In this paper

a new routing algorithm for arbitrary bit permutation operations is proposed combining with the divide and conquer strategy.The algorithm utilizes self-routing characteristics of the Inverse Butterfly Network.It can complete any

N

-bit fixed permutation in no more than

O

(lg

N

) instructions

and also can complete any

N

-bit dynamic permutation in no more than

O

(lg

i2N) instructions.On this basis

a new bit-permutation unit based on Inverse Butterfly

IBPU is developed and synthesized in SMIC 65-nm process.The results s

how that our IBPU has less resource consumption which decreased by about 32%

and lower latency which reduced by nearly 30% compared with the similar designs.Moreover

when it performs fixed permutation

the cost of the functional unit is minimal

which is not more than 60% of what was previously designed.When it performs dynamic permutation

though its cost is greater

the cost has smaller increase accompanying with the increase of permutation width N

so it has higher stability and its comprehensive performance advantages are obvious.