
Electrical and electronic principles
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Figure 1.34 Logic gates and truth tables
The AND and OR gates can each be combined with the NOT gate to produce
the NAND and NOR gates, respectively. These two gates have been found
to be the most versatile and are used extensively for construction of more
complicated logic circuits. The output of these two is the inverse of the original
AND and OR gates.
The nal gate, known as the exclusive OR gate, or XOR, can only be a two-
input device. This gate will produce an output only when A OR B is at logic ‘1’
but not when they are both the same.
1.4.3 Combinational logic
Circuits consisting of many logic gates, ...