What is Embedded System: Types and Working

An embedded computer is a combination of both hardware and software that performs highly specific functions. It is an integral component of embedded systems.

An embedded system is a specialized computing system designed for a specific task or function, often within a larger device or system. These systems are "embedded" as part of a complete device, distinguishing them from general-purpose computers like PCs or smartphones. Let us learn more about it.

Table of Contents

• What is Embedded System?
• Examples of Embedded System
• Characteristics of an Embedded System
• How Do Embedded Systems Work?
• Types of Embedded Systems
• Advantages
• Components of embedded systems

What is Embedded System?

An embedded system is a computer system that is programmed to perform specific functions within larger electronic devices or systems. The functions performed by embedded computers are predetermined by the devices and systems in which this computer is embedded. Embedded system is a combination of hardware and software that are designed for specific functions. These systems function with larger systems that are programmable or may have fixed functionalities.

Let us consider a case to understand what an embedded computer is. The type of embedded computer used in a camera would be completely different from the embedded computer used in a washing machine. The reason behind the difference in the use of the software is due to the fact that these are meant to execute only certain tasks and hence they are totally distinct from one another. 

Modern embedded systems are based on microprocessors that come with integrated memory and peripheral interfaces. In complex systems, ordinary microprocessors are more commonly used. In both types of embedded computers, processors used range from general purpose to specialized ones in computations. 

Examples of Embedded Systems

Embedded systems are the types of systems that are used in different technologies in several industries:

• Industrial machines: These contain embedded systems such as Programmable Logic Controllers, SCADA Systems, CNC Machines, RFID systems, Temperature Controllers, etc.
• Automobiles: Modern cars consist of embedded systems that can perform several tasks within the vehicle. These embedded systems perform utility as well as user-facing functions.
• Medical equipment: These equipment consist of embedded systems such as control mechanisms. Patient monitoring systems, infusion pumps, imagining equipment, ventilators are some of the medical equipment that use embedded systems. 

Characteristics of an Embedded System

The following are the characteristics of embedded systems:

• Dedicated Functionality: Embedded systems are designed for performing a specific task or set of tasks, often with real-time constraints.
• Integration with Hardware: They are closely integrated with the physical hardware they control and often have minimal user interfaces.
• Real-Time Operation: Many embedded systems operate in real-time, meaning they must complete their tasks within strictly defined time constraints.
• Limited Resources: They typically have limited processing power, memory, and storage, requiring efficient use of resources.
• Low Power Consumption: Embedded systems are often designed for minimal power consumption that makes them ideal for battery-operated devices.
• High Reliability and Stability: Given their use in critical applications, embedded systems are designed for high reliability and stability over extended periods.
• Compact Size: Many embedded systems are small in size, designed to fit within the devices they control without occupying excessive space.
• Embedded Software: The software in embedded systems is usually highly specific to the particular application and can be pre-installed or firmware that can be updated.
• Connectivity: With the help of the Internet of Things (IoT), many embedded systems now feature connectivity options like Wi-Fi, Bluetooth, and cellular networks for data exchange.
• Scalability and Upgradability: While designed for specific functions, some embedded systems offer scalability or upgradability to adapt to evolving requirements.
• Cost-Effectiveness: They are often cost-effective solutions for controlling devices and processes, balancing performance and functionality against cost constraints.
• Security: Embedded systems in critical applications incorporate security features to protect against any unauthorized access and tampering.

How Does An Embedded System Work?

An embedded system works as a part of complete device. These are the small computers that are embedded in mechanical or electrical systems. They have a power supply, memory, processor and communication ports. An embedded system uses a communication port for transmitting data between the processor and peripheral devices using a communication protocol. The processor interprets the data using software stored in the computer's memory. Embedded system uses real-time operating systems (RTOS) for communicating with the hardware. 

Any embedded computer must contain a larger electronic or mechanical system as well as perform specific tasks. It is a combination of computer memory, processor and I/O peripheral devices with a dedicated function. At first, the computer will receive electronic data input via a user interface or a sensor. This information is computed by the microprocessor. Based on the physical system containing the embedded computer, the computer interacts with the mechanical components of the system.

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Uses of Embedded Systems

Embedded systems are the part of operations of most technologies that we use in our day-to-day lives. Without the availability of embedded computers, many systems would stop working effectively. These are used for the following purposes:

• Healthcare industry: For imaging and diagnostic devices, surgical and treatment tools as well as patient monitoring systems.
• Lifesciences industry: Used for proteomics, bioinformatics and genome sequencing systems and devices.
• Industrial automation industry: For manufacturing systems and supervising specific operations. This includes packaging, testing, production and safety management within extensive electrical systems.
• Military and defence industry: Embedded computers are used for training and simulations systems, autonomous and unmanned vehicles and C4ISR systems.

Types of Embedded Systems

These can range from having no user interface (designed to perform single task) to complex graphic user interfaces. It may even contain remote interfaces. The following are the main types of embedded systems:

1. Standalone embedded systems

These are independent embedded systems that can work on their own without depending on the host system. Such embedded systems take in input in either analogue or digital form and then give the output. Microwave ovens, MP3 players and calculators are examples of such embedded computers.

2. Real-time Embedded System 

A real-time embedded system is a type of embedded computer that works on the basis of real-time computing. It is represented by a dedicated operating system called RTOS. It further falls into the categories of soft and hard based on the acceptability of violation of time constraints.

2.1 Soft Real-Time System

It is a real-time system where operations are degraded when results are not produced as per the specified timing requirement. Here, it is not important to meet the deadline for every task but the process should be processed to yield results. In case the system misses the deadline every time, the performance of the system will worsen resulting in the inability of users to use the computer.

2.2 Hard Real-Time System

In this type of real-time system, the timeline is considered a deadline and must not be omitted in any case. It does not use any permanent memory due to which their processes must be completed properly the first time. Such a real-time system must generate accurate responses to events within a specified time. It is a purely time-constrained and deterministic system.

3. Network Embedded System

Network embedded systems have network connectivity along with the components of the embedded system. The software construction of such embedded computers differs slightly from other embedded systems. The real-time operating system is used in such embedded systems so that controlling can handle network hardware components. 

These are connected to a network that may be wireless or wired and provides output to the attached device. These communicate with an embedded web server via a network. Card swipe machines, ATM machines and home security systems are some of the examples.  

Types of Embedded System Based on Performance

Embedded systems are further categorized based on the performance and micro-controller:

• Small-scale embedded systems: These are designed with 8-bit or 16-bit microcontroller and can be powered via battery. Limited resources of memory and processing speed are used by the processor. 
• Medium-scale embedded systems: These are designed with 16-bit or 32-bit microcontroller. These are faster in comparison with small embedded systems. In such systems, integration of the software and hardware is complex. 
• Complex Embedded Systems: These are designed using a 32-bit or 64-bit microcontroller to perform larger and more complex functions. Such embedded computing systems have more software and hardware complexities. 

Advantages of Embedded System

The following points explain the advantages of embedded system:

• Dedicated Functionality: Embedded systems are designed for specific tasks, ensuring optimized performance for those functions.
• Size Efficiency: Typically smaller in size, making them suitable to integrate them into a wide range of devices.
• Cost-Effective: Due to their specialized nature, they often have lower costs compared to general-purpose computers.
• Low Power Consumption: Designed to operate under constrained power sources, making them energy efficient.
• Real-time Operations: Capable of real-time response, making them crucial for applications like medical devices and automotive safety systems.
• Stable and Reliable: Since they perform specific functions and don’t require frequent updates, they tend to be stable and reliable.
• Long Lifecycle: Embedded systems often have a longer lifecycle compared to general-purpose computers.
• Enhanced Security: Limited functionality can mean fewer vulnerabilities, making some embedded systems more secure against certain types of attacks.
• Fast Performance: Due to dedicated functionality and optimized design, they can offer quick responses and performance.
• Ease of Management: With fewer complexities than full-fledged computers, they can be easier to manage and maintain.
• Customizability: Can be tailored to meet the specific requirements of an application or device.

Components of Embedded System

1. Hardware Components of Embedded Systems

The hardware components of an embedded system often include a microcontroller or microprocessor, memory (RAM, ROM), input/output interfaces (I/O), and a user interface. The microcontroller or microprocessor is the heart of the embedded system and is responsible for executing the software that runs on the system. The memory is used to store the software and any data that the system processes. The I/O interfaces allow the system to interact with the outside world, and the user interface allows for human interaction with the system.

2. Software Components of Embedded Systems

The software components of an embedded system typically include the operating system (OS) and the application software. Operating System manages the hardware resources of the system and provides services to the application software. The application software is designed to perform the specific tasks that the embedded system is designed for. It interacts with the OS and the hardware to provide the desired functionality.

3. Real-Time Operating System (RTOS) in Embedded Systems

A Real-Time Operating System (RTOS) is an operating system that is designed to process data as it comes in, typically without buffering delays. In an embedded system, an RTOS allows the system to respond to external events in real-time. This is critical in many embedded systems where timely response to external events is required. An RTOS typically provides services such as task management, memory management, and I/O services.