Binary Numbers and Integer Representations

Question 1

Binary Number Features

Answer 1

Are base 2 numbers / Use binary digits (bits) 0 and 1 / Easy to encode on a computer, since only 2 states need to be distinguished / Binary numbers are encoded using 1 or more bits in combination

Question 2

How many bit patterns can be held by an N-bit register

Answer 2

2^N (e.g. 4bit register can hold 16 distinct bit patterns)

Question 3

How are unsigned integers encoded?

Answer 3

Using binary numbers

Question 4

What is the range for binary numbers

Answer 4

0 to 2^N -1

Question 5

How are signed integers encoded?

Answer 5

Using two’s complement representation

Question 6

What is the range for two’s complement representation?

Answer 6

-2^(N-1) to +2^(N-1)-1

Question 7

How can a number be negated (2’s complement)

Answer 7

Take the one’s complement 0(Reverse 0s and 1s) / Add 1 to the result

Question 8

All positive numbers have a _ in the sign-bit (left-most bit)

Answer 8

0

Question 9

All negative numbers have a _ in the sign-bit (left-most bit)

Answer 9

1

Question 10

Are sign-magnitude and one’s complement representations possible?

Answer 10

Yes but they are awkward to handle in hardware, have two 0s (-0 and +0)

Question 11

Hexadecimal conversion table (base 16)

Answer 11

Screenshot

Question 12

What is the prefix for Hex. #s?

Answer 12

0x

Question 13

What are Octal numbers used for?

Answer 13

They are used as a shorthand for denoting bit patterns / Each digit corresponds to a 3-bit pattern e.g. 0756

Question 14

What is the prefix for Oct #s

Answer 14

0

Question 15

Linux on ARMv8 in AArch64 uses the ____ data model

Answer 15

LP64 (long integers and pointers are 64-bits long)

Question 16

A64 Keyword / Size in Bits / C Keyword

Answer 16

Question 17

In c use the “________” keyword to denote unsigned integers

Answer 17

• unsigned*
• e.g. unsigned* int x;