Q. Explain about Butterfly permutation?
Butterfly permutation: This kind of permutation is attained by interchanging the most significant bit in address with least significant bit.
Figure: Butterfly permutation
E.g. X_{n-1}, X_{n-2}, and X_{1}.X_{0} = X_{0 }X_{n-2} ....... X_{1} X_{n-1}
001↔100, 010↔010
011↔110,
An interconnection network derived from this permutation is the butterfly network. A butterfly network falls under the type of blocking networks and it doesn't permit an arbitrary connection of N inputs to N outputs without conflict. The butterfly network is customized in Benz network. The Benz network comes under non-blocking network and it is produced by combining two butterfly networks end to end, in a manner that data flows forward by one and in reverse by the other.