Chapter 1

Question 1

is the basis of computers, and computers are intrinsically
at the heart of digital systems

Answer 1

Digital Logic

Question 2

are used in scientific calculations, commercial and business data
processing, air traffic control, space guidance and many other areas.

Answer 2

Computers

Question 2

Characteristic of a _____________ is its manipulation of discrete elements of information. Such discrete elements may be electric impulses, the decimal digits, an alphabet, arithmetic operations or any other set of meaningful symbols

Answer 2

digital system

Question 3

Discrete elements of information are represented in a digital system by physical quantities called __________. Electrical signals such as __________ and __________ are the most common.

Answer 3

signals, voltages, currents

Question 4

The signals in all electronic digital systems have only two discrete values and are said to be _________.

Answer 4

binary

Question 5

Most natural quantities and vary continuously. It can generally handle higher power than digital systems.

Answer 5

Analog systems

Question 6

It can process, store, and transmit data more efficiently but can only assign discrete values to each point.

Answer 6

Digital systems

Question 7

Digital circuits operate in the binary mode where each input and output voltage is either ___ or ___ . 1 and 0 designations represent the logical state which has a pre-defined voltage ranges.

Answer 7

1 or 0

Question 8

A typical CD player accepts digital data from the CD drive and converts it to an analog signal for ______________.

Answer 8

amplification

Question 9

Digital electronics uses circuits that have two states, which are represented by two different voltage levels called _____ and _____. The voltages represent numbers in the binary system.

Answer 9

HIGH and LOW

Question 10

In binary, a single number is called a ____ (for binary digit). A bit can have the value of either a 0 or a 1, depending on if the voltage is HIGH or LOW.

Answer 10

bit

Question 11

it is the change between the LOW and HIGH levels

Answer 11

Digital Waveforms

Question 12

A _________ going pulse is one that goes from a normally LOW logic level to a HIGH level and then back again

Answer 12

positive

Question 13

Series of pulses:

Answer 13

1) positive-going pulse
2) negative-going pulse

Question 14

are not ideal but are described by the rise time, fall time, amplitude, and other characteristics.

Answer 14

Pulses

Question 15

composed of pulses that repeats in a fixed interval called the period.

Answer 15

Periodic pulse waveforms

Question 16

The ___________ is the rate it repeats and is measured in hertz.

Answer 16

frequency

Question 17

is a basic timing signal that is an example of a periodic wave.

Answer 17

Clock

Question 18

In addition to frequency and period, repetitive pulse waveforms are described by the amplitude (A), pulse width (tW) and duty cycle. Duty cycle is the ratio of tW to T.

Answer 18

Pulse

Question 19

is the fraction of time that a system is in an “active” state. It is also the proportion of time during which a component, device, or system is operated.

Answer 19

Duty Cycle

Question 20

is used to show the relationship between two or more digital waveforms,

Answer 20

Timing diagram

Question 21

All logic circuit combinations are based on the three major types of logic gates. (3)

Answer 21

1) AND Gate
2) OR Gate
3) NOT Gate

Question 22

True only if all input conditions are true.

Answer 22

AND Gate

Question 23

True only if one or more input conditions are true.

Answer 23

OR Gate

Question 24

Indicate the opposite condition

Answer 24

NOT Gate

Question 25

And, or, and not elements can be combined to form various logic functions. A few examples are:

Answer 25

comparison function
Basic arithmetic functions
encoding function
decoding function

Question 26

(DIP)

Answer 26

Dual-In-Line Package

Question 27

(SOIC)

Answer 27

Small Outline IC

Question 28

• are an alternative to fixed function devices.
• The logic can be programmed for a specific purpose.
• In general, they cost less and use less board space that fixed function devices.

Answer 28

Programmable logic devices (PLDs)

Question 29

A PAL ( Programmable Array Logic) device is a form of ______ that uses a combination of a programmable AND array and a fixed OR array

Answer 29

PLD (Programmable Logic Device)