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ENGG 1015 Tutorial

Introduction to Electrical and Electronic Engineering – 2012 Fall Semester

Time and Venue Class: 1430-1520 P4, every other Monday

Tutor Leon LEI (me): CB 806 Contact me and TAs via Piazza

Tutorial materials http://www.eee.hku.hk/~culei/ENGG1015.html

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ENGG 1015 Tutorial

Each class: 40 min. tutorial + 10 min. Q/A Tutorial materials

Regular tutorials Revision tutorial before examination (Tentatively) Question banks

Homework 2011, 2010 (may be obsolete) Past paper 2011, 2010 (may be obsolete)

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ENGG 1015 Tutorial

Lecture/Lab materials, announcements Course site http://www.eee.hku.hk/~engg1015/fa12/index.html

Moodle HKU Computer Center http://www.its.hku.hk/lms/moodle/v2/support_student.php,

eLearningTeam@hku.hk, 2859 2480 Prompt learning materials help, peer learning Piazza

https://piazza.com/class#fall2012/engg1015 Admin help Piazza (Private post) Extra lab check-off session TA office hour (CB LG205)

Tue 1530, Tue 1630, Fri 1430, Fri 1530 Textbook No textbook

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ENGG 1015 Tutorial

Systems and Digital Circuits (I) 24 Sept Learning Objectives

Identify concepts of systems Converts between three representations of digital

logic News

Start to have laboratory sessions this week (Suggest to bring your laptop)

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Question 1: Top-down vs Bottom-up

Item Top-down Bottom-up

Driven by system requirement

Driven by component integration

Construct system by composing smaller parts

Construct system by decomposing

Generate new ideas from system requirements

Synthesize new ideas from existing components

Must work with unknown system components as black-boxes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

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Question 2: Procedures in top-down and bottom-up Making a dinner (Top-down)

Decide the types of dishes according to the location, number of people, time and purpose of dinner

Design dishes according to the types of dishes, diet requirements, kitchen equipment

Find out required ingredients andsauces for each decided dishes

Get all things ready(e.g. buy and clean ingredients, prepare sauces)

Cook every dishes Bring dishes to the table

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Question 2: Procedures in top-down and bottom-up Making a dinner (Bottom-up)

Find out the ingredients available Clean and cut the ingredients according to your own skill and

available kitchen equipment Mix and match available ingredients as different dishes to meet

the dinner requirements, such as dietary requirements, location, number of people, time and purpose of dinner, etc.

Cook every dishes by the given kitchen equipment Bring dishes to the table

Making a Rube Goldberg Machine?

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Question 2: Procedures in top-down and bottom-up Making a Rube Goldberg Machine (Top-down)

Decide the types of stages according to the location, number of stages, and interface of each stage

Design stages according to the types of stages, input and output requirements

Find out the required components for each stage Get all things ready (e.g. acquire from the TA and technician) Prepare and assemble each stage Combine each stage together Fine-tune the connection between stages

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Question 2: Procedures in top-down and bottom-up Making a Rube Goldberg Machine (Bottom-up)

Find out the components available Mix and match available components as different stages to meet

the project requirements such as types of stages according to the location, number of stages, and interface of each stage etc.

Prepare and assemble each stage by the given equipment Combine each stage together Fine-tune the connection between stages

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Quick quiz 1

What is the only set of input conditions that will produce a LOW output for any OR gate?• Any one of the input is LOW• Any one of the input is HIGH• All inputs are LOW• All inputs are HIGH

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Quick quiz 2

What is the only input combination that will produce a HIGH at the output of a five-input AND gate?• Any one of the input is LOW• Any one of the input is HIGH• All inputs are LOW• All inputs are HIGH

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Quick quiz 3

What logic level should be applied to the second input of a two-input AND gate if the logic signal at the first input is to be inhibited (prevented) from reaching the output?• A LOW input will keep the output LOW• A LOW input will keep the output HIGH• A HIGH input will keep the output LOW• A HIGH input will keep the output HIGH

Digital Logic - ENGG1015 - K. Wong

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Representing logic operations Each function can be represented

equivalently in 3 ways: Truth table Boolean logic expression Schematics

1st semester, 2011

Truth Table

Boolean ExpressionSchematics

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Conversion of three representations Truth table

Try every 0/1 combinations of every input variables

Boolean expression Simplification (Next tutorial)

Logic circuit From Boolean expression Using AND/OR/NOT gates Alternative: Bottom-up approach

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Bottom-up: Construct NOT gate, AND gate and OR gate from NAND gate

Conversion between NOT, AND, OR, NAND

1 0 1 0i)

ii)

iii)

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Question 3: From logic equations For the expression , construct the

corresponding logic circuit, using only AND, OR gates and INVERTERs (NOT gate).

x AB C D

AB C D A DCAB CD B

Draw the circuit diagram to implement the expression

Draw the circuit diagram that implements the expression

using gates having no more than three inputs.

)( DABCAx

X (A B)(B C)

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Question 3: From logic equations Boolean expressions Truth table and logic circuit (AND/OR/NOT)

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Question 3: From logic equations Boolean expressions Truth table and logic circuit (AND/OR/NOT)

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Question 4: From truth tables

Derive the Boolean expression of the output x in terms of the input

Construct the logic circuit using AND gates, OR gates, and INVERTERs.

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Solution 4

x ABC ABC ABC ABC

ABC ABC ABC ABC ABC ABC

AC B B AB C C BC A A

AC AB BC

1. Construct A/B/C2. Construct not A/B/C3. Construct AND gates4. Construct OR gate

1 2 3 4

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Question 4: From truth tables Truth table Boolean expressions and logic

circuit

Determining output level from a diagram

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Question 5: From logic circuits

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Question 5: From logic circuits

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Quick quiz 4 What is the output expression of the following logic-

circuit diagram?

• • • • x D A B C E

x D A B C E

x D A BC E

x D A B C E

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Quick checking

True or false An AND gate output will always differ from an OR gate

output for the same input conditions.

Lecture: http://www.eee.hku.hk/~engg1015/ Tutorial: http://www.eee.hku.hk/~culei/ENGG1015.html

False