Embedded Systems

• An embedded system is a computer system with either one function or limited specific functions built within a larger mechanical device.
• The purpose of an embedded system is to control the device and allow a user to interact with it.
• An embedded system runs on firmware.
• An embedded system is different to a general purpose computer system like a laptop or desktop computer which can be used to perform many different tasks.
• The vast majority of microprocessors manufactured are for use as embedded systems.
• Some embedded systems are microcontrollers meaning they are part of an integrated circuit with built-in memory.
• Two types of embedded systems:

  1. Microcontrollers.
  2. Microprocessor.
• A microcontroller is an integrated circuit containing a CPU and memory (RAM or ROM) built in to the same chip.
• A microprocessor is an integrated circuit containing only a CPU on the chip. RAM and ROM peripherals need to be added.
• The microprocessor used in an embedded system is often custom designed.
• Firmware is software built into the system which cannot be reprogrammed by the user. The software may be able to be updated.
• Embedded systems usually have some form of analog or digital input.
• Diagram of an embedded system:

  A) Input via sensors/ keypad

  B) Microchip (Hardware)

  C) Built in software

  D) Memory (RAM/ ROM)

  E) Output via actuators/ sound/ visual display

  
• Examples of embedded systems:

  • Digital clock.
  • Traffic lights.
  • Lighting system.
  • Security system.
  • Vending machine.
  • Central heating system.
• Advantages of embedded systems:

  • Small physical size.
  • Low cost to the manufacturer.
  • They can be controlled remotely.
  • Can operate in real time and respond to inputs very quickly.