Embedded Systems
Computers hidden inside other devices. Discover how single-function firmware controls the mechanical world around us.
Concept Explorer: Inside the Microwave
Hover over the different parts of the microwave to distinguish between the physical/mechanical parts, and the actual Embedded System that controls them.
Understanding Embedded Systems
The Definition
An embedded system is a computer system that is built into another device in order to control it. It is entirely dedicated to a single task (or very limited set of tasks).
Dedicated Purpose
Firmware (Software)
Because they do one job, the software they run is usually custom-written and stored permanently in non-volatile memory (like ROM). This permanent software is called Firmware.
Key Characteristics
Low Power
Consumption
Rugged / Operates
in harsh conditions
Low Cost per Unit
Minimal UI
(Buttons/Dials)
Check Your Understanding
Examiner's Eye Trap
1. Is a Laptop an embedded system?
2. The software running on an embedded system is usually permanently stored in non-volatile memory (like ROM). What is this software called?
Written Exam Scenario (AO2/AO3)
"A modern automotive Anti-Lock Braking System (ABS) is controlled by an embedded system. Justify why an embedded system is used here rather than a general-purpose processor." (4 marks)
Dedicated execution: The ABS is dedicated entirely to a single, critical task (stopping wheel lock) and requires instant execution without distraction.
Immutable software: Its software is securely fixed in non-volatile ROM/firmware, meaning it boots instantly the moment the car turns on.
Reliability: It cannot easily crash due to unexpected background apps or user OS updates which are typical of general-purpose computers, ensuring maximum safety.