logic gates in computer organisation
TYPES OF LOGIC GATES:
Typically, there are seven basic logic gates.
- AND – it is so named because if 0 is false and 1 is true, the gate acts like a logical and operator. The output is true when both of the inputs are true. Else, the output results to be false.
- OR – it is so named because it behaves like the fashion of logical inclusive “or”. The output is only true if either or both of the inputs are said to be true. If both of the inputs are false, then the output also results to be false.
- XOR – it is also called exclusive-OR. It acts in the way of either/or. The output is true if either of the inputs are true. The output is false for both false inputs. The output is false if both inputs are true. The output is true if both of the inputs is not true.
- NOT – it is also called a logical inverter. Unlike other types of electronic inverter devices, this has only one input. It always reverses the logic state.
- NAND – it operates like an AND gate which is then followed by a NOT gate. It follows negation after following the manner of logical operation. The output is false for both of the true inputs. Else, the output is true.
- NOR – it is a combination of OR gate which is followed by an inverter. The output is true for both the false inputs. Else, the output remains to be false.
- XNOR – it is also known as exclusive-NOR gate. It is a combination of XOR gate which is then followed by an inverter. The output is true if the inputs are same and the output is false if the inputs are different.
Using a combination of such logic gates, can help in solving of complex operations. Theoretically, infinite number of logic gates can be arrayed together in a single device but practically, there is a set limit to the number of logic gates that can be arrayed together in a given physical space.
Digital integrated circuit (ICs) uses the arrays of logic gates.