Computers have become as the basic need in our day-to-day life. Computers are basically used to perform multitude of tasks, operations, and computations within quite less amount of time. One of the significant functions of the CPU in a computer is to perform a logical operation which is done by utilizing some hardware, including electronic kits, chips & integrated circuits and software (programming) technologies. But, how these hardware & software interact and perform all these operations is quite a big puzzle.
In order to have a better understanding of such a complex issue, we must have to acquaint with the term Boolean Logic, developed by George Boole. We are aware of the fact that computers utilize binary digits instead of decimal digits for ease of operation. All the logical operations are carried out by the logic gates.
What are Logic Gates?
The physical building blocks of integrated circuits that make use of Boolean logic to execute logical operations or tasks in digital circuits are known as Logic Gates.
These are primarily implemented using electronic switches such as diodes or transistors electronically, but they can also be realized using different logics such as pneumatic logic, molecules, optics, fluidic logic, relay logic (electromagnetic relays) and mechanical elements. However, in practice gates are built using CMOS technology, FETs, MOSFETs.
As these basic logic gates utilize Boolean function and they always use binary digits in their truth tables as their inputs or output. Hence, they are also called as binary logic gates or Boolean logic gates.
Logic gates are used in embedded system applications, microprocessor & microcontroller, electronic project and electrical project circuits
The different types of basic logic gates are as follows:
AND gate, OR gate, NOT gate, NAND gate, NOR gate, XOR (EXOR) gate and XNOR (EXNOR) gate.
These binary logic gates are explained below with their logic gate symbols and logic gates truth tables.
1. AND gate
The basic digital logic gate is an electronic circuit that executes logical conjunction based on the combinations of its truth table.
If we consider 0 as false and 1 as true, then this gate acts similar to a logical ‘and’ operator and hence, it is named as AND gate.
These gates can have different number of inputs and are termed as n-inputs AND gates. If we consider two inputs AND gate, and if both the inputs of the gate are high or true, then the output will be high or true. If any one of the inputs is low or false, then the output will be low or false.
2. OR gate
The basic digital logic gate is an electronic circuit that executes logical operation based on the combinations of its truth table.
These gates can have different number of inputs and are termed as n-inputs OR gates. If we consider the two inputs AND gate and if any one or more inputs of the gate are high or true, then the output will be high or true. If all the inputs of the gate are low or false, then the output will be low or false.
3. NOT gate
The basic digital logic NOT gate is an electronic circuit that performs a NOT operation or an invert operation of the input. Hence, it is also termed as an inverter.
The output of the NOT gate is the invert of the input. If the input is high or true then the output will be low or false and vice versa. NOT gate symbol and truth table are shown below.
By using NOT gate we can implement NAND and NOR gates.
4. NAND gate
The electronic circuit that performs the operation of the AND gate followed by the operation of the NOT gate is called as NAND gate. We have already studied the operations of the AND and NOT gates in the preceding paragraphs of this article. Now, by combining both the operations of AND and NOT gates, if any input of the NAND gate is low or false, then the output of the NAND gate will be high or true, as shown in the below truth table.
The symbol of the NAND gate can be obtained from the AND gate’s symbol joined together with the small circle of the NOT gate symbol at the output end, which represents an inversion of the operation.
5. NOR gate
The electronic circuit that performs the operation of the OR gate followed by the operation of the NOT gate is called as NOR gate. The operations of the OR gate and NOT gate are explained above. If any of the inputs of the NOR gate is high or true, then the output will be low or false.
The symbol and truth table of the NOR gate are shown below.
The symbol of the NOR gate can be obtained from the OR gate’s symbol, followed by the small circle of the NOT gate at the output terminal of the gate, which represents the inversion operation.
6. EX-OR gate
The EX-OR is a short form of Exclusive-OR gate. It is a logic gate which operates based on the principle of OR operation.
If we consider 2-input EX-OR gate, and if only any one of the inputs (but not both) is high or true, then the output of the EX-OR gate will be high or true.
The symbol and truth table of the EX-OR are shown above.
7. EX-NOR gate
The EX-NOR gate is an electronic circuit that performs an invert operation of the EX-OR gate. The EX-OR gate followed by the NOT gate gives the EX-NOR gate. If both the inputs of the EX-NOR gate are high or true, then the output will be high or true, and if both the inputs are low or false, then the output will be high or true.
But, if any one of the inputs is high or true (but not both), then the output will be low or false.
The truth table and symbol of EX-NOR gate are as shown above. The symbol of EX-NOR gate can be obtained from the EX-OR gate symbol, followed by a small circle of NOT gate at the output end representing the inversion operation.
8. Redstone Logic Gates
These are similar to the digital logic gates. In minecraft games, certain combination of inputs such as Redstone signals are used to obtain a particular output for activation and controlling mechanisms. There are different applications in which logic gates are used and Redstone circuit is used for the controlling mechanisms of the minecraft games. These controlling mechanisms can be constructed using different logic gate circuits.
In this article, we have discussed about the basic logic gates, operations of the digital logic gates with their symbols and truth tables. We have also seen the typical application of logic gates: Redstone circuits in minecraft gaming zones. For additional information regarding the logic gates and their applications, please post your queries as your comments in the comments section below.