Basic logic gates
- Logic gates are small (several micron) structures which take
one or more bits as input, and produce another bit as output
- Different logic gates use different techniques to calculate their output
- The most common logic gates used perform the following logic functions:
- AND: output is 1 iff all inputs are 1
- OR: output is 0 iff all inputs are 0
- XOR: output is the sum (mod 2) of all inputs
- NOT: output is the opposite of the single input
- NAND: output is 0 iff all inputs are 1
- NOR: output is 1 iff all inputs are 0
- XNOR: output is the inverse of the XOR gate
- By linking the output of one gate to the inputs of other gates,
we can carry out more powerful calculations
Copyright © 1997, David M. Wessels. All rights reserved.