Logic Gates
- Performs a basic operation on electrical signals
- Accepts one or more inputs and produces a single output signal
- Easiest gates to make are
NOT
, NAND
, and NOR
gates
NOT
![Representations of a NOT gate](/assets/second-brain/2020-09-23-16-57-26.png)
- Accepts an input
- Output is inverted of input
- An inverter
- Boolean algebra:
A'
- The mark comes after a value being negated
- Sometimes shown as horizontal bar over value being negated
- Logic diagram:
NOT Truth Table
AND
![Representations of an AND gate](/assets/second-brain/2020-09-23-16-58-32.png)
- Accepts two inputs
- Outputs
1
if both inputs are 1
- Outputs
0
if either input is 0
- Boolean algebra:
A • B
or A * B
or AB
or A ^ B
AND Truth Table
OR
![Representations of an OR gate](/assets/second-brain/2020-09-23-17-00-24.png)
- Accepts two inputs
- Outputs
0
if both inputs are 0
- Outputs
1
otherwise
- Boolean algebra:
OR Truth Table
XOR
![Representations of an XOR gate](/assets/second-brain/2020-09-23-17-01-55.png)
- Exclusive
OR
- Only differs from an
OR
if both inputs are 1
- "When I say or, I mean one or the other, not both."
- Accepts two inputs
- Outputs
0
if the two inputs are the same
- Outputs
1
otherwise
- Boolean algebra:
XOR Truth Table
NAND
![Representations of a NAND gate](/assets/second-brain/2020-09-23-17-07-25.png)
NOT
+ AND
- It's an
AND
gate that gets inverted
- Accepts two inputs
- Outputs
0
if both are 1
- Outputs
1
otherwise
- Boolean algebra:
NAND Truth Table
NOR
![Representations of a NOR gate](../../public/assets/second-brain/2020-09-23-17-12-09.png)
NOT
+ OR
- It's an
OR
gate that gets inverted
- Accepts two inputs
- Outputs
1
if both input is 0
- Outputs
0
otherwise
- Boolean algebra:
NOR Truth Table
Computer Science