1. What are Logic Gates?

2. Computers are electronic devices.
In computers, an “on” state when electricity is flowing represents true. The “off” state when no electricity is flowing represents false.
The most fundamental hardware elements of a computer control the flow of electricity. We use electrical signals to represent and manipulate binary values (the data in the computer).
This Photo by Unknown Author is licensed under CC BY-SA
This Photo by Unknown Author is licensed under CC BY-SA

3. What are Logic Gates?
In electronics, a logic gate is an idealized or physical device implementing a Boolean function.
Most logic gates have two inputs and one output. At any moment, every terminal is one of two binary conditions.
Low(0) or High(1) where the low state is approximately zero volts (0V) and the high state is approximately 5 volts(5V)
Gates are combined into circuits to perform more complicated tasks.
The gates in a computer are referred to as logic gates because they perform just one logical function

4. Three notational methods are used to determine the behavior of gates and circuits:
Boolean Algebra – a form of algebra in which variables and functions take on only one of two possible values (0 and 1)
Logic diagrams – a graphical representation of a circuit. Each type of gate is represented by a specific graphical symbol.
Truth tables – defines a gate by listing all the possible input combinations that the gate could encounter, along with the corresponding output.

5. The 6 types of gates we are exploring in this class:
NOT AND OR XOR NAND NOR

6. NOT Gate True False 1 Input Output Input Output
The NOT gate is an electronic circuit that produces an inverted version of the input at its output. It is also known as an inverter You might also see “NOT” as the ~ or ‘ symbol
Input
Output
True
False
Input
Output 1

7. AND Gate
The AND gate is an electronic circuit that gives a high output (1) only if all its inputs are high.
Logically, if one of two things are true, the entire statement is false
Input A
Input B
Output C
True
False
Input A
Input B
Output C 1
EX: I am Taylor Swift AND im a teacher

8. OR Gate
The OR gate is an electronic circuit that gives a high output (1) if one or more of its inputs are high.
Logically, if one statement is true, then the entire statement can be true
Input A
Input B
Output C 1
Input A
Input B
Output C
True
False
EX: I am Taylor Swift OR I am a teacher

9. XOR gate
The “Exclusive OR” gate produces a 0 if its two outputs are the same, and a 1 otherwise *Note, this is basically the OR gate except for one input situation (when both input signals are 1, the XOR gate produces a 0.

10. NAND and NOR Gates Essentially the opposites of the AND and OR gates.
Input A
Input B
Output C 1
Input A
Input B
Output C 1

11. Another visual…

12. You Try!
AND 1 OR
a) 0 b) 1 c) 1 d) 1
NAND 1
XOR 1

13. You don’t need to memorize the shapes of the gates

14. Warm Up Next classAP Practice Question

15. Start your Logic Gate HW

17. True
AND
False
NOT
AND
True OR
False