An embedded system is a specialized computing system that is designed to perform dedicated functions or tasks, often in real-time and in a resource-constrained environment.
An Embedded system is defined as a way of working, organizing, performing single or multiple tasks according to a set of rules. In an embedded system, all the units assemble and work together according to the program.
Unlike general-purpose computers, which are designed to run a variety of applications, embedded systems are integrated into specific devices or products to control particular functions.
Key Characteristics of Embedded Systems
Key characteristics of embedded systems include:
- Dedicated Functionality: Embedded systems are built to perform specific tasks or functions within a larger system. Examples include the control systems in appliances, automotive control systems, industrial automation, medical devices, and more.
- Real-Time Operation: Many embedded systems are required to respond to external events or inputs in real-time. This means they must meet specific timing constraints to ensure accurate and timely operation.
- Resource Constraints: Embedded systems often have limited resources, including processing power, memory, and storage. These constraints necessitate efficient design and optimization of software and hardware components.
- Integration: Embedded systems are integrated into larger systems or products. They may consist of a combination of hardware and software components, and they often work alongside other systems within the same device.
- Reliability: Many embedded systems are designed for critical applications where reliability is essential. For example, embedded systems in automotive applications must operate reliably to ensure the safety and proper functioning of the vehicle.
- Low Power Consumption: Embedded systems are commonly used in battery-powered devices or applications where power consumption is a critical consideration. Optimizing power usage is often a key design goal.
Block Diagram of Embedded System
- At the heart of the embedded system is the central processing unit or processor. It is the hardware that executes the software and brings life to the embedded system. It also controls the activities of all the other circuits.
- There are varieties of processors available for embedded systems, and the main criteria for selection is to provide the processing power needed to perform the tasks within the system.
- Besides, the system cost, power consumption, software development tools, and component availability are also important factors to be considered while selecting a processor for embedded system design.
- The embedded system also has memory, often several different types in one system. The memory is an important part of any embedded system because how the software is designed, written, and developed is decided by memory.
- The memory is used to store the software that the processor will run. It also provides storage for data such as program variables, intermediate results, status information and any other data generated throughout the operation.
An embedded system communicates with the outside world through peripherals. The main types of peripherals that are used include:
- Digital inputs and outputs: These are simple external pins whose logic state can be controlled by the processor to either be a logic 1 or a logic 0. They can also be used as input pins so that the processor can receive binary inputs from the external world. They can be used individually or grouped together to create parallel ports.
- Serial interfaces: These are interfaces that send or receive data using one or two pins in a serial mode. They are less complex to connect but are more complicated to program because the data may also be augmented with additional information as required by the data transfer protocol.
- Analog to digital converters: While processors operate on the digital data, the surrounding world is analog in nature. Therefore, interfaces between the system and the external world requires analog to digital conversions and vice versa.
- Displays: Displays are used by the processor to display the status information, error messages, and output results. They could be simple LEDs, seven segment displays, or character LCD panels.
- Keypads: Keypads are used by the end user to provide inputs to the embedded system. The inputs could be anything such as entering the password, changing functional settings, switching between menu items, etc.