2. Logic Gates Chapter 5 Subject: Digital System Year: 2009

3. 3 Overview The Inverter The AND Gate The OR Gate The NOR Gate The Exclusive-OR & Exclusive NOR Gates Timing diagram

4. 4 The Inverter The inverter (NOT circuit) performs the operation called inversion or complementation. The inverter changes one logic level to opposite level. In terms of bits, it change a 1 to a 0 and a 0 to a 1

5. 5 The Inverter Logic

6. 6 The AND Gate The AND gate produces a HIGH output only when all of the inputs are HIGH.When any of the inputs is LOW, the output is LOW.

7. 7 The AND Gate logic

8. 8 The AND Gate Example

9. 9 The AND Gate Example con’t

10. 10 The AND Gate Application

11. 11 The OR Gate An OR gate produce a HIGH on the output when any of the inputs is HIGH. The output is LOW only when all the inputs are LOW.

12. 12 The OR Gate Logic

13. 13 The OR Gate Example

14. 14 The OR Gate Application

15. 15 The Exclusive-OR Gate The output of an Ex-OR gate is HIGH only when the two inputs are at the opposite logic level.

16. 16 The Exclusive-NOR Gate The output of an Ex-NOR gate is LOW only when the two inputs are at the opposite logic level.