Chapter 4

Question 1

it is a representation of the state of voltage variables.

Answer 1

Logic level

Question 2

Logic “0” and logic “1” can be
represented by —————-

Answer 2

voltage levels

Question 3

In logic circuits, logic 1 is represented by ———————— which is the maximum voltage level to represent logic 1. Above this voltage level is considered as ——————————- level. On the other hand a voltage from ————————- represents logic “0”.

Answer 3

• 2 volts (min) to 5 volts
• invalid voltage or illegal logic
• zero(0V) to 0.8volts

Question 4

Voltage levels in between the maximum voltage allowed for logic 0 and the minimum voltage to represent logic 1 is Invalid, this is called the ————————

Answer 4

Invalid Voltage Range

Question 5

It is a means for describing how logic circuits output depends on the logic levels present at the circuits inputs.

Answer 5

Truth Table

Question 6

It also contains the list of possible combinations of the inputs and the corresponding output for that logic combination.

Answer 6

Truth Table

Question 7

A tool for the analysis and design of digital systems.

Answer 7

Boolean Algebra

Question 8

It is a relatively simple mathematical tool that allows us to describe the relationship between a logic circuits output(s) and its inputs as an algebraic equation (a Boolean expression).

Answer 8

Boolean Algebra

Question 9

Boolean algebra is an —————- that was developed by ———————–.

Answer 9

algebraic system, George Boole in 1854

Question 10

performs the Boolean NOT operation. When the input is Logic 0, the output becomes Logic 1; when the input is logic 1, the output becomes logic 0.

Answer 10

The Inverter (NOT Gate)

Question 11

The NOT operation (complement) is shown with an ———- on the variable you used (sometimes prime ‘ is used).

The Inverter (NOT Gate)

Answer 11

over-bar

Question 12

One application of this function is when you need to form the 1’s complement of a binary number.

Answer 12

The Inverter (NOT Gate)

Question 12

produces a Logic 1 output when all inputs are also Logic 1; otherwise, the output is Logic 0.

Answer 12

AND gate

Question 13

is usually shown with a dot (.) between the variables but it may be implied (no dot).

Answer 13

AND operation

Question 14

The AND operation is used in computer programming as a ——————–. If you want to retain certain bits of a binary number but reset the other bits to 0, you could set a mask with 1’s in the position of the retained bits.

Answer 14

selective mask

Question 15

produces a Logic 1 output if any input is logic 1; if all inputs are logic 0, the output is Logic 0.

Answer 15

OR gate

Question 16

shown with a plus sign (+) between the variables

Answer 16

OR gate

Question 17

The OR operation can be used in computerprogramming to set certain bits of a binary number to 1.

Answer 17

computer programming

Question 18

can have two or more inputs

Answer 18

NAND gate

Question 19

The output will be logic 0 only when all the inputs are logic 1. Conversely, the output will be logic 1 when any or all of the inputs are logic 0.

Answer 19

NAND gate

Question 20

performs two functions, AND and NOT.

Answer 20

NAND gate

Question 21

is shown with a dot between the variables and an overbar covering them.

Answer 21

NAND operation

Question 22

The NAND gate can replace the functions of all the basic gates, that’s why it is called a

Answer 22

“universal” gate.

Question 23

is an OR gate followed by an inverter.

Answer 23

NOR gate

Question 24

will have a logic 1 output only when all the inputs are logic 0.

Answer 24

NOR gate

Question 25

is shown with a plus sign (+) between the variables and an overbar covering them.

Answer 25

NOR operation

Question 26

is a modified OR gate that produces a logic 1 output when only one of the inputs is logic 1. You will often see the abbreviation X-OR used to identify this gate.

Answer 26

eXclusive OR (XOR) gate

Question 27

When both inputs are logic 1 or when both inputs are logic 0, the output is equal to logic 0.

Answer 27

eXclusive OR (XOR) gate

Question 28

is nothing more than an X-OR gate followed by an inverted gate at the output.

Answer 28

exclusive NOR (X-NOR) gate

Question 29

It produces logic 1 output when all inputs are either logic 1 or logic 0.

Answer 29

exclusive NOR (X-NOR) gate

Question 30

will produce logic 1 when both inputs are the same. One of the applications of this logic gate is for comparing the two binary signals.

Answer 30

XNOR gate

Question 31

Two major fixed function logic families are ---- and --------

Answer 31

1. TTL 2. CMOS

Question 32

TTL and CMOS. A third technology is ----------, which combines the first two.

Answer 32

BiCMOS

Question 33

2 Packaging for fixed function logic

Answer 33

1. DIP package 2. SOIC package