Practice question · True or false
NAND is called universal because every other logic gate can be built from NAND gates alone.
Hints
- Can you make NOT from a NAND?
- NOT, AND and OR are enough to build anything.
Show the answer
True
Why
True. Tying a NAND's inputs together gives NOT; NAND followed by NOT gives AND; De Morgan gives OR from NANDs with inverted inputs. Since {AND, OR, NOT} is functionally complete, so is NAND alone, which is why fabs optimise one gate type and build whole chips from it.
Practise Boolean Variables and Logic Gates
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