Chapter 1

Question 1

digital def

Answer 1

uses discrete physical states (ie high and low)

Question 2

logic def

Answer 2

uses basic logic operations to interpret and process information

Question 3

design def

Answer 3

to plan, analyze and construct the system that will fulfill the working requirements

Question 4

analog

Answer 4

quantities measured continuously (wall clock)

Question 5

digital (as in not analog)

Answer 5

quantities measured discretely

Question 6

analog electronic system

Answer 6

accept and process continuous signals in the form of continuous voltage or current signals

Question 7

digital electronic system

Answer 7

accept and process discrete samples that represent the actual continuous signal using an analog to digital converter

Question 8

___ volts represents a logic 1 or logic high

Answer 8

+5

Question 9

___ volts represents a logic 0 or logic low

Answer 9

0

Question 10

advantages of digital system (6)

Answer 10

• storing and processing data is more efficient
• transmission of data is more efficient and reliable
• detecting and correcting error is easier
• data can be easily and precisely reproduced
• digital systems are easy to design and implement
• they require less space

Question 11

Radix of a number

Answer 11

the base, each digit has a weight that is a power of the radix

Question 12

a number system with radix r has how many allowed digits?

Answer 12

0, 1, … (r-1)

Question 13

most significant digit

Answer 13

leftmost digit, has highest weight

Question 14

least significant digit

Answer 14

rightmost digit, has lowest weight

Question 15

what is the largest value that can be expressed in n digits in terms of the radix

Answer 15

r^n - 1

Question 16

positional number system

Answer 16

each digit has a position that is associated with a fixed weight

Question 17

bit

Answer 17

one binary digit

Question 18

nibble

Answer 18

four bits

Question 19

byte

Answer 19

eights bits

Question 20

kilobyte

Answer 20

2^10

Question 21

megabyte

Answer 21

2^20

Question 22

gigabyte

Answer 22

2^30

Question 23

terrabyte

Answer 23

2^40

Question 24

Sum of weights method

Answer 24

multiply each binary digit with its fixed weight and add to get decimal value

Question 25

Sum of non-zero terms

Answer 25

multiply each binary digit that is not one with its fixed weight and add to get

Question 26

repeated division by 2 method

Answer 26

- to go from decimal to binary - divide the decimal number repeatedly by 2, recording the remainder each time. - the last remainder becomes the msb and the first remainder becomes the lsb

Question 27

repeated multiplication by 2 method

Answer 27

- to go from decimal fractions to binary - multiply the fraction part by the base (2) - record the integer (0 or 1) then take the fraction part and multiply again - repeat until no more fraction - msb is the one recorded first, lsb is the one recorded last

Question 28

Base-8

Answer 28

Octal, digits 0 - 7

Question 29

base 16

Answer 29

hexadecimal, values 0-15, digits 0-F

Question 30

binary to octal

Answer 30

started at lsb, take groups of 3 bits and convert each to decimal form to get octal representation

Question 31

octal to binary

Answer 31

convert each octal digit into its 3bit form

Question 32

decimal to octal (not fraction)

Answer 32

use repeated division by 8

Question 33

binary to hexadecimal

Answer 33

group bits into groups of four starting with lsb, each group will represent one hexadecimal digit

Question 34

hexadecimal to binary

Answer 34

each hexadecimal digit is replaced with the equivalent 4 bit string

Question 35

decimal to hexadecimal

Answer 35

repeated division by 16

Question 36

binary addition

Answer 36

similar to decimal, a sum bit and a carry bit are generated 4 possibilities for adding 2 bits together

Question 37

basic binary subtraction

Answer 37

- results in a difference bit and a borrow bit

Question 38

binary multiplication

Answer 38

- similar to decimal - when multiplying 2 bits, product will be zero unless both bits are 1

Question 39

binary division

Answer 39

- same procedure as decimal, may result in a remainder

Question 40

signed binary numbers (or signed-magnitude representation)

Answer 40

msb is reserved to signify if number is positive (0) or negative (1)

Question 41

unsigned binary numbers

Answer 41

assumed to be positive so msb is not reserved for the sign

Question 42

diminished radix complement

Answer 42

- (r-1)'s complement - for a number N with n digits, its complement is (r^n - 1) - N

Question 43

1's complement of a binary number

Answer 43

obtained by changing zero to one and one to zero

Question 44

radix complement

Answer 44

- for a number N with n digits, its complement is (r^n - N) - equivalent to one more than the diminished radix complement

Question 45

2's complement of a binary number

Answer 45

- add one to the 1's complement

Question 46

the msb of the 2's complement of a negative number should be ____

Answer 46

1

Question 47

subtraction by 2's complement

Answer 47

- if any numbers are negative, take 2's complement (msb should be 1, so msb doesn't change from signed magnitude to complement) - then take 2's complement of the subtrahend including the sign bit - if there is a carry out bit, ignore it - then add the two numbers

Question 48

an n-bit binary code can have up to ____ distinct combinations of 1's and 0's

Answer 48

2^n

Question 49

BCD

Answer 49

- binary coded decimal - used for applying a decimal input to a digital circuit - each decimal digit is represented by 4 bits that can go up to a max value of 9 (1001) (other values are dont care on k map)

Question 50

BCD addition

Answer 50

- if binary sum is equal to or less than 1001, BCD digit is correct - if binary sum is more than 1001, add 6 to it to get the correct digit and carry

Question 51

ASCII code

Answer 51

- american standard code for information interchange - uses 7 bits to code 128 characters - includes uppercase, lowercase, punctuation, numbers 0-9, and some nonprinting characters for control functions

Question 52

parity bit

Answer 52

a bit added to the front of the code to make there an odd or even number of bits to check correctness of code