Embedded system was first used in “Building Apollo Guidance System” by Charles Stark Draper at MIT (Massachusetts Institute of Technology) in the year 1960; it is one of the modern embedded systems, which is used for navigation and control of the respective crafts. Usage of the Apollo Guidance System is a risk because it is developed by using a keypad and numeric display. It was frequently used and refined in a lot of NASA’s space missions. Then, the Autonetics D-17 Guidance Computer has come for the Minuteman Missile- an ICBM (Intercontinental Ballistic Missile) is used by the United States Air Force. Let’s look at an overview of the advanced embedded system basics and applications.
What is Embedded Systems?
Embedded system is defined as a way of working, performing or organizing one or many tasks according to a fixed set of rules (or) an arrangement in which all the units assemble and work together according to the program or plan. Examples of embedded systems are a watch and washing machine.
An embedded system is a system that has software embedded in computer hardware. It makes a system dedicated to a specific part of an application or product of a larger system. Depending on the application, embedded system may be programmable or non-programmable. Examples of embedded systems include various products such as washing machine, microwave ovens, cameras, printers and automobiles. They use microprocessors and microcontrollers as well as specially designed processors such as digital signal processors (DSP).
Embedded Systems Basics
The embedded systems basics include the components of embedded system hardware, embedded system types and several characteristics. An embedded system has three main components: Embedded system hardware, Embedded system software and Operating system.
Embedded System Hardware:
As with any electronic system, an embedded system requires a hardware platform on which it performs the operation. Embedded system hardware is built with a microprocessor or microcontroller. The embedded system hardware has elements like input output (I/O) interfaces, user interface, memory and the display. Usually, an embedded system consists of:
- Power Supply
- Serial communication ports
- Output/Output circuits
- System application specific circuits
Embedded System Software:
The embedded system software is written to perform a specific function. It is typically written in a high level format and then compiled down to provide code that can be lodged within a non-volatile memory within the hardware. An embedded system software is designed to keep in view of the three limits:
- Availability of system memory
- Availability of processor’s speed
- When the system runs continuously, there is a need to limit power dissipation for events like stop, run and wake up.
Real Time Operating System
A system is said to be real time, if it is essential to complete its work and deliver its service on time. Real time operating system manages the application software and affords a mechanism to let the processor run. The Real Time operating system is responsible for handling the hardware resources of a computer and host applications which run on the computer.
An RTOS is specially designed to run applications with very precise timing and a high amount of reliability. Especially, this can be important in measurement and industrial automation systems wherein downtime is costly or a program delay could cause a safety hazard.
In an embedded system, there are different types of memories. The various forms of memories are presented in the below chart.
Different processors used in embedded systems are microprocessor, (DSP) Digital Signal Processor, microcontroller, RISC processor, ASIP processor, Arm processor and ASSP processor.
Embedding a Microprocessor
Microprocessor is a general purpose processor, which can be embedded on a VLSI chip. The different streams of microprocessors used in embedded systems are given in the table.
Embedding a Microcontroller:
The different streams of Microcontrollers used in embedded systems are usually among the five streams of families given in the table.
Embedding a DSP:
A digital signal processor is a processor and, it is an essential unit of an embedded system. The DSP applications, are audio, video, multimedia, image processing, DSP modem, HDTV and telecommunication processing systems. These processors are also used in systems for recognizing DNA sequence and image pattern. The different streams of DSPs used in embedded systems are given in the table.
Classification of Embedded Systems:
Embedded systems are classified into three:
- Small Scale Embedded Systems
- Medium Scale Embedded Systems
- Sophisticated Embedded Systems
Small Scale Embedded Systems
Small scale embedded systems are designed with a single 8 or 16-bit microcontroller which may even be operated with a battery. For developing embedded software for these types of systems, an editor, assembler, (IDE) integrated development environment, and cross assembler are the main programming tools.
Medium Scale Embedded Systems:
Medium scale embedded systems are designed with a single or few 16 or 32 bit microcontrollers, DSPs or RISCs. These systems have both hardware and software complexities. When developing embedded software for these types of systems, the following programming tools are available.
They are C, C++, Visual C++, Java, and RTOS, source code engineering tool, debugger, simulator and integrated development environment.
Sophisticated Embedded Systems
Sophisticated embedded systems have huge hardware and software complexities and may need PLAs, IPs, ASIPs, scalable processors or configurable processors. They are used for cutting-edge applications that need hardware and software co-design & components which have to combine in the final system.
Embedded Systems Applications:
Embedded systems have different applications. A few select applications of embedded systems are smart cards, telecommunications, satellites, missiles, digital consumer electronics, computer networking, etc.
- Motor Control System
- Cruise Control System
- Engine or Body Safety
- Robotics in Assembly Line
- Car Entertainment
- Car multimedia
- Mobile and E-Com Access
Embedded systems in Telecommunications
- Mobile computing
- Wireless Communications
Embedded Systems in Smart Cards
- Security Systems
Embedded Systems in Missiles and Satellites
Embedded Systems in Computer Networking & Peripherals
- Networking Systems
- Image Processing
- Networks Cards
- Monitors and Displays
Embedded Systems in Digital Consumer Electronics
- Set top Boxes
- High Definition TVs
- Digital Cameras
This is about embedded systems basics with its applications. We all know that embedded systems are incredibly fabulous systems that play an essential role in many devices, industrial instrumentation, equipments and appliances irrespective of circuit complexity. Considering the huge significance of embedded systems, this embedded systems article deserves readers’ feedback, queries, suggestions and comments. Therefore, readers can post their comments below.