Alternate Logic-Gate Representations

Alternate Logic-Gate Representations

We have discussed the five basic logic gates (AND, OR, INVERTER, NAND, and NOR) and the standard symbols used to represent them in a logic circuit diagram. Most of the logic networks use standard symbols. But in some networks an alternative set of symbols is used in addition to the standard symbols. The table shows the alternate set of symbols for the five basic gates.

Table: Alternate Logic Gate Representations

To convert any normal symbol to its corresponding alternate symbol, the following steps are used:

METHODOLOGY: TO CONVERT STANDARD SYMBOL TO ALTERNATE SYMBOL

  • Step 1: Add bubbles (indication of inversion) at those input or output points where it is not present.
  • Step 2: Remove all pre-existing bubbles of the normal symbol, if there is any at the point (only NOT, NAND and NOR gates)
  • Step 3: If the existing normal logic symbol is AND, change it to OR, Similarly, if it is OR, then change it to AND. There is no change for the triangular symbol of NOT gate.

REFERENCES

1.        Digital Design by M. Morris Mano, Michael D Ciletti, Pearson
2.        Digital Fundamentals by Thomas L. Floyd, R. P. Jain, Pearson
3.        Digital Circuits and Design by S Salivahanan, S Arivazhagan, Vikas Publishing House Pvt Ltd.
4.        Digital Systems by Ronald J. Tocci, Neal S. Widmer, Gregory L. Moss, Pearson
5.        Digital Electronics Principles And Integrated Circuits by Anil K. Maini
6.        Fundamentals of Digital Circuits by Anand Kumar
7.        Digital Electronics by John Morris 
8.        Digital Electronics : An Introduction To Theory And Practice By William Gothmann.

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