A NOR gate is a fundamental digital logic gate that performs the logical NOR (NOT-OR) operation on two or more binary inputs to produce a single binary output. The output of a NOR gate is the complement of the result obtained from an OR gate. In other words, the output of a NOR gate is high (1) only when all of its input signals are low (0); otherwise, the output is low (0).
The logic symbol for a NOR gate is represented as follows:
---- ----
A | | B | |
| NOR | | |
---| | ---| |
---- ----
Output
In this symbol:
- A and B represent the input signals.
- The NOR symbol in the middle represents the logical NOR operation.
- The output is the complement of the OR operation’s output.
The truth table for a 2-input NOR gate is as follows:
A | B | Output |
---|---|---|
0 | 0 | 1 |
0 | 1 | 0 |
1 | 0 | 0 |
1 | 1 | 0 |
The truth table shows the output for all possible combinations of input values. As per the truth table, the output is 1 only when both inputs are 0; otherwise, the output is 0.
NOR gates have various applications in digital systems, including:
- Building more complex logic gates, such as AND, NOT, and XOR gates.
- Logic circuits for control and decision-making.
- Implementing universal gates that can realize any logical function.
- Memory circuits, such as static random-access memory (SRAM) cells.
- Creating latch and flip-flop circuits for sequential logic.
By combining NOR gates with other logic gates, intricate digital circuits can be designed to perform a wide range of tasks in electronic devices and systems.