The N
OR gate
Contents 1 Symbols 2 Hardware description and pinout 2.1 Availability 3 Implementations 3.1 Alternatives 4 See also 5 References 6 External links Symbols[edit]
There are three symbols for NOR gates: the American (ANSI or
'military') symbol and the IEC ('European' or 'rectangular') symbol,
as well as the deprecated
DIN
MIL/ANSI Symbol
IEC Symbol
DIN
NOR Full adder Hardware description and pinout[edit]
NOR Gates are basic logic gates, and as such they are recognised in
TTL and
CMOS
Pinout Diagram of a 4001 Quad NOR DIPformat IC 1 Input A1 2 Input B1 3 Output Q1 4 Output Q2 5 Input B2 6 Input A2 7 Vss 8 Input A3 9 Input B3 10 Output Q3 11 Output Q4 12 Input B4 13 Input A4 14 Vdd Availability[edit]
These devices are available from most semiconductor manufacturers such
as Fairchild Semiconductor,
Philips
CMOS 4001: Quad 2input NOR gate 4025: Triple 3input NOR gate 4002: Dual 4input NOR gate 4078: Single 8input NOR gate TTL 7402: Quad 2input NOR gate
7427: Triple 3input NOR gate
7425: Dual 4input N
OR gate
In the older RTL and ECL families, NOR gates were efficient and most commonly used. Implementations[edit] PMOS N
OR gate
The diagrams above show the construction of a 2input N
OR gate
The physical layout of a
CMOS
The diagram below shows a 2input N
OR gate
Unbuffered
CMOS
Alternatives[edit]
Further information:
NAND logic
Desired gate NAND Construction See also[edit] AND gate OR gate NOT gate NAND gate XOR gate XNOR gate Boolean algebra (logic) Logic gates NOR logic References[edit] ^ Mano, M. Morris and Charles R. Kime. Logic and Computer Design Fundamentals, Third Edition. Prentice Hall, 2004. p. 73. External links[edit] Interactive NOR gate, Displays the logic simulation of the NOR Gate. Wikimedia Commons has media related to NOR gates. v t e Logical connectives Tautology/True ⊤ displaystyle top Alternative denial (NAND gate) ↑ displaystyle uparrow Converse implication ← displaystyle leftarrow Implication (IMPLY gate) → displaystyle rightarrow Disjunction (OR gate) ∨ displaystyle lor Negation (NOT gate) ¬ displaystyle neg Exclusive or (XOR gate) ↮ displaystyle nleftrightarrow Biconditional (XNOR gate) ↔ displaystyle leftrightarrow Statement Joint denial (NOR gate) ↓ displaystyle downarrow Nonimplication ↛ displaystyle nrightarrow Converse nonimplication ↚ displaystyle nleftarrow Conjunction (AND gate) ∧ displaystyle land Contradiction/False ⊥
