrical appliances today, such as in mobile phones, industrial machines, automobiles, cameras, household appliances, airplanes, vending machines and toys as well as in medical equipment such as ECG recorders.
Embedded systems are usually based on micro controllers (however in the past they were mostly based on microprocessors). The basic difference between a microprocessor and a micro controller is simply that microprocessors contain only the CPU – they don’t have an inbuilt RAM or ROM, so these needed to be added externally. Micro controllers however are superior in the sense that they have a CPU as well as a fixed amount of RAM and ROM.
Embedded systems need to be very reliable as issues with the embedded system can have devastating consequences in terms of the larger system it is part of.
Embedded systems can be found in a variety of common electrical appliances today, such as in mobile phones, industrial machines, automobiles, cameras, household appliances, airplanes, vending machines and toys as well as in medical equipment such as ECG recorders.
Embedded systems are usually based on micro controllers (however in the past they were mostly based on microprocessors). The basic difference between a microprocessor and a micro controller is simply that microprocessors contain only the CPU – they don’t have an inbuilt RAM or ROM, so these needed to be added externally. Micro controllers however are superior in the sense that they have a CPU as well as a fixed amount of RAM and ROM.
Embedded systems need to be very reliable as issues with the embedded system can have devastating consequences in terms of the larger system it is part of.
A simple depiction of the architecture of an embedded system:
Hardware components of an embedded system:
- CPU
- ROM and RAM
- Input devices
- Output devices
- Communication interfaces
- Circuitry
Types
Embedded systems can be classified in the following four categories based on performance and functional requirements:
- Stand-alone embedded systems – these are obviously ‘stand-alone’ systems. They don’t require a host system. Examples of these can be found in video game consoles and microwave ovens.
- Real time embedded systems – these are used when a specific task needs to be done in a specific time frame. They follow strict deadlines. These are further classified into soft and hard real time systems. Soft real time systems have deadlines, however if these are not met, there is no significant harm (e.g. a time delay between pressing a button on your TV remote and the TV sensing it and changing the channel). Hard real time systems are found in industrial machines for example, where strict deadlines need to be adhered to.
- Networked embedded systems – these are connected to a network to access resources
- Mobile embedded systems – as the name suggests, these are found in portable electronics
Advantages
- Since an embedded system is specialized for carrying out the same tasks, there is rarely any need to change the hardware
- Compact size
- Low cost
- Simple design
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