Logic NAND / NOR Conversions
- using inverters to enable logic NAND / AND gates and NOR / OR gates
to provide alternative functions
It often happens on a logic circuit board that an NAND gate
and a few inverters may be available, whereas in reality an NOR function is
required. If this occurs then all is not lost. It is still possible to create an
OR function from an AND / NAND gate and inverters, or an AND gate from a NOR /
OR function.
The diagram below gives some of the conversions. As an
example it can be seen that a NOR gate is the same as an AND gate with two
inverters on the input. It is then possible to add inverters to create the
function that is required.
![AND and OR Gate Equivalents](/images/electronics/circuits/AND_OR_equivs.gif)
AND Gate and OR Gate Equivalents
These simple conversions can be used to save adding
additional logic circuits into circuits. By using chips with spare gates, it is
often possible to save adding additional chips, and thereby save cost and board
space.
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