This document is a compilation of my notes for COE 718: Embedded Systems Design at TMU. All information comes from my professor’s lectures, as well as the course textbook Fundamentals of Embedded Software with the ARM Cortex M3, 2nd Edition, by Daniel W. Lewis.

Adam Szava - 2tor.ca

F2023

COE718 (Embedded Systems Design): Midterm Review Slides Flashcards

• Table of Contents

Lecture 0

Embedded Systems Definition

<aside> 💡 Definition (Embedded System)

An embedded system is any device that includes a programmable computer but is not itself a general-purpose computer.

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Embedded systems are typically also real-time systems meaning they must respond to external stimuli within a finite and specified period. The correctness not only depends on the logical result but also the time it was delivered in.

Embedded systems lack all the bells and whistles of full general-purpose computers which makes them smaller, cheaper, and easier to be purpose built.

Embedded systems importantly also exist in relation to all the other peripheral devices it is connected to.

Below is a sketch of a general embedded system:

A computer is used in embedded systems to simplify the system design and to provide flexibility in the device. Of all computers manufactured, ~99% are embedded within another system. Of those embedded computers, ~99% use ARM CPUs (this course studies the ARM M3 and M4 CPUs).

Real-Time Systems

Real time systems process events, which occur on external inputs causing other events to occur as outputs from the embedded system. For a real-time system, minimizing the response time is usually a primary objective.

There are sub-categories of real time systems, described by the following graphic:

• Hard real-time — systems where it is absolutely imperative that the responses occur within the required deadline.
  • Real real-time — systems which are hard real-time and their response times are very short.
• Soft real-time — systems where deadlines are important, but which will still function if deadlines are occasionally missed.
  • Firm real-time — systems which are soft real-time but in which there is no benefit from late delivery of service (the delayed service is no longer desired, eg. temperature sensor that takes 10 mins)