Exam 2

Question 1

The output depends only on the input

Answer 1

Combinational circuits

Question 2

Methods to describe a combinational circuit

Answer 2

Truth table
Boolean algebraic expression
Logic diagram

Question 3

Lists the output for every combination of the input

Answer 3

Truth table

Question 4

Computers, as we know them today, are implementations of:

Answer 4

Boole’s Laws of Thought.

Question 5

is a mathematical system for the manipulation of variables that can have one of two values .

Answer 5

Boolean algebra

Question 6

A Boolean function has:

Answer 6

At least one Boolean variable,
At least one Boolean operator,
and At least one input from the set{0,1}.

Question 7

What is xy and x+y using DeMorgans Law?

Answer 7

Negate and switch ors and ands

x’ + y’ and x’y’

Question 8

An interconnection of logic gates

Closely resembles the hardware

Answer 8

Logic diagrams

Question 9

is a matrix consisting of rows and columns that represent the output values of a Boolean function .

Answer 9

A Kmap

Question 10

is a product term that contains all of the function’s variables exactly once, either complemented or not complemented .

Answer 10

A minterm

Question 11

If a circuit is designed so that a particular set of inputs can never happen , we call this set of inputs a:

Answer 11

don’t care condition

Question 12

In a sigma(E) expression

Answer 12

represents the 1 outputs

Question 13

In a PI notation

Answer 13

Represents the 0s

Question 14

Enable line

Answer 14

Turns the device on or off. If 0 the output is 0. If 1 the output is 1

Question 15

Invert

Answer 15

Turns the device on or off. If 0 the output is 1. If 1 the output is 0

Question 16

What is a multiplexer?

Answer 16

A multiplexer selects one of several data inputs to be routed to a single data output

Question 17

What is a binary decoder?

Answer 17

A decoder takes a binary number as input and sets one of the data output lines to 1 and the rest to

Question 18

What is a demultiplexer?

Answer 18

a A demultiplexer routes a single input value to one of several output lines

Question 19

What is a half adder?

Answer 19

The half adder adds the right-most two bits of a binary number
Inputs : The two bits
Outputs : The sum bit and the carry bit

Question 20

What is a full adder?

Answer 20

The full adder adds one column of a binary number

Question 21

adds two n-bit binary numbers

Answer 21

The ripple-carry adder

Question 22

You can only get an overflow in one of two cases:

Answer 22

A and B are both positive, and the result is negative

A and B are both negative, and the result is positive

Question 23

are perfect for situations when we require the immediate application of a Boolean function to a set of inputs.

Answer 23

Combinational logic circuits

Question 24

a circuit that can change its value with consideration to its current state as well as its inputs .

Answer 24

Sequential logic circuits

Question 25

Circuits that change state on the rising edge , or falling edge of the clock pulse are called

Answer 25

edge triggered

Question 26

change state when the clock voltage reaches its highest or lowest level.

Answer 26

Level- triggered circuits

Question 27

To retain their state values, sequential circuits rely on:

in digital circuits occurs when an output is looped back to the input.

Answer 27

feedback

Question 28

The difference between a latch and a flip flop is that a latch is:

Answer 28

asynchronous , and the outputs can change as soon as the inputs do

Question 29

is edge triggered and only changes state when a control signal goes from high to low or low to high

Answer 29

A flip-flop

Question 30

is a group of wires connecting two subsystems

Answer 30

A bus