Imbedded Systems

An embedded system is a combination of computer hardware and software, designed to work together for a specific task. Generally, it comprises a processor, power supply, memory and communication ports. The system is an arrangement in which all of its units assemble and work together according to a set of rules. They are low-cost and power-consuming, small computers?that are embedded in other mechanical or electrical systems.

The word “embedded” refers to combination or synchronization. Which means a system that performs a particular task in a given time by synchronizing software (microcontroller) and hardware (PCB) together.

Embedded systems can range from having no user interface (UI) -- for example, on devices designed to perform a single task -- to complex graphical user interfaces (GUIs), such as in mobile devices.

User Interface can include:?buttons, LEDs (light-emitting diodes) and touchscreen sensing. Some systems use remote user interfaces as well.

Chip manufacturers for embedded systems include many known technology companies, such as Apple, IBM, Intel and Texas Instruments.

How does an embedded system work?

Embedded systems always function as part of a complete device. Embedded systems use the communication ports to transmit data between the processor and peripheral devices -- often, other embedded systems -- using a communication protocol. The processor interprets this data with the help of minimal software stored on the memory. The software is usually highly specific to the function that the embedded system serves.

Characteristics of an Embedded System

Unlike general computer systems, embedded systems work only for a particular function in a time-bound manner. For instance, a washing machine can not multitask like a laptop. In this regard, here are some unique characteristics of an embedded system.

Sophisticated Functionality

The functionality of no two embedded system applications is bound to be the same. The functionality of a washing machine is different from that of a microwave. However, the functionality of a laptop and a desktop are almost the same.

Real-Time Operation

Means the software programs hardware to operate in a time-bound fashion. It could also have two modes: Hard and Soft. The former mode indicates the task has to be completed within the allotted time (ex: clock), but in the soft mode, the system could use additional time over the allotted time (ex: microwave).

Low Manufacturing Cost

Embedded system involves less manufacturing cost as compared to a versatile general computing system. Therefor require less power to perform operations.

Processor and Memory

Small embedded systems would require less memory, but sophisticated systems demand more memory and run on multi-core processors.

Tight Design Constraint

There are many design constraints to consider around the cost, performance, size, and power of an embedded system to realize its absolute performance. These design factors are kept to a minimum to justify their simple function.

Types of Embedded Systems

All types of embedded systems can be classified into two basic categories and their following subcategories as follows.

Based on Performance and Functional Requirements

Real-Time systems

• Perform a task in real-time
• Offer quick responses under critical situations.
• Further divided into two types of embedded systems:

1. Soft real-time embedded system: no time-bound operation is required. For instance, in a microwave oven, there is no strict cooking time instruction. You can customize time delays as per your requirement.
2. Hard real-time embedded system: strictly time-bound operation is necessary for a successful output, ex: traffic light control.

Stand-alone systems

• Process digital/analog input signals into digital output
• Less complex
• Independent of any system

Ex: doorbell, calculator, MP3 player

Network systems

• Operate through a network interface
• Communication to network happens through LAN, WAN, or other protocols
• May be wired or wireless

Ex: ATM machines, weather monitoring systems

Mobile systems

• Small, portable and easy-to-carry
• Work on restricted memory space
• Constantly evolving to get into a miniature model
• Ex: mobile phones, digital camera

History of embedded systems

Charles Stark Draper developed an integrated circuit in 1961 to reduce the size and weight of the Apollo Guidance Computer, it helped astronauts collect real-time flight data.

In 1965, Autonetics, now a part of Boeing, developed the D-17B, the computer used in the Minuteman I missile guidance system. It is widely recognized as the first mass-produced embedded system. In 1968, the first embedded system for a vehicle was released; the Volkswagen 1600 used a microprocessor to control its electronic fuel injection system.

By the late 1960s and early 1970s, the price of integrated circuits dropped and usage surged. The first microcontroller was developed by Texas Instruments in 1971.

In 1971, Intel released what is widely recognized as the first commercially available processor, the 4004. The 4-bit microprocessor was designed for use in calculators and small electronics, though it required eternal memory and support chips. The 8080's successor, the x86 series, was released in 1978 and is still largely in use today.

In 1987, the first embedded operating system, was released by Wind River. By the late 1990s, the first embedded Linux products began to appear. Today, Linux is used in almost all embedded devices.

Embedded system trends

The embedded system is expected to continue growing rapidly, driven in large part by the internet of things. Expanding IoT applications, such as?wearables, drones, smart homes, smart buildings, video surveillance, 3D printers?and smart transportation, are expected to fuel embedded system growth.