Adders & Flip-Flops

Question 1

What is a half adder?

Answer 1

This is a logic circuit containing TWO gates which produces the ADDITION of two bits.

Question 2

In a half adder, what gate does the sum bit require?

Answer 2

XOR

Question 3

In a half adder, what gate does a carry bit require?

Answer 3

AND

Question 4

What does the diagram of a half adder look like?

Answer 4

Question 5

What is the limitation of a half adder?

Answer 5

Does not allow for a carry bit from previous addition.

Question 6

What is a full adder?

Answer 6

A logic circuit containing five gates that produce the addition of three bits.

Question 7

What does the diagram of a full adder look like?

Answer 7

Question 8

What is a flip flop?

Answer 8

A memory unit that can store one bit.

Question 9

What is an edge-triggered D-type flip flop?

Answer 9

A memory unit that updates state/output to the current value of the data input with each pulse of the clock.

Question 10

What is a clock?

Answer 10

A device that generates the signal used to synchronise the components of a computer.

Question 11

What is the purpose of a D-type flip flop?

Answer 11

It is used to store the state of the data input, used as a memory unit for one bit.

Question 12

What are the two inputs of a D-type of flip flop?

Answer 12

Data - the data to be retained.

Clock - output updates to reflect current status of input.