ENEL 353 Fall 2019 Lecture Section 02Lecture #1

Friday, September 6, 2019Steve Norman, PhD, PEng

Electrical & Computer EngineeringSchulich School of Engineering

Today’s Lecture

• Introduction to ENEL 353• Course policies

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ENEL 353: Course Instructors

• This lecture section, tutorial section T02, lab sections B03 and B04: Steve Norman …https://people.ucalgary.ca/~norman

• Course coordinator, lecture 01, tutorial T01, labs B01 and B02: Norm Bartley …https://people.ucalgary.ca/~nbartley

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When do tutorials and labs start?

• There are NO tutorials or labs this week or next.

• Tutorials start Tuesday, September 17.• Labs start the week of Monday, September 16.

Check the lab schedule on Norm Bartley’s ENEL 353 Home Page to find exact dates for your lab periods. Please read the schedule carefully!

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ENEL 353: Digital Circuits

• What does the word digital mean?• One way to explain it is to contrast analog

information with digital information.• Let’s use audio recording as an example.

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A microphone converts sound (variation in air pressure) to a time-varying electrical voltage …

Analog information

• The microphone output is an example of an analog signal: a physical quantity varying continuously as a function of time or space.

• In this example, the voltage varies as a function of time.

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Analog recording: Audio tape

• The microphone output, with suitable amplification, can be used to modify the magnetization of iron oxide molecules on the surface of an audio tape.

• The magnetization of the tape is an analogsignal. The magnetization varies spatially, as a function of distance from the start of the tape.

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Analog recording: Vinyl records

• We’re going to skip a lot of steps here … !!!• Starting with audio tape, complicated analog

electrical and mechanical equipment was used to create a metal stamper, which could be used over and over to press an analog groove into each of thousands of soft vinyl disks.

• Producing vinyl records used to be a purely analog process … that’s likely not true for current production of vinyl records.

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Playback of vinyl records

• A needle in a turntable follows the groove in a vinyl record as the record spins.

• Vibrations in the needle generate a voltage, which can be amplified to drive speakers to make variations in air pressure, which we hear as sound.

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Digital information

• A digital signal is nothing more than a sequence of numbers.

• How can a digital signal be created from an analog signal, such as a microphone output? An analog-to-digital converter circuit generates numbers corresponding to samplesof voltage levels in the analog input.

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A-to-D conversion of CD-quality audio samples the input 44,100 times per second …

Digital audio is just a list of numbers!

• The first 20 samples might be 14745, 13942, 11781, 8564, 4729, 778, -2798, -5597, -7352, -7970, -7534, -6273, -4513, -2619, -926, 314, 969, 1038, 636, -36.

• For audio playback, these numbers have to be fed into a digital-to-analog converter which will produce a high-quality approximation of the original analog voltage.

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Ones and Zeros

• Digital information is usually recorded using only two symbols: 1 and 0.

• 1 sometimes goes by other names, such as ON, TRUE, HIGH, or SET.

• Similarly, 0 has other names, such as OFF, FALSE, LOW, or CLEAR.

• Numbers are represented as sequences of 1’s and 0’s. For example 14745 might be recorded as 0011 1001 1001 1001 on a CD or disk drive.

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Digital systems are everywhere!

• Computers!• Audio! Still images! Video!• Wired and wireless voice and data networks!• Machines using 1’s and 0’s to communicate

with other machines: consumer products, transportation systems, industrial equipment, medical equipment, …

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ENEL 353: Course Content

• This course is about the very basics of working with 1’s and 0’s.

• It’s about description, analysis, and design of electronic circuits that have 1’s and 0’s as inputs, and more 1’s and 0’s as outputs.

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ENEL 353 Web pages:make sure you can find them!

• The MAIN page is managed by Norm Bartley:people.ucalgary.ca/~nbartley/Enel353/

• Steve Norman (your lecture instructor) also has a course page: people.ucalgary.ca/~norman/enel353fall2019/This page will be used mostly to post lecture slides and notes for this section—lecture section 02.

• The main page is EASY to find by typingenel 353 fall 2019into Google.

• The main page has a link to the section 02 page.• There will also be some important information within the

course D2L pages.

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Read the course outline!

• There’s a link to it on the main course web page.

• This document has important information, such as LEARNING OUTCOMES, GRADING POLICY, and TEXTBOOK INFORMATION.

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From the course outline:Grading Policy

Component Weight

Assignments 0%

Quizzes 15%

Lab Work 15%

Midterm Test 20%

Final Exam 50%

TOTAL 100%

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A mark of 35% or higher on the final exam is needed to pass the course as a whole.The course instructors reserve the right to reduce this threshold of 35% if it is judged after marking the final exam that the final exam was more difficult than intended.

From the course outline: Textbook

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We will follow this textbook very closely and you will need it for ENCM 369 in Winter 2019 2020! Buy it once, use it for two courses! (Bonus: It has some great background material for some third-year courses.)

The textbook is available online

• Go to library.ucalgary.ca• Click on “Research” and select “All Databases”• Find “O’Reilly Safari” and click on the link• Search for “Digital Design and Computer

Architecture”• (Note: Both ENCM 335 textbooks are also in

O’Reilly Safari, along with many other helpful books!)

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From the course outline:Assignments, Quizzes and Labs

• You will be given regular assignments of problems from the textbook. You won’t hand in solutions, but can check your work against posted solutions.

• Four of the tutorial periods will be used for quizzes.

• Each lab section will complete four lab sessions; check the main course Web page for details.

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Next Lecture

• Number systems: decimal, binary, octal, and hexadecimal.

• Related material in Harris & Harris (our course textbook): pages 1 to 19.

• You can find lecture slides posted on Steve Norman’s ENEL 353 Web page; printing a copy and bringing them to the lecture is highly recommended!

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