1

EX 1 DIGITAL ELECTRONICS G________

After completing the task and studying Units 1.1, 1.2, 1.3, and 1.4, you will be able to (tick all that apply):

� Use your official UPC e-mail address

� Use and manage an e-mail client like Thunderbird or Outlook

� Use a SFTP client like WinSCP to remotely access your network disk drive “L”

� Produce a concept map (or a mind map) to explain a topic on the subject

� Define a combinational system and its high level and binary level description

� Express positive integers in different number systems (binary, octal, decimal hexadecimal)

� Codify data elements or information (signal values) by binary variables (signals) using standard codes for

positive integers (binary, BCD, Gray) and characters (ASCII code)

� Codify signed integers (positive and negative) using the two’s-complement system

� Perform basic arithmetic operations (addition, subtraction, multiplication) of signed integers by means of the

2’s complement system

� Explain the concept of a top-down design of a digital circuit and its schematic entry and simulation by a

CAD/EDA tool (Computer Aided Design / Electronic Design Automation)

� List a set of simulation tools for digital electronics

� Simulate a digital circuit (inside a black box) using the virtual laboratory software Proteus-VSM1

� Produce a written solution for the exercise using the instructions from:

http://epsc.upc.edu/projectes/ed/unitats/unitat_1_1/Criteris_Correccio_Exercici.pdf

� Work cooperatively in a team of 3 members using the method described in:

http://epsc.upc.edu/projectes/ed/problemes/metode_resolucio_cooperativa_recomanat.pdf

Write down the most significant questions you have had while or after completing the task:

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-

-

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STATEMENT:

My signature below indicates that I have (1) made equitable contribution to EX 1 as a member of the group, (2) read

and fully agree with the contents (i.e., results, conclusions, analyses, simulations) of this document, and (3)

acknowledged by name anyone outside this group who assisted this learning team or any individual member in

completing this document.

Today’s date: __________________

Active members Roles: (reporter, simulator, etc.)

(1) ___________________________ _______________

(2) ___________________________ _______________

(3) ___________________________ _______________

Acknowledgement of individual(s) who assisted this group in completing this document:

(1) _______________________

(2) _______________________

Study time

(in hours)

Group work Sessions TGA,

TGB

Sessions

TGC

Individual Student 1

Student 2

Student 3

1 Proteus-VSM is the proprietary software in use for the whole course: http://www.labcenter.com for having effectively a “digital circuits’

laboratory in the classroom”

2

Introduction: activate your e-mail address, e-mail and SFTP clients 1. Basic communication tools using the same user/password required to access the Atenea intranet:

a) Follow instruction to activate your professional e-mail address2 from UPC (Correu K2pim (estudiantat)

https://upcnet.upc.edu/serveis/entorn-de-treball/correu-electronic/correu-upc-edu#faqs

b) Download and install an e-mail client like Thunderbird3 or Outlook in your desktop or portable computer.

Configure an account to access the UPC e-mail server and try to read and send e-mails using the client. In

the same way, you can redirect any other private e-mail address to this Thunderbird client, so you will

never miss an e-mail, private, professional or institutional.

https://upcnet.upc.edu/serveis/entorn-de-treball/correu-electronic/correu-upc-edu/correu-dn-vs-correu-

k2#clients

c) Download a SFTP client like WinSCP and ask for information4 about how to map your remote network

disk “L” in your PC.

Winscp.lnk

http://winscp.net/eng/docs/lang:ca

Introduction: install Proteus – ISIS and run circuit simulations in EPSC computers

2. Download from the ED web a digital circuit or any other sample design and try to run it in the EPSC-licensed

Proteus – ISIS (release 7.6 SP0). For example, try with this one, from the previous 07-08 Q2 course edition:

http://epsc.upc.edu/projectes/ed/ED/grups_classe/07-08-q2/1BM2/EX/EX4/est/g2_EX4.DSN

Fig. 1 Proteus ISIS design suite

2 http://schubert.upc.es/upc/epsc/ecsq-gi.nsf/Tots/3A041EA9408C3FB3C1256DB40035B5E4

3 http://www.mozilla-europe.org/ca/products/thunderbird/

4 http://schubert.upc.es/upc/epsc/ecsq-gi.nsf/Tots/DF9EDCD4D7F58205C1256DB40034FFE0

3

How do computers represent and operate numbers?

3. Determine

5 the decimal equivalent of the following binary numbers:

a) A(7.. 0) = 11110101

b) B(14..0) = 110101010100101

c) C(24..0) = 0110101111101111000001001

4. Convert to the hexadecimal number system (radix-16) the following numbers expressed in radix-2, radix-8 and

radix-10 respectively:

a) (10011110010111011)2

b) (65776315201)8

c) (9876543210)10; (39758) 10

5. A PC has the following memory map expressed in hexadecimal number system in order to make it easier to read.

Rewrite in decimal some of the hexadecimal numbers in the memory and I/O maps in Fig. 2. Calculate the

memory range or addressing capacity for this PC. Calculate the I/O addressing capacity of the PC.

Fig. 2 A computer memory and I/O map

6. Fig. 3 shows a high-level block diagram of a 12-bits adder/subtractor. Determine the range of the operands (A, B)

and the results (C) which can be correctly processed by the circuit of Fig. 3 (so that you could enhance later the

circuit introducing an additional overflow output). Applying this circuit up to 6 times, perform the following

operations (binary additions and subtractions) with signed integers of 12-bits (11 bits for the magnitude plus 1

bit for the sign) using two’s-complement system.

5 You must follow the proceeding depicted in: http://epsc.upc.edu/projectes/ed/grups_classe/03-04-

q2/1bt6/Exemple%20de%20solucio%201a.pdf

4

Fig. 3 Block diagram of a basic calculator for performing addition and subtraction of 12-bit integers.

What you have to do here in order to reach the solution for every operation, is determine the value of

all the binary vectors A, B, D, E, F, and C, that is, all the blocks’ inputs and outputs

7. Search the ED web pages to find the Proteus-VSM design project shown in Fig. 4. This block represents precisely

the design entry for the adder/subtractor of 12-bits. Simulate the circuit to check your previous results. Write

down the circuit output for all the operations from a) to f). Which is the meaning and functionality of outputs Z

and D? Why a calculator has to have a D output?

Fig. 4 A combinational circuit for adding/subtracting two’s-complemented 12-bit integers

D[11..0]

F[11..0]

E[11..0]

Sb

Sa

CS2

TWO'S-COMPLEMENT ENCODER

S

X[10..0] Y[11..0]

B[11]

B[10..0]

CS1

TWO'S-COMPLEMENT ENCODER

S

X[10..0] Y[11..0]

A[11]

A[10..0]

CS3

COMBINATIONAL SYSTEM

OP

X[11..0] Y[11..0]

OP

SUM12

12-BIT BINARY ADDER

B[11..0]

A[11..0]

S[11..0]

C0

C12

C[11..0]

{ADDITION, OP = 0; SUBTRACTION, OP = 1}

12-BIT ADDER/SUBTRACTOR

A[11..0]

B[11..0]

binary numberstw o's-complemented signed operands

A[11..0]

B[11..0]

A0

A1

A2

A3

A4

A5

A6

A7

B0

B7

B1

B2

B3

B4

B5

B6

A8

A11

A9

A10

B10

B8

B9

B11

S9

SUMADOR-RESTADOR DE12 BITS

11001000

OP

A[11..0]

10001000

B[11..0]

0

R-S_L 00

00100

0

S0S1S2S3S4S5S6S7

D

0Z

(+17) + (+19) = +36

0000

0000

1

0000

S8S9

S10S11

a) (+103) + (+987)

b) (-736) – (-2026)

c) (+2026) + (-213)

d) (+2010) + (+77)

e) (-2026) – (+213)

f) (-2032) + (+512)

5

8. Fig. 5 shows a high-level block diagram of a multiplier6 of positive integers. Determine the range of the operands

(A, B) and the results (C) which can be correctly processed by the circuit. Find and simulate it in the ED web

performing several operations to demonstrate whether it operates correctly.

a) 12 x 11

b) 31 x 31

c) 22 x 0

d) 19 x 1

e) 22 x 13

Fig. 5 A positive integer multiplier block and some operations to be performed

9. Convert to BCD the following numbers represented in different radix number systems and add them.

a) (748)10 + (101011110110011001)2

b) (2765)8 + (100011011100)2 ; (CFD7)16 + (4673)8

c) Represent the functional block or entity and its internal architecture, of the combinational system (a drawing

very similar to the one represented in Fig. 4 that will have the capacity to perform all the specified

operations in BCD).

10. How many bits is the minimum needed to represent a temperature range from -210 °C to +1350 °C in binary if:

a) the temperature information will be encoded in 2’s complement; and b) in BCD code. Draw the black boxes

that will represent the thermometer if the thermocouple sensor (type K7) has 2 wires, a 5 V battery is used and

we intent to display the temperature measurement using 7-segment displays.

And here is the theory… producing a concept map to explain something to your team …

11. Search the EPSC library or the Internet to find information in order to produce a concept map of a maximum

length of two sheets, to explain to your team mates one of the following subjects:

a) Algorithms to convert Gray to binary and vice versa (up to 8-bit vectors)

b) Deduce, or search in the library or Internet, an algorithm for performing multiplications with signed integers

using blocks like the one in Fig. 5 and others. Thus, in the same way that a subtractor was implemented using

adders and others blocs like a 2’s complement, try to build this new multiplier for signed integers using the

circuit in Fig. 5 in its core.

c) Universal Product Code (UPC) barcodes and Article Numbering System (EAN).

6 Developed by: Andreu Martínez AND Juan P. Vicente, course 06-07 (Q2) in their application project. Accessible in

http://epsc.upc.edu/projectes/ed/ED/projectes_aplicacio/Projectes_aplicacio_ED.htm 7 http://www.omega.com/temperature/Z/pdf/z204-206.pdf

0. P90. P81. P70. P60. P50. P41. P30. P21. P10. P0

1A21A11A0

0B40B3

0A31A4

1B21B10B0

5X5_BIT_MULT

5X5_BIT

A4

A3

A1

A0

B4

B3

B2

B0

M9

M8

M7

M6

M5

M4

M3

M2

M1

M0B1

A2

6

IMPORTANT:

After this exercise, each member of the cooperative group has to be able to a) install the software Proteus-VSM; b)

open the design file to be simulated; c) examine the internal architecture of the calculator in Fig. 4; d) and simulate the

circuit functionality applying several inputs and checking the outputs.

Check with your peers and with the teacher any kind of doubt related to this very important point, and assure yourself

you understand the key points because circuit simulation using PC’s will be a must for the whole course.

Some general notes

• Exercises and control are written in English with the aim to teach contents through English8. Yu have to

know English to become an ICT engineer. Ask me any question about this matter because I am going to help

you as much as possible. Probably most of you will end your telecommunication bachelor studying in any

European university. So take this language issue very seriously, and take this course as another tool offered

to you to improve your English skills.

• All exercises have proposal and due dates. Find this information in the course agenda. Up to 8 exercises

which will are going to be downloaded from the web pages, are programmed for the semester. Exercises 4

and 8 include instruction to develop the application project.

• Delivering your exercise after the due date does not add marks!!

• All the exercises can be voluntarily improved by all the team or simple by any individual student who wants

to, during the week that follows the deadline. Delivering improved exercises means achieving higher marks.

And for sure, if you are getting higher marks is simply because you are learning better the course content.

• It’s mandatory to solve your exercises in teamwork following the “systematic approach for solving problems

in cooperative groups” described in the ED web page.

• In every exercise you will be required to annotate the total study time (first page) and the working plan used

to carry out the task (last page).

8 http://ec.europa.eu/education/languages/language-teaching/doc236_en.htm

REMEMBER that all the course exercises, even the

easy ones, have to be solved applying the

proceedings established in the following

document: CRITERIS DE QUALITAT PER

REALITZAR I CORREGIR EXERCICIS I CONTROLS

7

DIGITAL ELECTRONICS G________

Working plan9 for solving the exercise EX 1

Explain succinctly how the cooperative group has carried out the exercise: i.e., which was your working plan; in

which way did you divide the task fairly so that more or less all of you were doing a similar amount of work; how did

you learn each other’s materials; what was worked out in class time (sessions A and B) and what was resolved in

sessions C; and so on... write down also your impressions or opinions on the subject and how your group work is

going10

...

--------------------------------- -------------------------------------- ---------------------------------------

Active members’ signatures

9 This document, filled before delivering the exercise, will be included in the group learning portfolio

10 Check similar documents in http://epsc.upc.edu/projectes/ed/ED/unitats/ED_05-06_Q1_Autoavaluacio_Grup_Base.pdf, and

http://epsc.upc.edu/projectes/ed/ED/unitats/que_va_malament_al_grup.pdf