Fundamental Logic Gates And Or Not Logic Gates

Fundamental Logic Gates And, Or, Not

Logic Gates: The Basics Regulate the flow of electricity within circuits to perform desired functionalities n Each gate receives one or more inputs but has only one output n Represented using Schematics, Words, Symbols, and Boolean Equations n

Logic Gates and Transistors

Logic Gates: AND Schematic Symbol Boolean Equation • Y=A • B (Output) Y is True: Only if both (Inputs) A and B are true.

Aside Boolean Variables n Boolean variables are always capital letters and can only take on the values T (true) or F (false). n For Example: A=True B=False X=true…

Logic Gates: AND continued… n Ex. Are the following statements true or false ? ¨ My name is Mr. Kurz and this is Room 231. ¨ I am a human and I am the Prime Minister of Canada. n Truth Tables: A F F T T B F T Y F F F T or A 0 0 1 1 B 0 1 Y 0 0 0 1

Note on Truth Tables n There is only one pattern to follow! A F F T T B F T Y F F F T A 0 0 1 1 ANY other way is wrong! B 0 1 Y 0 0 0 1

Logic Gates: OR Schematic Symbol Boolean Equation + Y=A+B (Output) Y is True: Only if (Inputs) A, B, or both A and B are true.

Logic Gates: OR continued… n Ex. Are the following statements true or false ? ¨ This class is ICE 4 M or is in Room 503. ¨ I am a human or I am the Prime Minister of Canada. n Truth Tables: A F F T T B F T Y F T T T or A 0 0 1 1 B 0 1 Y 0 1 1 1

Logic Gates: NOT Schematic Symbol Boolean Equation ¯ Y=A Output (Y) is True: Only if Input (A) is false.

Logic Gates: NOT continued… n Ex. Which of these are true or false? ¨ This class is not ICE 4 M. ¨ I am not the Prime Minister of Canada. n Truth Tables: A Y F T T F or A Y 0 1 1 0

Example: n Create a truth table for the following circuit: n Steps: Create Table ¨ Fill in A, B, C ¨ Solve one gate at a time using in between columns on the table ¨ Solve for Y ¨ A 0 0 1 1 B 0 0 1 1 C A • B 0 0 1 0 0 0 0 1 1 (A+B) • C 0 1 0 1 1 1

Additional Info n n Equivalent Terminology: True 1 on open High V False 0 off closed Low V For ‘n’ inputs into any logic gate, there will be 2 n rows in your truth table.

The other three gates NOR – “Not Or” n NAND – “Not And” n Xor - “One or the other, not both” n

Today 1. 2. Complete the Logic Gate Summary Chart Use the IC schematics on the resources page to set up and test each of the 6 logic gates. Pin 14 goes to Power Pin 7 to ground.