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Essentials of Electrical and Computer Engineering

David V. Kerns, Jr., J. David Irwin

Chapter 13

Digital Logic Circuits - all with Video Answers

Educators


Chapter Questions

01:46

Problem 1

If $A=0111, B=1010, C=0101$, and $D=1011$, find
(a) $A+B$
(b) $C+D$

Manik Pulyani
Manik Pulyani
Numerade Educator
01:33

Problem 2

Given the data in problem 13.1 , find
(a) $A+C$
(b) $B+D$

Dharmendra Jain
Dharmendra Jain
Numerade Educator
01:23

Problem 3

Using the data in problem 13.1 , find
(a) $B+C$
(b) $A+D$

Tyler Moulton
Tyler Moulton
Numerade Educator
03:15

Problem 4

If $A=111, B=011, C=110$, and $D=010$, find
(a) $A \times D$
(b) $C \times D$

Lauren Shelton
Lauren Shelton
Numerade Educator
02:02

Problem 5

Given the data in problem 13.4 , find
(a) $B \times D$
(b) $B \times C$

Gopesh Vishwakarma
Gopesh Vishwakarma
Numerade Educator
View

Problem 6

Using the data in problem 13.4, determine
(a) $A \times C$
(b) $A \times B$

Adriano Chikande
Adriano Chikande
Numerade Educator
04:02

Problem 7

Given the data in problem 13.1 , find
(a) $A \times B$
(b) $C \times D$

Supratim Pal
Supratim Pal
Numerade Educator

Problem 8

Using the data in problem 13.1, compute
(a) $A \times C$
(b) $B \times D$

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03:55

Problem 9

Using the data in problem 13.1 , find
(a) $B \times C$
(b) $A \times D$

Gopesh Vishwakarma
Gopesh Vishwakarma
Numerade Educator
02:55

Problem 10

Convert the following numbers in base 2 to base 10 :
(a) 1100
(b) 10101
(c) 1010
(d) 11111111

Manisha Sarker
Manisha Sarker
Numerade Educator

Problem 11

Convert the following numbers in binary to decimal:
(a) 1111
(b) 10010
(c) 100001
(d) 101011

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02:55

Problem 12

Convert the following numbers from base 2 to base 10:
(a) 101010
(b) 110111
(c) 11101
(d) 1110001111

Manisha Sarker
Manisha Sarker
Numerade Educator
02:36

Problem 13

Convert the following numbers in binary to decimal:
(a) 1100011
(b) 110110111
(c) 10000001
(d) 11111000000

PK
Plamen Kamenov
Numerade Educator
04:56

Problem 14

Convert the following numbers from decimal to binary:
(a) 7
(b) 13
(c) 15
(d) 27

Sanchit Jain
Sanchit Jain
Numerade Educator
04:56

Problem 15

Convert the following numbers from base 10 to base 2 :
(a) 19
(b) 25
(c) 33
(d) 72

Sanchit Jain
Sanchit Jain
Numerade Educator
04:56

Problem 16

Convert the following numbers from decimal to binary:
(a) 48
(b) 57
(c) 99
(d) 100

Sanchit Jain
Sanchit Jain
Numerade Educator
02:55

Problem 17

Convert the following numbers from base 10 to base 2 :
(a) 101
(b) 172
(c) 210
(d) 255

Manisha Sarker
Manisha Sarker
Numerade Educator

Problem 18

Use the Boolean postulates and theorems to simplify the following expressions:
(a) $\mathrm{f}(A, B, C)=\bar{A} \bar{B}+\bar{B} C+A \bar{B}$
(b) $\mathrm{f}(A, B, C)=\bar{A} B \bar{C}+A B D+\bar{A} B C$

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01:39

Problem 19

Compute the truth table for the following functions:
(a) $\mathrm{f}(A, B, C)=B \bar{C}+\bar{B} C$
(b) $\mathrm{f}(A, B, C)=\bar{B}+C$

Manik Pulyani
Manik Pulyani
Numerade Educator

Problem 20

Compute the truth table for the following functions:
(a) $\mathrm{f}(A, B, C)=\bar{A} \bar{B}+C$
(b) $\mathrm{f}(A, B, C)=\bar{A} \bar{B}+\bar{B} C+A \bar{B}$

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Problem 21

Use a Venn diagram, show that $\mathrm{f}(A, B, C)=$ $\Sigma m(1,2,5,6)=B \bar{C}+\bar{B} C$

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Problem 22

Using a Venn diagram, show that $\mathrm{f}(A, B$, $C)=\Sigma m(0,1,3,4,5,7)=C+\bar{B}$

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Problem 23

Use a Venn diagram to demonstrate that $\mathrm{f}(A$, $B, C)=B C+\bar{A} \bar{B}+A \bar{B} C=C+\bar{A} B$

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Problem 24

Find the minimum form for the Boolean functions
(a) $\mathrm{f}(A, B, C)=\Sigma m(0,1,3,4,5,7)$
(b) $\mathrm{f}(A, B, C)=\Sigma m(1,2,5,6)$

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Problem 25

Find the minimum form for the Boolean functions
(a) $\mathrm{f}(A, B, C)=\Sigma m(1,2,5,7)$
(b) $\mathrm{f}(A, B, C)=\Sigma m(0,1,3,6,7)$

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Problem 26

Expand the following function into a set of minterms and then use the K-map to find a minimum SOP form.
$$
\mathrm{f}(A, B, C)=\bar{A} \bar{B}+\bar{B} C+A \bar{B}
$$

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Problem 27

Expand the following function into a set of minterms and then use the K-map to find the minimum SOP realization.
$$
\mathrm{f}(A, B, C)=B C+\bar{A} \bar{B}+A \bar{B} C
$$

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Problem 28

Expand the following function into a set of minterms and then use the K-map to find the minimum SOP realization.
$$
\mathrm{f}(A, B, C, D)=\bar{A} B \bar{C}+A B D+\bar{A} B C
$$

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Problem 29

Expand the following function into a set of minterms and then use the K-map to find the minimum SOP realization.
$$
\mathrm{f}(A, B, C, D)=\bar{A} \bar{B} D+\bar{A} B \bar{C} D+A B \bar{C}+A \bar{B} D
$$

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Problem 30

Expand the following function into a set of minterms and then use the K-map to find the minimum SOP realization.
$$
\begin{aligned}
& \mathrm{f}(A, B, C, D)=\bar{B} \bar{C} D+ \\
& \bar{A} B \bar{C} D+A \bar{C} D+\bar{B} C D+B C D
\end{aligned}
$$

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Problem 31

Find a minimum SOP form for the switching functions
(a) $\mathrm{f}(A, B, C, D)=\Sigma m(1,4,7,9,12,15)$
(b) $\mathrm{f}(A, B, C, D)=\Sigma m(4,6,7,12,14,15)$

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Problem 32

Find the minimum SOP form for the switching functions
(a) $\mathrm{f}(A, B, C, D)=\Sigma m(2,3,11,13,14,15)$
(b) $\mathrm{f}(A, B, C, D)=\Sigma m(0,2,3,7,9,13)$

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Problem 33

Find the minimum SOP form for the switching functions
(a) $\mathrm{f}(A, B, C, D)=\Sigma m(0,2,4,10,12,14)$
(b) $\mathrm{f}(A, B, C, D)=\Sigma m(3,4,6,7,11,12,13,15)$

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Problem 34

Find the minimum SOP form for the switching functions
(a) $\mathrm{f}(A, B, C, D)=\Sigma m(1,4,5,7,9,15)$
(b) $\mathrm{f}(A, B, C, D)=\Sigma m(0,2,5,7,8,10,13,15)$

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01:51

Problem 35

Design a logic circuit with a $B C D$ input that detects all numbers that are greater than or equal to 7.

Nick Johnson
Nick Johnson
Numerade Educator
01:51

Problem 36

Design a logic circuit with a $B C D$ input that detects the decimal numbers 3,4 , and 5 .

Nick Johnson
Nick Johnson
Numerade Educator

Problem 37

In the network in Figure P13.37, circuit $A$ inputs certain bit patterns to circuit $B$. A bit pattern containing exactly two 1's is an error and should trigger the alarm circuit. Design an alarm circuit that produces a 1 if exactly two 1's appear in the input bit pattern to circuit B.
Figure P13.37 can't copy

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Problem 38

A half adder circuit has two input bits, $a_i$ and $b_i$. The output is a sum bit, $s_i$, and a carry bit, $c_{i+1}$. Derive the logic equations for the sum and carry bits that are necessary for designing a half adder circuit.

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Problem 39

The 4221 code is a weighted code in which the four bit positions are assigned the weights (4221). The code is listed below.
$$
\begin{array}{ll}
0-0000 & 5-0111 \\
1-0001 & 6-1100 \\
2-0010 & 7-1101 \\
3-0011 & 8-1110 \\
4-1000 & 9-1111
\end{array}
$$

Design a BCD to 4221 code converter.

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02:00

Problem 40

Design a logic circuit with three inputs $A, B$, and $C$, such that the output will be high when at least two of the inputs are high.

Manik Pulyani
Manik Pulyani
Numerade Educator
02:08

Problem 41

Design a logic circuit with four inputs $A, B, C$, and $D$, such that the output will be high only when an even number of the inputs, greater than zero, are high.

Manik Pulyani
Manik Pulyani
Numerade Educator
02:40

Problem 42

A logic circuit has four input lines, $A, B, C$, and $D ; A$ represents the MSB and $D$ represents the LSB. Design a logic circuit in such a way that the output is high if the input signal is outside the midrange of the input numbers, that is, in the range $(0)_{10}$ to $(3)_{10}$ or $(12)_{10}$ to $(15)_{10}$.

Nick Johnson
Nick Johnson
Numerade Educator

Problem 43

Three sensors are strategically placed along a production line. The sensor outputs are low if all measurements are in the normal range. Measurements outside the normal range produce a high output. The sensors are used to trigger an alarm if any two of the measurements are simultaneously high. Design a logic circuit that will produce a high signal for the alarm.

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Problem 44

A tank of fluid employed in a chemical process is being monitored with three sensors. The sensors measure temperature, pressure, and fluid level. If all the sensor measurements are in the normal range, the sensor outputs are low. If the measurements are outside the normal range, the sensor outputs are high. Design a logic circuit that will produce a high signal for an alarm under the following conditions:
$\bullet$ pressure and temperature are too high
$\bullet$ fluid level is too high and either pressure or temperature or both are too high

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Problem 45

An industrial plant has two reservoirs that are used to temporarily store fluid $A$ and fluid $B$. Each reservoir is equipped with two sensors: one detects the incoming flow rate and the other detects the fluid level. Assume the flow rate sensor outputs are low when the flow rate is satisfactory and high when the flow rate is too high. In addition, assume the fluid level sensor outputs are low when the fluid level is satisfactory and high when the level is too high. Design a detector circuit that will produce a high output whenever the fluid level in either or both reservoirs is too high and the flow rate for either of both reservoirs is too high.

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01:53

Problem 46

A circuit that displays voting results is required. There are three voters who can vote yea or nay. The circuit output should be high if the majority of the votes are yea. Produce the smallest possible circuit.

WZ
Wen Zheng
Numerade Educator

Problem 47

A circuit is needed that identifies prime numbers between 0 and 9 . The input to the circuit is in BCD format. The output is low if the input is prime. Draw the minimum possible circuit.

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01:39

Problem 48

Unfortunately, Alice, Bob, and Carol own a .com company. They have decided to hire David, a shrewd business major, to guide them through these perilous business times. However, they must decide whether to offer David significant stock options or just compensation. Each person votes STOCKS or CASH. Draw a truth table for this voting scenario where votes and the resulting decision are encoded in ones and zeros. Create your own code scheme.

WM
William Mead
Numerade Educator

Problem 49

Compute the state table for the synchronous sequential circuit shown in Figure P13.49.
Figure P13.49 can't copy

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Problem 50

Compute the state table for the synchronous sequential circuit shown in Figure P13.50.
Figure P13.50 can't copy

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Problem 51

Determine the state table for the synchronous sequential circuit shown in Figure P13.51.
Figure P13.51 can't copy

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Problem 52

Determine the state table for the synchronous sequential circuit shown in Figure P13.52.
Figure P13.52 can't copy

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Problem 53

Compute the state table for the synchronous sequential circuit shown in Figure P13.53.
Figure P13.53 can't copy

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Problem 54

Compute the state table for the synchronous sequential circuit shown in Figure P13.54.
Figure P13.54 can't copy

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Problem 55

Find the logic equations for a $J-K$ flip-flop realization of the state table in Figure P13.55 using the state assignment $A=00, B=01$, $C=11$, and $D=10$.
Figure P13.55 can't copy

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Problem 56

Find the logic equations for a $J-K$ flip-flop realization of the state table in Figure P13.56 using the state assignment $A=00, B=01$, $C=11$, and $D=10$.
Figure P13.56 can't copy

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Problem 57

Determine the state diagram for a synchronous sequential circuit that has a single input and single output that will recognize the input string 0000 with overlap, that is, if
$$
\begin{aligned}
& x=0000010000 \\
& z=0001100001
\end{aligned}
$$

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Problem 58

Determine the state diagram for a synchronous sequential circuit that has a single input and single output that will recognize the input string 0110 with overlap, that is, if
$$
\begin{aligned}
& x=101101100 \\
& z=000010010
\end{aligned}
$$

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Problem 59

Determine the state diagram for the synchronous sequential circuit that has a single input and a single output that will recognize the input string 1001 with overlap, that is, if
$$
\begin{aligned}
& x=10100100100 \\
& z=00000100100
\end{aligned}
$$

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Problem 60

Determine the state diagram for the synchronous sequential circuit that has a single input and single output that will recognize the input string of exactly one 1 followed by two 0s.

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Problem 61

A PC's serial port transfers data in byte-size units. Typically, several additional bits are exchanged between transmitter and receiver to coordinate the transfer. This is called handshaking. A part of handshaking is a short bit sequence called the stop bits, which immediately follow the data byte. In a particular serial communication protocol the stop bits are the four-bit sequence 1111. This sequence does not occur elsewhere in the transmission. Using $\mathrm{J}-\mathrm{K}$ flip-flops, design a detection circuit that will recognize the stop bits sequence. The output, STOP, is high when the sequence is detected.

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Problem 62

Design a serial adder where inputs $A$ and B arrive least significant bit first. Call the output $\Sigma$. Draw the circuit using J-K flipflops.

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Problem 63

Design a serial subtractor where inputs $A$ and $B$ arrive least significant bit first. Call the output $\Delta$. Draw the circuit using $J-K$ flipflops.

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05:26

Problem 64

Design a serial comparator that compares two inputs $X$ and $Y$, which arrive LSB first. There are three outputs: L, G, and E. L is high if $\mathrm{X}<\mathrm{Y}, \mathrm{G}$ is high if $\mathrm{X}>\mathrm{Y}$, and $\mathrm{E}$ is high if $\mathrm{X}=\mathrm{Y}$.

WZ
Wen Zheng
Numerade Educator

Problem 65

Draw a state diagram for a serial circuit that performs the mathematical operation $\mathrm{Z}=2 \mathrm{X}-\mathrm{Y}$ where $\mathrm{X}$ and $\mathrm{Y}$ are serial inputs arriving least significant bit first and $\mathrm{Z}$ is the result exiting the circuit least significant bit first.

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