Microcontrollers vs. Microprocessors
Unit 7 Summary - part 2
Embedded system:
Microcontrollers are different from Microprocessors.
Microcontrollers are embedded systems.
Microprocessors are in PCs, laptops, smartphones.
Embedded systems / Microcontrollers:
are computers in devices, machines, and common household objects. They are part of a bigger system.
Example: remote controls, refrigerators, washing machines, air conditioners, microwave ovens, television, burglar alarms, routers, etc.
All components are joined together in a single chip, that's why it's small, cheap, and simple because it's made to only do one task.
Embedded systems / Microcontrollers are created to only do a task, that's why they have these characteristics:
- Little memory
- Low processor speed and power
- Small and light processor
- Low power consumption, can run from a small battery.
- limited controls and display (may have a small screen, or few buttons only, may not have user interface).
- Reliable processor (may operate for years).
Firmware:
is software in an embedded system, usually stored in ROM.
Advantages:
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Embedded systems such as refrigerators work non-stop all the time to make devices operate better, use less energy, safer.
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smaller, cheaper, lighter than microprocessors (PCs, laptops, smartphones).
Disadvantages:
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If a system breaks, you can't modify or upgrade it, the whole device needs to be replaced.
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Only able to do one task, embedded systems are not flexible/versatile than microprocessors (PCs, laptops, smartphones).
Oxford AQA IGCSE 2019
13.1.
What is an embedded system?
__________________________________________________________________________________
Alternative answers:
Computer system that is part of a larger/another (electrical/ mechanical) system;
13.2.
Describe two differences between an embedded system and a standard desktop computer. [2 marks]
Difference 1
__________________________________________________________________________________
Difference 2
__________________________________________________________________________________
Alternative answers:
Microcontrollers/Embedded system
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Embedded system has lower power/slower/fewer cores in processor
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Embedded system has less memory
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Embedded system has more ROM than RAM
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Embedded system may not have secondary storage
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Embedded system has fixed input and output devices
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Embedded system has single / limited purpose
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Embedded system has less modular design (of software/hardware)
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Embedded system software is firmware/stored in ROM
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Embedded system is part of a larger/another (electrical/ mechanical) system
Microprocessors
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desktop computer has higher power/faster/more cores in processor;
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desktop computer has more memory;
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desktop computer has more RAM than ROM;
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desktop computer (usually) has secondary storage;
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desktop computer can have new input/output devices added;
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desktop computer is general purpose;
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desktop computer has modular design;
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desktop computer software is changeable/largely executed from RAM;
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desktop computer is an independent device
Oxford AQA IGCSE 2020
08.1.
Explain what an embedded system is. [1 mark]
__________________________________________________________________________________
Answer:
computer (system) that is part of a bigger system//controls a device;
08.2.
State two differences between an embedded system and a non-embedded system such as a desktop computer. [2 marks]
Difference 1
__________________________________________________________________________________
Difference 2
__________________________________________________________________________________
Answer:
08.3.
The software that is used to control an embedded system is often written using assembly language. Explain why this is the case. [1 mark]
__________________________________________________________________________________
Alternative answers:
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Needs to directly control hardware
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assembly language provides direct control of hardware.
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Needs to run on system with slow processor/minimal RAM.
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Assembly language produces code that is efficient/will run quickly/has minimal memory usage.
