Logic Gates

Logic Gates

Logic gate: Block of hardware's, on getting input they produce output 0 or 1.

Input for logic gates are either 0 or 1.

Output for logic gates are either 0 or 1.

Each logic gate has its symbol.

Operations of logic gate are represented by algebraic expressions.

Names of logic gates:

1. AND logic gate
2. OR logic gate
3. NOT logic gate
4. XOR logic gate
5. NAND logic gate
6. NOR logic gate
7. XNOR logic gate

Logic gate operations:

Input variables : A, B

Output variable : OP

1. AND : OP = A.B
2. OR : OP = A+B
3. NOT : OP = A'
4. XOR : Exclusive OR : OP = A'B+AB' = A  B
5. NAND : NOT AND : OP = (AB)'
6. NOR : NOT OR : OP = (A+B)'
7. XNOR : Exclusive NOR : OP = A'B'+AB = (A     B)'

Logic gate symbols:

Truth Table: Table shows relationship between input and output variables in logic gates.

More topics from Computer Organization to read

Computer Organization and Architecture:

EasyExamNotes.com covered following topics in these notes.

1. Structure of desktop computers
2. Logic gates
3. Register organization
4. Bus structure
5. Addressing modes
6. Register transfer language
7. Direct mapping numericals
8. Register in Assembly Language Programming
9. Arrays in Assembly Language Programming

References:

1. William stalling ,“Computer Architecture and Organization” PHI
2. Morris Mano , “Computer System Organization ”PHI