# what is logic gate? in DLD Digital Logic Design

### LOGIC GATES

We are familiar with basic addition and subtraction operation. There are also many other functions that digital systems are able to perform with the help of logic gates.

• Logic Gates can be used to implement large complex systems.
• Digital Logic Gates are identified by unique symbols. These symbols are used in circuit diagrams. Circuit diagram in whole define the function of a digital circuit.
• Digital Logic Gates function can be represented by the followings;\
• Boolean expression
• Truth table / Function table
• Logic circuit diagram

### What is truth table?

Truth table is a table that stores inputs values and output after performing the operation on given inputs.

### What is example of truth table?

Following table shows truth table for NOT Gate.

 Input Output o 1 1 o

### What are boolean expressions?

Some symbols and operators are used to represent the given inputs and output.

### What are some examples of boolean expressions?

 Operator Meaning Expression + OR X+ Y * AND X  AND  Y

### What is logic circuit diagram?

Logic circuit diagram is a graphical representation of given inputs and outputs.