Floyd Digital Fundamentals, 9/e Slide 1 Digital Fundamentals
CHAPTER 3 Logic Gates • Inverter • AND Gate • OR Gate • Exclusive -OR Gate • NAND Gate • NOR Gate • Exclusive -NOR Gate
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 2 The Inverter
Truth table Boolean expression
0 = LOW Pulsed waveforms 1 = HIGH
The output of an inverter is always the complement (opposite) of the input.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Floyd Digital Fundamentals, 9/e Slide 3 The AND Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of an AND gate is HIGH only when all inputs are HIGH.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 4 The AND Gate
3-Input AND Gate
4-Input AND Gate
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Floyd Digital Fundamentals, 9/e Slide 5 The OR Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of an OR gate is HIGH whenever one or more inputs are HIGH
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 6 The OR Gate
3-Input OR Gate
4-Input OR Gate
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Floyd Digital Fundamentals, 9/e Slide 7 The NAND Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of a NAND gate is HIGH whenever one or more inputs are LOW.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 8 The NAND Gate
3-Input NAND Gate 4-Input NAND Gate
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Floyd Digital Fundamentals, 9/e Slide 9 The NOR Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of a NOR gate is LOW whenever one or more inputs are HIGH.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 10 The NOR Gate
3-Input NOR Gate 4-Input NOR Gate
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Floyd Digital Fundamentals, 9/e Slide 11 Exclusive -OR Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of an XOR gate is HIGH whenever the two inputs are different.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Floyd Digital Fundamentals, 9/e Slide 12 Exclusive -NOR Gate
Boolean expression Truth table 0 = LOW 1 = HIGH Pulsed waveforms
The output of an XNOR gate is HIGH whenever the two inputs are identical.
Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.