Section 8 - Boolean Algebra

Question 1

What 3 gates make up a full adder?

Answer 1

AND
OR
XOR

Question 2

What type of logical circuit is a D-type flip-flop?

Answer 2

A sequential logic circuit

Question 3

What is needed to change the state of D-type flip-flops?

Answer 3

A clock or an oscillator

Question 4

What does the D in D-type flip-flop stand for?

Answer 4

Data or delay

Question 5

What is meant by a positive edge-triggered flip-flop? (D-type flip-flop)

Answer 5

A D-type flip-flop can only change the output value from 0 to 1 or vice versa when the clock is at a rising or positive edge. i.e. at the beginning of a clock period.

Question 6

What is meant by a rising or positive edge in a clock cycle?

Answer 6

On a diagram depicting the change in state of a clock, a rising or positive edge is the one that shoots up from 0 to 1. It represents the start of a clock period.

Question 7

Why are D-type flip-flops important?

Answer 7

They can store the state of a bit and act as memory.

Question 8

What happens in a D-type flip-flop when the clock is not at a positive edge?

Answer 8

The input value in the flip-flop is held and does not change.

Question 9

How is Q (the output) related to D (the input) and C (the clock) in a D-type flip-flop?

Answer 9

The output Q assumes the value currently at D whenever the clock reaches a rising edge

Question 10

Where are flip-flops used in modern CPUs?

Answer 10

The registers in the CPUs are all multiple flip-flops constructed in a row to store temporary information within a processor.