The logic NOR function is a combination of two separate logic functions, the Not function and the OR function (NOT-OR) connected together to form one single logic function which is the same as the OR function except that the output is inverted.
To create a NOR gate, the OR function and the NOT function are connected together in series with its operation given by the Boolean expression as, A + B
The Logic NOR Function only produces and output when “ALL” of its inputs are not present and in Boolean Algebra terms the output will be TRUE only when all of its inputs are FALSE.
Switch Representation
The truth table for the NOR function is the opposite of that for the previous OR function because the NOR gate performs the reverse operation of the OR gate. Then we can see that the NOR gate is the complement of the OR gate.
Logic NOR Function Truth Table
Switch A |
Switch B |
Output |
Description |
0 |
0 |
1 |
Both A and B are open, lamp ON |
0 |
1 |
0 |
A is open and B is closed, lamp OFF |
1 |
0 |
0 |
A is closed and B is open, lamp OFF |
1 |
1 |
0 |
A is closed and B is closed, lamp OFF |
Boolean Expression (A OR B) |
A + B |
The NOR Function is sometimes known as the Pierce Function and is denoted by a downwards arrow operator as shown, A NOR B = A↓B.
The logical functions are decision-making functions that compare two or more input conditions, and returns an output when these conditions are met. This makes logic functions capable of performing mathematical and binary logic operations.
Logic NOR gates are available as standard i.c. packages such as the TTL 74LS02 Quadruple 2-input NOR Gate, the TTL 74LS27 Triple 3-input NOR Gate or the 74LS260 Dual 5-input NOR Gate.
Iwant to know differene b/n NOT and NOR
How do I design a logic circuit to meet the requirements of the expression:Z=D.(Ā+B+`C)?
Z=D.(Ā+B+`C) = (D.Á) + (D.B) + (D.Ć)
Three 2-input AND gates for A.D, B.D, C.D with inverters (NOT gates) on lines A and C feeding a 3-input OR gate
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Thanks for your note!
The only thing you do is do nothing that you did not do also XOR gate
Please make an effort to use the tutorials: Ex-OR Gate
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Please answer this,
A’B+B’A=?
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