Digital Logic Toolkit

Digital Logic Toolkit — NOR gate

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

A = 0, B = 0 — NOR gate

introthe only true row

Answer

output 1

Why this example is worth doing

NOR is high only when every input is low, which makes it the strictest of the two-input gates in the opposite direction from AND. Landing on this row first is deliberate: a student who has just read the OR page sees the single false row there become the single true row here, and the inversion relationship needs no further explanation. The permalink opens the live toggle already in this state.

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

The probed row

A = 0, B = 01— Row 0 of 4.

Truth table

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

Compare with

Open this example in the NOR gate

The field arrives filled in with this example’s input.

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