Digital Logic Toolkit

Digital Logic Toolkit — NOR gate

Source
https://digitallogictoolkit.com/nor-gate/
Printed

Full 2-input truth table — NOR gate

intro1 of 4 rows true

Answer

output column 1000

Why this example is worth doing

The OR column inverted, and one of the highest-volume tables on the site. The page prints it beside OR and beside NAND — three columns that differ only in which rows are complemented — because the tables are individually trivial and collectively the point. It also gives the algebraic form (A + B)′ and its De Morgan twin Ā·B̄ together, since the second is what you actually substitute when simplifying.

Try your own input in the NOR gate. Truth table, symbol and algebraic form for (A + B)′, the other universal gate.

How the answer is reached

Truth table

Truth table — columns #, A, B, A ↓ B
#ABA ↓ B
0001
1010
2100
3110

Compare with

Open the NOR gate

This input is entered in the tool itself — it is too rich for a link to carry.

Note:

Notation this page assumes

  • Symbols: · is AND, + is OR, ⊕ is XOR, a prime or an overline is NOT. The field also takes ∧ ∨ ¬ ~ ! & | and the words.
  • Operator precedence, tightest first: NOT, then AND (including juxtaposition), then XOR/XNOR, then NAND/NOR, then OR, then IMPLIES, then IFF.
  • Gate symbols follow whichever standard the header toggle is set to: ANSI/IEEE Std 91-1984 distinctive shapes, or IEC 60617-12 rectangles.

Sources

  • ANSI/IEEE Std 91-1984, Graphic Symbols for Logic Functions
  • IEC 60617-12, Graphical Symbols for Diagrams — Binary Logic Elements