Digital Logic Toolkit

Digital Logic Toolkit — Buffer

Source
https://digitallogictoolkit.com/buffer-gate/
Printed

Three-state buffer, enable = 1 — buffer gate

corethe enabled case

Answer

Y = 1

Why this example is worth doing

With the enable asserted, a three-state buffer is an ordinary buffer and the input appears at the output. The page introduces the enable as a second input entering the top of the triangle rather than the left, which is a notational convention worth pointing out because it signals control rather than data. The disabled case, covered next, is where the part becomes genuinely different from a buffer.

Try your own input in the Buffer. Truth table, symbol and algebraic form for the non-inverting buffer, and what it is for.

How the answer is reached

The probed row

A = 1, OE = 1

Output table

Output table — columns A, OE, Y
AOEY
000
010
100
111

Compare with

Open the Buffer

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